,illu/ration3 ,,frontispiece4--,half-/]eogram ( ,m\nt ,ellswor?1 drawn to illu/rate ! =m ( ! displacem5t & ! progress ( ! erosion4 ,! base ( ! figure repres5ts ! sea-level4 ,! remote half %[s ! result ( uplift alone2 ! ne> half1 ! result ( uplift & erosion1 or ! actual condition4 7,see page #ie47 ,,dep>tm5t ,,( ,,! ,,int]ior4 ,u4 ,s4 ,,geographical ,,& ,,geological ,,survey ,,( ,,! ,,rocky ,,m\nta9 ,,region4 ,j4 ,w4 ,,p[ell1 ,,9 ,,*>ge4 ,,report ,,on ,,! ,,geology ,,( ,,! ,,h5ry ,,m\nta9s4 ,by ,g4 ,k4 ,,gilb]t4 ,illu/ration3 ,logo ,,wa%+ton3 ,,gov]nm5t ,,pr9t+ ,,(fice4 #ahgg4 ,,dep>tm5t ,,( ,,! ,,int]ior1 ,u4 ,s4 ,,geographical ,,& ,,geological ,,survey ,,( ,,! ,,rocky ,,m\nta9 ,,region1 ,wa%+ton1 ,d4 ,c41 ,m>* #e1 #ahgg4 ,,sir3 ,i h ! honor to transmit h]e) a report on ! ,geology ( ! ,h5ry ,m\nta9s1 by ,mr4 ,g4 ,k4 ,gilb]t4 ,i am1 ) great respect1 y\r ob$i5t s]vant1 ,j4 ,w4 ,,p[ell1 ,9 *>ge4 ,! ,hon4 ,,secret>y ,,( ,,! ,,int]ior1 ,wa%+ton1 ,d4 ,c4 ,,dep>tm5t ,,( ,,! ,,int]ior1 ,u4 ,s4 ,,geographical ,,& ,,geological ,,survey ,,( ,,! ,,rocky ,,m\nta9 ,,region1 ,wa%+ton1 ,d4 ,c41 ,m>* #a1 #ahgg4 ,,de> ,,sir3 ,i submit h]e) my report on ! ,geology ( ! ,h5ry ,m\nta9s1 prep>$ f mat]ial ga!r$ "u y\r direction 9 ! ye>s #ahge & #ahgf4 ,i am1 ) great respect1 y\r ob$i5t s]vant1 ,g4 ,k4 ,,gilb]t4 ,pr(4 ,j4 ,w4 ,,p[ell1 ,9 *>ge4 ,,preface4 ,if ^! pages fail to give a correct acc\nt ( ! /ructure ( ! ,h5ry ,m\nta9s ! fault is m9e & ,i h no excuse4 ,9 all ! e>li] exploration ( ! ,rocky ,m\nta9 ,region1 z well z 9 mu* ( ! m rec5t survey1 ! geologi/ has m]ely accompani$ ! geograph] & has _h no voice 9 ! det]m9ation ( ei!r ! r\te or ! rate ( travel4 ,:5 ! /ructure ( a m\nta9 0 9 d\bt he 0 r>ely able to visit ! po9ts :i* %\ld resolve ! d\bt1 b 0 compell$ to turn regretfully away4 ,n s 9 ! survey ( ! ,h5ry ,m\nta9s4 ,geological exploration _h %[n t !y 7 well dispos$ = exam9ation1 & t !y promis$ to give ! key to a type ( /ructure :i* 0 at be/ obscurely kn[n2 & ,i 0 s5t by ,pr(essor ,p[ell to make a /udy ( !m1 )\t re/riction z to my ord] or me?od4 ,i 0 limit$ only 9 "t1 ! sn[ /opp+ my "w two mon?s aft] x 0 begun4 ,two mon?s w\ld be f> too %ort a p]iod 9 :i* to survey a ?\s& squ>e miles 9 ,p5nsylvania or ,ill9ois1 b among ! ,colorado ,plateaus x prov$ suffici5t4 ,a few compreh5sive views f m\nta9 tops gave ! g5]al di/ribution ( ! =mations1 & ! rema9d] ( ! "t 0 sp5t 9 ! exam9ation ( ! localities :i* be/ display$ ! peculi> features ( ! /ructure4 ,s ?or\gh 0 ! display & s satisfactory ! exam9ation1 t 9 prep>+ my report ,i h felt less ?an ev] be=e ! desire to revisit ! field & prove my conclusions by m ext5d$ obs]vation4 ,9 ! description ( ! details ( ! /ructure a dem& arose = a great] numb] ( geographic titles ?an 7 readily sugge/$ by natural =ms or o!r accid5ts1 & rec\rse 0 _h to ! names ( geologi/s4 ,except t ! pres5t memb]s ( my own corps are n includ$1 ! names *os5 are ( ^? ^: cognate /udies h giv5 me mo/ aid4 ,mr4 ,/ew>d & ,mr4 ,h[ell saw ! ,h5ry ,m\nta9s be=e ,i did1 & glean$ some?+ ( _! /ructure f a di/ance2 ,dr4 ,newb]ry1 ,mr4 ,m>v9e1 ,dr4 ,peale1 & ,mr4 ,holmes h describ$ alli$ ph5om5a 9 ,colorado & ,new ,mexico2 & ! works ( ,messrs4 ,jukes1 ,geikie1 ,scrope1 & ,dana h be5 among my *ief s\rces ( in=mation 9 reg>d to igne\s m\nta9s 9 g5]al4 ,if any ( ^! g5tlem5 feel (f5d$ t _! names h be5 atta*$ to natural features s insignificant1 ,i c assure !m t ! affront w nev] be repeat$ by ! future d5iz5s ( ! region4 ,! h]d]s :o build _! hut at ! base ( ! ,newb]ry ,ar* are sure to call x 8! ,c$> ,knoll02 ! ,jukes ,butte w be dubb$ 8,pilot ,knob01 & ! ,scrope1 8,rocky ,po9t04 ,dur+ ! prep>ation ( my report e "p ( ! discussion has be5 submitt$ to ,pr(essor ,p[ell = criticism1 & _m ( 8 sugge/ions are embodi$ 9 ! text4 ,simil> & valuable aid 0 receiv$ f ,capt4 ,c4 ,e4 ,dutton & ,mr4 ,william ,b4 ,taylor 9 ! /udy ( ! physical problems to :i* ! discussion ( ! intrusive ph5om5a gave rise4 ,capta9 ,dutton r5d]$ an important s]vice also by ! /udy ( ! collection ( igne\s rocks1 & 8 report1 includ$ 9 ! f\r? *apt]1 te/ifies to ! ?or\ghness ( 8 "w4 ,! sup]vision ( ! publication has fall5 9 l>ge %>e ^u ,mr4 ,j4 ,c4 ,pill+1 & ! text has _h ! advantage ( 8 lit]>y criticism1 z well z ( 8 wat*ful c>e4 ,g4 ,k4 ,g4 ,,cont5ts4 ,page4 ,,*apt] ,i4 ,,introductory #a ,! rock s]ies #c ,uncon=mities #h ,! ,great ,folds #aa ,cliffs & plateaus #ac ,h[ to rea* ! ,h5ry ,m\nta9s #ad ,,*apt] ,,ii4 ,,/ructure ,,( ,,! ,,h5ry ,,m\nta9s #ah ,,*apt] ,,iii4 ,,detail$ ,,description ,,( ,,! ,,m\nta9s #bb ,m\nt ,ellswor? #bb ,m\nt ,holmes #bg ,m\nt ,hill]s #cj ,m\nt ,p5nell #ce ,m\nt ,ell5 #ch ,/]eogram ( ! ,h5ry ,m\nta9s #di ,,*apt] ,,iv4 ,,! ,,laccolite #ea ,! ,h5ry ,m\nta9s intrusives1 by ,capta9 ,c4 ,e4 ,dutton #fa ,! "q ( cause #gb ,! /ret*+ ( /rata #hj ,! conditions ( rock flexure #hc ,! "q ( cov] & ! "q ( age #hd ,! hi/ory ( ! laccolite #ie ,laccolites ( o!r regions #ig ,possible analogues ( ! laccolite #ih ,,*apt] ,v4 ,,l& ,,sculpture #ii ,i4 ,erosion #ii ,a4 ,processes ( erosion #ii ,wea!r+ #ajj ,transportation #aja ,corrasion #aja ,b4 ,conditions controll+ erosion #ajb ,rate ( erosion & declivity #ajb ,rate ( erosion & rock texture #ajc ,rate ( erosion & climate #ajc ,transportation & comm9ution #ajf ,transportation & declivity #ajh ,transportation & quantity ( wat] #aji ,corrasion & transportation #aaa ,corrasion & declivity #aab ,declivity & quantity ( wat] #aac ,,ii4 ,sculpture #aae ,sculpture & declivity #aae ,! law ( /ructure #aae ,! law ( divides #aaf ,sculpture & climate #aag ,bad-l&s #abj ,equal action & int]dep5d5ce #abc ,,iii4 ,sy/ems ( dra9age #abd ,! /ability ( dra9age l9es #abd ,! in/ability ( dra9age l9es #abe ,! /ability ( divides #ach ,! in/ability ( divides #aci ,consequ5t & inconsequ5t dra9age #adc ,! dra9age ( ! ,h5ry ,m\nta9s #add ,,*apt] ,,vi4 ,,economic #aea ,,*apt] ,i4 ,,introductory4 ,! ,h5ry ,m\nta9s h be5 visit$ only by ! explor]4 ,previ\s to #ahfi !y 7 n plac$ ^u any map1 nor 0 m5tion made ( !m 9 any ( ! publi%$ acc\nts ( exploration or survey 9 ! ,rocky ,m\nta9 region4 ,9 t ye> ,pr(essor ,p[ell :ile desc5d+ ! ,colorado ,riv] 9 boats pass$ ne> _! foot1 & gave to !m ! "n :i* !y be> 9 honor ( ,pr(4 ,joseph ,h5ry1 ! di/+ui%$ physici/4 ,9 #ahgb ,pr( ,a4 ,h4 ,?ompson1 engag$ 9 ! cont9uance ( ! survey ( ! riv]1 l$ a p>ty across ! m\nta9s by ! ,p5ell5 ,pass1 & climb$ "s ( ! highe/ peaks4 ,fronti]sm5 9 se>* ( f>m+ & graz+ l&s or ( ! preci\s metals h s9ce t "t paid sev]al visits to ! m\nta9s2 b no survey 0 made ( !m until ! ye>s #ahge & #ahgf1 :5 ,mr4 ,walt] ,h4 ,graves & ! writ] visit$ !m = t purpose4 ,!y are situat$ 9 ,s\!rn ,utah1 & are cross$ by ! m]idian ( #aaj #de & ! ?irty-eigh? p>allel4 ,!y /& ^u ! "r bank ( ! ,colorado ,riv] ( ! ,we/1 & betwe5 its tribut>ies1 ! ,dirty ,devil & ! ,escalante4 ,at ! "t ( _! discov]y by ,pr(essor ,p[ell ! m\nta9s 7 9 ! c5t] ( ! l>ge/ unexplor$ di/rict 9 ! t]ritory ( ! ,unit$ ,/ates--a di/rict :i* by its peculi> rugg$ness _h turn$ aside all previ\s travel]s4 ,up to t "t ! great] "p ( ! k t _h be5 ga9$ ( ! int]ior ( ! cont95t _h be5 acquir$ 9 ! se>* = r\tes = transcont95tal railways2 & ! caons ( ! ,colorado ,bas91 oppos+ m s]i\s ob/acles to travel ?an ! m\nta9 ranges :i* 7 met 9 o!r latitudes1 7 by common cons5t avoid$ by ! eng9e]s4 ,! same g5]al causes :i* h r5d]$ ! region s difficult ( access & passage h made x a des]t1 almo/ )\t economic value4 ,! physical conditions ( elevation & aridity :i* h caus$ x to be s deeply c>v$ 9 caons1 h prev5t$ ! /reams ) :i* x is scantily wat]$ f be+ bord]$ by tracts ( l& :i* c be irrigat$2 & agriculture )\t irrigation be+ 9 t climate an impossibility1 !re is no?+ to attract ! f>m]4 ,z w be expla9$ 9 ! sequel1 ! m\nta9s (f] no inducem5ts to ! m9] ( ! preci\s metals4 ,!re is timb] ^u _! flanks & !re is coal ne> at h&1 b bo? are too f> remov$ f o!r economic int]e/s to f9d ! m>ket :i* w\ld give !m value4 ,x is only = purposes ( graz+ t !y c be said to h a money value1 & s di/ant are !y at pres5t f any m>ket t ev5 t value is small4 ,b :ile ! ,h5ry ,m\nta9s contribute almo/ no?+ to our direct mat]ial int]e/s1 !y (f] 9 common ) ! plateaus :i* surr\nd !m a field ( surpass+ int]e/ to ! /ud5t ( /ructural geology4 ,! deep c>v+ ( ! l& :i* r5d]s x s inhospitable to ! travel] & ! settl]1 is to ! geologi/ a dissection :i* lays b>e ! v anatomy ( ! rocks1 & ! dry climate :i* makes ! region a nak$ des]t1 soilless & almo/ plantless1 p]fects ! prep>ation = 8 exam9ation4 ,! /udy ( ! m\nta9s is fur!r facilitat$ by _! isolation4 ,!y m>k a limit$ sy/em ( di/urbances1 :i* int]rupt a region ( geological calm1 & /ructurally1 z well z topographically1 /& by !mselves4 ,! ,h5ry ,m\nta9s are n a range1 & h no tr5d2 !y are simply a gr\p ( five individual m\nta9s1 sep>at$ by l[ passes & arrang$ )\t disc]nible sy/em4 ,! highe/ rise ab\t #e1jjj feet above ! plateau at _! base & #aa1jjj feet above ! level ( ! ocean4 ,project+ s f> above ! surface ( ! des]t1 !y act z local cond5s]s ( moi/ure1 & receive a comp>atively g5]\s supply ( ra94 ,spr+s ab\nd ^u _! flanks1 & _! upp] slopes are clo!d ) a luxuriant h]bage & ) groves ( timb]4 ,! small] m\nta9s & ! foot-hills ( ! l>g] are less g5]\sly wat]$ & b scantily clo!d ) vegetation4 ,_! ext5t is small4 ,f ,ell5 ,peak to ,m\nt ,ellswor?1 ! two summits :i* are ! mo/ widely sep>at$1 ! di/ance is b tw5ty-eight miles1 & a circle ( eighte5 miles radius w include ! :ole gr\p4 ,m\nt ,ell5 :i* is ! mo/ nor!rly ( ! gr\p1 has an extreme altitude ( #aa1bej feet1 & surpasses all its companions 9 horizontal ext5t z well z altitude4 ,its cre/-l9e is cont9u\s = two miles1 ) an elevation v>y+ little f #aa1jjj feet4 ,f x !re radiate spurs 9 all directions1 desc5d+ to a s]ies ( foot-hills z conspicu\s 9 _! topography z !y are int]e/+ 9 _! /ructure4 ,9 "s places ! base ( ! m\nta9 is gu>d$ by a cont9u\s1 /eep ridge1 ?r\gh :i* a passage mu/ be s\ght by ! approa*+ travel]1 b )9 :i* movem5t 9 any direction is comp>atively unimp$$4 ,m\nt ,p5nell is a s+le peak ris+ to an altitude ( #aa1aej feet4 ,on "o side its slopes jo9 ^? ( ,m\nt ,ell5 9 ,p5nell5 ,pass 7#g1eej feet71 & on ! o!r ^? ( ,m\nt ,hill]s 9 ! ,d9ah ,creek ,pass 7#g1cjj feet74 ,its pr(iles are simple1 & x lacks ! sali5t spurs t *>act]ize ,m\nt ,ell54 ,f ! we/ x is difficult ( approa*1 be+ gu>d$ by a b>ri] ridge cont9u\s ) t ( ,m\nt ,ell54 ,m\nt ,hill]s is m rugg$ 9 its "*1 & al?\gh compact 9 its g5]al =m1 is c>v$ 9 deep gorges & massive spurs4 ,its rugosity is contra/$ by ! smoo?ness ( its p$e/al1 :i* to ! s\? & we/ & nor? is a slop+ pla9 m]g+ ) ! surr\nd+ plateau4 ,m\nt ,ellswor? 7#h1jjj feet7 & ,m\nt ,holmes 7#g1gej feet7 /& close toge!r1 b at a little di/ance f ! o!rs4 ,! pass :i* sep>ates !m f ,m\nt ,hill]s has an altitude ( #e1bej feet4 ,!y are s+le peaks1 peculi>ly rugg$ 9 _! =ms1 & unwat]$ by spr+s4 ,!y /& almo/ ^u ! br9k ( ! ,colorado1 :i* "h fl[s ?r\gh a caon #a1ejj feet 9 dep?4 ,,! ,,rock ,,s]ies4 ,! s$im5t>y rocks :i* occur 9 ! ,h5ry ,m\nta9s & _! imm$iate vic9ity1 range f ! summit ( ! ,cretace\s to ! summit ( ! ,c>bonif]\s4 ,x is probable t !y 7 cov]$ at "o "t by "s ?\s&s ( feet ( ,t]ti>y /rata1 b f ! imm$iate banks ( ! ,colorado ^! h be5 entirely erod$1 & _! ne>e/ ve/iges lie ?irty miles to ! we/w>d1 :]e !y h be5 protect$ by ! lava-b$s ( ! ,aqu>ius ,plateau4 ,cretace\s4--,! ,cretace\s /rata d n rea* to ! ,colorado ,riv]1 b !y ext5d to ! ,h5ry ,m\nta9s1 & are well display$ ^u ! flanks4 ,!y include f\r pr9cipal s&/ones1 ) int]v5+ %ales1 9 ! foll[+ 7desc5d+7 ord]3 #a4 ,! ,ma-suk ,s&/one1 yell[1 heavy-b$d$ #ejj feet4 #b4 ,! ,ma-suk ,%ale1 gray1 argillace\s1 & t[>d ! top slightly ar5ace\s #ejj feet4 #c4 ,! ,blue ,gate ,s&/one1 yell[ & heavy-b$d$ #ejj feet4 #d4 ,! ,blue ,gate ,%ale1 blue-black & argillace\s1 wea!r+ to a f9e gray clay 7,inoc]amus de=mis & ,i4 problematicus7 #a1jjj feet4 #e4 ,! ,tu-nunk ,s&/one1 yell[ & heavy-b$d$ #ajj feet4 #f4 ,! ,tu-nunk ,%ale1 blue-black & argillace\s1 wea!r+ to a f9e gray clay 7,inoc]amus problematicus & ,baculites anceps7 #djj feet4 #g4 ,! ,h5ry's ,=k ,gr\p1 consi/+ (-- a4 ,friable yell[ s&/one ) num]\s fossils 7,o/rea prud5tia1 ,gryphea ,pit*]i1 ,exogyra lviuscula1 ,exogyra pond]osa1 ,plicatula hydro!ca1 ,camptonectes platessa1 & ,calli/a ,deweyi7 #aj feet4 b4 ,ar5ace\s %ales1 purple1 gre51 & :ite1 ) local b$s ( conglom]ate #aij feet4 c4 ,co>se s&/one & conglom]ate1 ) _m :ite gra9s & pebbles1 int]leav$ ) local b$s ( purple & r$ %ale1 & conta9+ imm5se silicifi$ tree-trunks #cjj feet4 ---------- ,total ,cretace\s #c1ejj feet4 ,! ?ree upp] s&/ones1 ! ,masuk1 ! ,blue ,gate1 & ! ,tununk1 are s ne>ly id5tical 9 _! li?ologic *>act]s t ,i 0 unable to discrim9ate !m 9 localities :]e _! sequ5ce 0 unkn[n4 ,?is 0 especially ! case ^u ! summits ( ,m\nts ,ell5 & ,p5nell :]e !y occur 9 a some:at metamorphos$ condition4 ,all ( !m conta9 ?9 b$s ( coal1 none ( :i* are cont9u\s ov] l>ge areas1 & only "o ( :i* 0 obs]v$ ( workable ?ickness4 ,at ! we/]n foot ( ,m\nt ,ell51 a b$ f\r feet ?ick lies at ! base ( ! ,blue ,gate ,s&/one4 ,!re is almo/ equal difficulty 9 discrim9at+ ! ,masuk1 ! ,blue ,gate1 & ! ,tununk %ales4 ,! fir/ is usually ( a pal] color & is m apt to include ar5ace\s b&s4 ,x has n be5 f\nd to conta9 fossils1 :ile ! l[] %ales r>ely fail to af=d !m :5 se>* is made4 ,! ,blue ,gate & ,tununk %ales are typical examples ( f9e argillace\s s$im5ts4 ,!y are beautifully lam9at$ & are rem>kably homog5e\s4 ,x is only 9 fre% esc>pm5ts t ! lam9ation is se51 ! wea!r$ surface pres5t+ a /ructureless clay4 ,! fossils ( ^! %ales are s num]\s1 :5 !y h be5 s\ght out & /udi$1 t !y w probably s]ve n m]ely to discrim9ate ! two1 b also to correlate !m ) "s ( ! b$s :i* h be5 exam9$ else:]e 9 ! ,colorado ,bas94 ,= ! pres5t ,i am unable to ref] any ( ! ,cretace\s rocks above ! ,h5ry's ,=k ,gr\p to ! divisions :i* h be5 recogniz$ else:]e1 & x is = ?is reason t ,i h giv5 local1 & p]haps tempor>y names to su* b$s z ,i h ne$ to m5tion 9 ! discussion ( ! /ructure ( ! m\nta9s4 ,! fossils ( ! ,h5ry's ,=k ,gr\p h be5 m fully collect$1 & !y h be5 ref]r$ )\t "q by ,dr4 ,:ite to ! gr\p ( t "n1 z recogniz$ 9 ! ,gre5 ,riv] ,bas9 7,geology ( ! ,u9ta ,m\nta9s1 pp4 #hb & #id74 ,! :ite grit :i* lies at ! base ( ! gr\p is a conspicu\s b$ ( unusual p]si/5ce1 & is recogniz$ :]ev] ,cretace\s rocks are f\nd 9 ! upp] bas9 ( ! ,colorado4 ,jura-,trias4--,! rocks :i* int]v5e betwe5 ! base ( ! ,cretace\s & ! summit ( ! ,c>bonif]\s are ( d\btful age1 hav+ be5 ref]r$ to ! ,trias by "o geologi/ & to ! ,jura & ,trias by o!rs1 :ile ! fossils rec5tly discov]$ by ,mr4 ,h[ell 7,geology ( ,u9ta ,m\nta9s1 page #hj7 lead to ! suspicion at lea/ t !y are all ,jurassic4 ,x is probable t ! unc]ta9ty w soon be dispell$ by ! m ?or\gh work+ ( ,mr4 ,h[ell's new localities2 b :ile x rema9s1 x seems be/ to recognize its exi/5ce 9 our nom5clature1 & ,i %all include ! :ole ( ! d\btful s]ies "u ! title ( ,jura-,trias4 ,at ! ,h5ry ,m\nta9s x is easily divid$ into f\r gr\ps1 z foll[s3 #a4 ,flam+ ,gorge ,gr\p2 ar5ace\s %ales or bad-l& s&/ones1 purple & :ite at top & r$ bel[ #a1bjj feet4 #b4 ,gray ,cliff ,gr\p2 massive cross-lam9at$ s&/one1 buff to r$ 9 color #ejj feet4 #c4 ,v]milion ,cliff ,gr\p2 massive cross-lam9at$ s&/one1 r$1 ) a purple b& at ! top #ejj feet4 #d4 ,%9-ar-ump ,gr\p2 consi/+ (-- a4 ,v>iegat$ clay %ale2 purple & :ite above & *ocolate bel[1 ) silicifi$ wood #cjj feet4 b4 ,gray conglom]ate1 ) silicifi$ wood2 ! 8,%9>ump ,conglom]ate0 #cj feet4 c4 ,*ocolate-color$ %ale1 9 "p s&y #djj feet4 ---------- ,total ,jura-,trias #b1icj feet4 ,! rock ( ! ,flam+ ,gorge ,gr\p is ( a peculi> "*4 ,x is ord9>ily s s(t t 9 its mann] ( wea!r+ x appe>s to be a %ale4 ,x is erod$ s mu* m rapidly ?an ! ,h5ry's ,=k conglom]ate above x1 t ! latt] is und]m9$1 & always appe>s 9 ! topography z ! cap ( a cliff4 ,nev]!less1 x is n /rictly speak+ a %ale4 ,! *ief product ( its wea!r+ is s&1 & :]ev] x c be exam9$ 9 an unwea!r$ condition x is f\nd to be a f9e-gra9$ s&/one1 massive & cross-lam9at$ l ^? ( ! ,gray & ,v]milion ,cliffs1 b devoid ( a firm cem5t4 ,9 a numb] ( localities x has acquir$1 locally & accid5tally1 a cem5t1 & x is !re h>dly di/+ui%able f ! firm] s&/ones :i* und]lie x4 ,9 ! imm$iate vic9ity ( ! ,h5ry ,m\nta9s x v>ies little except 9 color f summit to base1 b 9 o!r localities n f> di/ant x is int]rupt$ ne> ! base by ?ick b$s ( gypsum & gypsif]\s clays1 & by a sectile1 fossilif]\s lime/one4 ,! ,gray ,cliff & ,v]milion ,cliff s&/ones are (t5 difficult to di/+ui%1 b ! latt] is usually ! firm]1 /&+ 9 bold relief 9 ! topography1 ) level top1 & at its edge a precipit\s face4 ,! =m] is apt to wea!r into a wild]ness ( dome-l p9nacles1 s /eepsid$ t !y _c (t5 be scal$ by ! exp]i5c$ m\nta9e]1 & sep>at$ by n>r[ clefts :i* are equally impassable4 ,! colors ( ! two s&/ones are n inv>iable4 ,! l[]1 :i* al?\gh n r$d5$ ?r\gh\t its mass is usually /a9$ ^u its surface ) a uni=m deep color1 appe>s 9 ,m\nt ,ellswor? & at o!r po9ts ( elevation ) z pale a t9t z t ( ! ,gray ,cliff4 ,! latt] s&/one1 on ! o!r h&1 :]e x lies l[1 is (t5 z deep 9 color z ! ,v]milion4 ,/&+ ^u "o ( ! summits ( ! ,h5ry ,m\nta9s & look+ ea/w>d1 ,i f\nd myself unable to di/+ui% ! ,gray ,cliff ,s&/one by color ei!r f ! l[] "p ( ! ,flam+ ,gorge ,gr\p or f ! ,v]milion ,s&/one4 ,! blea*+ ( ! r$d] s&/one 9 ,m\nt ,ellswor? is probably a result ( metamorphism2 ! r$d5+ ( ! gray s&/one may dep5d on ! hydration ( ! iron :i* x conta9s4 ,! ?ickness ( individual /rata 9 ^! great s&/ones is rem>kable1 & is "o ( ! elem5ts :i* mu/ be tak5 into acc\nt 9 ! discussion ( ! problem--:i* to my m9d is yet unsolv$--( ! mann] 9 :i* su* imm5se quantities ( homog5e\s s& 7 accumulat$4 ,ord9>ily ! dep? ( /rata is indef9able1 on acc\nt ( ! impossibility ( di/+ui%+ /ratification f lam9ation2 b :]e1 z 9 ?is case1 ! lam9ation is oblique to ! /ratification1 ! upp] & l[] limits ( ea* /ratum are def9itely m>k$4 ,i h at sev]al po9ts measur$ s+le /rata ) ?icknesses ( ab\t fifty feet1 & ne> ,wat]pocket ,caon a /ratum ( ,v]milion ,cliff s&/one 0 f\nd to be #aje feet ?ick4 ,"o o!r measurem5t is wor?y ( record2 ! incl9ation :i* oblique lam9ation be>s to ! plane ( ! /ratum 9 :i* x occurs appe>s to h a def9ite limit4 ,! maximum ( a s]ies ( measurem5ts made at po9ts :]e to ! eye ! dip seem$ to be unusually great1 is #bd4 ,! s&y lay]s at ! base ( ! ,%9>ump ,gr\p are *>act]iz$ by pr(use ripple-m>ks4 ,c>bonif]\s4--,b5ea? ! ,jura-,trias is ! ,c>bonif]\s4 ,a few hundr$ feet ( its upp] memb]1 ! ,aubrey ,s&/one1 are expos$ ne> ! summit ( ,m\nt ,ellswor?4 ,at t po9t ! s&/one is alt]$ to ! condition ( a qu>tzite1 b :]e x is cut by ! upp] & l[] caons ( ! ,dirty ,devil ,riv] x is massive & cross-lam9at$1 diff]+ f ! ,gray ,cliff s&/one *iefly 9 ! abundance ( its calc>e\s cem5t4 ,,uncon=mities4 ,f ! ,masuk ,s&/one to ! ,aubrey ,s&/one1 inclusive1 !re is p]fect con=mity ( dip4 ,! fold sy/em ( ! region1 ( :i* a description w be f\nd 9 succe$+ pages1 0 e/abli%$ aft] ! deposition ( all ^! /rata1 & ! :ole s]ies 7 flex$ toge!r4 ,nev]!less1 ! /rata d n repres5t cont9u\s deposition4 ,!re 7 int]vals 9 :i* ! sea rec$$ & expos$ to erosion ! s$im5ts :i* x _h accumulat$4 ,%all[ valleys & wat]ways 7 excavat$1 & :5 ! sea return$ x deposit$ new s$im5ts ^u ! some:at unev5 surface ( ! old4 ,! fir/ occurr5ce ( ?is sort 0 at ! close ( ! ,aubrey epo*4 ,its evid5ce 0 n f\nd 9 ! ,h5ry ,m\nta9s2 b at ! conflu5ce ( ! ,p>ia ) ! ,colorado1 eighty miles to ! s\!a/1 ! surface ( ! upp] memb] ( ! ,aubrey ,gr\p1 :i* is !re a *]ty lime/one1 is unev5ly worn1 & 9 its depressions are b$s ( conglom]ate1 ! pebbles ( :i* are d]iv$ f ! *]t ( ! lime/one itself4 ,! %aly1 rippl$ s&/ones :i* succe$ ?is conglom]ate indicate t ! wat] rema9$ %all[ = a "t1 & 9 ! middle ( ! ,%9>ump epo* ! region 0 once m ab&on$ by ! sea4 ,! *ocolate %ales & %aly s&s 7 unev5ly worn1 & ! fir/ deposit t ! return+ sea spread ov] !m 0 a conglom]ate4 ,! evid5ce ( ?is break is f\nd at _m po9ts4 ,! ,%9>ump conglom]ate al?\gh rem>kably p]si/5t = a conglom]ate ?9s out & disappe>s at a numb] ( po9ts1 & at ! m>g9s ( its areas x is evid5t to ! eye t x occupies depressions ( ! surface on :i* x re/s4 ,! next break is at ! base ( ! ,v]milion ,cliff ,gr\p4 ,9 ! region ( ! ,virg9 ,riv] & ,kanab ,creek ! *ange f ! v>iegat$ %ales ( ! ,upp] ,%9>ump to ! homog5e\s s&/one ( ! ,v]milion ,cliff is gradual1 ! int]val be+ fill$ by a s]ies ( alt]nat+ %ales & s&/ones2 b fur!r to ! ea/1 9 ! region ( ! ,h5ry ,m\nta9s & ,wat]pocket ,caon1 ! *ange is abrupt1 & ! firm s&/one re/s directly ^u ! s(t %ale4 ,! abruptness ( ! *ange w\ld sugge/ t ! curr5ts :i* br\ght ! s& _h swept away all evid5ce ( ! int]m$iate conditions :i* are likely to h connect$ ! epo*s repres5t$ by ! two s$im5ts2 b 9 "o locality1 at lea/1 !re is direct evid5ce t ! surface ( ! clay 0 expos$ to ! air be=e x 0 cov]$ by ! s&4 ,on ! nor!rn flank ( ,m\nt ,ellswor? are ! ve/iges ( a sy/em ( mud-cracks1 su* z =m :]e wet clays are dri$ 9 ! sun4 ,:]e ! "u surface ( ! ,v]milion s&/one is expos$ to view1 x is se5 to be m>k$ by a network ( ridges :i* once occupi$ ! sun-cracks ( ! ,%9>ump clay2 & :]e ! clay is se5 9 juxtaposition1 tap]+ fillets ( s& c be trac$ f ! ridges d[nw>d t5 feet into ! clay4 ,illu/ration3 ,,fig4 #a4--;,fossil ,suncracks 9 ! ,%9>ump ,%ale4 ,f ! base ( ! ,v]milion to ! summit ( ! ,cretace\s no evid5ce ( l& erosion has be5 f\nd2 b ! association ( coal seams ) all ( ! ,cretace\s s&/ones except ! l[e/1 %[s t ! sea-bottom 0 frequ5tly br\ght to ! surface ( ! wat] if x 0 n c>ri$ above4 ,?us x is evid5t t ! /rata ( ! ,h5ry ,m\nta9 region d n repres5t cont9u\s s$im5tation4 ,at ! close ( ! ,aubrey epo*1 9 ! middle ( ! ,%9>ump1 & aga9 at ! close ( ! ,%9>ump1 n m]ely 0 ! accumulation ( s$im5ts int]rupt$1 b ! process 0 rev]s$1 & a portion ( ! deposits :i* _h already be5 =m$ 7 excavat$ by ! ag5cy ( ra9s & riv]s1 & swept away to "s o!r region4 ,ea* break is indef9ite1 alike z reg>ds ! int]val dur+ :i* ! record ( ! sea 0 int]rupt$ & z reg>ds ! ext5t ( ! record :i* 0 at ! same "t oblit]at$4 ,& yet ! evid5ce ( ^! breaks is ( su* nature t x w\ld probably elude obs]vation if a s+le section only 7 exam9$1 & 9 a region mask$ by ! soil & vegetation ( a humid climate x w\ld h>dly be discov]$ except by accid5t4 ,! p>allelism ( contigu\s /rata is n alone suffici5t evid5ce t !y 7 consecutive 9 "t4 ,at ! close ( ! ,cretace\s p]iod !re came an epo* ( di/urbance4 ,! sy/em ( /rata :i* has be5 describ$ 0 b5t into great waves1 & ! cre/s ( ! waves 7 lift$ s high above ! sea t !y lo/ ?\s&s ( feet by erosion4 ,9 ! tr\ghs betwe5 ! waves lakes rema9$1 9 :i* ! mat]ial remov$ f ! cre/s 0 r$eposit$1 & by a lat] *ange ! lake wat]s rose s z to cov] ! truncat$ cre/s1 & deposit ^u ! worn edges ( ! upb5t /rata a s]ies ( uncon=m+1 fre%-wat]1 ,t]ti>y s$im5ts4 ,?us 0 produc$ ! only uncon=mity ( dip :i* involves ! ,h5ry ,m\nta9 rocks1 & ev5 ?is is n to be obs]v$ 9 ! imm$iate vic9ity ( ! m\nta9s1 = a lat] erosion has !nce remov$ all ( ! ,t]ti>y /rata1 & has resum$ ! degradation ( ! old] b$s4 ,,! ,,great ,,folds4 ,! di/urbances at ! close ( ! ,cretace\s p]iod 7 ( ! ,kaibab type#a4 ,x seems z ?\gh ! cru/ ( ! e>? _h be5 divid$ into great blocks1 ea* _m miles 9 ext5t1 :i* 7 mov$ f _! orig9al positions 9 v>i\s ways4 ,"s 7 c>ri$ up & o!rs d[n1 & ! majority 7 left high] at "o m>g9 ?an at ! o!r4 ,b al?\gh !y mov$ indep5d5tly1 !y 7 n cleft asund]4 ,! /rata rema9$ cont9u\s1 & 7 flex$ in/ead ( fault$ at ! m>g9s ( ! blocks4 ,subsequ5t erosion has oblit]at$ 9 great "p ! inequality ( ! surface1 & ! high]-ly+ blocks d n /& z m\nta9s1 b are outl9$ by zones ( tilt$ /rata :i* m>k ! flexures by :i* ! blocks are sep>at$4 ,along ! zones ( flexure x frequ5tly happ5s t a h>d /ratum outcropp+ betwe5 two t are s(t] w be pres]v$ f erosion & =m a long1 cont9u\s ridge4 ,su* ridges1 & o!r =ms produc$ by ! erosion ( ! flexures1 are conspicu\s features ( ! topography1 & ! trac+ out ( ! limits ( ! blocks is a simple matt]4 ,inde$ ! flexures are ! fir/ elem5ts ( ! /ructure to attract att5tion1 & x is easy 9 /udy+ !m to ov]look ! fact t !y m]ely m>k ! limits betwe5 displac$ masses ( great ext5t4 ,if ! read] w exam9e ,plate ,i at ! end ( ! volume1 he w obs]ve t ! sy/em ( p>allel ridges & valleys :i* foll[ ! l9e ( ! ,wat]pocket flexure are v conspicu\s features2 b x is only by "s su* g5]alization z t giv5 9 ! /]eogram ( ! same region 7,plate ,,ii7 t ! full /ructural significance ( ! flexures c be realiz$4 ,ea* map 0 obta9$ by photography f a model 9 relief1 9 :i* ! proportionate heights ( ! sev]al features 7 n exagg]at$4 ,! /]eogram 0 produc$ by ! re/oration ( ! top ( ! ,cretace\s1 ! ,masuk s&/one1 9 ! =m & position x w\ld h1 _h !re be5 no erosion ( ! region1 b displacem5t only4 ,footnote #a3 ,= a def9ition ( ! ,kaibab /ructure1 see 8,geology ( ! ,u9ta ,m\nta9s10 pp4 #ad & #ag1 & ,am]ican ,j\rnal ( ,sci5ce = ,july & ,augu/1 #ahgf1 pp4 #ba & #he4 ,i mu/ caution ! read] aga9/ an implication ( rigidity :i* might atta* to ! mean+ ( ! ^w 8block01 z ,i h us$ x 9 speak+ ( ! great displac$ rock masses4 ,to :at ext5t !y may be reg>d$ z rigid is unc]ta91 b ! pres5ce ^u _! surfaces ( num]\s m9or flexures1 su* z appe> 9 ! /]eogram1 w\ld seem to imply t _! rigidity is n ( a high ord]4 ,9 ! nor?we/ corn] ( ! area repres5t$ by ! /]eogram are a few faults belong+ to a sy/em :i* occupies a l>ge area 9 t direction4 ,! sy/em ( faults & ! sy/em ( flexures are indep5d5t1 ! latt] hav+ orig9at$ at ! close ( ! ,cretace\s p]iod1 & ! =m] aft] ! =mation ( ! ,t]ti>y rocks ( ! region1 :i* are ref]r$ by ,pr(essor ,p[ell to ! ,bitt] ,creek epo*4 ,ov] a l>ge di/rict ! ,t]ti>y /rata 7 cov]$ by a deep mantle ( lava1 :i* has protect$ !m f erosion to su* an ext5t t ! /ructure ( ! di/rict is portray$ 9 its topography4 ,! di/rict is its own /]eogram1 ea* uplift$ block con/itut+ a m\nta9 & ea* depress$ block floor+ a valley4 ,n all ! displacem5ts ( ! lat] sy/em are by fault+1 b by f> ! great] numb]4 ,( ! e>li] sy/em ( displacem5ts none are simple faults1 b a few are comb9ations ( fault & flexure4 ,illu/ration3 ,,fig4 #b4--;,cross-section ( ! ,wat]pocket ,flexure1 opposite ! ,masuk ,plateau4 ,scale1 "o in* #c1ejj feet4 #a1 ,masuk ,s&/one4 #b1 ,masuk ,%ale4 #c1 ,blue ,gate ,s&/one4 #d1 ,blue ,gate ,%ale4 #e1 ,tununk ,s&/one4 #f1 ,tununk ,%ale4 a1 ,gryphea ,s&/one4 #g1 ,h5ry's ,=k ,conglom]ate4 #h1 ,flam+ ,gorge ,%ale4 #i1 ,fossilif]\s ,lime/one4 #aj1 ,gray ,cliff ,s&/one4 #aa1 ,v]milion ,cliff ,s&/one4 #ab1 ,upp] ,%9>ump ,%ale4 #ac1 ,%9>ump ,conglom]ate4 #ad1 ,l[] ,%9>ump ,%ale4 #ae1 ,aubrey ,s&/one4 ,illu/ration3 ,,fig4 #c4--,view ( ! ,wat]pocket ,caon & ! ,wat]pocket ,flexure4 ,! cliff at ! left is capp$ by ! ,h5ry's ,=k ,conglom]ate4 ,! ar*$ rocks at ! "r are ! ,gray & ,v]milion ,cliff ,s&/ones4 ,illu/ration3 ,,fig4 #d4--,wat]pocket ,flexure1 z se5 f ! s\? end ( ,m\nt ,ell54 ,! ,wat]pocket flexure1 repres5t$ 9 ! /]eogram 7,plate ,,ii71 is bett] kn[n 9 detail ?an any o!r ( ! great flexures ( ,s\!rn ,utah4 ,x is f> f foll[+ a /raight l9e1 b l mo/ l9es ( orographic di/urbance sw]ves to ! "r & left1 :ile ma9ta9+ a g5]al tr5d4 ,! am\nt ( its 8?r[01 or ! diff]5ce 9 level betwe5 adjac5t p>ts ( ! two blocks :i* x divides1 is incon/ant1 its maximum be+ #g1jjj feet4 ,at "s po9ts ! flex$ /rata are incl9$ at an angle ( #ej :ile at o!rs _! greate/ dip is b #ae4 ,t[>d ! nor? ! flexure twice divides4 ,"o ( its bran*es1 ! ,blue ,gate flexure1 has a ?r[ 9 ! same direction1 & by its sep>ation dim9i%es ! ?r[ ( ! ma9 flexure4 ,! o!r1 ! ,r$ ,gate flexure1 has a ?r[ 9 ! opposite direction1 & by its sep>ation increases ! ?r[ ( ! ma9 flexure4 ,or 9 o!r words1 ! blocks at ! we/ ( ! ma9 flexure /& high] ?an ^? at ! ea/2 & ( two blocks :i* lie at ! we/1 t at ! nor? ( ! ,r$ ,gate flexure /&s high] ?an t at ! s\?2 :ile ( two blocks at ! ea/1 t :i* lies nor?we/ ( ! ,blue ,gate flexure is high] ?an ! "o at ! s\!a/4 ,,cliffs ,,& ,,plateaus4 ,let u n[ return to ! topographic map 7,plate ,i7 & exam9e ! =ms into :i* erosion has wr\ght ! di/urb$ /rata4 ,?anks to ! aridity ( ! climate1 ! erosion has be5 greatly influ5c$ by ! v>y+ texture ( ! rocks4 ,e h>d /ratum1 if incl9$1 /&s =? 9 a ridge1 or if level1 caps a plateau4 ,! ,masuk ,s&/one1 und]m9$ by ! wea!r+ ( ! ,masuk ,%ale1 breaks (f ev]y:]e 9 a cliff :i* completely encircles ! ,masuk ,plateau4 ,! plateau /&s ^u ! ,blue ,gate ,s&/one1 & ?is break+ (f 9 a cliff ^u all sides con/itutes ano!r plateau4 ,! ,blue ,gate ,plateau1 9 turn1 re/s ^u ! ,tununk1 & t aga9 ^u ! ,h5ry's ,=k4 ,pass+ ei!r to ! nor? or to ! s\? f ! ,masuk ,plateau1 "o desc5ds a great geological /airway1 ( :i* ea* /ep is a h>d s&/one & ea* ris] a s(t %ale4 ,t[>d ! ,wat]pocket flexure ! edge ( ea* plateau is upturn$1 & if "o goes we/w>d f ! ,masuk ,plateau1 he w cross 9 ! fir/ mile ! upturn$ rocks ( all ! l[] tables4 ,! pres]vation ( ! ,masuk ,plateau is due 9 "p to ! fact t x lies 9 a slight syncl9al1 b *iefly to ! arrangem5t ( ! dra9age l9es4 ,no /reams cross ! ,h5ry ,m\nta9s1 b all g ar\nd1 & ! plateau occupies ! divide betwe5 ^? :i* fl[ s\?w>d to ! ,colorado & ^? :i* fl[ nor?w>d to ! ,dirty ,devil4 ,! anti!sis ( ! ,masuk ,plateau is to be se5 9 ! ,circle ,cliffs1 on ! summit ( ! ,wat]pocket fold4 ,at ! l[e/ po9t ( ! ,masuk syncl9al a circl+ cliff has be5 =m$1 :i* fac+ outw>d surr\nds a plateau4 ,at ! highe/ po9t ( ! ,wat]pocket fold1 :i* is 9 a c]ta9 s5se anticl9al1 a circl+ cliff has be5 =m$ :i*1 fac+ inw>d1 surr\nds a valley4 ,! two ph5om5a are alike illu/rations ( ! law t 9 regions ( incl9$ /rata cliffs face t[>d di/ricts ( elevation & away f di/ricts ( depression4 ,,h[ ,,to ,,rea* ,,! ,,h5ry ,,m\nta9s4 ,illu/ration3 ,,fig4 #e4--,ways & ,means4 ,no "o b a geologi/ w ev] pr(itably seek out ! ,h5ry ,m\nta9s1 & ,i w !re=e1 9 m>k+ out a r\te by :i* !y may be rea*$1 select :5ev] !re is option ^? pa?s :i* w give him ! be/ introduction to ?is wond]ful l&4 ,!re is no wagon-road to ! m\nta9s1 & al?\gh a wagon might c>ry 8 baggage ! great] "p ( ! way1 he mu/ provide himself ) o!r means ( transportation4 ,at ,salt ,lake ,city he c procure pack-mules & pack-saddles1 or app>ajos1 & ev]y?+ necess>y = a m\nta9 8outfit04 ,8 r\te s\?w>d foll[s ! l9e ( ! ,utah ,s\!rn ,railway to ,juab ,valley1 & !n t\*es ! ,mormon t[ns ( ,nephi1 ,gunnison1 & ,sal9a4 ,at ,sal9a he halts 8 tra9 = a day :ile he rides a few miles up ! creek to see ! uncon=mity betwe5 ! ,t]ti>y above1 & ! ,jura-,trias & ,cretace\s bel[4 ,?is is at pres5t ! la/ settlem5t on ! r\te1 b !re are 8ran*es0 z f> z ,rabbit ,valley1 & if he delays a few ye>s he w f9d a t[n !re4 ,by way ( ! 8,twi/0 road & ,k+'s ,mead[s he goes to ,grass ,valley1 & !nce to ,fi% ,lake4 ,! lake lies betwe5 two upheav$ blocks ( tra*yte1 & cov]s "o :i* is relatively depress$1 & tilt$ to ! nor?4 ,at ! s\? end ( ! lake he /&s on ! high] end ( ! depress$ block1 & if he foll[s ! %ore to ! outlet at ! nor? he w f9d t ! wat] is conta9$ by a mora9e1 :i* has be5 ?r[n across ! valley by an anci5t glaci]1 desc5d+ f ! m\nta9 at ! we/4 ,f ,fi% ,lake he goes to ,rabbit ,valley1 & !re delays a day or two to climb ,?\s& ,lake ,m\nta94 ,look+ we/ f ! summit he sees ! lava-capp$ plateaus ( ! fault$ di/rict among :i* he has j\rney$ s9ce he left ! 8,twi/0--huge tables ( tra*yte b\nd$ by cliffs ( displacem5t1 ( :i* only ! %>pe/ edges h be5 worn away2 & :5 8 eye has become accu/om$ to ! facies ( ! faults1 he p]ceives t !re is an id5tity 9 /ructure betwe5 ! great & ! small features4 ,j z ! :ole di/rict is divid$ into blocks1 ( :i* ! dim5sions are measur$ by miles1 & ! displacem5ts by ?\s&s ( feet1 s ! great] blocks are sometimes divid$ into small]1 ( :i* ! dim5sions are measur$ by rods & furlongs & ! displacem5ts by t5s & hundr$s ( feet4 ,look+ ea/w>d he sees ! region ( ! great flexures spread out be=e him l a map4 ,! ,wat]pocket flexure />ts f ! v m\nta9 b5ea? him1 & curv+ to ! "r1 runs f> to ! s\? & is lo/ 9 ! di/ance4 ,beyond x are ! ,h5ry ,m\nta9s spr++ abruptly f ! des]t2 & aga9/ ! horizon are outl9$ o!r isl& m\nta9s1 gray 9 ! di/ance4 ,to ! left is ! ,san ,rafael ,fold1 ! rival ( ! ,wat]pocket 9 gr&eur2 & all ab\t are tables & cliffs4 ,! vivid hues ( ! nak$ rocks are obscur$ only by ! des]t haze1 & ! :ole /ructure is pictur$ =? by =m & color4 ,illu/ration3 ,,fig4 #f4--,! ,uncon=mity ( ! l[] caon ( ,sal9a ,creek4 ,! horizontal /rata are ,t]ti>y2 ! incl9$1 ,cretace\s4 ,to rea* ! ,h5ry ,m\nta9s f ,rabbit ,valley1 he mu/ cross ! ,wat]pocket flexure2 & s cont9u\s & /eep are ! monocl9al ridges :i* foll[ ! l9e ( flexure1 t !re are b f\r po9ts kn[n :]e he c effect a passage4 ,except at ^! po9ts1 ! b>ri] is impassable f ,?\s& ,lake ,m\nta9 to ! ,colorado ,riv]1 a di/ance ( eighty miles4 ,! mo/ difficult & circuit\s r\te ,i w n describe4 ,! rema9+ ?ree div]ge b slightly f ea* o!r4 ,/>t+ f ,rabbit ,valley he foll[s = a few miles ! valley ( ! ,dirty ,devil1 :i* "h1 ?r\gh ! 8,r$ ,gate01 passes f ! tra*yte plateaus & ent]s ! l& ( caons4 ,he does n foll[ x f>1 b :]e ! riv] ent]s a caon 9 ! ,aubrey ,s&/one1 be>s to ! left1 & by ! aid ( a trail :i* ,indians h made f9ds a s9u\s b easy pa?way along a monocl9al valley1 foll[+ ! outcrop ( ! l[] ,%9>ump4 ,at 8 "r ! ,aubrey ,s&/one rises to =m ! plateau ?r\gh :i* ! riv] defiles4 ,at 8 left ! ,v]milion ,s&/one /&s 9 a v]tical wall4 ,b5ea? 8 feet are ! %aly s&/ones ( ! ,%9>ump ,gr\p1 b>e ( vegetation & display+ a pr(usion ( ripple-m>ks1 su* z is r>ely if ev] equal$4 ,a ride ( twelve miles br+s him once m to ! ,dirty ,devil ,riv]1 :i* em]g+ f its ,c>bonif]\s caon dives at once into a /ill deep] caon ?r\gh ! ,v]milion & ,gray ,cliff ,s&/ones4 ,he c foll[ ! riv] if he tries1 & em]ge ) x beyond ! flexure2 b ! way is difficult & ! ,indian trail he has foll[$ ?us f> leads on to ano!r caon4 ,! monocl9al valley :i* has op5$ s easy a way cont9ues = fifte5 miles f>!r1 & 9 t di/ance is cross$ by f\r wat]ways1 ea* ( :i* leads by a n>r[ caon ?r\gh ! great s&/ones4 ,! fir/ & f\r? are impassable4 ,! second c>ries no p]man5t /ream1 & is call$ ! 8,capitol ,caon04 ,! ?ird af=ds passage to ,temple ,creek4 ,! smoo!/ road lies ?r\gh ,capitol ,caon1 b ! ,temple ,creek ,caon has an advantage 9 ! pres5ce ( wat]1 & is fur!rmore attractive by reason ( ! picture-writ+s on ! walls4 ,he has n[ to cross ! ,blue ,gate flexure1 & to d ?is he leaves ,temple ,creek a little bel[ ! m\? ( its caon4 ,seek+ once m ! guidance ( a trail1 he j\rneys s\!a/w>d ov] ! gypsum & s& ( ! ,flam+ ,gorge ,gr\p to a pass :i* f a di/ance he has detect$ 9 ! monocl9al ridge m>k+ ! ,h5ry's ,=k conglom]ate4 ,?r\gh ?is pass ,tantalus ,creek sometimes runs on its way to jo9 ! ,dirty ,devil1 & he may f9d a /ream ( muddy wat]2 b ! bottom is m likely to be dry ) ! exception ( a few pools4 ,pass+ ?r\gh ! gap he f9ds be=e him a simil> op5+ 9 ! ,tununk ,ridge1 & beyond t a break 9 ! ,blue ,gate ,cliff4 ,f ,tantalus ,creek he asc5ds to ! pass 9 ! ,blue ,gate ,cliff1 & climb+ to ! summit ( a %>p divide 9 ! %ales desc5ds aga9 to ,lewis ,creek1 :i* !re foll[s a caon ?r\gh ! ,blue ,gate ,plateau4 ,"h he f9ds b[ld]s ( ! ,h5ry ,m\nta9 tra*yte--= ,lewis ,creek rises 9 ! ,h5ry ,m\nta9s--& a few h\rs' ride t[>d ! s\rces ( ! /ream br+s him to ! base ( ,m\nt ,ell54 ,di/ances4 ,f ,salt ,lake ,city to ,sal9a #aee miles4 ,f ,sal9a to ,fi% ,lake #ch miles4 ,f ,fi% ,lake to ,rabbit ,valley #bg miles4 ,f ,rabbit ,valley to ,temple ,creek ,caon #bg miles4 ,f ,temple ,creek ,caon to ,lewis ,creek #ah miles4 ,!nce to ! base ( ,m\nt ,ell5 #aj miles4 ------ ,total f ,salt ,lake ,city to ! ,h5ry ,m\nta9s #bge miles4 ,,*apt] ,,ii4 ,,! ,,/ructure ,,( ,,! ,,h5ry ,,m\nta9s4 ,! m\nta9s /& )9 ! prov9ce ( ! great flexures1 b are indep5d5t ( !m4 ,fifte5 miles to ! we/w>d runs ! ,wat]pocket flexure4 ,?irty miles to ! nor? is ! ,san ,rafael fold4 ,at ! ea/ ! /rata rise t[>d a great uplift1 ( :i* ! full =m is unkn[n4 ,b :]e ! ,h5ry ,m\nta9s /& ! rocks are unaffect$ by ^! di/urbances4 ,!y h a uni=m dip ( ab\t #de to ! nor?we/1 & =m a p]fect datum-plane f :i* to measure ! magnitude ( ! displacem5ts :i* h giv5 rise to ! m\nta9s4 ,! m\nta9s are compos$ ( a l>ge numb] ( p>ts :i* are 9 a c]ta9 degree individual & homolog\s4 ,by ! g5]alization ( ! *>act]s ( ^? p>ts a conception has be5 obta9$ ( a type /ructure to :i* ! entire s]ies ( ph5om5a has be5 ref]r$4 ,9 lay+ ! mat]ial be=e ! read]1 ! foll[+ plan w be foll[$3 ,fir/4 ,! type ( /ructure w be briefly set =?4 ,second4 ,! ph5om5a by :i* ! type is at once demon/rat$ & illu/rat$ w be describ$ 9 detail4 ,?ird4 ,! type ( /ructure w be discuss$4 ,if ! /ructure ( ! m\nta9s be z novel to ! read] z x 0 to ! writ]1 & if x be z /rongly oppos$ to 8 preconception ( ! mann] 9 :i* igne\s m\nta9s are con/itut$1 he may well "q ! conclusions 9 reg>d to x :ile !y are unsu/a9$ by pro(4 ,i c only beg him to susp5d 8 judgm5t until ! :ole case %all h be5 pres5t$4 ,on "s acc\nts x w\ld h be5 well to foll[ 9 writ+ ! ord] ( inve/igation1 & develop ! g5]al plan ( /ructure z x 0 develop$ 9 ! field1 by ! addition "h ( "o elem5t & !re ( ano!r2 or at lea/ to assemble ! facts be=e ann\nc+ my d$uctions4 ,b su* a c\rse w\ld be at ! exp5se ( an important elem5t ( conv5i5ce & brevity4 ,z w appe> 9 ! sequel1 ! prelim9>y explanation ( ! type /ructure furni%es a complem5t ( categories & t]ms by ! aid ( :i* ! description ( ! details ( obs]vation1 ess5tially t$i\s1 is greatly abbreviat$4 ,illu/ration3 ,,fig4 #g4--;,ideal ,cross-section ( a ,m\nta9 ( ,eruption4 ,illu/ration3 ,,fig4 #h4--;,ideal ,cross-section ( a ,laccolite1 %[+ ! typical =m & ! ar*+ ( ! ov]ly+ /rata4 ,x is usual = igne\s rocks to asc5d to ! surface ( ! e>?1 & !re issue =? & build up m\nta9s or hills by successive eruptions4 ,! molt5 matt] />t+ f "s region ( unkn[n dep? passes ?r\gh all sup]9cumb5t rock-b$s1 & piles itself up on ! upp]mo/ b$4 ,! lava ( ! ,h5ry ,m\nta9s behav$ diff]5tly4 ,in/ead ( ris+ ?r\gh all ! b$s ( ! e>?'s cru/1 x /opp$ at a l[] horizon1 ins9uat$ itself betwe5 two /rata1 & op5$ = itself a *amb] by lift+ all ! sup]ior b$s4 ,9 ?is *amb] x congeal$1 =m+ a massive body ( trap4 ,= ?is body ! "n laccolite 71 ci/]n1 & 1 /one7 w be us$4 ,figure #g & ,figure #h are ideal sections ( a m\nta9 ( eruption & ( a laccolite4 ,! laccolite is ! *ief elem5t ( ! type ( /ructure exemplifi$ 9 ! ,h5ry ,m\nta9s4 ,x is evid5t t ! intrusion ( a laccolite w produce ^u ! surface z great a hill z ! extrusion ( ! same quantity ( matt]1 ! mass :i* is c>ri$ above ! orig9al surface be+ precisely equival5t to t :i* is displac$ by ! laccolite2 & x is fur!r evid5t t :]e ! sup]ior rock is horizontally /ratifi$ e /ratum above ! laccolite w be uplift$1 &1 unless x is fractur$1 w be upb5t1 & w portray1 m or less fai?fully1 by its curvature1 ! =m ( ! body x cov]s4 ,associat$ ) ! laccolites ( ! ,h5ry ,m\nta9s are %eets & dikes4 ,! t]m %eet w be appli$ 9 ?is report to broad1 ?91 /ratifi$ bodies ( trap1 :i* h be5 intrud$ along ! p>t+s betwe5 s$im5t>y /rata1 & con=m ) ! inclos+ /rata 9 dip4 ,dikes diff] f %eets 9 t !y int]sect ! s$im5t>y /rata at great] or less angles1 occupy+ fissures produc$ by ! rupture ( ! /rata4 ,! logical di/9ction betwe5 dike & %eet is complete1 b 9 nature x n unfrequ5tly happ5s t ! same body ( trap is a %eet 9 "o place & a dike 9 ano!r4 ,betwe5 ! %eet & ! laccolite !re is a complete gradation4 ,! laccolite is a greatly ?ick5$ %eet1 & ! %eet is a broad1 ?91 att5uat$ laccolite4 ,illu/ration3 ,,fig4 #i4--;,ideal ,cross-section ( a ,laccolite1 ) accompany+ ,%eets & ,dikes4 ,9 ! di/rict "u consid]ation ! laccolite is usually1 p]haps always1 accompani$ by dikes & %eets 7see ,figure #i74 ,!re are %eets b5ea? laccolites & %eets above !m4 ,! sup]ior %eets h nev] be5 obs]v$ to ext5d beyond ! curv$ portion ( ! sup]ior /rata4 ,dikes rise f ! upp] surfaces ( ! laccolites4 ,!y are l>ge/ & mo/ num]\s ab\t ! c5t]1 b1 l ! sup]ior %eets1 !y (t5 ext5d ne>ly to ! limit ( ! flexure ( ! uplift$ /rata4 ,! l>g] (t5 radiate f ! c5t] outw>d1 b !re is no con/ancy ( arrangem5t4 ,:]e !y are num]\s !y reticulate4 ,9 ! accompany+ diagrams dikes are repres5t$ b5ea? z well z above ! laccolites4 ,^! are purely hypo!tical1 s9ce !y h n be5 se54 ,9 a g5]al way1 ! molt5 rock mu/ h come f bel[1 b ! *annel by :i* x rose has 9 no in/ance be5 det]m9$ by obs]vation4 ,! horizontal di/ribution ( ! laccolites is z irregul> z ! arrangem5t ( volcanic v5ts4 ,!y lie 9 clu/]s1 & ea* clu/] is m>k$ by a m\nta94 ,9 ,m\nt ,ell5 !re are p]haps ?irty laccolites4 ,9 ,m\nt ,holmes !re are two2 & 9 ,m\nt ,ellswor? "o4 ,m\nt ,p5nell & ,m\nt ,hill]s ea* h "o l>ge & sev]al small] ones4 ,illu/ration3 ,,fig4 #aj4--;,ideal ,cross-section ( ,gr\p$ ,laccolites4 ,_! v]tical di/ribution likewise is irregul>4 ,"s h intrud$ !mselves betwe5 ,cretace\s /rata1 o!rs betwe5 ,jura-,triassic1 & o!rs betwe5 ,c>bonif]\s4 ,f ! highe/ to ! l[e/ ! range is n less ?an #d1jjj feet4 ,^? :i* are above n unfrequ5tly ov]lap ^? :i* lie bel[1 z repres5t$ 9 ! ideal section1 ,figure #aj4 ,! erosion ( ! m\nta9s has giv5 ! utmo/ v>iety ( exposure to ! laccolites4 ,9 "o place are se5 only ar*+ /rata2 9 ano!r1 ar*+ /rata cross$ by a few dikes2 9 ano!r1 ar*+ /rata fill$ ) a network ( dikes & %eets4 ,else:]e a portion ( ! laccolite itself is b>$1 or "o side is remov$ s z to exhibit a natural section4 ,"h ! s$im5t>y cov] has all be5 remov$1 & ! laccolite /&s free1 ) its orig9al =m2 !re ! h>d tra*yte itself has be5 attack$ by ! elem5ts & its =m is *ang$4 ,some:]e1 p]haps1 ! laccolite has be5 de/roy$ & only a dike rema9s to m>k ! fissure ?r\gh :i* x 0 inject$4 ,,*apt] ,,iii4 ,,detail$ ,,description ,,( ,,! ,,m\nta9s4 ,,m\nt ,,ellswor?4 ,x has already be5 /at$ t ! /rata ab\t ! bases ( ! ,h5ry ,m\nta9s are ne>ly level2 b ! c\ntry :i* is built ( !m is f> f level4 ,! arrangem5t ( ! dra9age l9es has caus$ ! degradation ( "s p>ts to greatly exce$ t ( o!rs1 s t :ile ! di/rict at ! s\?1 :i* bord]s ! ,colorado ,riv]1 is pav$ ) ! r$ s&/ones ( ! ,jura-,trias s]ies1 ! adjac5t region at ! nor? /ill c>ries ! yell[ s&/ones & blue %ales ( ! ,cretace\s s]ies4 ,all ab\t ,m\nt ,ellswor? are ! upp] /rata ( ! ,jura-,trias4 ,! l[] b$s ( ! same s]ies rise ^u its flanks & ar* ov] its summit4 ,a description ( ! /ructure ( ! m\nta9 mu/ include1 fir/1 ! ar* ( ! /rata2 second1 ! faults :i* modify ! ar*2 ?ird1 ! sy/em ( tra*yte dikes & tra*yte %eets2 & f\r?1 ! sculpture ( ! m\nta94 ,9 its g5]al proportions ! ar* is at once simple & symmetrical4 ,f all sides ! /rata rise1 sl[ly at fir/1 b ) /eadily increas+ rate1 until ! angle ( #de is rea*$4 ,!n ! dip z /eadily dim9i%es to ! c5t]1 :]e x is no?+4 ,a model to exhibit ! =m ( ! dome w\ld resemble a r\nd-topp$ hat2 only ! level rim w\ld jo9 ! side by a curve in/ead ( an angle1 & ! sides w\ld n be p]p5dicul>1 b w\ld fl>e rapidly outw>d 7see ,figure #aa74 ,! base ( ! ar* is n circul>1 b is slightly oval1 ! long diamet] be+ "o-?ird great] ?an ! %ort4 ,! l5g? ( ! uplift is a little m ?an f\r miles2 ! wid? a little m ?an ?ree miles1 & ! height ab\t #e1jjj feet4 ,! curvature fades away s gradually at its out] limit t x is n easy to tell :]e x ends1 & ! horizontal dim5sions assign$ to ! dome are no m ?an rude approximations4 ,b !re is ano!r elem5t :i* c be giv5 m exactly4 ,! l9e ( maximum dip1 :i* sep>ates ! convex upp] portion ( ! dome f ! concave p]iph]y1 is easily trac$ out 9 nature1 & runs at ! foot ( ! /eep "p ( ! m\nta94 ,x surr\nds an area two miles 9 wid? & two & two-?irds miles 9 l5g?4 ,illu/ration3 ,,fig4 #aa;,a4--,view f ! we/ spur ( ,m\nt ,ellswor?1 %[+ ! tra*yte dikes ( ! nor? spur & revetm5ts ( s&/one & tra*yte4 ,illu/ration3 ,,fig4 #aa4--,/]eogram ( ,m\nt ,ellswor?2 an ideal re/oration ( ! =m ( ! ov]>*+ /rata4 ,! ,ellswor? ar* is almo/ b n completely isolat$4 ,! ,holmes ar*1 ^u ! ea/ side1 /&s s ne> t ! bases ( ! two imp+e & coalesce1 & ! same ?+ happ5s1 ?\gh less notably1 ) ! ,hill]s ar* at ! nor?4 ,! simplicity ( ! ar* is fur!r impair$ by faults--n great faults divid+ ! :ole uplift1 b a sy/em ( small displacem5ts :i* are !mselves subord9ate ph5om5a ( ! uplift4 ,!y are re/rict$ to ! c5tral portion1 & nev] occur s l[ d[n z ! l9e ( maximum dip4 ,! /rata ( ! upp] "p ( ! ar* are divid$ into a numb] ( prismoid blocks :i* /& at slightly diff]5t levels b are n suffici5tly d]ang$ to de/roy ! g5]al =m ( ! ar*4 ,! greate/ ?r[ is only a few hundr$ feet4 ,all or ne>ly all ( ! fault planes are occupi$ by dikes ( tra*yte4 ,! tra*yte injections are n conf9$ to ! fault planes1 nor is _! area s re/rict$ z ! fault area4 ,dikes & %eets ab\nd f ! cre/ ( ! dome d[n to :at might be call$ its spr++ l9e--! l9e ( maximum dip4 ,at ! c5t]1 dikes are m num]\s2 ne> ! limit1 %eets4 ,! c5tral area is cr[d$ s full ( dikes1 & ! wea!r+ br+s !m s conspicu\sly to ! surface1 t ! s(t] s$im5t>ies are half conceal$1 & f "s po9ts ( view ! tra*yte appe>s to make ! entire mass4 ,! accompany+ plan 7,figure #ab7 %[s ! arrangem5t ( ! dikes 9 "o ( ! out] amphi!at]s ( ! m\nta91 :]e !y are less complicat$ ?an 9 ! c5tral region4 ,! tr5ds ( two spurs 7a b & c d7 are indicat$ by ! hat*+s4 ,!y jo9 ! ma9 cre/ ( ! m\nta9 at e1 & inclose betwe5 !m a deep amphi!at] :i* op5s to ! we/4 ,^u ! /eep walls ( ! amphi!at] ! dikes outcrop 9 l9es ( crags1 divid+ r\gh slopes ( yell[ & purple & br[n s&/one4 ,! pr(ile ( "o ( ! walls ( ! amphi!at] 7f a to b1 ,figure #ab7 is drawn 9 ,figure #ac = ! sake ( exhibit+ ! relation ( ! dikes to fault$ blocks ( s&/one4 ,x w be se5 t ! ?r[ ( ! faults is n con/antly 9 "o direction4 ,illu/ration3 ,,fig4 #ad4--,pr(ile ( ! ,nor!rn ,spur ( ,m\nt ,ellswor?4 #a1 #b1 #c1 #d1 & #e are ,tra*yte ,dikes4 ,a1 ,aubrey ,s&/one4 ,s1 ,%9>ump ,%ale4 ,v1 ,v]milion ,cliff ,s&/one4 ,g1 ,gray ,cliff ,s&/one4 ,! zone ( %eets is j inside ! l9e ( maximum dip4 ,usually only "o or two %eets are laid b>e by ! erosion1 b at "o po9t 7see ,figure #ad7 f\r c be c\nt$4 ,t[>d ! c5t] ( ! uplift all ( ^! are limit$ by ! erosion & exhibit _! brok5 edges4 ,d[nw>d1 or t[>d ! p]iph]y1 !y dip out ( sight4 ,lat]ally !y c be trac$ along ! m\nta9 side = v>y+ di/ances1 b !y soon w$ge out & are replac$ by o!rs en e*elon4 ,9 ?ickness ! %eets r>ely exce$ #ej feet1 & nev] #ajj4 ,!y are always ?9 z comp>$ to ! rock masses :i* sep>ate !m1 b1 by reason ( _! sup]ior ability to resi/ erosion1 monopolize a l>ge %>e ( ! surface1 & mask a /ill great] am\nt ) _! dbris4 ,illu/ration3 ,,fig4 #ab4--;,gr\nd plan ( ,tra*yte ,dikes on ! we/]n flank ( ,m\nt ,ellswor?4 ,illu/ration3 ,,fig4 #ac4--,pr(ile ( a we/]n spur ( ,m\nt ,ellswor?1 %[+ ! arrangem5t ( ,dikes & ,faults4 ,! dott$ b$ is ! purple b& at ! top ( ! ,v]milion ,cliff ,s&/one4 ,! dikes ( tra*yte are indicat$ by lett]s4 ,! s$im5t>y rocks are n alt]$ beyond ! region ( tra*yte intrusion4 ,! m]e flexure ( ! /rata 0 n accompani$ by a p]ceptible *ange ( con/itution4 ,9 ! zone ( %eets !re is little *ange except along ! surfaces ( ! contact4 ,= a few feet1 or p]haps only a few in*es1 !re is a discoloration 7usually a decolorization7 & a slight induration1 )\t notable alt]ation ( m9]als4 ,b 9 ! region ( reticulat$ dikes none ( ! s$im5t>ies are un*ang$2 cry/als are develop$1 colors are modifi$1 & h>dness is increas$1 s t ! physical prop]ties ( famili> /rata no long] s]ve = _! id5tification4 ,/ill !re is no crumpl+4 ,! tra*yte masses & ! alt]$ rocks 9 contact ) !m are s mu* m durable ?an ! unalt]$ /rata ab\t !m t !y h be5 left by ! erosion 9 protub]ances4 ,! outcrop ( e dike & %eet is a crag or a ridge1 & ! m\nta9 itself survives ! g5]al degradation ( ! c\ntry only 9 virtue ( its firm] rock masses4 ,nev]!less1 ! m\nta91 because x 0 high] ?an its surr\nd+s1 has be5 expos$ to m rapid erosion1 & has be5 depriv$ ( a great] dep? ( /rata4 ,f ! base ( ! ar* !re h be5 worn #c1ejj feet ( ,cretace\s1 & f #ejj to #a1ejj feet ( ! ,jura-,trias s]ies1 :i* is "h ab\t #c1jjj feet ?ick4 ,f ! summit ( ! ar* m ?an #b1ejj feet ( ! ,jura-,trias h be5 remov$4 ,! /rata expos$ high up on ! m\nta9 be+ old] ?an ^? at ! base1 & ! dip be+ ev]y:]e direct$ away f ! c5t]1 x is evid5t t ! m\nta9 is surr\nd$ by conc5tric outcrops ( b$s :i* lift _! esc>pm5ts t[>d x4 ,x is usually ! case1 :]e ! /rata :i* incl9e aga9/ ! flank ( a m\nta9 are erod$1 t ! s(t] are excavat$ ! m rapidly1 :ile ! h>d] are left /&+ 9 ridges2 & an alt]nation ( b$s suitable = ! =mation ( a ridge occurs "h4 ,"o ( ! upturn$ b$s is ! massive ,v]milion ,cliff s&/one1 & b5ea? x are ! %ales ( ! ,%9>ump ,gr\p4 ,by ! yield+ ( ! %ales ! s&/one is left prom95t1 & x circles ! base ( ! m\nta9 9 a monocl9al ridge4 ,b ! ridge is ( a peculi> "*1 & has really no title to ! "n except 9 ! homology ( its /ructure ) t ( ! typical monocl9al ridge4 ,x lacks ! cont9uity :i* is impli$ by ! ^w 8ridge04 ,! dra9age ( ,m\nt ,ellswor? is f ! c5t] ( ! dome outw>d4 ,a half doz5 dra9age l9es orig9ate 9 ! high cre/s & pass outw>d ?r\gh ! zone ( upturn$ /rata4 ,l[] d[n _! int]spaces are divid$ by o!rs1 & :5 !y rea* ! circl+ esc>pm5t ( ! ,v]milion s&/one _! numb] is fifte54 ,ea* ( ^! cuts ! ridge to its base1 & ! effect ( ! :ole is to r$uce x to a r[ ( s&/one po9ts circl+ ab\t ! m\nta94 ,ea* po9t ( s&/one lies aga9/ ! foot ( a m\nta9 spur1 z ?\gh x _h be5 built = a reta9+ wall to resi/ ! out-?ru/ ( ! spur4 ,borr[+ a "n f ! analogy1 ,i %all call ^! elem5t>y ridges revet-crags1 & speak ( ! spurs :i* be> !m z be+ revett$4 ,! accompany+ sket* is design$ to illu/rate ! /ructure1 b is n drawn f nature4 ,9 ! view ( ,m\nt ,hill]s 7,figure #bg7 ! revetm5ts may be se51 & 9 ! bird's-eye view ( ! ,h5ry ,m\nta9s 7,plate ,v71 z well z 9 ! ,frontispiece1 ! revet-crags ( ,m\nt ,ellswor? also are portray$4 ,! diagram ( ! nor? spur ( ,m\nt ,ellswor? 7,figure #ad7 %[s ! revet-crag ( t spur at ,v4 ,illu/ration3 ,,fig4 #ae4--,revet-,crags4 ,! revet-crags ( ,v]milion s&/one foll[1 9 a g5]al way1 ! l9e ( maximum dip ab\t ! base ( ,m\nt ,ellswor?2 b a few ( !m rise high]1 & "o--t :i* jo9s ! nor?we/ spur--climbs until x is b little l[] ?an ! summit ( ! m\nta94 ,outside ! circle ( ,v]milion ,cliff s&/one lies ! ,gray ,cliff s&/one1 & 9 a few places x takes ! =m ( a revetm5t4 ,inside ! same circle !re are _m revetm5ts1 con/itut$ by tra*yte %eets b$d$ 9 ,%9>ump %ales 7,figure #ad74 ,con=m+ p]fectly ) ! /rata1 ! %eets yield by erosion =ms :i* are id5tical ) ^? af=d$ by h>d s$im5t>y b$s1 & to ! di/ant eye ! impression ( ! ar*+ /ructure ( ,m\nt ,ellswor? is convey$ less by :at c be se5 ( ! /rata ?an by asc5d+ revetm5ts ( tra*yte %eets1 :i* simulate & int]pret ! /rata4 ,illu/ration3 ,,fig4 #af4--,m\nt ,holmes1 f ! nor?4 ,! laccolite ( ,m\nt ,ellswor? is n expos$ to view1 b ,i am nev]!less confid5t ( its exi/5ce--t ! visible ar*+ /rata envelop x1 t ! visible =e/ ( dikes jo9 x1 & t ! visible fault$ blocks ( ! upp] m\nta9 a*iev$ _! displacem5t :ile float$ by ! /ill liquid lava4 ,! pro(1 h[ev]1 is n 9 ! m\nta9 itself1 b dep5ds on ! association ( ! ph5om5a ( curvature & dike & %eet ) laccolites1 9 o!r m\nta9s ( ! same gr\p4 ,9 ! sequel ^! w be describ$1 b x *ances t ! m\nta9 next to be consid]$ is ev5 less develop$ by erosion ?an ,m\nt ,ellswor?4 ,,m\nt ,,holmes4 ,! ord] ( sequ5ce :i* places ,m\nt ,ellswor? be=e ,m\nt ,holmes is ! ord] ( complexity4 ,! =m] conta9s "o laccolite1 ! latt] two4 ,nei!r ( ! two is visible1 b ! /rata :i* envelop !m %ad[ =? _! =ms & leave no "q ( _! duality4 ,!y are s closely comb9$ t ! less] seems a m]e app5dage ( ! great]4 ,f ! c5t] ( ! great] !re is a desc5t ( /rata 9 all directions1 b f ! c5t] ( ! less] ! rocks incl9e t[>d "o-half only ( ! horizon4 ,:]e ! two convex ar*es jo9 !re is a curv$ gro9--a zone ( concave curvature unit+ ! two convexities4 ,ab\t ! comp\nd figure c be obscurely se5 a l9e ( maximum dip1 & beyond t ! fad+ ( ! curves4 ,! curves ?r\gh\t are s g5tle t x 0 f\nd exce$+ly difficult to e/abli% _! limits4 ,9 a g5]al way x may be said t ea* ( ! ,holmes ar*es is z broad z ! ,ellswor? ar*1 b ! v]tical displacem5t is less4 ,9 ! =mation ( ! great] ,holmes ar* ! am\nt ( uplift 0 #c1jjj feet2 = ! less] ar*1 #a1ejj feet4 ,!re is no evid5ce 9 ! =ms ( ! ar*es :i* proves "o to be old] ?an ! o!r4 ,/udy+ ! curves 9 ! field1 ,i c\ld n discov] t ei!r ar* ass]t$ itself m /rongly ?an ! o!r 9 _! common gr\nd4 ,!y seem to meet ^u equal t]ms4 ,/ill x is probable1 a priori1 t !y 7 =m$ successively & n simultane\sly4 ,! co9cid5ce 9 "t ( two eruptions ( lava f neighbor+ v5ts is no m unlikely ?an ! co9cid5ce ( ! two irruptions1 & ! same pr9ciple ( lea/ resi/ance :i* causes individual laccolitic ar*es to assume sph]oidal =ms1 w\ld h giv5 to ! comp\nd ar* ( two laccolites1 co9cid5t 9 "t1 a simple in/ead ( a comp\nd =m4 ,assum+ t ! ar*es 7 successive 9 orig9 ,i %all 9 ano!r & m appropriate *apt] discuss ! problem ( _! *ronological ord] 9 ! light ( _! some:at peculi> dra9age sy/em4 ,! less] ar* betrays no dikes nor %eets4 ,! ,v]milion ,cliff s&/one cov]s x to ! top4 ,! great] is cr[n$ by a few gr& dikes :i* gov]n its topography4 ,f ! c5t] a long dike runs to ! s\?1 a %ort "o to ! nor?1 two to ! ea/1 & "o to ! we/4 ,! c\rse ( ea* is a m\nta9 spur1 & betwe5 !m are amphi!at]s & gorges4 ,cl++ to ! dikes are bodies ( alt]$ s&/one1 b ! great s&/one masses ( ! summit 7 unalt]$ & f !m h be5 excavat$ ! gorges4 ,along ! dike-fill$ fissures !re has be5 "s fault+1 b !re is no reason to believe t ! displacem5t is great 9 am\nt4 ,t[>d ! flanks ( ! m\nta9 !re are a few %eets1 ! out]mo/ ( :i* is f> )9 ! l9e ( maximum flexure4 ,_! esc>pm5ts in/ead ( fac+ upw>d l ! revett+ %eets ( ,m\nt ,ellswor?1 face d[nw>d2 _! buri$ & unkn[n edges are ! edges t[>d ! m\nta94 ,_! ?9n+ t[>d ! p]iph]y ( ! ar* is conspicu\s to ! eye 9 _m in/ances1 z is also ! ?9n+ ( ! dikes4 ,ano!r peculi>ity ( dike =m1 "o :i* has s9ce be5 not$ 9 a numb] ( localities1 0 fir/ detect$ 9 ,m\nt ,holmes4 ,x consi/s 9 a def9ite upp] limit4 ,! dike s m>k$ is (t5 z ev5 ^u its upp] surface z an artificial /one wall4 ,! upp] surface may be level or may incl9e t[>d "o end ( ! dike1 b 9 ei!r case x is sure to be f\nd p>allel to ! b$d+ ( ! /rata :i* inclose ! dike4 ,?is fact l$ to ! suspicion1 aft]w>d confirm$ by m direct evid5ce1 t ! flat top ( ! dike 0 mold$ by an unbrok5 /ratum ( rock bridg+ across ! fissure :i* ! lava fill$ 7,figure #bj74 ,! conv]se ph5om5on c be obs]v$ 9 ! ridge :i* jo9s ,m\nts ,ellswor? & ,holmes4 ,a great dike !re =ms ! cre/ ( ! ridge = half a mile1 its base be+ buri$ 9 s&/one2 b at ! end ( ! ridge ! /rata are se5 to be cont9u\s b5ea? x 7,figure #ba74 ,illu/ration3 ,,fig4 #ag4--,/]eogram ( ! ,holmes ,ar*es2 an ideal re/oration ( ! =m ( ! ov]>*+ /rata4 ,illu/ration3 ,,fig4 #ah4--;,ideal cross-section ( ! ,laccolites ( ,m\nt ,holmes4 ,illu/ration3 ,,fig4 #ai4--;,a flat-topp$ dike4 ,illu/ration3 ,,fig4 #bj4--;,ideal ,cross-section ( ,flat-topp$ ,dikes2 a1 be=e d5udation2 b1 aft] d5udation4 ,illu/ration3 ,,fig4 #ba4--;,ideal ,cross-section ( a ,flat-bottom$ ,dike4 ,illu/ration3 ,,fig4 #bb4--;,diagram to illu/rate a hypo!tical explanation ( ,flat-edg$ ,dikes4 ,t a fissure sev]al feet or sev]al scores ( feet 9 wid? %\ld end ?us abruptly1 dem&s explanation1 & ! ph5om5a imm$iately conc]n$ (f] none4 ,nev]!less x is easy to make an assumption :i* if true r5d]s bo? cases cle>4 ,if we assume t ! fissure in/ead ( end+ at ! cros%ead is m]ely (fset1 & resumes its c\rse beyond1 & t ! dike conta9$ 9 x has two bodies connect$ by a ?9 %eet 7,figure #bb71 we %all h no difficulty 9 conceiv+ ! erosion :i* w produce ei!r ( ! natural appe>ances describ$4 ,! rocks :i* con/itute ,m\nt ,holmes are ! same z ^? ab\t its base4 ,! ,v]milion ,cliff & ,gray ,cliff ,s&/ones alone appe> 9 ! cre/s4 ,! und]ly+ ,%9>ump %ales are cut by ! erosion at a few po9ts only1 & ^? are ne> ! base4 ,= ?is reason ! ,v]milion ,s&/one is n und]m9$ ab\t ! base1 & ! circle ( revet-crags :i* surr\nds ,m\nt ,ellswor? f9ds no c\nt]p>t4 ,!re are1 inde$1 a few revetm5ts ( ,gray ,cliff s&/one1 b !y are scatt]$ & = ! mo/ "p inconspicu\s4 ,9 ! g5]al view ( ,m\nt ,holmes 7,figure #af71 "o ( ! ma9 dikes cr[ns ! ne>e/ spur1 & ano!r ! spur lead+ to ! "r4 ,at ! left are m9or dikes1 & high up is a trap %eet not*$ on its l[] edge4 ,at ! left base ( ! m\nta9 lies ! less] ar*4 ,figure #bc gives a section exhibit$ by "o ( ! nor?w>d caons4 ,x %[s "o ( ! faults ( ! upp] "p ( ! ar* & illu/rates ! ?9n+ ( ! %eets z !y desc5d4 ,illu/ration3 ,,fig4 #bc4--,section %[n 9 a nor?w>d caon ( ,m\nt ,holmes4 a1 ,ve/ige ( ,tra*yte %eet4 b b b1 ,tra*yte %eets4 c1 ,tra*yte dike4 #a1 ,gray ,cliff ,s&/one4 #b #b1 ,purple ,s&/one4 #c1 ,v]milion ,cliff ,s&/one4 #d1 ,%9>ump ,%ale4 ,,m\nt ,,hill]s4 ,next 9 ord] to ! nor? is ,m\nt ,hill]s4 ,let x n be suppos$1 h[ev]1 t !re is disc]nible sy/em 9 ! geographic arrangem5t ( ! m\nta9s or ( ! laccolites4 ,a *>t ( ! m\nta9 peaks & a *>t ( ! laccolites w\ld alike prove intractable 9 ! h&s ( ^? geologi/s :o draw p>allel l9es ?r\gh gr\ps ( volcanic v5ts by way ( %[+ _! tr5d4 ,!y are z p]fectly het]otact\s z !y c\ld be made by an artificial arrangem5t4 ,! diagram 7,figure #bd7 %[s ! relation ( ! laccolite gr\ps to ea* o!r & to ! m]idian4 ,! pr9cipal m\nta9 summits are indicat$ by triangles1 & ! curv$ l9es inclose areas ( di/urbance4 ,m\nt ,hill]s & its foot-hills are con/itut$ by a gr\p ( no less ?an eight laccolites1 & a n9?1 ! ,h[ell laccolite1 is conv5i5tly class$ ) !m1 al?\gh n contigu\s4 ,illu/ration3 ,,fig4 #be4--;,cross-section ( ,m\nt ,hill]s4 ,,fig4 #bf4--,! same1 ) ideal repres5tation ( ! und]gr\nd /ructure4 ,scale1 #a in* #d1jjj feet4 #a4 ,tununk ,s&/one2 #b4 ,h5ry's ,=k ,conglom]ate2 #c4 ,gray ,cliff ,s&/one4 ,! full black l9es repres5t tra*yte %eets1 & ! broad black area ! ,hill]s ,laccolite4 ,illu/ration3 ,,fig4 #bg4--,m\nt ,hill]s1 f ! s\?4 ,! ,hill]s laccolite is ! l>ge/ 9 ! ,h5ry ,m\nta9s4 ,its dep? is ab\t #g1jjj feet1 & its diamet]s are f\r miles & ?ree & ?ree-qu>t] miles4 ,its volume is ab\t t5 cubic miles4 ,! upp] half con/itutes ! m\nta91 ! l[] half ! m\nta9's deep-laid f\ndation4 ,( ! portion :i* is above gr\nd1 s to speak1 & expos$ to atmosph]ic degradation1 less ?an "o-half has be5 /ripp$ ( its cov] ( ov]>*+ /rata4 ,! rema9d] is /ill mantl$ & %ield$ by s$im5t>y b$s & by _m int]leav$ %eets ( tra*yte4 ,! portion :i* has be5 uncov]$ is n left 9 its orig9al %ape1 b is sculptur$ into alp9e =ms & scor$ s deeply t n less ?an #a1jjj feet ( its mass are %[n 9 section4 ,all ab\t ! erod$ 7s\?7 face ( ! m\nta9 ! base is revett$ by walls ( ,v]milion & ,gray ,cliff s&/one1 /r5g!n$ by tra*yte %eets4 ,at ! extreme s\? ^! /& ne>ly v]tical 7#hj71 & _! incl9ation dim9i%es gradually 9 ea* direction1 until at ! ea/ & we/ bases ( ! m\nta9 x is n m ?an #fj4 ,on ! nor? side !re are no revet-crags1 & ! incl9ation is comp>atively slight4 ,x w\ld appe> t ! laccolite 0 asymmetric1 & 0 s mu* /eep]-sid$ on ! s\? t t side suff]$ mo/ rapid degradation4 ,illu/ration3 ,,fig4 #bd4--;,gr\nd ,plan ( ! ,h5ry ,m\nta9s4 ,! curv$ l9es %[ ! limits ( ! pr9cipal displacem5ts2 ! triangles1 ! positions ( ! ma9 peaks4 ,n1 ,m\nt ,ell54 ,p1 ,m\nt ,p5nell4 ,h1 ,m\nt ,hill]s4 ,m1 ,m\nt ,holmes4 ,e1 ,m\nt ,ellswor?4 ,by ref]5ce to ! section 7,figure #be7 x w be se5 t ! s$im5t>y /rata ( ! nor? flank /ret* q to ! summit ( ! m\nta94 ,! same b$s :i* =m ! revet-crags on ! s\!rn base con/itute also "s ( ! highe/ peaks4 ,s9ce ^! re/ directly ^u ! laccolite1 x is assum$ t ! next l[] b$s ( ! /ratigraphic s]ies =m its floor2 & ! base ( ! laccolite is drawn 9 ! ideal section on ! level :i* ! ,%9>ump ,gr\p holds :]e x is unaffect$ by ! displacem5ts ( ! m\nta94 ,x is notewor?y t :]ev] ! s$im5t>ies appe> ^u ! m\nta9 top !y are highly metamorphic4 ,b 9 ! revet-crags !re is v little alt]ation4 ,massive s&/one1 divid$ by %eets & dikes sev]al hundr$ feet 9 ?ickness1 is discolor$ & indurat$ at ! contact surface only1 & t5 feet away betrays no *ange4 ,! engrav+ ( ,m\nt ,hill]s 7,figure #bg7 exhibits ! s\? face ) its revet-crags & bold spurs ( trap4 ,9 nature ! effect is height5$ by ! contra/ ( color1 ! bright r$ revetm5ts be+ /rongly reliev$ aga9/ ! d>k gray ( ! laccolite4 ,! /rata ( ! summits _c be discrim9at$ at a di/ance4 ,!y are too ne> ! laccolite 9 h>dness to diff] f x 9 ! /yle ( _! sculpture4 ,( ! m9or laccolites ( ! clu/] !re are ?ree s closely jo9$ to ! *ief t !y m]ge topographically ) ! m\nta94 ,!y are n well expos$ = /udy4 ,! smalle/1 :i* ov]looks ! pass betwe5 ,m\nt ,hill]s & ,m\nt ,p5nell 7,a1 ,figure #bh7 has probably lo/ ! :ole ( its cov] & ) x s mu* ( its sub/ance t ! orig9al =m & surface _c be se54 ,its floor is probably ! ,tununk s&/one4 ,ea/ ( x & ly+ a little deep] 9 ! ,cretace\s s]ies is a second laccolite 7,b71 broad]1 l[]1 & less erod$4 ,! ?ird 7,c7 jo9s ! great "o on ! nor!a/1 & is s closely unit$ t x 0 at fir/ suppos$ to be ! same body4 ,lat] exam9ations h %[n1 h[ev]1 t its imm$iate ro( is ! ,h5ry's ,=k conglom]ate1 & its horizon is ?us e/abli%$ z m ?an two ?\s& feet above t ( its great companion4 ,illu/ration3 ,,fig4 #cj4--,! ,/ew>d ,laccolite4 ,illu/ration3 ,,fig4 #bh4--;,diagram ( ! ,hill]s ,clu/] ( ,laccolites2 ,gr\nd plan4 ,illu/ration3 ,,fig4 #bi4--;,diagram ( ! ,hill]s ,clu/] ( ,laccolites2 ,elevation4 ,! upp] horizontal l9e m>ks ! base ( ! ,cretace\s2 ! middle1 ! base ( ! ,jura-,trias2 ! l[]1 ! level ( ! sea4 ,! ,/ew>d laccolite 7,figure #cj7 is bett] expos$ = /udy4 ,x 0 buri$ 9 ! s(t bad-l& s&/one ( ! ,flam+ ,gorge ,gr\p1 & its matrix has be5 s f> wa%$ away t ne>ly ! :ole body ( trap is reveal$4 ,x is wea!r$ out1 l a *]t-nodule on ! face ( a block ( lime/one4 ,at "o end x is b>$ q to ! base1 & ! s&/one floor on :i* x re/s is br\ght 9 sight4 ,! wa/e ( ! s&/one has und]m9$ its edge1 & a small portion ( ! laccolite has fall5 away4 ,ne> ! opposite end a fragm5t ( its cov] ( ar*+ s&/one survives--j en\gh to indicate t ! s$im5t>ies 7 once b5t ov] x1 & t ! smoo? l[-ar*+ surface :i* n[ cr[ns x portrays ! orig9al =m :i* ! molt5 lava assum$4 ,! laccolite is ab\t two & a half miles long & "o & "o-half broad4 ,! height ( its ea/w>d face1 :]e x is sapp$ by ! erosion ( ! bad-l& rock1 is six hundr$ feet1 & ! c5tral dep? mu/ be m ?an eight hundr$ feet4 ,illu/ration3 ,,fig4 #ca4--;,cross-section ( ! ,pulpit ar*1 ) ideal repres5tation ( ! ,pulpit ,laccolite4 ,scale1 #a in* #c1ejj feet4 #a1 ,v]milion ,cliff ,s&/one4 #b1 #b1 ,gray ,cliff ,s&/one4 #c1 #c1 ,flam+ ,gorge ,%ale4 #d1 ,h5ry's ,=k ,conglom]ate4 #e1 ,tununk ,%ale4 ,pulpit ar* is z high & z broad z ! less] ar* ( ,m\nt ,holmes1 b its place is n m>k$ 9 ! topography by an em95ce = ! reason t ! degradation ( ! l& has n yet progress$ s f> z to une>? its core ( tra*yte4 ,! dra9age f ,m\nt ,hill]s crosses x f we/ to ea/ & has giv5 x an oblique truncation1 z illu/rat$ 9 ! diagram4 ,at ! upp] end ( ! slope ! ,h5ry's ,=k conglom]ate outcrops2 at ! l[] end ! base ( ! ,flam+ ,gorge s]ies1 & 9 ! int]val ! ,gray ,cliff s&/one is lift$ to ! surface4 ,! same /reams :i* plan$ away ! cr[n ( ! ar* h n[ cut !mselves deep] *annels & divide ! massive s&/one by picturesque caons1 betwe5 :i* x is grotesquely c>v$ into p9nacles & ridges4 ,a curi\s sali5t ( ! s&/one has giv5 its "n to ! ar*4 ,h[ deeply ! ,pulpit laccolite lies buri$ is n kn[n1 no %eet nor dike ( tra*yte betray+ its proximity4 ,! valley ( ! ,colorado may h to be deep5$ ?\s&s ( feet be=e x w be laid b>e4 ,! ,j]ry ,butte is ! mo/ conspicu\s adjunct to ,m\nt ,hill]s & topographically is m important & /rik+ ?an ! features :i* h j be5 describ$1 b its /ructure is less cle>4 ,its cre/ is =m$ by a great dike sev]al hundr$ feet 9 wid? & two miles 9 l5g?1 & ) an ev5 top l ^? obs]v$ on ,m\nt ,holmes4 ,! we/]n end ( ! dike is ! high] & =ms ! culm9at+ po9t ( ! butte1 & f x !re radiate ?ree o!r dikes ( notable size4 ,! inclos+ /rata1 pres]v$ f erosion only by ! %elt] ( ! dikes1 are ! l[] portion ( ! ,cretace\s s]ies1 & !y are s little lift$ above _! normal level t !re is room = no consid]able laccolite b5ea? !m4 ,! incl9ation ( ! b$s is s complicat$ by ! dips ( ! ,pulpit1 ,/ew>d1 & ,hill]s ar*es1 all ( :i* are contigu\s1 t no?+ c be made out ( ! =m ( ! laccolite1 if x exi/s4 ,! ,h[ell laccolite lies ap>t f ! clu/] & is well expos$4 ,x diff]s f all t h be5 enum]at$ 9 its extreme ?9ness4 ,) a bread? ( m ?an two ?\s& feet1 x has a dep? ( only fifty4 ,se5 f ! ea/1 x might readily be mi/ak5 = a c\le1 = on t side x is ! ?91 h>d1 black cap ( a table c>v$ out ( s(t1 s&y %ale 7,flam+ ,gorge ,gr\p7 by circumd5udation4 ,b foll[$ we/w>d1 ! table is f\nd gradually to lose its height by ! ris+ ( ! adjac5t l&1 & at la/ ! lava-b$ runs into ! slope & disappe>s b5ea? ! upp] lay]s ( ! same s&y %ale on :i* x re/s4 ,h[ f> x ext5ds "u gr\nd c only be conjectur$4 ,h[ f> x orig9ally /ret*$ 9 ! opposite direction _c be kn[n because x is brok5 away4 ,! orig9al edge is conceal$ at "o end & has be5 und]m9$ & de/roy$ at ! o!r1 s t ! only place :]e x c be se5 is ! po9t at :i* x em]ges f ! %ale4 ,at ?is po9t1 :]e erosion has b>$ b has n yet attack$ ! lava1 ! =m & "* ( ! edge are exhibit$4 ,9 place ( ! tap]+ w$ge :i* usually t]m9ates intrusive %eets1 !re is a blunt1 r\nd$ m>g91 & ! lava sc>cely dim9i%es 9 dep? 9 approa*+ x4 ,! und]ly+ /rata1 locally h>d5$ to s&/ones1 lie level2 ! ov]ly+ curve d[nw>d to jo9 !m1 & betwe5 ! curv$ /rata is int]leav$ a curv$ lava-%eet4 ,9 all ^! *>act]s ! intrusive body is affiliat$ ) ! typical laccolites1 & di/+ui%$ f ! typical %eets4 ,illu/ration3 ,,fig4 #cb4--,! ,h[ell ,laccolite1 z se5 f ! nor?4 ,illu/ration3 ,,fig4 #cc4--,! ,edge ( ! ,h[ell ,laccolite4 ,illu/ration3 ,,fig4 #cd4--,m\nt ,p5nell1 f ! we/4 ,! laccolite :i* is m>k$ 8,d0 on ! diagrams ( ! ,hill]s clu/] is id5tical 9 ne>ly all its *>act]s ) ! ,h[ell2 x is ?9 & broad4 ,"o m>g9 is wa/+ z its f\ndation is sapp$2 ! o!r is hidd5 f view4 ,its dep? does n dim9i% t[>d ! edge4 ,moreov]1 a few dikes issue f its m>g91 or f b5ea? its m>g94 ,x 0 intrud$ )9 ! same =mation z ! ,h[ell 7! ,flam+ ,gorge %ale71 b at a horizon sev]al hundr$ feet high]2 &1 :at is specially notewor?y1 ! rock ( :i* x is compos$ is id5tical 9 facies ) t ( ! ,h[ell laccolite1 & notably diff]5t f all o!rs :i* 7 obs]v$ 9 ! ,hill]s clu/]4 ,?us !re are gr\p$ 9 ?is "o clu/] laccolites ( ! mo/ v>i$ "*1 diff]+ 9 =m1 9 magnitude1 9 ! /ratigraphic dep? at :i* !y 7 intrud$1 9 ! ext5t to :i* !y h be5 uncov]$ or demoli%$ 9 ! progress ( erosion1 & also1 b v slightly1 9 _! li?ologic *>act]s4 ,! greate/ is "o ?\s& times z bulky z ! lea/4 ,! l5g? ( ! mo/ obese is ?ree times its dep?2 ! l5g? ( ! mo/ att5uat$ is m ?an "o hundr$ times its dep?4 ,! "o highe/ 9 ! /rata lies a ?\s& feet above ! base ( ! ,cretace\s rock s]ies2 ! l[e/ is n high] ?an ! summit ( ! ,c>bonif]\s4 ,! latt] has n yet be5 t\*$ by erosion1 o!rs h be5 completely d5ud$1 & "s h be5 p>tially demoli%$ & remov$4 ,,m\nt ,,p5nell4 ,m\nt ,p5nell & ,m\nt ,ell5 are di/9ct m\nta9 masses sep>at$ by a l[ pass1 b !re is no int]val betwe5 ! clu/]s ( laccolites by :i* !y are con/itut$4 ,:e!r ! site ( a laccolite %all be m>k$ by a m\nta9 dep5ds 9 great measure on ! relation ( ! laccolite to ! progress ( erosion4 ,9 ! ,h5ry ,m\nta9s ! laccolites :i* h n be5 rea*$ by ! d5udation sc>cely affect ! topography4 ,! ar*$ s$im5t>ies above !m are no h>d] ?an ! same /rata 9 ! surr\nd+ pla91 & !y are br\ght sub/antially to ! same level4 ,x is to ^? :i* ! d[nw>d progress ( erosion has rea*$ & pass$ t ! m\nta9s are due4 ,9 virtue ( _! h>dness !y survive ! g5]al degradation1 & cons]ve ) !m broad f\ndations ( m p]i%able mat]ial4 ,m\nts ,ell5 & ,p5nell m>k ! positions ( ! highe/ ( a great clu/] ( laccolites1 & ! pass betwe5 !m m>ks a "p ( ! clu/] :]e all ! laccolites lie l[ 9 ! /rata4 ,illu/ration3 ,,fig4 #ce4--;,cross-section ( ,m\nt ,p5nell4 #a1 ,blue ,gate ,s&/one4 #b1 #b1 ,blue ,gate ,%ale4 #c1 #c1 ,tununk ,s&/one4 ,! full black l9es repres5t ,tra*yte4 ,m\nt ,p5nell is n s easily /udi$ z ! l[] m\nta9s at ! s\?4 ,its summits are timb]$ & are c>v$ into alp9e =ms :i* d n portray ! /ructure b r mask x4 ,^u its flanks h[ev] ! topography & ! /ructure are 9 s close sympa?y t ! latt] is easily read2 & by _! /udy "s ( ! g5]al features ( ! m\nta9 h be5 made out4 ,f ! ea/ & s\? & we/ ! /rata c be se5 to rise t[>d x4 ,! upris+ /rata on ! we/ are ! ,tununk s&/one & ! %ales above & bel[ x4 ,! s&/one =ms no revetm5ts1 b accords s closely 9 its dips ) ! slopes ( ! m\nta9 t x is ! surface rock ov] a broad area1 outcropp+ :]ev] !re is rock exposure4 ,at ! head ( ! foot-slope tra*yte %eets are associat$ ) x1 "s ov]ly+ & o!rs und]ly+ x2 & at "o po9t a gorge reveals a laccolite n f> bel[ x--a laccolite t may or may n be ! great nucleus ( ! m\nta94 ,on ! we/ & s\? flanks ! upris+ /rata are ! ,blue ,gate & ,tununk s&/ones1 ) _! %ales4 ,! ,gate s&/one has be5 worn away ne>ly to ! foot ( ! slope1 & =ms a monocl9al ridge circl+ ab\t ! base4 ,! ridge is int]rupt$ by a numb] ( wat]ways1 & x s5ds sali5ts well up ^u ! flank1 b x is too cont9u\s to be reg>d$ z a m]e l9e ( revetm5ts4 ,! ,tununk s&/one is n to be se5 )\t se>*1 be+ cov]$ by heavy tra*yte %eets4 ,tra*yte %eets also und]lie x1 & ! :ole are c>v$ into a conspicu\s s]ies ( revet-crags4 ,illu/ration3 ,,fig4 #cf4--,m\nt ,p5nell1 f ! nor?4 ,! association ( ov]>*+ /rata ) %eets ( tra*yte leaves no d\bt 9 my m9d t ! core ( ,m\nt ,p5nell is laccolitic1 b :e!r x is simple or comp\nd is n s cle>4 ,! collation ( all ! obs]v$ dips %[s t if !re be b "o laccolite x has n ! simplicity ( =m :i* usually *>act]izes !m4 ,!re are l[ ar*es ( ! /rata at ! s\!rn1 nor!rn1 & nor!a/]n bases1 :i* reveal no tra*yte & give ! impression t !re may be a f\ndation ( l[-ly+ laccolites ^u :i* ! ma9 tra*yte mass or masses ( ! m\nta9 are bas$4 ,"o ( ^! l[ ar*es1 t at ! nor!a/1 is %[n 9 ! =egr\nd ( ,figure #cf4 ,! /rata :i* portray x are ( ! ,h5ry's ,=k conglom]ate1 & ! laccolite :i* !y cov] is ( necessity di/9ct f t :i* is reveal$ on ! ea/ flank ( ! m\nta94 ,illu/ration3 ,,fig4 #cg4--,s5t9el ,butte4 ,9 addition to ! laccolites ( ! f\ndation & ( ! ma9 body1 !re is a s]ies :i* jut =? f ! nor!rn flank l s _m dorm] w9d[s4 ,!y are comp>atively small b are r5d]$ conspicu\s by ! removal ( ! s(t rocks :i* orig9ally inclos$ !m4 ,!y are high] 9 ! /rata ?an any o!r obs]v$ laccolites1 _! position be+ above ! ,tununk s&/one & 9 ! ,blue ,gate %ale4 ,! core ( ! ma9 body ( ! m\nta9 is probably inclos$ 9 ! ,tununk %ale1 & ! laccolites "u ! l[ ar*es 7at ! nor? at lea/7 are entirely bel[ ! ,cretace\s4 ,! high] s]ies /& on top ( ! l[ ar*es1 & are j outside ( ! %eets :i* inclose ! c5tral body4 ,! l>ge/ ( !m con/itutes ,s5t9el ,butte1 & /&s gu>d ov] ,p5ell5 ,pass4 ,sapp$ by ! yield+ ( its s(t f\ndation x is rapidly wa/+1 & on ?ree sides its faces are precipit\s4 ,! huge blocks :i* cleave f x z !y are und]m9$ /rew ! surr\nd+ slopes = a great di/ance4 ,its dep? ( #djj feet is made up ( two lay]s1 ( :i* ! l[] is ! deep]1 & betwe5 :i* !re is a slight li?ologic diff]5ce4 ,! upp] surface ( ! butte is smoo? & plane ) an incl9ation to ! s\?4 ,x is probably a portion ( ! orig9al surface ( ! laccolite4 ,?us we h 9 ,m\nt ,p5nell a great c5tral body consi/+ ( a s+le laccolite or ( a numb] closely mass$ toge!r2 an inf]ior gr\p ( ?ree or m1 evid5c$ by l[ broad ar*es2 & a sup]ior gr\p ( n less ?an f\r1 all ( :i* are p>tially de/roy$4 ,,m\nt ,,ell54 ,! cre/ ( ,m\nt ,ell5 is z l(ty z t ( ,m\nt ,p5nell & x is m ext5d$4 ,x /ret*es = two miles f nor? to s\? & is buttress$ by _m spurs4 ,! sculpture ( ! cre/ is alp9e1 & ! /ructure is consequ5tly obscur$4 ,!re are dikes ( tra*yte & p]haps ! remnants ( laccolites2 !re are ,cretace\s s&/ones greatly indurat$2 & !re are ,cretace\s %ales bak$ to cl9k+ slate2 b !y are all c>v$ into smoo?1 pyramidal =ms1 & ea* is half hidd5 by ! dbris f ! re/ s t _! ord] & mean+ _c be se54 ,! flanks h[ev] are full ( int]e/ to ! geologi/4 ,! ,ell5 clu/] ( laccolites is a broad "o1 & all b ! c5tral portion is well expos$ = /udy4 ,9 ! spurs & foot-slopes & m>g9al buttes no less ?an sixte5 individual laccolites h be5 discrim9at$1 a numb] ( !m mo/ beautifully display$4 ,!y w be enum]at$ 9 ! ord] ( _! position1 beg9n+ at ! we/ ( ,p5ell5 ,pass & pass+ along ! we/]n1 nor!rn1 & ea/]n flanks to ! ,scrope ,butte1 ea/ ( ! pass4 ,illu/ration3 ,,fig4 #ch4--;,gr\nd ,plan ( ! ,ell5 ,clu/] ( ,laccolites4 ,9 ! *>t ( ! ,ell5 clu/]1 ,figure #ch1 an attempt is made to %[ ! horizontal gr\p+ ( ! laccolites & ! ord] ( _! sup]position :]ev] !y ov]lap4 ,x w be obs]v$ t :]e ! limits are imp]fectly kn[n ! outl9es are left incomplete1 & t ! c5tral area rema9s blank1 n because x conta9s no tra*yte masses1 b because its alp9e sculpture has prev5t$ _! /udy4 ,:]e x is n evid5t :i* ( two encroa*+ laccolites is ! sup]ior1 !y are sep>at$ by a /raight l9e4 ,illu/ration3 ,,fig4 #dj4--,section ( ! ,lewis ,creek ,caon ?r\gh ! ,newb]ry ,ar*4 #a1 ,h5ry's ,=k ,conglom]ate4 #b1 ,upp] portion ( ,flam+ ,gorge ,%ale4 #c1 ,newb]ry ,laccolite4 ,! l9e a a 9 ! *>t is ! spr++ l9e ( a broad1 flat ar* :i* und]lies all ! o!r ar*es ( ! we/]n flank4 ,if x cov]s b "o laccolite1 t "o is ! rival 9 magnitude ( ! ,hill]s nucleus1 al?\gh widely diff]5t 9 proportions2 b x is m probable t x conta9s a great] numb]4 ,! upp] surface is roll+ & unev51 & has n ! degree ( symmetry :i* laccolites usually display4 ,at ! po9ts b1 c1 d1 & e ! altitude ( ! ar* is #c1hjj1 #c1ejj1 #b1jjj 7e/imat$7 & #b1ejj feet4 ,nev]!less !re is no?+ 9 its simple outl9e to indicate a comp\nd /ructure2 ! monocl9al ridges by :i* x is m>g9$ d n exhibit ! flexu\s curves :i* are commonly se5 ab\t ! bases ( conflu5t ar*es4 ,:e!r ! nucleus is simple or comp\nd x s5ds no bran*es to ! surface2 ! only outcrops ( tra*yte belong to ! ov]ly+ ar*es4 ,! upp] p>ts ( ! ar* h be5 s c>ri$ away t ! /eepness ( ! m\nta9 flank is n increas$ by x1 & inf]ior /rata are br\ght to ! surface4 ,at ! nor? ! cr[n ( ! ar* be>s ! ,h5ry's ,=k conglom]ate1 :ile beyond its base ! plateau is built ( ,blue ,gate s&/one4 ,at ! s\? ! ar* be>s ! ,tununk s&/one1 & ! ,masuk lies outside4 ,illu/ration3 ,,fig4 #ci4--,! ,newb]ry ,ar* & ,laccolite4 ,! laccolite m>k$ 8,e0 on ! *>t re/s ^u ! ,tununk s&/one4 ,! ,blue ,gate %ale :i* once buri$ x has be5 all wa%$ away except "s metamorphos$ remnants ^u ! top1 & ! tra*yte itself has wa/$ to su* an ext5t t its orig9al =m _c be trac$4 ,! laccolite has no ne> neighbor1 & ! erosion has left x prom95t ^u ! m\nta9 flank4 ,a cont9u\s & solit>y spur jo9s x to ! c5tral ridge4 ,! ,newb]ry laccolite makes a knob #a1gjj feet high1 & /&s by itself4 ,its cov] ( ,h5ry's ,=k conglom]ate is re-en=c$ by a numb] ( tra*yte %eets1 & is brok5 ?r\gh at "o po9t only4 ,at t po9t ,lewis ,creek cuts ) a /raight c\rse across a flank ( ! ar*1 & exposes a portion ( ! nucleus 9 section 7,figures #ci & #dj74 ,! conglom]ate does n re/ directly ^u ! tra*yte1 b is sep>at$ by "o or two hundr$ feet ( %ale ( ! ,flam+ ,gorge ,gr\p4 ,illu/ration3 ,,fig4 #da4--,! ,geikie ,laccolite 7,g71 ov]lapp$ by ! ,h5ry's ,=k ,conglom]ate 7,h ,h71 & ! ,%\ld] ,laccolite 7,s74 ,two miles to ! nor?w>d is ! ,geikie laccolite1 small] ?an ! re/ b simil> 9 "*4 ,x lies close to ! top ( ! ,flam+ ,gorge %ale1 & is enwrapp$ by ! ,h5ry's ,=k conglom]ate4 ,^u ?ree sides ! conglom]ate c be se5 to curve ov] its m>g9 f top to bottom1 & ^u two ( ^! sides ! curves are s brok5 ?r\gh by erosion t ! tra*yte is visible )94 ,on ! nor? two caons cut d[n to ! nucleus1 & on ! s\? !re is a broad face ( tra*yte fram$ all ab\t by ! cut edges ( ! conglom]ate b$s4 ,! ,%\ld] laccolite ov]laps ! ,geikie1 & ! two are expos$ 9 su* mann] z to %[ _! relation 9 section4 ,! conglom]ate runs "u ! "o & ov] ! o!r & sep>ates !m4 ,! upp] laccolite is a broad & deep "o1 & takes its "n f ! fact t x makes a great %\ld] or t]race on ! m\nta9 side4 ,t[>d ! m\nta9 x is buri$2 t[>d ! valley x is uncov]$1 & 9 "p b\nd$ by a cliff4 ,x is deeply cleft by caons4 ,x has n be5 subject$ to measurem5t1 b its dep? is n ov]e/imat$ at fifte5 hundr$ feet nor its area at five squ>e miles4 ,9 ! sket* 7,figure #db7 _m ( ^! features c be trac$--! ,geikie laccolite at ! left & ! ,%\ld] 9 ! c5t]1 ) an outcrop ( ! conglom]ate curv+ d[n f ! ro( ( ! "o to ! floor ( ! o!r1 & ! ,newb]ry ar* 9 ! =egr\nd ) its cleft side4 ,at ! re> is ! pyramidal ,ell5 ,peak & ! ,f laccolite1 ov]look+ ! ,%\ld]4 ,9 ! di/ance at ! left is ! ,m>v9e laccolite4 ,little m c be said ( ! ,f laccolite ?an t x exi/s & is ! nucleus ( a l(ty spur4 ,its summit rises too ne>ly to ! cre/ ( ! m\nta9 to be well def9$1 & at its base ! s$im5t>ies are hidd5 by talus4 ,illu/ration3 ,,fig4 #db4--,! ,we/]n ,flank ( ,m\nt ,ell54 ,n1 ,newb]ry ,ar*2 ,s1 ,%\ld] ,laccolite2 ,g1 ,geikie ,laccolite4 ,illu/ration3 ,,fig4 #dc4--,! ,nor!rn face ( ! ,m>v9e ,laccolite4 ,illu/ration3 ,,fig4 #dd4--,! ,we/]n face ( ! ,m>v9e ,laccolite4 ,n s ! ,m>v9e laccolite4 ,ly+ at ! foot ( ! m\nta9 :]e erosion is s condition$ z to discrim9ate betwe5 h>d & s(t1 & surr\nd$ by no?+ firm] ?an ! ,tununk %ale & ,tununk s&/one1 x has suff]$ a rapid d5udation1 9 :i* ne>ly ! :ole ( its cov] has be5 c>ri$ away )\t s]i\sly impair+ its =m4 ,x /&s =? on a p$e/al1 devoid ( talus1 nak$ & alone4 ,! upp] surface undulates 9 l[ waves pres]v+ ! orig9al =m z x 0 impress$ on ! molt5 mass4 ,ov] a portion !re is a ?9 coat+ ( s&/one1 ! lay] next to ! tra*yte be+ sav$ f de/ruction by ! induration acquir$ dur+ ! hot contact4 ,f ! rema9d] ?is also has disappe>$1 & ! contact face ( ! tra*yte is b>e4 ,= "s reason ! ext]ior portion ( ! laccolite dis9tegrates m sl[ly ?an ! int]ior4 ,x may be t !re 0 "s reaction f ! surr\nd+ s$im5t>ies dur+ ! cool+1 :i* modifi$ ! cry/allization4 ,or x may be t at a lat] epo* a reciprocal metamorphism 0 induc$ along ! contact ( ! div]se rocks4 ,at all ev5ts !re is a cru/ a few feet 9 ?ickness :i* is specially qualifi$ to resi/ de/ructive ag5ts1 & :i* by ?is peculi>ity c be di/+ui%$ f ! tra*yte ( ! int]ior4 ,all ab\t ! nor!rn & we/]n faces1 :i* are /eep1 ?is cru/ has be5 brok5 ?r\gh & ! int]ior excavat$2 b x is only along ! upp] edge ( ! face t ! cru/ is completely de/roy$4 ,along ! l[] edge x is pres]v$ 9 remnants suffici5tly num]\s to fully def9e ! outl9e ( ! base4 ,ea* remnant is a sort ( revet-crag /&+ ne>ly v]tical & jo9$ by a buttress to ! cliff beh9d x4 ,9 ! accompany+ sket*es 7,figures #dc & #dd7 ! mo/ ( ^! features f9d bett] expression ?an words c give !m4 ,! solemn ord] ( ! tomb/one-l revetm5ts is n exagg]at$1 nor is ! contra/ betwe5 ! rugg$ness ( ! cliff & ! smoo?ness ( ! upp] cru/4 ,at ! left 9 ! upp] view1 & at ! "r 9 ! l[]1 !re c be se5 incl9$ /rata1 ! remnants ( ! ar* :i* once cov]$ ! :ole4 ,! extreme dep? ( ! laccolite is #a1bjj feet1 & its diamet]s are #f1jjj & #d1jjj feet4 ,! ,g ar*1 ! ,dana1 ! ,cresc5t1 & ! ,maze agree 9 hav+ no visible laccolites4 ,!y are m]e dome-l uplifts1 by :i* inf]ior b$s are br\ght to light4 ,9 ! middle ( ! ,cresc5t ar*1 & !re only1 is a small dike4 ,!y diff] 9 _! dim5sions & 9 _! erosion & topography4 ,! ,g ar* is l[ & broad1 & lifts ! ,h5ry's ,=k conglom]ate a few hundr$ feet only4 ,x is cov]$ by t b$ except :]e ,b[l ,creek & "o or two o!rs cross x 9 %all[ caons4 ,! ,dana ar* be>s ! same relation to ,m\nt ,ell5 & ,jukes ,butte t ! ,pulpit ar* be>s to ,m\nt ,hill]s4 ,! /reams :i* fl[ d[n h truncat$ x1 & aft]w>d c>v$ a sy/em ( caons bel[ ! plane ( truncation4 ,! ,h5ry's ,=k conglom]ate ov]looks x f ! base ( ! ,jukes laccolite on "o side1 & on ! o!r m>g9s x ) a monocl9al ridge2 & 9 ! int]val ! ,flam+ ,gorge & ,gray ,cliff rocks come to ! surface4 ,illu/ration3 ,,fig4 #de4--,! ,jukes ,butte1 z se5 f ! s\!a/1 %[+ ! ,jukes ,laccolite1 re/+ ^u ! ,dana ,ar*4 ,! ,cresc5t ar* is s p]fectly truncat$ by ! exi/+ m\nta9 /reams t _! flood-pla9s unite above x 9 a s+le broad slope4 ,on ! side t[>d ! m\nta9 !re are a few insul> hills ( ! conglom]ate1 & on ! side t[>d ! plateau ! same rock lifts a l[ monocl9al ridge :i* circles ab\t ! base ( ! ar* 9 a cresc5t4 ,)9 ! cresc5t !re are few outcrops1 b x is probable t ! ,gray ,cliff ,s&/one is br\ght to ! surface4 ,ne> ! c5t] a solit>y ?9 dike juts =?1 l a buoy set to m>k ! place :]e a laccolite is sunk4 ,judg+ ! magnitude ( ! laccolite by ! proportions ( ! uplift1 x has a diamet] ( ne>ly f\r miles & a dep? ( #b1ejj feet2 & ^! dim5sions indicate a volume ( ?ree & a half cubic miles4 ,! ,maze ar* cov]s a small] area ?an ! ,cresc5t1 b its height is great]4 ,! dra9age f ! m\nta9 crosses x on a numb] ( l9es1 b !re is no indication t at any rec5t /age ( ! degradation !y h produc$ an ev5 truncation4 ,at pres5t !y divide ! ,gray & ,v]milion ,s&/ones by s intricate a labyr9? ( deep caons t ! :ole area ( ! uplift is almo/ impassable4 ,! monotony ( r$ s&/one1 = "h all memb]s ( ! ,jura-,trias are brick-r$1 ! v>iety ( dip1 complicat$ to ! eye by oblique lam9ation1 ! multiplicity ( caons & ridges1 conspire to give an impression ( *aos f :atev] po9t ! tract is view$2 & ev5 f ! mo/ comm&+ /ations ,i 0 unable to make out completely ! arrangem5t ( ! dra9age l9es4 ,/ill no faults 7 disc]n$1 & x is probable t ! ,maze ar*1 intricate z x seems1 is a simple circul> dome4 ,on ! nor? x adjo9s ! ,cresc5t ar*1 & ! monocl9al ridges ( conglom]ate :i* m>g9 ! two at ! ea/ are conflu5t4 ,on ! s\? x adjo9s r m closely "o ( ! l[ ar*es :i* h be5 ref]r$ to ! ,p5nell clu/]4 ,on ! we/1 or t[>d ! m\nta91 x is probably met by o!r ar*es at its own level2 b ^! if !y exi/ _c be fully kn[n until ! progress+ degradation ( ! c\ntry %all h remov$ c]ta9 laccolites :i* lie above !m & slightly ov]lap ! ,maze ar*4 ,! f\r ar*es j describ$ are ( ! f\ndation s]ies ( ! ea/]n base1 & cov] laccolites ( unkn[n dep?s4 ,high] 9 ! /rata1 & at ! same "t absolutely high]1 is a second s]ies1 :i* to a c]ta9 ext5t ov]lap !m4 ,! ,b[l ,creek encroa*es on ! ,g laccolite2 ! ,jukes1 on ! ,dana & on ! ,b[l ,creek2 ! ,h laccolite1 on ! ,cresc5t2 ! ,peale & ,scrope1 on ! ,maze4 ,illu/ration3 ,,fig4 #df4--;,cross-section ( ! ,b[l ,creek ,ar*4 c1 c m>ks ! wat] level ( ,b[l ,creek2 l1 ! ,b[l ,creek ,laccolite2 a1 a1 ,%ales2 & s1 ! ,gryphea ,s&/one4 ,scale1 #a in* #a1jjj feet4 ,! ,b[l ,creek ar* is s mask$ by ! ov]lapp+ ,jukes laccolite1 & by ! encroa*m5t ( c]ta9 l>ge dikes1 t its g5]al =m & proportions are n kn[n2 b x is laid b>e at "o po9t 9 a f9e natural section4 ,b[l ,creek crosses x ne> ! c5t]1 & 9 ! walls ( ! caon are exhibit$ two hundr$ feet ( ! laccolite1 toge!r ) two hundr$ & fifty feet ( sup]jac5t b$s4 ,! curve ( ! /rata is unbrok5 by faults or dikes1 & c>ries !m bel[ ! level ( ! creek at ea* end ( ! caon4 ,next above ! tra*yte lies a clay %ale :i* has be5 bak$ to ! h>dness ( lime/one4 ,x is "o hundr$ feet ?ick1 & is m or less alt]$ ?r\gh\t1 z is also ! s&/one :i* ov]lies x4 ,! ext5t ( ! metamorphism indicates t ! tra*yte mass by :i* x 0 produc$ is n a m]e %eet1 b is ! body ( ! laccolite itself4 ,! ,jukes laccolite encroa*es ^u ! ,g1 ! ,dana1 & ! ,b[l ,creek ar*es1 & is sup]ior to !m all2 x may be said to /& ^u !m4 ,! tra*yte has a dep? ( only "o ?\s& feet1 b x lies s high ) ref]5ce to ! g5]al degradation t x is a conspicu\s feature ( ! topography4 ,! edges ( ! laccolite are all eat5 away1 & only ! c5tral portion survives4 ,all ( its faces are precipit\s4 ,! cov] ( %ale or s&/one has completely disappe>$1 & ! upp] surface seems unev5 & worn2 b a di/ant view 7,figure #dg7 %[s t its wa/+ has n progress$ s f> z to de/roy all trace ( an orig9al ev5 surface4 ,! em95ces ( ! pres5t surface comb9e to give to ! eye :i* is align$ ) _! plane ! impression ( a /raight l9e4 ,! hill is l(ti] ?an ! laccolite1 = "u ! "o ?\s& feet ( tra*yte are five hundr$ feet ( s(t] rock :i* con/itute its p$e/al1 & by _! yield+ und]m9e ! laccolite & p]petuate its cliffs4 ,illu/ration3 ,,fig4 #dg4--,pr(ile ( ! ,jukes ,butte1 z se5 f ! nor?we/4 ,! ,h laccolite is n well expos$4 ,x lies on "o edge ( ! ,cresc5t ar* & is cov]$ by ! ,h5ry's ,=k conglom]ate4 ,illu/ration3 ,,fig4 #dh4--,! ,peale ,laccolite expos$ 9 natural cross-section4 a1 b1 c1 d1 & e are intrusive masses ( tra*yte4 ,h is ! ,h5ry's ,=k ,conglom]ate4 ,illu/ration3 ,,fig4 #di4--,! ,ea/ ,flank ( ,m\nt ,ell51 %[+ ! ,scrope1 ,peale1 & ,jukes ,laccolites1 & ! ,maze & ,cresc5t ,ar*es4 ,little is kn[n ( ! =m ( ! ,peale laccolite4 ,"o edge is lo/ 9 ! obscurity ( ! alp9e sculpture1 & ! o!r has be5 remov$ along ) ! cre/ ( ! ,maze ar*1 on :i* x re/$4 ,b by ?is removal a section has be5 op5$ across ! laccolite1 reveal+ its int]nal /ructure f top to bottom4 ,x is %[n to be composite1 atta9+ its height ( #hej feet by ! compilation ( ?ree di/9ct b$s ( tra*yte1 sep>at$ by p>t+s & w$ges ( %ale4 ,! l[e/ b$ is ?9 & ( small ext5t4 ,next is ! ma9 b$1 six hundr$ feet ?ick & a mile or m broad2 & on top is a b$ two hundr$ feet ?ick & proportionately n>r[4 ,ea* ( ! b$s is l5ticul> 9 section1 & ! pil+ ( ! less ^u ! great] produces a quasi-pyramidal =m4 ,! int]leav$ %ale b&s are metamorphos$ to ! condition ( slate4 ,"u ! laccolite are "o or two hundr$ feet ( %ale1 app>5tly unalt]$ except at ! contact4 ,!n come ! ,h5ry's ,=k conglom]ate1 #cej feet ?ick1 & ! ,flam+ ,gorge %ale1 sev]al times ?ick]4 ,)9 ! upp] %ale is a re/rict$ tra*yte %eet & ne> ! top ( ! l[] %ale is a broad] "o4 ,! latt] is d\ble ?r\gh\t1 its two lay]s hav+ be5 intrud$ at diff]5t times4 ,! top ( ! esc>pm5t is at ! top ( ! laccolite1 & only a %ort di/ance back f ! br[ are %ale & s&/one re/+ ^u ! tra*yte & con=m+ to its unev5 surface4 ,! ,scrope laccolite resembles ! ,jukes 9 ev]y?+ except t its erosion has progress$ s f> z to oblit]ate e trace ( ! orig9al upp] surface4 ,its position 9 ! /rata is ab\t ! same1 & ! erosion ( its matrix has left x a conspicu\s crag4 ,x re/s on ! flank ( ! ,maze ar*1 j z ! ,jukes laccolite re/s on ! ,dana ar*4 ,! remnant ( tra*yte is less ?an "o ?\s& feet high1 & has be5 c>v$ into a subconical =m 9 :i* no h9t ( ! orig9al size & proportions ( ! tra*yte body is convey$4 ,figure #di is a view ( ! ea/ flank ( ,m\nt ,ell51 z se5 f ,m\nt ,hill]s4 ,x gr\ps toge!r _m ( ! details t h be5 enum]at$4 ,! conical hill at ! left is ! ,scrope laccolite4 ,! spur f ! m\nta9 :i* ends j at ! "r ( x is ! ,peale laccolite4 ,! bold butte :i* t]m9ates ! la/ spur ( ! m\nta9 9 ! di/ance is ! ,jukes laccolite4 ,across ! base ( ! latt] "o c trace ! outcrop ( a h>d b$4 ,?is is ! ,h5ry's ,=k conglom]ate1 & ! upw>d curve :i* x %[s belongs 7probably7 to ! ,cresc5t ar*4 ,ne>] ?an ! ,jukes ,butte & 9 ! same direction is a l[ hill1 m>k+ ! dike )9 ! ,cresc5t4 ,j to ! left ( x is an insul> outcrop ( ! conglom]ate1 & ne>] by is ano!r outcrop 9 ! =m ( a cliff1 :i* is cont9u\s to ! base ( ! ,peale laccolite4 ,betwe5 ! ,peale & ,scrope laccolites ! conglom]ate is hidd5 by an embaym5t ( ! cliff1 & x reappe>s 9 ! base ( ! ,scrope ,butte4 ,9 all ^! outcrops ! esc>pm5ts ( conglom]ate face t[>d ! ea/ & at ! same "t t[>d ! ,maze & ,cresc5t ar*es4 ,on ! opposite side ( ! ar*es ! same conglom]ate outcrops 9 a monocl9al ridge ) its esc>pm5t fac+ to ! we/4 ,! ridge c be trac$ 9 ! sket* f a po9t 9 ! =egr\nd "u ! ,jukes ,butte ne>ly to ! ea/]n base ( ! butte1 ! c\rse at fir/ be+ almo/ directly t[>d ! butte & !n curv+ f> to ! "r & =m+ ! ,cresc5t4 ,betwe5 ! ,scrope & ,peale laccolites on "o side & ! monocl9al ridge on ! o!r1 lie ! ,maze & ! ,maze ar*4 ,beyond ! ,maze ar* & limit$ at ! "r by ! ,cresc5t1 is ! ,cresc5t ar*4 ,! ,scrope1 ! ,peale1 & ! ,jukes are visible laccolites2 ! ,maze & ,cresc5t ar*es cov] invisible laccolites4 ,! det]m9ate laccolites & ar*es :i* compose ! l[] slopes ( ,m\nt ,ell51 :ile !y are ( prime importance = purposes ( inve/igation1 mu/ n be consid]$ sup]ior 9 numb] & magnitude to ^? ( ! c5tral region4 ,t region is kn[n to ab\nd 9 tra*yte masses1 & x f> exce$s ! m>g9al di/rict 9 ! ext5t & degree ( its metamorphism4 ,!re is e reason to believe t ! m\nta9 cre/ m>ks ! zone ( greate/ igne\s activity1 & t ! foot-hills are z truly subsidi>y f a geological po9t ( view z !y are f a topographic4 ,!re is no evid5ce ( a great c5tral laccolite1 su* z ! ,hill]s & ,p5nell clu/]s possess1 & ,i am dispos$ to reg>d ! m\nta9 z a great cong]ies ( tra*yte masses ( mod]ate size1 sep>at$ & 9 ! ma9 cov]$ by %ales & s&/ones4 ,! s$im5t>y /rata ( ! summits are all ( ! ,cretace\s s]ies1 b !y are too greatly alt]$ to p]mit ! discrim9ation ( ! ,masuk1 ,gate1 & ,tununk gr\ps4 ,! ,h5ry's ,=k conglom]ate1 :i* might h be5 recogniz$ ev5 9 a metamorphic condition1 0 n se54 ,,/]eogram ,,( ,,! ,,h5ry ,,m\nta9s4 ,= ! d\ble purpose ( mapp+ & /udy+ ! m\nta9s a model 9 relief 0 con/ruct$1 9 :i* great pa9s 0 tak5 to give all ! pr9cipal features _! prop] altitudes & proportions4 ,?is model 0 photograph$1 & has be5 reproduc$ by ! heliotype process 9 ,plate ,,iii1 at ! end ( ! volume4 ,aft] x _h be5 complet$1 a second model 0 con/ruct$ by add+ to ! surface ( ! fir/4 ,:]ev] ! ,blue ,gate s&/one appe>$ 9 ! orig9al model no addition 0 made4 ,:]e ! ,tununk s&/one appe>$ !re 0 add$ an am\nt equival5t to ! comb9$ ?ickness ( ! ,blue ,gate s&/one & ! ,blue ,gate %ale2 & 9 g5]al1 en\gh 0 add$ 9 e "p to br+ ! surface up to ! summit ( ! ,blue ,gate s&/one4 ,9 ?is way a re/oration 0 made ( ! =m ( t s&/one previ\s to its erosion4 ,x is n to be und]/ood t ! m\nta9s ev] possess$ ?is =m2 = :5 ! surface ( ! ,blue ,gate s&/one 0 unbrok5 by erosion x 0 unbrok5 only because x 0 cov]$ by o!r /rata1 :i* :ile !y %ield$ x 7 !mselves erod$4 ,if ! s&/one _h be5 inde/ructible1 ?is is ! =m :i* w\ld h be5 develop$ by ! wa%+ away ( all ! ov]ly+ b$s2 & 9 ?is =m are embodi$ ! ar*es & domes :i* 7 impress$ ^u ! s&/one by ! upswell+ ( ! laccolites4 ,! model became a /]eogram ( ! displacem5ts ( ! ,h5ry ,m\nta9s1 & a photograph f ! /]eogram appe>s 9 ,plate ,,iv4 ,x w be obs]v$ t ov] ! c5tral di/rict ( ,m\nt ,ell51 :]e by reason ( ! peculi> sculpture ( ! rock its /ructure 0 conceal$1 ! re/oration ( ! s&/one 0 n c>ri$2 x seem$ bett] to repres5t our lack ( k by a blank ?an to bridge ov] ! int]val by ! aid ( ! imag9ation4 ,if ! read] w /udy ! plate1 he w f9d t x expresses a great body ( ! ph5om5a :i* h be5 describ$ 9 ?is *apt]4 ,! simplicity ( ! ,ellswor? & ,holmes ar*es is contra/$ ) ! complexity ( ! o!rs2 ! greatness ( ! ,hill]s & ,p5nell domes ) ! smallness ( ^? :i* lie ^u _! flanks4 ,"o po9t t is especially /rik+ is ! relation betwe5 ! upp] & l[] domes ( ! ,ell5 clu/]4 ,! upp]1 :i* give rise to all ! conspicu\s features ( ! m\nta9 flanks1 are comp>atively small1 :ile ! l[]1 :i* might almo/ be ov]look$ 9 a rapid exam9ation ( ! m\nta91 are comp>atively l>ge & con/itute ! great mass ( ! uplift4 ,! small] laccolites1 because !y are ! upp]1 h be5 d5ud$ ( _! cov]s1 & 9 virtue ( _! h>dness /& =? sali5t4 ,! l>g]1 because !y are ! l[]1 h n be5 laid b>e1 & ! comp>atively feeble resi/ance :i* _! cov]s h oppos$ to erosion has impress$ _! =ms b slightly on ! topography4 ,,*apt] ,,iv4 ,,! ,,laccolite4 ,! pr9cipal facts 9 reg>d to ! laccolites ( ! ,h5ry ,m\nta9s hav+ be5 set =? 9 ! prec$+ *apt]1 an attempt w n[ be made to d$uce f !m ! natural hi/ory ( ! ,laccolite4 ,!re is a "q :i* ! critical geologi/ w be likely to prop\nd1 & :i* %\ld be answ]$ at ! outset4 8,:at evid5ce01 he may dem&1 8is !re t ! orig9 ( ! laccolite 0 subsequ5t to ! =mation ( ! inclos+ /rata r ?an contemporane\s ) x8 ,may x n h be5 buri$ in/ead ( intrud$8 ,may n ! successive %eets & masses ( tra*yte h be5 spread or heap$ by eruption ^u ! bottoms ( ,mesozoic seas1 & successively cov]$ by ! accumulat+ s$im5ts80 ,! answ] is n difficult4 #a/4 ,no fragm5t ( ! tra*yte has be5 discov]$ 9 ! associat$ /rata4 ,! con/itution ( ! sev]al memb]s ( ! ,mesozoic sy/em 9 ! ,h5ry ,m\nta9 region does n diff] f ! g5]al con/itution ( ! same memb]s else:]e4 ,?is evid5ce is ( a negative "*1 b if !re 7 no o!r x w\ld be suffici5t4 ,= !re is indubitable pro( t at ! end ( ! ,%9>ump p]iod ! ,h5ry ,m\nta9 region 0 lift$ above ! ocean1 & if any ( ! nuclei ( ! m\nta9s _h !n exi/$ !y c\ld n h escap$ erosion by %ore waves1 & mu/ h modifi$ ! contemporane\s deposits4 #b;d4 ,! tra*yte is 9 no case vesicul>1 & 9 no case fragm5tal4 ,if x _h be5 extrud$ on dry l& or 9 %all[ wat]1 :]e ! pressure ^u x 0 n suffici5t to prev5t ! dilatation ( its gases1 x w\ld h be5 m or less inflat$1 aft] ! mann] ( rec5t lavas4 ,if x _h issu$ at ! bottom ( an ocean1 ! rapidity ( cool+ w\ld h crack$ ! surface ( ! fl[ :ile ! int]ior 0 yet molt5 & 9 motion1 & breccias ( tra*yte dbris w\ld h result$4 ,! abs5ce ( inflation & ( brecciation are ( c\rse ( ! nature ( negative evid5ce1 b !y d]ive weight f ! fact t a great numb] ( di/9ct bodies ( tra*yte h be5 exam9$ 9 ! c\rse ( ! inve/igation4 #c;d4 ,! incl9ation ( ! ar*$ /rata proves t !y h be5 di/urb$4 ,if ! laccolites 7 =m$ 9 ea* case be=e ! s$im5ts :i* cov] !m1 ! /rata mu/ h be5 deposit$ ) sub/antially ! dips :i* !y n[ possess4 ,?is is incr$ible4 ,! /eepe/ declivity ( e>?-slopes ^u ! l& is #cd f ! horizontal1 & !y h n be5 f\nd to equal ?is "u wat]4 ,pr(4 ,j4 ,d4 ,:itney not$ #bc z ! orig9al slope ( a deposit on ! ,pacific ,coa/1 & reg>d$ x z an extreme case4 ,! writ] has made _m measurem5ts ( ! incl9ation ( oblique lam9ation 9 massive s&/ones1 & f\nd ! maximum to be #bd4 ,b ! /rata :i* cov] ! laccolites dip 9 _m places #de to #fj1 & 9 ! revetm5ts ( ! s\? base ( ,m\nt ,hill]s !y atta9 #hj4 #d?4 ,x occasionally happ5s t a %eet1 :i* = a c]ta9 di/ance has cont9u$ betwe5 two /rata1 breaks ?r\gh "o ( !m & /rikes across ! b$d+ to "s new horizon1 resum+ its c\rse betwe5 o!r /rata4 ,e su* %eet is unque/ionably subsequ5t to ! b$d+4 #e?4 ,! /rata :i* ov]lie z well z ^? :i* und]lie laccolites & %eets1 are metamorphos$ 9 ! vic9ity ( ! tra*yte1 & ! greate/ alt]ation is f\nd 9 ! /rata :i* are 9 direct contact ) x4 ,! alt]ation ( sup]ior /rata has ! same "* z ! alt]ation ( inf]ior4 ,?is c\ld nev] be ! case if ! trap masses 7 contemporane\s ) ! s$im5ts2 ! /rata on :i* !y 7 impos$ w\ld be subject$ to ! heat ( ! lava1 b ! sup]ior /rata w\ld accumulate aft] ! heat _h be5 dissipat$4 ,9 ! ,h5ry ,m\nta9s a l>ge numb] ( obs]vations 7 made ( ! ph5om5a at & ne> ! contacts ( s$im5t>y & igne\s rocks1 & 9 e in/ance "s alt]ation 0 f\nd4 ,9 f9e1 all ! ph5om5a ( ! m\nta9s are ph5om5a ( intrusion4 ,!re is no evid5ce :atev] ( extrusion4 ,x is n inde$ inconceivable t dur+ ! p]iod 9 :i* ! subt]ranean *amb]s 7 op5$ & fill$1 a portion ( ! lava f\nd its way to ! top ( ! e>?'s cru/ & !re built m\nta9s ( eruption2 b if su* ev] exi/$1 !y h be5 oblit]at$4 ,! ,h5ry ,m\nta9s are simil> among !mselves 9 con/itution4 ,!y all exhibit dome-l uplifts2 !y all conta9 intrusive rocks2 & _! intrusive rocks are all ( "o li?ologic type4 ,!y are moreov] q by !mselves2 ! surr\nd+ c\ntry is dissimil> 9 /ructure1 & !re is no gradation nor m+l+ ( "*4 ,?us simil> & ?us isolat$ x is natural to reg>d ! m\nta9s z closely relat$ 9 orig91 to ref] _! tra*ytes to a common s\rce1 & to look = homology 9 all _! p>ts4 ,x 0 ! se>* = su* homology :i* l$ to ! hypo!sis t ! laccolite is ! dom9ant elem5t ( _! /ructure4 ,x is n[ "t to exam9e ?is hypo!sis1 ! tru? ( :i* has be5 assum$ 9 ! prec$+ pages1 & see h[ f> x accords ) ! facts ( obs]vation4 ,! facts to be correlat$ are ! foll[+3 #a/4 ,!re are sev5 laccolites :i* lie s f> above ! local plane ( erosion t !y are specially expos$ to d5ud+ ag5ts4 ,!y h no envelop+ /rata1 & _! only associat$ %eets lie 9 ! /rata "u !m4 ,_! orig9al =ms h be5 impair$ or de/roy$ by erosion4 ,!y are ! ,scrope1 ! ,jukes1 ! ,s5t9el & its ?ree companions1 & ! ,a laccolites4 #b;d4 ,!re are two laccolites s ne>ly b>$ t _! =ms are unmi/akable1 b :i* are /ill p>tially cov]$ by ar*+ /rata1 & :i* h associat$ %eets & dikes4 ,!y are ! ,m>v9e & ! ,/ew>d laccolites4 #c;d4 ,!re are five suppos$ laccolites situat$ :]e ! erosion planes are incl9$1 :i* run "u ! slopes & are cov]$ at "o side or end1 & at ! o!r project s f> above !m z to h lo/ some?+ by erosion4 ,^! are accompani$ by ov]>*+ /rata & by %eets & dikes4 ,!y are ! ,peale1 ! ,h[ell1 ! ,%\ld]1 ! ,d1 & ! ,e4 #d?4 ,!re are sev5 or eight suppos$ laccolites1 ( :i* only a small "p is 9 ea* case visible1 b :i* are outl9$ 9 =m by domes ( ov]>*+ /rata4 ,_! bases are n expos$4 ,associat$ ) !m are dikes & %eets4 ,!y are ! ,hill]s1 ! ,p5nell1 ! ,geikie1 ! ,newb]ry1 ! ,b[l ,creek1 ! ,c1 ! ,h1 & p]haps ! ,f4 #e?4 ,!re are five domes ( /rata accompani$ by dikes & 7) "o exception7 by %eets1 b %[+ no laccolite4 ,!y are ! ,ellswor?1 ! ,great] ,holmes1 ! ,cresc5t1 ! ,j]ry1 & ! ,b ar*es4 #f?4 ,!re are n9e or m domes ( /rata ) no visible accompanim5t ( tra*yte4 ,!y are ! ,less] ,holmes1 ! ,pulpit1 ! ,g1 ! ,dana1 & ! ,maze ar*es1 & ^? ( ! f\ndation ( ,m\nt ,p5nell & ( ! we/ base ( ,m\nt ,ell54 ,^u ! hypo!sis t all ^! ph5om5a are examples ( ! laccolitic /ructure1 !y h ! foll[+ explanation3 ,ea* individual case compris$ orig9ally a laccolite1 cov]$ by a great dep? ( uplift$ & ar*+ /rata1 & accompani$ by dikes & %eets :i* p5etrat$ ! /rata to a limit$ di/ance4 ,ly+ at diff]5t dep?s f ! surface1 !y h borne & /ill be> diff]5t relations to ! progressive degradation ( ! c\ntry1 & h be5 develop$ by erosion 9 diff]5t degrees4 ,9 n9e ( ! in/ances cit$ ! ar* ( /rata has be5 truncat$1 b at s high a level t no dikes nor %eets 7 une>!d4 ,9 five in/ances ! plane ( truncation 0 s l[ t dikes & %eets 7 br\ght to light1 b n ! ma9 body ( tra*yte4 ,! truncation 0 9 mo/ ( ^! cases less p]fect because ( ! resi/ance to erosion by ! h>d dikes & %eets & by ! /rata :i* _! heat _h h>d5$4 ,9 eight o!r in/ances ! erosion has left prom95t ! dome ( h>d5$ /rata ) its %eets & dikes1 b has some:]e brok5 ?r\gh x s z to reveal a massive core ( tra*yte4 ,9 five in/ances "o side ( ! dome ( /rata has be5 wa%$ away1 expos+ ! core ( tra*yte to its base & %[+ undi/urb$ /rata b5ea? x4 ,9 two in/ances ! s(t matrix has be5 s f> wa%$ away f ! laccolite z to expose its =m fully2 & sev5 laccolites h n only lo/ all cov] b h !mselves be5 p>tially demoli%$4 ,c]ta9ly1 ! hypo!sis accords ) all ! facts t h be5 obs]v$ & unites !m into a consi/5t :ole4 ,x expla9s f\rte5 dome-l ar*es ( s$im5t>y rock :i* are imp]fectly expos$1 by class+ !m ) sev5 o!r ar*es ( ! same region :i* h be5 op5$ 9 section to ! base & f\nd to conta9 laccolites2 & x /r5g!ns ! case by po9t+ to a connect$ s]ies ( int]m$iate ph5om5a4 ,until "s /rata-dome ( ! ,h5ry ,m\nta9s1 or ( a closely alli$ m\nta91 %all be f\nd to display "s diff]5t int]nal /ructure1 x w be safe to reg>d ! :ole ph5om5a ( ! gr\p z laccolitic4 ,=m ( laccolites4--,z a rule laccolites are compact 9 =m4 ,! base1 :i* 9 elev5 localities 0 se5 9 section1 0 f\nd flat1 except :]e x copi$ ! curvature ( "s inf]ior ar*4 ,:]ev] ! gr\nd plan c\ld be obs]v$ x 0 f\nd to be a %ort oval1 ! ratio ( ! two diamet]s n exce$+ t ( ?ree to two4 ,:]e ! pr(ile c\ld be obs]v$ x 0 usually f\nd to be a simple curve1 convex upw>d1 b 9 a few cases & especially 9 t ( ! ,m>v9e laccolite ! upp] surface undulates4 ,! height is nev] m ?an "o-?ird ( ! wid?1 b is frequ5tly mu* less1 & ! av]age ratio ( all ! measurem5ts ,i am able to comb9e is "o to sev54 ,! gr\nd plan approximates a circle1 & ! type =m is probably a solid ( revolution--su* z ! half ( an oblate sph]oid4 ,int]nal ,/ructure4--,( ! laccolites :i* are be/ exhibit$ 9 section1 !re are a numb] :i* appe> to be built up ( di/9ct lay]s4 ,! ,peale exhibits ?ree lay]s ) unev5 p>t+s ( %ale4 ,! ,s5t9el %[s two )\t visible int]val4 ,! ,h[ell %[s two4 ,! ,p5nell has a b&$ appe>ance b 0 n closely exam9$4 ,! ,m>v9e %[s at a di/ance a fa9t b&+1 :i* ne> by eludes ! eye4 ,no division nor horizontal /ructure 0 se5 9 ! ,hill]s1 ,jukes1 ,scrope1 or ,/ew>d laccolites1 b obs]vation 0 n suffici5tly ?or\gh to satisfy me ( its abs5ce4 ,x is probable t all ! l>g] laccolites are composite1 hav+ be5 built up by ! accession ( a numb] ( di/9ct intrusions4 ,!re is little or no prismatic /ructure 9 ! tra*ytes4 ,x is sometimes simulat$ by a v]tical cleavage induc$ 9 %eets & laccolites :i* are und]go+ dis9tegration by sapp+1 b ,i did n obs]ve ! peculi> prismatic cleavage :i* is produc$ by rapid cool+ 9 dikes1 %eets1 & c\les ( basalt4 ,! two /ructures are n (t5 discrim9at$1 b !y are really q di/9ct1 & _! peculi> *>act]s are easily recogniz$4 ,! cleavage planes produc$ by cool+ are z a rule p]p5dicul> to ! cool+ surface1 & ! sy/ems ( prisms :i* are bas$ on ! opposite walls ( a dike or %eet1 d n correspond ) ea* o!r1 & d n run across1 b meet midway 9 a confus$ mann]4 ,! cleavage planes :i* are produc$ by ! %e>+ =ce :5 a massive b$ ( trap or o!r rock is und]m9$ or sapp$ & yields "u its own weight1 ext5d f base to top1 & are p]p5dicul> to ! plane ( ! horizon in/ead ( ! plane ( ! b$4#b ,footnote #b3 ,see page #agb ( ! 8,exploration ( ! ,colorado ,riv]01 by ,j4 ,w4 ,p[ell4 ,v]tical ,di/ribution4--,! range ( altitudes at :i* laccolites h be5 =m$ is n less ?an #d1ejj feet1 & nei!r ! upp] nor ! l[] limit is kn[n4 ,! highe/ t are kn[n--^? :i* 7 intrud$ at ! highe/ geological horizon--are ne> ! base ( ! ,blue ,gate %ale 7,middle ,cretace\s71 b x is q possible t high] ones h be5 oblit]at$ by erosion4 ,! l[e/ t is kn[n 0 intrud$ 9 ! ,%9>ump %ale1 b x is kn[n ( ! invisible ,ellswor? laccolite t upp] ,c>bonif]\s /rata lie above x1 s t its horizon ( intrusion mu/ be /ill l[]4 ,! plexus ( dikes & %eets on ! ,ellswor? ar* indicates t ! laccolite is n deeply buri$2 b 9 ! s]ies ( ar*es !re are n9e :i* %[ no tra*yte1 & we h no data f :i* to inf] _! dep?4 ,h[ ! laccolites are di/ribut$ )9 ^! limits is m readily compreh5d$ by ! aid ( a diagram4 ,9 ,figure #ej ! triangles m>k ! horizons ( det]m9$ laccolites1 & ! crosses ! horizons :i* ! invisible laccolites _c exce$4 ,= example1 ! base ( ! ,scrope laccolite is visible & is se5 to lie on ! ,tununk %ale #djj feet above ! ,h5ry's ,=k conglom]ate2 to repres5t x a triangle is plac$ at ab\t ! middle ( ! space repres5t+ ! ,tununk %ale1 & 9 ! column devot$ to ! ,ell5 clu/]4 ,! upp] surface ( ! ,geikie laccolite is visible & ^u x re/1 fir/ a few feet ( ,flam+ ,gorge %ale1 & !n ! ,h5ry's ,=k conglom]ate2 to repres5t x a triangle is plac$ ne> ! top ( ! ,flam+ ,gorge space4 ,! cr[n ( ! ,pulpit ar* has be5 s f> erod$ t half ( ! ,v]milion ,cliff s&/one is %[n 9 section1 b no laccolite is reveal$4 ,x is evid5t t ! ,pulpit laccolite is l[] ?an ! middle ( t s&/one2 & to repres5t x a cross is plac$ bel[ ! middle ( ! ,v]milion ,cliff space & 9 ! column devot$ to ! ,hill]s clu/]4 ,illu/ration3 ,,fig4 #ej4--;,diagram ( ! ,v]tical ,di/ribution ( ! ,laccolites ( ! ,h5ry ,m\nta9s4 ,! fir/ feature :i* ?is graphic assemblage yields to ! eye is t !re are at lea/ two zones ( laccolites4 ,! upp] ranges f ! l[] "p ( ! ,blue ,gate ,gr\p1 ?r\gh ! ,tununk & ,h5ry's ,=k1 to ! upp] "p ( ! ,flam+ ,gorge ,gr\p4 ,! l[] has n yet be5 fully develop$ by erosion1 b its proximity is indicat$4 ,! ,hill]s laccolite is uncov]$ at top1 & ! dikes ( ! ,ellswor?1 ! ,great] ,holmes1 & ! ,cresc5t h be5 rea*$4 ,all ( ! invisible laccolites indicat$ 9 ! ,v]milion ,cliff & ,%9>ump spaces mu/ be ref]r$ to ?is zone2 & !re is reason to suspect t all b "o ( ! invisible laccolites ^: indication falls 9 ! ,tununk & ,flam+ ,gorge spaces belong also to ! l[] zone4 ,h[ev] ?is may be1 x is n probable t ! det]m9ation ( ! dep?s ( ! invisible laccolites w\ld vitiate ! conclusion t !re is an upp] zone ( laccolitic frequ5cy :i* is sep>at$ f a l[] zone by an int]space ( laccolitic infrequ5cy4 ,ano!r feature illu/rat$ by ! diagram is t all ! det]m9$ laccolites are inclos$ by s(t b$s4 ,!y h be5 intrud$ into ! %ales1 b n ! s&/ones4 ,!y clu/] ab\t ! ,h5ry's ,=k conglom]ate1 b none ( !m divide x4 ,?is selection ( matrix is conf9$ h[ev] to ! laccolites & is n ex]cis$ by %eets & dikes4 ,tra*yte %eets 7 se5 )9 ! ,h5ry's ,=k1 ! ,gray ,cliff1 ! ,v]milion ,cliff1 & ! ,aubrey s&/ones4 ,a ?ird feature ( ! diagram is ! re/riction ( ! upp] zone ( laccolites to ! nor?w>d clu/]s2 ,m\nts ,ellswor? & ,holmes conta9 laccolites ( ! l[] zone only4 ,?is fact ( di/ribution is correlat$ ) a fact ( d5udation--namely1 t 9 ! g5]al degradation ( ! c\ntry1 ! region ab\t ! s\!rn m\nta9s has lo/ two ?\s& feet m ?an ! nor!rn4 ,"o fact is probably ! cause ( ! o!r4 ,! abs5ce ( laccolites ( ! upp] zone at ! s\? may h p]mitt$ ! great] degradation2 or ! great] degradation may h caus$ ! de/ruction ( sev]al ( ! upp] laccolites4 ,! fact t ! diff]5ce 9 degradation c be indep5d5tly acc\nt$ = is favorable to ! latt] supposition4 ,! ,colorado ,riv] :i* is ! ma9 art]y ( dra9age = ! :ole region1 fl[s close to ! bases ( ! s\!rn m\nta9s1 & ! rapid declivity f ! m\nta9 summits to ! riv] has giv5 & /ill gives exceptionally great p[] to ! ag5ts ( erosion4 ,no o!r cause is ne$$ to expla9 ! diff]5ce ( degradation1 & ! abs5ce ( laccolites ( ! upp] zone is explicable )\t assum+ t !y 7 nev] pres5t4 ,! negative objection to ! idea t ! s\!rn m\nta9s orig9ally possess$ laccolites ( ! upp] zone be+ ?us dispos$ (1 x is wor? :ile to inquire :e!r !re is any evid5ce 9 its favor4 ,if sup]ior laccolites exi/$1 !y w\ld be sure to leave beh9d !m a record ( ! conduits ?r\gh :i* _! lava 0 inject$4 ,a dike or a *imney mu/ always connect a laccolite ) ! s\rce ( its mat]ial2 & ! removal ( ! laccolite necess>ily exposes a cross-section ( its /em4 ,! discov]y ( su* a dike c be reg>d$1 n inde$ z a pro( ( ! =m] exi/5ce ( a sup]ior laccolite1 b z demon/rat+ its possibility4 ,! summits & flanks ( ,m\nts ,holmes & ,ellswor? be> _m dikes1 :i* h be5 reg>d$ z subsidi>y features ( ! laccolites b5ea? !m1 b x is q possible t any "o ( !m =m]ly l$ to ano!r laccolite above4 ,! upp] laccolite may h be5 fir/ =m$ & !n h be5 lift$1 dike & all1 :5 ! l[] 0 intrud$2 or x may h be5 la/ =m$1 & be5 f$ ?r\gh a fissure :i* trav]s$ ! l[] aft] its congelation4 ,! only dike :i* 0 discov]$ 9 ! vic9ity ( ^! m\nta9s1 )\t be+ ^u !m1 /&s midway betwe5 !m4 ,x is ! only obs]v$ dike ( ! ,h5ry ,m\nta9s 7except+ always ! alp9e di/rict ( ,m\nt ,ell571 :i* is n s closely associat$ ) "s laccolite z to seem an accessory feature1 & its exceptional position has l$ to ! suspicion t x belong$ to an ov]ly+ laccolite4 ,^u su* unc]ta9 evid5ce no positive conclusion c be bas$1 & x is va9 to build laccolites 9 ! air4 ,! mo/ t c be said is t ! s\!rn m\nta9s ne$ n be di/+ui%$ f ! nor!rn1 because at ! pres5t /age ( degradation !y conta9 laccolites ( ! l[] zone only4 ,! ,mat]ial ( ! ,laccolites4 ,! intrusive rocks ( ! ,h5ry ,m\nta9s 7 sampl$ ) c>e4 ,specim5s 7 select$ :i* _h und]gone little decomposition & :i* repres5t$ all ! prom95t li?ologic v>ieties4 ,!y 7 *os5 f ! tra*ytes ( bo? zones & ( ea* ( ! m\nta9 masses2 & !y repres5t dikes & %eets1 z well z laccolites4 ,f ab\t ?irty specim5s ?9 slices 7 cut = microscopic exam9ation4 ,capta9 ,c4 ,e4 ,dutton1 ( ,omaha1 ,nebraska1 0 s k9d z to und]take ! /udy ( ! collection1 & ! lett] :i* embodies 8 conclusions is giv5 bel[4 ,9 accordance ) 8 diagnosis ,i %all call ! intrusive rocks porphyritic tra*yte2 & ,i am glad to h ! weight ( 8 au?ority 9 support ( my belief t all ! rocks ( ! s]ies are ( "o type1 _! resemblances f> outweigh+ _! diff]5ces4 ,,note4--,p]sons desir+ to exam9e ! ,h5ry ,m\nta9 tra*ytes "u ! microscope c obta9 m\nt$ ?9 sections f ,mr4 ,alexis ,a4 ,juli51 ,s*ool ( ,m9es1 ,columbia ,college1 ,new ,york4 ,,report ,,on ,,! ,,li?ologic ,,*>act]s ,,( ,,! ,,h5ry ,,m\nta9 ,,intrusives4 ,,by ,,capta9 ,c4 ,e4 ,,dutton4 8,i h exam9$ ) great int]e/ & att5tion ! ,h5ry ,m\nta9 rocks y s5t me1 & proce$ to acqua9t y ) su* results z my limit$ facilities h p]mitt$ me to d]ive f ! exam9ation4 ,x is a v well def9$ s]ies1 hav+ "s m>k$ *>act]s :i* di/+ui% x f ! ne>e/ alli$ gr\p ) :i* ,i am acqua9t$4 ,?is is all ! m int]e/+1 because ,i am incl9$ to ?9k t ^! peculi>ities may h a def9able association ) or relation to ! mann] 9 :i* ! intrusive rocks occur 9 ^? 8laccolites01 z y t]m !m4 8,! h& specim5s %[ 9 mo/ cases l>ge & unusually p]fect cry/als ( or?oclase imb$d$ 9 a v compact uni=m pa/e ?r\gh :i* hornbl5de is also dissem9at$ r m abundantly ?an is usually ! case :]e ! dom9ant felsp> is monocl9ic4 ,micace\s cry/als appe> to be :olly want+ & ?is is a notable circum/ance1 s9ce ! tra*ytes ( ! ,plateau c\ntry1 to :i* ^! rocks are mo/ ne>ly alli$1 are seldom )\t "o or m ( !m4 ,! only o!r m9]al :i* is ( frequ5t occurr5ce 9 ! specim5s is magnetite 7or possibly titanic iron71 :i* is diffus$ 9 ! usual =m ( m9ute granules 9 _m ( !m1 b is sc>ce 9 sev]al ( !m4 ,9 g5]al !re is a great sc>city ( m9]al species & any o!rs ?an ^? m5tion$ are ( ! greate/ r>ity4 8,! dom9ant felsp> is or?oclase1 b a portion ( x is tricl9ic1 & ,i presume ?is portion is albite1 ) an occasional occurr5ce ( oligoclase4 ,! gr\ndmass 9 :i* ! cry/als are includ$ is 9 mo/ cases decid$ly compact & )\t di/+ui%able cry/als1 b %[s betwe5 ! cross$ ,nicols closely aggregat$ lum9\s po9ts1 :i* ) a -in* objective are resolv$ indi/9ctly into felsp>4 ,9 "s cases ! cry/als ( ! gr\ndmass are q app>5t ) an in* objective1 & _! species det]m9able4 ,b ! great] portion ( ! gr\ndmass is q amorph\s1 & does n pol>ize light at all4 ,! proportion ( cry/all9e to amorph\s matt] 9 ! pa/e is highly v>iable--9 "s cases x is q bright betwe5 cross$ ,nicols1 9 o!rs f> less s1 & 9 none is x entirely d>k4 ,^? specim5s :i* h ! f9] & m amorph\s gr\ndmass h ! l>g] & m p]fect cry/als ( felsp>--an association ( prop]ties :i* is n :olly )\t qualification1 b /ill suffici5tly decid$4 8,turn+ to ! includ$ felsp>s1 _! mode ( occurr5ce is q an uncommon "o1 ,i believe1 s f> z ! eruptive rocks ( ! ,rocky ,m\nta9 region are conc]n$1 & give rise to "s hesitation be=e assign+ !m def9itely to ! tra*ytic gr\p4 ,9 a great _m cases ! felspa?ic cry/als are well develop$1 & s l>ge & s ne>ly p]fect t _! aspect is decid$ly porphyritic4 ,?is is especially ! case ) ! dikes ( ,m\nts ,ellswor? & ,holmes 7,nos4 #ef1 #fa1 #fh1 & #fi74 ,! or?oclase is inv>iably ( ! :ite 8milky0 v>iety1 ) ! exception ( a s+le specim5 f a ,m\nt ,ellswor? dike 7,no4 #eg71 :]e x is pres5t z sanid94 7,?is is an exceptional rock 9 all respects1 & w be spok5 ( h]eaft]47 ,ne>ly all ( !m appe> to h be5 subject to alt]ation by *emical action s9ce _! =mation z is indicat$ by _! dim9i%$ p[] to pol>ize light4 ,:e!r ?is is due to atmosph]ic wea!r+ or to *anges en masse x is ( c\rse impossible to di/+ui% ) c]ta9ty1 ?\gh ,i incl9e to ! latt] view s9ce x is manife/$ z decid$ly 9 specim5s :i* %[ no ext]nal indications ( wea!r+ z 9 ^? :i* d %[ !m4 ,x is n uncommon to f9d cry/als :i* h almo/ entirely ceas$ to pol>ize4 ,! zonal arrangem5t is v common 9 ! cry/als1 & "s ( ! zones conta9 numb]less m9ute fluid cavities 9 ! l>ge/ cry/als4 ,! =eign sub/ances includ$ 9 ! cry/als pres5t no novelty1 be+ ! ord9>y films ( hornbl5de1 m9ute ne$les ( felsp>1 granules ( magnetite1 & ^? du/-l po9ts ( br[ni% yell[ color :i* are ! prop] inclusives ( ! gr\ndmass4 8,! or?oclase occasionally pres5ts ! adul> v>iety1 b ?is nev] becomes a m>k$ feature4 ,i h obs]v$ ! same 9 _m ( ! tra*ytes ( ! ,high ,plateaus & ( ! ,great ,bas94 ,ano!r ph5om5on is ! occurr5ce ( cry/als :i* are q typically monocl9ic at "o end 7or?oclase71 & at ! o!r end h ! arrangem5t ( plagioclase4 ,?is is well kn[n else:]e1 & describ$ by ,zirkel4 7,mik4 ,bes*aff d] ,m9]ali5 u4 ,ge/e9e74 8,9 classify+ ^! rocks !re=e1 we may obs]ve t !y pres5t a bl5d+ ( ! *>act]i/ics :i* are common to tra*yte & felsitic porphyry4 ,^? :o reg>d porphyry z a di/9ct class ( eruptive rocks w\ld h no hesitation 9 call+ ,nos4 #ah1 #ef1 #fa1 #fh1 & #fi undebatable felsitic porphyries1 & to ! same s]ies might ) propriety be add$ ,no4 #cc4 ,) equal confid5ce ,nos4 #af1 #bj1 #ce1 & #dc may be call$ unqualifi$ tra*ytes4 ,! o!r rocks are int]m$iate 9 "* betwe5 ^! two extremes1 & ! :ole may be reg>d$ z a s]ies 9 :i* ! individuals =m a graduat$ scale4 8,y w recall ! fact t _m li?ologi/s object to ! t]ms porphyry or porphyritic be+ us$ to designate a di/9ct class or gr\p ( rocks1 hold+ t !y m]ely *>act]ize a s+le feature :i* is m or less frequ5tly pres5t$ by all igne\s rocks & hav+ no necess>y relation to any ( !m1 & t ?is is no m adequate to su* an important di/9ction ?an ! color or relative degree ( f95ess or co>s5ess ( texture4 ,al?\gh ?is latt] view seems to me to und]rate ! di/9ctive value ( ! porphyritic "* 9 g5]al1 ,i incl9e v decid$ly to ! belief t x is true z appli$ to ^! ,h5ry ,m\nta9 rocks4 ,"h at lea/ ! porphyritic "* has b little significance4 ,9 "s v>ieties ! cry/als are l>g] & m p]fect & ! gr\ndmass m homog5e\s2 9 o!rs ! cry/als are small] & imp]fect1 & ! gr\ndmass m co>se & irregul>2 :ile /ill o!rs are #8betwixt & betwe5'4 ,! mo/ c>eful scrut9y fails to %[ any fundam5tal diff]5ces 9 ! gr\ndmass or 9 ! includ$ m9]als4 ,h5ce ,i ?9k ^! rocks w\ld be accurately designat$ z a gr\p by call+ !m porphyritic tra*ytes4 ,su* v>ieties z ,nos4 #af1 #bj1 & #ce may by !mselves be call$ simply tra*yte1 ! porphyritic "* be+ insuffici5tly di/9ct 9 !m to w>rant any qualification ( ! "n4 8,!re is "o specim5 7,no4 #eg1 f dike 9 ,%9>ump %ale1 ,m\nt ,ellswor?7 :i* con/itutes an exception to ! =ego+4 ,by inspection ( a h& specim5 x might ha/ily pass = a v compact &esite1 b ! obs]v] w be in/antly undeceiv$ by apply+ ! microscope4 ,x consi/s ( imp]fect cry/als1 :i* mu/ be sanid91 imb$d$ 9 a v close gr\ndmass compos$ ( a mat]ial :i* diff]s f ! =ego+ tra*ytes 9 be+ :olly amorph\s4 ,betwe5 cross$ ,nicols ! pa/e transmits no light :atev]1 ?\gh betwe5 ! p>allel ,nicols x closely resembles ! o!rs4 ,! h& specim5 is v d>k color$ 7gray71 b ! slide is suffici5tly transluc5t4 ,! felsp> cry/als are ei!r fragm5tal or v imp]fectly develop$ z to _! edges & angles1 b pol>ize v %>ply4 ,! am\nt ( tw9n+ is v small1 b x appe>s occasionally4 ,! rock is und\bt$ly a tra*yte1 b an unusual "o4 ,its d>k color is n due to hornbl5de nor to magnetite1 bo? ( :i* occur 9 x v sp>+ly1 especially ! =m]4 8,i h already rem>k$ t ! only frequ5t m9]als besides felsp> are hornbl5de & magnetite4 ,apatite occurs & is tol]ably pl5tiful 9 a few ( ! specim5s1 b abs5t f mo/ ( !m4 ,! cry/als are all small1 requir+ a l[ p[] = ! det]m9ation ( ! l>g] & a high p[] = ! small]4 ,!y pres5t no peculi>ities4 ,( v r>e occurr5ce is nephel9e4 ,?is m9]al is usually associat$ ) ! m basic volcanic rocks & seldom p5etrates ! tra*ytic gr\p4 ,qu>tz is almo/ equally r>e4 ,! abs5ce ( any great v>iety 9 ! m9]al species is q normal1 except possibly ! total abs5ce ( mica1 :i* is usually pres5t & frequ5tly ! only associate ( felsp> 9 ! we/]n tra*ytes4 ,! ,h5ry ,m\nta9 rocks d n s f> z ,i c discov] conta9 a trace ( x4 8,9 answ] to y\r p>ticul> inquiries-- 8#a/4 #8,is ! pa/e vesicul>1 or is !re any evid5ce 9 ! cry/als to indicate ! pressure "u :i* !y 7 =m$8' ,i c only say t ! pa/e is extremely compact & conta9s no vesicles ev5 9 ^? specim5s ( :i* ! aspect is mo/ decid$ly tra*ytic4 ,"s ( ! l>g] cry/als ( felsp> conta9 an abundance ( pores or vesicles :i* may h conta9$ liquids1 b ) a -in* objective !y are too small = treatm5t by ! me?od y ref] to4 ,a few l>ge cavities1 usually ( irregul> %ape1 occur1 b ,i am q unfamili> ) ! practical treatm5t ( ?is subject & _c advise y4 ,i d n f9d any cavities /ill conta9+ fluids1 & ,i presume t ev5 if !y exi/$ !y w\ld be difficult if n impossible to gauge on acc\nt ( ! impellucidity ( ! felsp>4 ,i presume qu>tz is ! mo/ favorable m9]al = ?is inve/igation on acc\nt ( its transp>5cy & ! great] frequ5cy ( its l>ge cavities4 ,qu>tz h[ev] is almo/ ! sc>ce/ ( ! cont5ts ( ^! rocks4 8#b;d4 #8,d any m9]alogic diff]5ces correlate ) ! sup]ficial or geographic di/ribution ( ! rocks8' & 8#c;d4 #8,d any m9]alogic diff]5ces correlate ) ! v]tical di/ribution ( ! tra*ytes8' ,z x appe>s f y\r acc\nt ( ! di/ribution ( ! masses t ! upp] zone belongs 7) "o exception7 to ,m\nts ,ell5 & ,p5nell & ! l[] to ! o!r m\nta9s1 ! answ] to "o is ! answ] to bo?1 & ?is is 9 ! negative4 ,! m9]alogical diff]5ces are exce$+ly small1 consid]+ ! numb] ( di/9ct masses1 & ?is cov]s ! inquiry entirely4 ,reg>d+ ! texture or habitus1 on ! contr>y1 x appe>s to me t ! true tra*ytes pr$om9ate 9 ! upp] zone & ! porphyries 9 ! l[]1 b n )\t exceptions4 8#d?4 #8,d any m9]alogic diff]5ces correlate ) ! size ( ! intrusive masses8' ,no m9]alogical diff]5ces ?us correlate1 b ,i f9d a prepond]ance ( ! porphyritic texture 9 ! small] masses & ( ! tra*ytic texture 9 ! l>g]4 ,x is n )\t exception1 & ! prepond]ance is small40 ,metamorphism & ,contact ,ph5om5a4--,:]ev] ! tra*ytes came 9 contact ) ! s$im5t>ies ! latt] 7 m or less alt]$4 ,l>ge bodies ( tra*yte produc$ great] *anges ?an small4 ,! laccolites bo? metamorphos$ _! walls m completely1 & c>ri$ _! influ5ce to a great] di/ance ?an ! %eets & dikes4 ,! summits ( ! laccolites _h a great] influ5ce ?an ! edges2 a ph5om5on to :i* ,i %all h occasion to rev]t4 ,! s&/ones 7 less affect$ ?an ! %ales1 at lea/ 9 su* *>act]s z readily cat* ! eye4 ,clay %ales 7 indurat$ s z to cl9k "u ! hamm]1 & ,capta9 ,dutton discov]$ ) ! microscope t m9ute cry/als ( felsp> _h be5 develop$4 ,s&/ones 7 usually modifi$ 9 color1 & _! iron 0 segregat$ s z to give a mottl$ or speckl$ appe>ance to ! fracture4 ,!y 7 indurat$1 b ! granul> texture 0 always reta9$4 ,! tra*yte c>ries num]\s small fragm5ts ( s$im5t>y rock brok5 app>5tly f its walls1 & ^! are z ?or\ghly cry/all9e z _! matrix4 ,! alt]$ rocks are usually jo9t$1 b no?+ approa*+ to slaty cleavage 0 se51 nor has !re be5 any crumpl+4 ,! reciprocal influ5ce ( ! s&/one & %ale ^u ! tra*yte 0 small4 ,specim5s brok5 f ! contact surface ( a laccolite & f its int]ior _c be di/+ui%$4 ,9 ! ,m>v9e laccolite h[ev] !re is a diff]5ce betwe5 ! ext]ior & int]ior portions 9 _! ability to )/& erosion4 ,hi/orical4--,be=e leav+ ! subject ( ! /ructure ( ! m\nta9s x is prop] to place on record c]ta9 obs]vations by o!rs :i* ant$at$ my own b h nev] be5 publi%$4 ,:ile ,pr(essor ,p[ell's boat p>ty 0 explor+ ! caons ( ! ,colorado1 ,mr4 ,john ,f4 ,/ew>d a geologi/ & memb] ( ! p>ty climb$ ! cliff ne> ! m\? ( ! ,dirty ,devil ,riv] & approa*$ ! ea/]n base ( ! m\nta9s4 ,he report$ t ! /rata _h 9 ! m\nta9s a quaquav]sal dip1 ris+ ^u ! flanks f all sides4 ,! foll[+ ye> ,pr( ,a4 ,h4 ,?ompson !n z n[ 9 *>ge ( ! geographic "w ( ,pr(essor ,p[ell's survey cross$ ! m\nta9s by ! ,p5ell5 ,pass & asc5d$ "s ( ! pr9cipal peaks4 ,he not$ ! upris+ ( ! /rata ab\t ! bases & ! pres5ce ( igne\s rocks4 ,9 #ahgc ,mr4 ,e4 ,e4 ,h[ell at t "t ! geologi/ ( a division ( ! ,:eel] ,survey travel$ )9 twelve miles ( ! we/]n base ( ! m\nta9s1 & obs]v$ ! upris+ ( ! /rata4 ,my own obs]vations 7 begun 9 #ahge1 at :i* "t a week 0 sp5t among ! m\nta9s4 ,!y prov$ s attractive a field = inve/igation t 9 ! foll[+ ye> a p]iod ( ne>ly two m\?s 0 devot$ to _! /udy4 ,o!r ,igne\s ,m\nta9s4--,! ,h5ry ,m\nta9s are n ! only igne\s gr\p :i* ! ,plateau prov9ce comprises4 ,!y are scatt]$ "h & !re ?r\gh\t its :ole ext5t4 ,f ! summits ( ! ,h5ry ,m\nta9s "o c see ! ,si]ra ,la ,sal n9ety miles to ! nor!a/w>d1 & ! ,si]ra ,abajo sev5ty miles to ! ea/w>d4 ,beyond !m & two hundr$ miles away are ! ,elk ,m\nta9s ( ,colorado4 ,fifty miles to ! s\?we/w>d /&s ! ,navajo ,m\nta9 on ! br9k ( ! ,colorado2 & "o hundr$ & tw5ty miles to ! s\!a/ ! ,si]ra ,la ,lata & ! ,si]ra ,c>riso are outl9$ aga9/ ! horizon4 ,we/w>d x is less ?an ?irty miles to ! ,aqu>ius ,plateau1 ! ne>e/ memb] ( ! great sy/em ( volcanic tables among :i* ! ,sevi] & ,dirty ,devil ,riv]s rise4 ,beyond ! horizon at ! s\? & s\?we/ & s\!a/ are a s]ies ( ext9ct volcanoes2 ,m\nt ,taylor & ! ,m>c\ ,buttes 9 ,new ,mexico2 ! ,si]ra ,blanca1 ! ,si]ra ,mogollon1 ! ,san ,francisco ,gr\p & ! ,u9k>ets 9 ,arizona2 & ! ,panguit* ,lake ,buttes 9 ,utah4 ,( ! gr\ps :i* are visible1 all b t ( ! ,aqu>ius ,plateau are alli$ 9 "* to ! ,h5ry ,m\nta9s4 ,! ,si]ra ,abajo 0 /udi$ 9 #ahei by ,dr4 ,j4 ,s4 ,newb]ry1 geologi/ ( ! ,macomb ,exp$ition1 :o writes3 8,)9 ! la/ few weeks we h be5 on ?ree sides ( ?is si]ra1 & h le>n$ its /ructure q def9itely4 ,x is a m\nta9 gr\p ( no great elevation1 its highe/ po9t ris+ "s #b1jjj feet above ! ,sage-pla91 or p]haps #i1jjj feet above ! sea4 ,x is compos$ ( sev]al di/9ct ranges1 ( :i* ! mo/ we/]ly "o is q deta*$ f ! o!rs4 ,all ^! ranges1 ( :i* !re are app>5tly f\r1 h a tr5d ( ab\t #be ea/ ( nor?1 b be+ arrang$ some:at en e*elon1 ! mo/ we/]ly range rea*+ f>!/ nor?1 ! pr9cipal axis ( ! gr\p has a nor?we/ & s\!a/ direction4 ,! si]ra is compos$ geologically ( an erupt$ nucleus1 ma9ly a gray or blui%-:ite tra*yte1 sometimes becom+ a porphyry1 surr\nd$ by ! upheav$1 p>tially erod$1 s$im5t>y rocks4 ,! ,l[] ,cretace\s s&/ones & ,middle ,cretace\s %ales are cut & expos$ 9 all ! rav9es lead+ d[n f x1 :ile ne>ly ! entire ?ickness ( ! ,cretace\s s]ies is %[n 9 spurs :i*1 9 "s localities1 project f its sides2 app>5tly ! remnants ( a plateau correspond+ to1 & once connect$ )1 ! ,mesa ,v]de4 ,:e!r ! ,paleozoic rocks are any:]e expos$ ^u ! flanks ( ! ,si]ra ,abajo ,i _c c]ta9ly say1 ?\gh we discov]$ no traces ( !m4 ,x is1 h[ev]1 probable t !y w be f\nd 9 "s ( ! deep] rav9es1 :]e1 z 9 mo/ ( ^! isolat$ m\nta9s compos$ ma9ly ( erupt$ mat]ial1 !y are d\btless b little di/urb$1 b are buri$ b5ea? ! eject$ matt] :i* has be5 ?r[n up ?r\gh !m4 8,! relations ( ! ,cretace\s rocks to ! igne\s nucleus ( ! ,si]ra ,abajo are v peculi>1 =1 al?\gh we did n make ! entire circuit ( ! m\nta9 mass1 & ,i c1 !re=e1 n speak def9itely 9 reg>d to ! we/]n side1 z f> z our obs]vations ext5d$ we f\nd ! s$im5t>y /rata ris+ on to ! tra*yte core1 z ?\gh x _h be5 pu%$ up ?r\gh !m40 7,geology ( ! ,macomb ,exp$ition1 page #ajj47 ,( ano!r gr\p ,dr4 ,newb]ry says 9 ! same report 7page #ic73 8,( ! composition ( ! ,si]ra ,la ,sal we "k no?+ except :at 0 taught by ! drift$ mat]ials br\ght d[n 9 ! caons ?r\gh :i* ! dra9age f x fl[s4 ,( ?is transport$ mat]ial we saw b little1 b t consi/$ ma9ly ( tra*ytes & porphyry1 indicat+ t x is compos$ ( erupt$ rocks simil> to ^? :i* =m ! ,si]ra ,abajo1 ( :i* x is 9 fact almo/ an exact c\nt]p>t4 ,f ! cliffs ov] ,ojo ,v]de we c\ld see ! /rata compos+ bo? ! upp] & second plateaus1 ris+ f ! ea/1 s\?1 & s\?we/ on to ! base ( ! ,si]ra ,la ,sal1 ea* conspicu\s /ratum be+ di/9ctly traceable 9 ! walls ( ! caons & valleys :i* head 9 ! si]ra4 ,x is evid5t1 !re=e1 t ! rocks compos+ ! ,colorado ,plateau are !re locally upheav$1 precisely z ar\nd ! ,si]ra ,abajo 99 99 9940 ,^! m\nta9 gr\ps h be5 s9ce visit$ by ! geologi/s ( ,dr4 ,hayd5's survey1 ,dr4 ,a4 ,c4 ,peale asc5d+ ! ,si]ra ,la ,sal & ,mr4 ,w4 ,h4 ,holmes ! ,si]ra ,abajo4 ,mr4 ,holmes has also exam9$ ! ,la ,lata & ,c>riso ,m\nta9s & f\nd 9 !m ! same upb5d+ ( ,cretace\s /rata & ! same association ( igne\s mat]ial4 ,! ,navajo ,m\nta9 has be5 view$ by ,mr4 ,h[ell & by ! writ] f a comm&+ position on ! opposite side ( ! ,colorado ,riv]1 & fragm5ts ( its tra*yte h be5 ga!r$ on ! riv] bank by ,pr(essor ,p[ell1 b no geologi/ has yet climb$ x4 ,/ill !re c be no "q ( its g5]al /ructure4 ,x is a simple dome ( ,jura-,triassic s&/one1 spr++ abruptly f a plateau ( ! same mat]ial1 & ve9$ at ! surface by %eets & dikes ( tra*yte--! c\nt]p>t 9 f9e ( ,m\nt ,ellswor?1 only ( m impos+ proportions4 ,! ,la ,sal1 ! ,abajo1 ! ,la ,lata1 ! ,c>riso1 ! ,navajo1 & ! ,h5ry ,m\nta9s agree 9 _! ess5tial features4 ,/ructurally !y h no tr5ds4 ,_! ph5om5a are gr\p$ ab\t c5t]s & n axes4 ,9 all ( !m ! /rata are lift$ into dome-l ar*es1 & associat$ ) ^! ar*es are bodies ( tra*yte4 ,! tra*ytes are all ( "o li?ologic type1 & are s closely relat$ t a collection ( rock specim5s repres5t+ all ! gr\ps w\ld %[ sc>cely m v>iety ?an a collection repres5t+ ! ,h5ry ,m\nta9 laccolites4 ,) s _m *>act]s 9 common !y c h>dly fail to agree 9 ! possession ( laccolitic nuclei4#c ,footnote #c3 ,:ile ^! pages are pass+ ?r\gh ! press a pap] by ,dr4 ,a4 ,c4 ,peale 8,on a peculi> type ( eruptive m\nta9s 9 ,colorado0 7,bullet9 ,u4 ,s4 ,geol4 ,sur41 ,vol4 ,,iii1 ,no4 #c7 comes to h&4 ,he gr\ps toge!r z ( "o type n only ! ,elk1 ,la ,sal1 ,abajo1 ,la ,lata1 & ,c>riso ,m\nta9s1 b also ! ,spani% ,peaks1 ,p>k ,view ,m\nta91 ,m\nt ,guyot1 ,silv]heels ,m\nta91 ! ,san ,miguel ,m\nta9s1 ! ,la ,plata ,m\nta9s1 & c]ta9 small] masses 9 ,middle ,p>k & ne> ! ,hu]fano ,riv]4 ,he says1 8,al?\gh modifi$ 9 sev]al in/ances1 ! g5]al plan appe>s to be ! same4 ,! igne\s mat]ial came up ?r\gh fissures 9 ! s$im5t>ies1 sometimes tipp+ up _! ends1 & sometimes pass+ ?r\gh )\t di/urb+ !m4 ,on rea*+ ! ,cretace\s %ales1 x g5]ally spread out 9 !m1 & pu%$ into & across !m dikes & intrusive %eets ( ! same igne\s rock4 ,! elevation 9 "s cases appe>s to be due to actual upheaval caus$ by ! eruptive =ce4 ,! m\nta9s z !y n[ exi/ are d\btless l>gely ! result ( erosion1 ! h>d igne\s rock oppos+ great] resi/ance to erosive influ5ces ?an d ! surr\nd+ s(t s$im5t>y b$s40 ,! ,elk ,m\nta9s are at ! v m>g9 ( ! plateau1 & geographically might be connect$ ) ! ,sawat* ,range :i* b\nds ! plateau prov9ce on t side4 ,b /ructurally !y are a gr\p in/ead ( a range1 & affiliate ) ! gr\ps :i* are insulat$ by an environm5t ( tables4 ,?anks to ! labors ( ,mr4 ,holmes & ,dr4 ,peale _! g5]al /ructure is kn[n4 ,! ,ea/]n ,elk ,m\nta9s consi/ ( f\r great bodies ( 8eruptive granite01 ov] :i* are ar*$ n only ,mesozoic b ,paleozoic /rata4 ,_! f\ndation mu/ be a floor ( ,ar*an metamorphics4 ,two ( !m1 ! ,sn[ ,mass & ,:ite ,rock laccolites1 are jo9$ by a cont9u\s l9e ( di/urbance1 9 ! description ( :i* by p5 & p5cil ,mr4 ,holmes has made an important contribution1 n only to dynamical geology1 b to ! me?ods ( geological illu/ration4 ,! o!rs are m symmetric & are complem5t>y illu/rations ( ! common /ructure4 ,"o1 ! ,sopris1 is half truncat$ by erosion s t ! core is expos$ at top ) an encircl+ fr+e ( upturn$ s$im5t>ies2 & ! o!r1 ! ,treasury1 reta9s a complete ar* ( ,paleozoic /rata4 ,! ,we/]n ,elk ,m\nta9s are a clu/] ( small] laccolites :i* are ins]t$ betwe5 /rata ( ,cretace\s age4 ,_! traps include porphyritic tra*ytes undi/+ui%able f ^? ( ! ,h5ry ,m\nta9s1 & eruptive granites id5tical ) ^? ( ! ,ea/]n ,elk ,m\nta9s2 & !y exhibit a gradation f "o to ! o!r4 ,inde$ ! two rocks are ne>ly relat$1 & _! assignm5t to classes s div]se z tra*yte & granite is m]ely an illu/ration ( ! imp]fection ( our classification ( rocks4 ,! description ( ! ,elk ,m\nta9s w be f\nd on pages #fa to #ga & #afc to #afh ( ! ,annual ,report = #ahgd ( ! 8,geological & ,geographical ,survey ( ! ,t]ritories40 ,if we turn n[ to ! di/9ctively volcanic m\nta9s ( ! ,plateau prov9ce--to ^? :i* are built by eruption at ! surface--we leave at once ! porphyritic tra*ytes4 ,m\nt ,san ,francisco1 ,m\nt ,bill ,williams1 ,m\nt ,sitgreaves1 ,m\nt ,k5drick1 ,m\nt ,floyd & ! ,si]ra ,blanca 7( ,arizona7 are all compos$ ( basic tra*ytes1 & s are ! ,aqu>ius ,plateau & ! _m tables t lie beyond x4 ,! ,mogollon gr\p1 ! ,m>c\ ,buttes1 ! m9or cones ab\t ,m\nt ,san ,francisco1 ! ,u9k>ets1 & ! ,panguit* ,lake gr\p are basaltic4 ,9 ea* ( ^! in/ances ! igne\s rock issu$ above ! surface & !re is no evid5ce by displacem5t t any portion ( x 0 deposit$ bel[4 ,m\nt ,taylor may be an exception4 ,9 ! "* ( its lava & its g5]al features x resembles ,m\nt ,san ,francisco1 b !re are di/urb$ /rata on its s\!rn flank1 & x is possible ! m\nta9 is bo? extrusive & intrusive4 ,extrusion & intrusion are probably comb9$ 9 "s small tables ly+ fifty miles nor? ( ! ,h5ry ,m\nta9s4 ,!y are built ( ,flam+ ,gorge %ale1 pres]v$ f erosion by dikes1 %eets1 & 7probably7 outfl[s ( basalt4 ,comb9+ all ^! facts we atta9 to a simple relation betwe5 two types ( igne\s rock on ! "o h&1 & two types ( m\nta9 /ructure on ! o!r4 ,"o type ( rock is acidic1 includ+ 8porphyritic tra*yte0 & 8eruptive granite01 & its occurr5ce is )\t exception intrusive4 ,! o!r type ( rock is basic1 includ+ basic tra*yte & basalt1 & its occurr5ce is almo/ uni=mly extrusive4 ,x is n possible to comb9e ! two gr\ps ( ph5om5a by say+ t 9 "o case ! eruptive cones cov] laccolites1 & 9 ! o!r ! laccolites h be5 cov]$ by eruptive cones :i* h disappe>$2 fir/1 because _m ( ! eruptive cones are too well expos$ to admit ( ! concealm5t ( laccolitic ar*es b5ea? !m2 second1 because ! two types ( lava are ess5tially diff]5t4 ,! acidic type if extrud$ at ! surface w\ld be an ord9>y tra*yte2 ! basic type if cry/alliz$ "u pressure w\ld be class$ ) ! gre5/ones4 ,! basis = ! g5]alization is exce$+ly broad4 ,i h enum]at$ only sev5 gr\ps ( laccolitic m\nta9s & t5 gr\ps ( eruptive2 b ) few exceptions ea* gr\p is compos$ ( _m individuals1 ea* "o ( :i* is entitl$ to rank z a sep>ate ph5om5on4 ,9 ! ,u9k>et ,m\nta9s ,pr(essor ,p[ell has di/+ui%$ no less ?an "o hundr$ & eighte5 eruptive cones1 & 9 ! ,h5ry ,m\nta9s ,i h enum]at$ ?irty-six individual laccolites4 ,9 "o locality basic lava has "o hundr$ & eighte5 times ris5 to ! surface by *annels m or less di/9ct1 in/ead ( op5+ *amb]s = itself bel[4 ,9 ! o!r locality porphyritic tra*yte has ?irty-six times built laccolites in/ead ( ris+ to ! surface4 ,if our att5tion 0 re/rict$ to ^! two localities we might z naturally correlate ! types ( /ructure ) "s accid5ts ( locality z ) types ( lava2 b :5 all ! localities are tak5 into acc\nt x is evid5t t !re is no common m>k by :i* ei!r ! laccolitic or ! volcanic are di/+ui%$4 ,,! ,,"q ,,( ,,cause4 ,we are n[ ready to consid] ! "q3 ,:y is x t 9 "s cases igne\s rocks =m volcanoes & 9 o!r cases laccolites8 ,x is n necess>y to broa* ! m difficult problem ( ! s\rce ( volcanic en]gy4 ,we may assume t molt5 rock is be+ =c$ upw>d ?r\gh ! upp] portion ( ! e>?'s cru/1 & disreg>d+ its s\rce & its propell+ =ce may re/rict our inquiry to ! circum/ances :i* det]m9e its /opp+ place4 ,let u fur!r assume1 b = a mom5t only1 t ! cohesion ( ! solid rocks ( ! cru/ does n imp$e ! upw>d progress ( ! fluid rock1 nor prev5t x f spread+ lat]ally at any level4 ,! lava w !n obey /rictly ! g5]al law ( hydro/atics1 & assume ! /ation :i* w give ! l[e/ possible position to ! c5t] ( gravity ( ! /rata & lava comb9$4 7#a7 ,if ! fluid rock is less d5se ?an ! solid1 x w pass ?r\gh x to ! surface & build a subarial m\nta94 7#b7 ,if ! upp] portion ( ! solid rock is less d5se ?an ! fluid1 :ile ! l[] portion is m d5se1 ! fluid w n rise to ! surface b w pass betwe5 ! heavy & light solids & lift or float ! latt]4 7#c7 ,if ! cru/ be compos$ ( _m horizontal b$s ( div]se & alt]nat+ d5sity1 ! fluid w select = its re/+ place a level s condition$ t no sup]ior gr\p ( successive b$s1 includ+ ! b$ imm$iately above x1 %all h a great] mean specific gravity ?an its 7! fluid's7 own2 & t no inf]ior gr\p ( successive b$s1 includ+ ! b$ imm$iately b5ea?1 %all h a less mean specific gravity ?an its own4 ,illu/ration3 ,,fig4 #ea4--;,diagram to illu/rate ! application ( ! law ( ,hydro/atic ,equilibrium to ! movem5ts ( lavas4 ,! %ad$ b&s repres5t heavy /rata2 ! op51 light4 ,9 ! diagram1 a s]ies ( light & heavy b$s are repres5t$ 9 section by op5 & %ad$ spaces4 ,a lava /ream free to move upw>d or lat]ally w intrude itself at "s po9t 7c7 s plac$ t e comb9ation ( sup]ior b$s 7a71 :i* includes ! l[e/1 %all h a less av]age d5sity2 & e comb9ation ( inf]ior /rata 7b71 :i* includes ! highe/1 %all h a great] av]age d5sity ?an t ( ! lava4 ,! fir/ case is t ( a volcano2 ! second is t ( a laccolite2 & ! ?ird is ! g5]al case1 includ+ ! o!rs & apply+ to all volcanoes & laccolites4 ,conv]sely we may say t1 giv5 a s]ies ( /rata ( div]se & alt]nat+ d5sity1 a v light lava w trav]se x to ! top & be extrud$2 a heavi] w intrude itself at "s l[] level2 & a s]ies ( dissimil> lavas may select an equal numb] ( di/9ct levels4 ,x is easy to imag9e su* a balanc+ ( conditions t a slight *ange 9 a lava w det]m9e a great *ange 9 its level ( intrusion4 ,hav+ se5 ! g5]al application ( ! hydro/atic law1 x is "t to recall ! condition :i* we laid aside at ! />t4 ,cohesion1 or rigidity1 is nev] abs5t & mu/ affect e phase ( vulcanism4 ,x c]ta9ly opposes ! free circulation ( lavas1 & x _c b modify _! ob$i5ce to ! hydro/atic law4 ,b grant+ ?is1 & believ+ t a full compreh5sion ( ! subject mu/ include ?is condition1 ,i am at a loss to tell 9 :at way x influ5ces ! selection by a lava flood ( a subarial or a subt]ranean b\rne4 ,:e!r x w on ! :ole oppose upw>d progress m ?an lat]al1 or vice v]sa1 is n cle>4 ,if x resi/s lat]al intrusion ! m /rongly1 x favors ! =mation ( volcanoes2 if x resi/s upw>d p5etration ! m /rongly1 x favors ! =mation ( laccolites2 & 9 ei!r case ! work+ ( ! hydro/atic law is modifi$4 ,b 9 nei!r case is ! work+ ( ! law m ?an modifi$4 ,! law is n abrogat$1 & 9 ob$i5ce to x light lavas /ill t5d to rise high] ?an heavy h[ev] mu* ! ris+ ( all lavas may be h9d]$ or favor$4 ,9 brief1 s9ce lavas are fluids !y are subject to ! law ( fluid equilibrium1 & _! behavior is condition$ by ! relations ( _! d5sities to ! d5sities ( ! solids :i* !y p5etrate2 & s9ce ! latt] solids are rigid & coh]5t1 x is fur!r condition$ by ! resi/ance :i* is oppos$ to _! p5etration4 ,:5 ! resi/ance to p5etration is ! same 9 all directions1 ! relation ( d5sities det]m9es ! /opp+ place ( ! ris+ lava2 b :5 ! v]tical & lat]al resi/ances are unequal1 _! relation may be ! det]m9+ condition4 ,if we c decide :e!r ! det]m9ative condition 9 ! ,plateau region 0 t ( d5sities or t ( p5etrability1 we %all h solv$ our problem4 ,assum+1 fir/1 t ! ess5tial condition is t ( p5etrability1 we %\ld expect t "s p>ticul> /ratum or t a few p>ticul> /rata1 be+ less p5etrable ?an o!rs1 w\ld *eck ! ris+ lavas & accumulate !m 9 a sy/em ( laccolites1 :i* w\ld occupy "o1 or a few def9ite horizons4 ,volcanoes w\ld occur 9 di/ricts f :i* su* imp5etrable /rata ei!r 7 orig9ally abs5t or _h be5 remov$ be=e ! igne\s epo*2 & we %\ld expect to f9d ! same v>iety ( mat]ial 9 laccolites & 9 volcanoes4 ,assum+1 second1 t ! ess5tial condition is t ( d5sities1 we %\ld expect z be=e to f9d c]ta9 /ratigraphic horizons m favorable ?an o!rs to ! accumulation ( laccolites1 & we %\ld also expect to f9d c]ta9 lavas usually volcanic & c]ta9 o!rs usually laccolitic4 ,t is to say--s9ce ! condition ( imp5etrability resides 9 ! solid rock only1 & ! condition ( d5sity p]ta9s to bo? solid & fluid1 ei!r condition might det]m9e laccolites at c]ta9 /ratigraphic horizons1 :ile ! latt] only c\ld discrim9ate c]ta9 lavas z intrusive & o!rs z extrusive4 ,! v]tical di/ribution ( laccolites is n inconsi/5t ) ei!r assumption4 ,9 ! ,h5ry ,m\nta9s !re are two zones ( occurr5ce2 9 ! ,ea/]n ,elk ,m\nta9s !re is a ?ird2 & x is probable 9 ! pres5t /ate ( our k t all o!r laccolites ( ! ,plateaus c be assign$ to "o or ano!r ( ^!4 ,! fact t ! laccolites ( ! upp] zone h a v]tical range ( two ?\s& feet is r favorable to ! idea t _! /ations 7 det]m9$ by relations ( d5sity1 b is n decisive4 ,:5 h[ev] we turn to ! relation betwe5 ! con/itutions & ! behaviors ( lavas1 we f9d ! entire weight ( ! evid5ce 9 favor ( ! assumption t conditions ( d5sity det]m9e ! /ructure4 ,! co9cid5ce ( ! laccolitic /ructure ) a c]ta9 type ( igne\s rock is s p]si/5t t we _c d\bt t ! rock conta9$ 9 itself a condition :i* det]m9$ its behavior4 ,we are !n l$ to conclude t ! conditions :i* det]m9$ ! results ( igne\s activity 7 ! relative d5sities ( ! intrud+ lavas & ( ! invad$ /rata2 & t ! fulfillm5t ( ! g5]al law ( hydro/atics 0 n mat]ially modifi$ by ! rigidity & cohesion ( ! /rata4 ,hav+ rea*$ ?is conclusion x is natural to seek = confirmation by ! inve/igation ( ! d5sities ( ! rocks conc]n$ 9 ! ph5om5a4 ,z w appe> by a table giv5 fur!r on1 ! d5sity ( ! ,h5ry ,m\nta9 tra*yte has be5 det]m9$ to be #b4fa42 b ! d5sities ( ! erupt$ lavas ( ! ,plateaus are n yet kn[n4 ,!re c be no d\bt h[ev] t ! latt] are heavi]4 ,von ,cotta 9 8 ,li?ology gives #b4i to #c4a z ! d5sity ( basalt1 & #b4f to #b4i z ! d5sity ( ! m basic tra*ytes4 ,& 9 g5]al1 x is well e/abli%$ t :]e ! /ate ( aggregation is ! same1 basic igne\s rocks are always heavi] ?an acidic4 ,b 9 ord] t ! laccolitic /ructure %\ld h be5 det]m9$ by d5sity1 ! acidic rock ( ! laccolites mu/ h be5 heavi] 9 its molt5 condition ?an ! m basic rocks ( ! neighbor+ volcanoes2 & s9ce 9 ! cry/all9e condition ! acidic is ! light]1 x foll[s t x has ga9$ less d5sity 9 cool+ ?an ! basic4 ,if ! am\nt ( contraction ( ! sev]al rocks 9 pass+ f _! natural molt5 condition to ! cry/all9e condition c\ld be det]m9$ exp]im5tally1 a crucial te/ w\ld be appli$ to our conclusions z to ! orig9 ( laccolites4 ,! matt] is h[ev] beset ) difficulties4 ,bis*( attempt$ by melt+ eruptive rocks 9 clay crucibles to obta9 _! ratios ( expansion & contraction1 b 8 me?od involv$ s _m s\rces ( error t 8 results h be5 g5]ally di/ru/$4 ,he conclud$ t ! contraction 9 pass+ f ! molt5 to ! cry/all9e /ate is great] 9 acidic ?an 9 basic rocks4 ,delesse by an ext5d$ s]ies ( exp]im5ts 9 :i* cry/all9e rocks 7 melt$ & aft]w>d cool$ to glasses1 %[$ t acidic rocks increase 9 volume f #i to #aa p] c5t4 9 pass+ f ! cry/all9e /ate to ! vitre\s1 :ile basic increase only #f to #i p] c5t4 ,mallet conclud$ f "s exp]im5ts ( 8 own t ! contraction ( rocks 9 cool+ f ! molt5 condition is nev] m ?an #f p] c5t41 & t x is great] ) basic ?an ) acidic rocks2 b consid]+ t ! sub/ances :i* he treat$ 7 artificial & n natural products1 t 8 me?ods 7 n uni=m1 & t he ignor$ ! di/9ction betwe5 ! vitre\s & ! cry/all9e1 ( :i* ,delesse _h demon/rat$ ! importance1 no weight c be giv5 to 8 results4 ,if h[ev] all ( ^! exp]im5ts 7 tru/wor?y & _! results 7 concordant1 _! be>+ ^u ! problem ( ! laccolites w\ld /ill be slight4 ,x is g5]ally conc$$ t ! fusion ( lavas is hydro!rmal1 :ile 9 all ! exp]im5ts rec\rse 0 _h to dry fusion2 & ! d5sities atta9$ 9 ! two ways are necess>ily diff]5t4 ,! practical difficulty 9 ! way ( re/or+ ! natural molt5 condition is great & may be insup]able1 b unless x %all be ov]come we _c le>n exp]im5tally ! *anges ( d5sity :i* igne\s rocks und]go 9 congelation4 ,!re is a fact ( obs]vation :i* t5ds to su/a9 ! view t ! laccolitic rocks contract$ less 9 cool+ ?an ! volcanic4 ,! prismatic /ructure is produc$ by ! contraction ( cool+ rocks dur+ & aft] solidification4 ,t x does n occur 9 ! ,h5ry ,m\nta9 tra*ytes indicates t _! contraction 0 small4 ,t x does occur at num]\s localities 9 ,utah 9 basalts1 indicates t _! contraction 0 relatively great4 ,mr4 ,jukes1 9 8 ,manual ( ,geology1 says t x is mo/ frequ5tly exhibit$ 9 8dol]itic lavas & traps1 be+ especially *>act]i/ic ( basalt1 b occurs almo/ z p]fectly 9 "s gre5/ones & fel/ones02 & 9 ! range ( my own obs]vation ,i c recall no in/ance ( its occurr5ce 9 o!r ?an basic rocks4 ,= ! sake ( comp>+ ! d5sities ( ! intrusive rocks ) ^? ( ! /rata :i* conta9 !m1 a numb] ( det]m9ations 7 made ( ! specific gravities ( specim5s repres5tative ( ! tra*ytes & ( ! sev]al s$im5t>y gr\ps ( ! ,h5ry ,m\nta9s4 ,tra*ytes 7 select$ to repres5t z great a v>iety ( locality & relation z possible1 & at ! same "t exclude all specim5s :i* %[$ traces ( decomposition4 ,h& specim5s weigh+ f "o hundr$ to f\r hundr$ gra9s 7 us$1 & ^! 7 weigh$ fir/ dry1 & !n susp5d$ 9 wat]4 ,by us+ su* l>ge quantities av]ages 7 obta9$ ( a rock :i*1 m9utely consid]$1 is het]og5e\s2 & by us+ ! blocks entire in/ead ( pulv]iz$ or granulat$1 ! /ate ( aggregation ( its m9]als 0 includ$ z an elem5t ( ! specific gravity ( ! rock4 ,x w be obs]v$ t ! range1 #b4ed to #b4ff1 is v small4 ,table ( ,specific ,gravities ( ,tra*ytes ( ! ,h5ry ,m\nta9s4 ,locality4 ,specific gravity4 ,ea/ flank ( ,m\nt ,p5nell2 %eet #b4ff ,m>v9e ,laccolite2 nor? base ( ,m\nt ,ell5 #b4fe ,peale ,laccolite2 ea/ flank ( ,m\nt ,ell5 #b4fd ,dike on ,m\nt ,ellswor? #b4fd ,s\? base ( ,m\nt ,hill]s2 %eet #b4fc ,%eet "u ! ,peale ,laccolite #b4fb ,scrope ,laccolite2 s\!a/ base ( ,m\nt ,ell5 #b4fj ,b[l ,creek ,laccolite2 nor!a/ base ( ,m\nt ,ell5 #b4eh ,nor? spur ( ,m\nt ,p5nell2 dike #b4eh ,s5t9el ,laccolite2 nor? base ( ,m\nt ,p5nell #b4ed -------- ,mean #b4fa ,specim5s to repres5t ! /ratigraphic s]ies 7 select$ at ! m>g9s ( ! di/urb$ region s f> z possible1 to avoid ! effect ( metamorphism4 ,b z x 0 n practicable to elim9ate ?is s\rce ( error 9 e case1 ! d5sities ( highly metamorphic specim5s 7 also measur$ = ! purpose ( indicat+ ! effect ( ! metamorphism4 ,9 ord] to re/ore s f> z practicable ! condition ( ! rocks at ! "t ( ! lavic intrusion1 ! specim5s 7 saturat$ ) wat]1 & 9 ?is condition 7 weigh$ 9 air z well z 9 wat]4 ,! results = ! por\s s&/ones are f "o-sev5? to "o-f\rte5? l[] ?an w\ld h be5 obta9$ by ! usual me?od4 ,h& specim5s 7 us$ z be=e4 ,table ( ,specific ,gravities ( ,s$im5t>y ,rocks ( ! ,h5ry ,m\nta9s4 ,rock4 ,condition4 ,specific gravity4 #a,masuk ,s&/one ,unalt]$ #b4af #b;,blue ,gate ,s&/one ,unalt]$ #b4ad #c;,blue ,gate ,%ale ,unalt]$ #b4de #d;,flam+ ,gorge ,%ale ,unalt]$ #b4db #e;,gray ,cliff ,s&/one ,unalt]$ #b4ac #f,v]milion ,cliff ,s&/one1 7top7 ,unalt]$ 787 #b4ba #g,v]milion ,cliff ,s&/one1 7base7,unalt]$ 787 #b4bh #h;,h5ry's ,=k ,conglom]ate ,slightly alt]$ #b4be #i,v]milion ,cliff ,s&/one1 ,alt]$ #b4dh #aj;,aubrey ,s&/one ,alt]$ #b4ee #aa,tununk ,%ale ,alt]$ #b4fj ,x is pla9 f ?is table t ! effect ( ! metamorphism 0 to increase ! d5sities ( ! rocks affect$4 ,! ,blue ,gate %ale :i* unalt]$ gave #b4de1 is li?ologically id5tical ) ! ,tununk %ale :i* alt]$ gave #b4fi4 ,! ,aubrey s&/one _c be obs]v$ unalt]$ 9 ! vic9ity ( ! m\nta9s1 b at a di/ance ( =ty miles :]e x aga9 comes to ! surface x closely resembles ! ,gray ,cliff s&/one4 ,if x has ! same normal weight z ! latt]1 !n x has increas$ f #b4ac to #b4ee4 ,! specim5s ( ! ,v]milion ,cliff s&/one numb]$ #f & #g 7 n visibly *ang$1 b z !y 7 obta9$ f ! flank ( ! ,holmes ar* !re 0 reason to suspect t _! condition 0 n normal1 & ! det]m9$ d5sities /r5g!n ! suspicion4 ,judg$ by o!r localities1 ! normal d5sity ( ! ,v]milion ,cliff rock is n f> f t ( ! ,gray ,cliff rock1 namely #b4ac2 & x is easy to believe t ! upp] portion ( ! b$ :]e x lay on ! side ( ! ,holmes ar* 0 *ang$ 9 d5sity to #b4ba2 :ile ! l[] portion ly+ ne>] ! laccolite 0 *ang$ to #b4bh2 & :ile ! same b$ among ! ,ellswor? dikes acquir$ ! d5sity ( #b4dh4 ,tak+ into acc\nt bo? ^! consid]ations & c]ta9 o!rs :i* ne$ n be enum]at$1 ,i d]ive ! foll[+3 ,table ( ! ,specific ,gravities ( ! ,h5ry ,m\nta9 ,s$im5t>y s]ies 9 ! ,ord] ( ,sup]position4 ,b$4 ,specific gravity4 ,masuk ,s&/one #b4af ,masuk ,%ale e/imat$ #b4dj ,blue ,gate ,s&/one #b4ad ,blue ,gate ,%ale #b4de ,tununk ,s&/one #b4ae ,tununk ,%ale e/imat$ #b4de ,h5ry's ,=k ,conglom]ate #b4be ,flam+ ,gorge ,%ale #b4db ,gray ,cliff ,s&/one #b4ac ,v]milion ,cliff ,s&/one e/imat$ #b4ae ,%9>ump ,%ale e/imat$ #b4dj ,aubrey ,s&/one e/imat$ #b4ae ,tak+ into acc\nt ! ?icknesses ( ! sev]al b$s enum]at$ 9 ! =ego+ table1 x is easy to obta9 ! mean specific gravity ( all :i* lie above a giv5 horizon2 & by mak+ ?is det]m9ation = ! horizon ( ! base ( ea* ( ! indicat$ b$s1 ! foll[+ table has be5 d]iv$4 ,! figures are bas$ on ! assumption t ! rock s]ies includ$ no?+ above ! ,masuk s&/one4 ,if 7z is probable7 !re 7 ,t]ti>y b$s also1 ! e/imates are too l[1 = ! ,t]ti>ies ( ! vic9ity are calc>e\s & argillace\s & consequ5tly d5se4 ,table %[+ ! ,mean ,specific ,gravities ( ! ,rock ,s]ies conta9$ betwe5 c]ta9 horizons & ! summit ( ! ,masuk ,s&/one4 ,horizons4 ,specific gravities4 ,base ( ,masuk ,s&/one #b4af ,base ( ,masuk ,%ale #b4bh ,base ( ,blue ,gate ,s&/one #b4bc ,base ( ,blue ,gate ,%ale #b4cb ,base ( ,tununk ,s&/one #b4ca ,base ( ,tununk ,%ale #b4cd ,base ( ,h5ry's ,=k ,conglom]ate #b4cc ,base ( ,flam+ ,gorge ,%ale #b4cf ,base ( ,gray ,cliff ,s&/one #b4cc ,base ( ,v]milion ,cliff ,s&/one #b4cb ,base ( ,%9>ump ,%ale #b4cc ,f ?is x appe>s t ! laccolites ( ! upp] zone1 ext5d+ f ! l[] "p ( ! ,blue ,gate ,%ale to ! upp] "p ( ! ,flam+ ,gorge ,%ale1 bore loads ( :i* ! mean d5sities 7 f #b4ca to #b4cd1 & t laccolites ( ! l[] zone1 :i* has its upp] limit 9 ! ,%9>ump ,%ale1 bore loads ( :i* ! mean d5sities 7 #b4cb & upw>d4 ,if ! positions ( ! laccolites 7 det]m9$ purely by ! law ( hydro/atic equilibrium1 !n ^! figures def9e ! d5sity ( ! molt5 tra*yte1 & %[ t its contraction 9 cool+--f ! d5sity #b4cd to ! d5sity #b4fa--0 ab\t "o-t5? ( its volume4 ,,! ,,/ret*+ ,,( ,,/rata4 ,x has be5 ! op9ion1 n only ( ! writ] b ( o!r /ud5ts ( ! displacem5ts ( ! ,we/1 t ! ord9>y s$im5t>y rocks1 s&/one1 lime/one1 & %ale1 are frequ5tly elongat$ z well z compress$ by orographic movem5ts1 & t ?is takes place )\t any appreciable metamorphism2 b x is difficult to f9d opportunity = ! demon/ration ( ! ph5om5on by measurem5t4 ,:5 a fold is made 9 a level /ratum1 ei!r ( two ?+s may take place2 ! portions ( ! /ratum :i* rema9 level at ! sides may approa* ea* o!r2 or ! /ratum may be /ret*$4 ,b :5 a circul> portion ( a cont9u\s level /ratum is lift$ into a quaquav]sal ar* 7z illu/rat$ 9 ,figure #aa71 an approa* ( ! level portions is out ( ! "q1 & !re mu/ be a /ret*+ or a fracture4 ,( ! unfractur$ quaquav]sals ( ! ,h5ry ,m\nta9s !re is "o :i* comb9es all ! ess5tials ( a crucial case4 ,! ,less] ,holmes ar* is ne>ly isolat$2 on ?ree sides x rises f ! undi/urb$ plateau1 & on ! f\r? x jo9s a simil> b fractur$ dome4 ,! major "p ( its surface is compos$ ( "o b$1 ! ,v]milion ,cliff s&/one1 brok5 only by erosion4 ,comp>+ ! l5g? ( ?is b$ 9 its pres5t curv$ =m ) ! space x mu/ h occupi$ be=e x 0 upb5t1 ,i f9d t 9 a di/ance ( ?ree miles x has be5 elongat$ ?ree hundr$ feet4 ,moreov] !re is e reason to suppose t ! elongation 0 produc$ quickly1 or at lea/ by a succession ( f9ite r ?an inf9itesimal increm5ts2 = ! lift+ ( ! ar* 0 caus$ by ! intrusion ( a laccolite1 & ?\gh ! latt] may h be5 built by ! addition ( _m sep>ate lava fl[s1 x c\ld n h ris5 ) secul> & cont9u\s sl[ness4 ,! molt5 tra*yte1 ris+ ?r\gh a passage & into a res]voir t 7 comp>atively cool1 w\ld h clogg$ itself by congelation _h x n mov$ ) a c]ta9 degree ( rapidity4 ,illu/ration3 ,,fig4 #eb4--;,cross-section ( an uplift$ dome4 ,! dott$ l9es %[ ! orig9al position ( a b$2 ! curv$ l9es1 ! impos$4 ,! condition :i* r5d]$ possible ! elongation & ! sudd5 b5d+ ( s rigid & brittle a rock z a massive s&/one1 0 pressure4 ,at ! "t ( ! uplift ! s&/one 0 buri$ by o!r s$im5ts to a dep? ( f five ?\s& to eight ?\s& feet1 & su/a9$ a pressure ( f five ?\s& to eight ?\s& p\nds to ! squ>e in*4 ,n[ ! exp]im5ts :i* h be5 made ^u build+ /ones %[ t ! weight requir$ to cru% simil> s&/ones 9 a dry condition1 is ?ree ?\s& to five ?\s& p\nds to ! in*2 & x is a fact famili> to qu>rym5 t s&/one & lime/one :i* are qu>ri$ bel[ ! wat] level are bo? s(t] & weak] :ile !y are /ill saturat$ ?an !y are aft] dry+4 ,s we may fairly assume t ! ,v]milion s&/one 0 load$ at ! "t ( its displacem5t ) a cru%+ weight4 ,no "p c\ld yield to ! pressure :ile x 0 su/a9$ by ! surr\nd+ p>ts2 b e "p 0 ready to yield :5ev] its support 0 )drawn4 ,x 0 9 a quasi-pla/ic /ate & abhorr$ a fissure z /rongly z 8nature abhors a vacuum01 & = ! same reason4 ,a fissure c\ld n be op5$ 9 x unless x 0 co9cid5tly fill$ by some?+--su* z lava--:i* w\ld resi/ ! t5d5cy ( its walls to fl[ toge!r4 ,! =mation ( a gap+ fissure be+ ?us prev5t$1 & ! uplift+ ( ! dome requir+ t ! s&/one %\ld cov] a great] area1 an ext5sion ( ! b$ 0 ! necess>y result4 ,x 0 n /ret*$ into ! dome =m2 x 0 compress$4 ,! effici5t =ce did n act 9 ! direction ( ! ext5sion1 b v]tically4 ,! s&/one 0 pu%$1 n pull$4 ,if ?is explanation is ! true "o1 !n x is true 9 g5]al t j z = ea* rock !re is a cru%+ weight1 s !re is = ea* rock a c]ta9 dep? at :i* x _c be fissur$ & c be flex$4 ,! s(t] rocks are pla/ic at small dep?s4 ,fire-clays "u coal seams exude1 or 8creep01 ev5 ) ! pressure ( a few feet ( sup]9cumb5t /rata4 ,spr+s ( wat] rise at ! outcropp+s ( s(t /rata because ! jo9ts :i* int]sect mo/ rocks ne> ! surface ( ! gr\nd _c cross ^? :i* are s(t en\gh to yield "u ! pressure incid5t to !m4 ,if ! s(t b$s 7 jo9t$ !y w\ld n int]cept p]colat+ wat]1 & ! di/ribution ( spr+s w\ld be v diff]5t4 ,! ph5om5a ( fissure ve9s are 9 po9t4 ,:5 a fault takes place1 & "o rock mass is slidd5 pa/ ano!r to :i* x _h be5 jo9$ x is usually ! case t ! oppos$ surfaces no long] fit toge!r z !y did be=e ! movem5t1 & int]spaces are left4 ,^! become fill$1 at fir/ by wat]1 & aft]w>d by m9]als deposit$ f ! wat]1 & ! m9]al masses ?us deposit$ are call$ fissure ve9s4 ,b ! pres]vation ( ! int]spaces dep5ds ^u ! rigidity ( ! rocks :i* inclose !m2 & x frequ5tly happ5s t :]e a sy/em ( rocks is trav]s$ by a fault1 ! h>d] w keep some:at ap>t & ma9ta9 a fissure1 :ile ! s(t] w be cru%$ toge!r )\t an int]space4 ,if ! m9]al ve9 :i* =ms 9 su* a fissure is aft]w>d explor$ 9 m9+1 x is f\nd to be traceable & cont9u\s s f> z x is wall$ by ! h>d rock ^u bo? sides1 b :5 ! h>d is replac$ by ! s(t 9 "o or bo? walls1 ! ve9 is ei!r r$uc$ to a m]e fillet or disappe>s completely4 ,if ! fault ext5ds to a great dep?1 x w f9ally rea* a region :]e ! h>de/ rocks :i* x sep>ates are co]c$ by s great a pressure t !y _c hold !mselves asund]1 b are =c$ toge!r be=e ! fissure c be fill$ by m9]al deposits4 ,?us !re is a def9able inf]ior limit to ! region ( ve9 =mation2 & ev5 :ile x is impossible to assign a d[nw>d limit to ! fault :i* made place = a ve91 x may be possible to assign a d[nw>d limit to ! ve9 itself4 ,accordant ) ?is view is ! abs5ce ( fissure ve9s f ! ,h5ry ,m\nta9s4 ,displacem5t & !rmal di/urbance are usually reg>d$ z ! conditions ( m9]al conc5tration2 & "h 7 displacem5t & lavic intrusion co9cid5t 9 "t & place4 ,! heat :i* metamorphos$ great bodies ( %ale & s&/one 0 surely compet5t to excite ! curr5ts & reactions :i* conc5trate m9]als 9 ve9s2 b ! displacem5ts did n op5 fissures1 & ! heat$ wat] c\ld circulate only ?r\gh ! pores ( rocks4 ,fissure ve9s 7 impossible1 & ! sluggi% curr5ts :i* 7 eng5d]$ 9 cont9u\s rock masses did n effect a great *ange 9 ! di/ribution ( m9]als4 ,,! ,,conditions ,,( ,,rock ,,flexure4 ,!re are ?ree kn[n conditions "u :i* /rata ( ! mo/ rigid "* may be b5t )\t fracture2 or 9 o!r words !re are ?ree ways 9 :i* flexibility may be ei!r induc$ or demon/rat$4 ,at ord9>y temp]atures & at ! surface ( ! e>? a h>d /ratum _c be quickly flex$4 ,b no rigidity is absolute1 & a con/ant /ra91 ev5 ?\gh slight1 w 9 ! c\rse ( "t produce de=mation4 ,! same result may be accompli%$ quickly if ! temp]ature ( ! /ratum is rais$ to ne> ! po9t ( fusion4 ,or x may be accompli%$ ) nei!r great heat nor great "t if only ! /ratum is s deeply buri$ t ! weight ( its cov] keeps x f op5+ fissures4 ,! ?ree conditions ( flexure are "t1 heat1 & pressure2 & :5ev] ! circum/ances ( a displacem5t include none ( ^!1 ! rocks are brok54 ,a f\r? condition1 moi/ure1 is ( great importance z an accessory1 b alone x is n suffici5t to prev5t fracture4 ,! :ole body ( /rata ( ! e>?'s cru/ is saturat$ ) wat]1 except a v little at ! surface1 & all rock movem5ts are !reby facilitat$4 ,if ! /rata 7 dry1 _! flexure w\ld require mu* m "t1 or heat1 or pressure1 ?an is necess>y 9 _! moi/ condition4 ,(t5 ! ?ree conditions complem5t ea* o!r2 b n always4 ,we may say1 ! great] ! load :i* /rata be> ! m rapidly !y c be flex$2 & conv]sely1 ! m sl[ly /rata are displac$ ! less ! pressure necess>y to prev5t fracture4 ,& we may say1 ! high] ! temp]ature ( /rata ! m rapidly !y c be flex$2 & conv]sely1 ! m sl[ly /rata are displac$ ! l[] ! temp]ature necess>y to prev5t fracture4 ,= bo? ^! /atem5ts we f9d support 9 a great s]ies ( homologies4 ,b we _c affirm t su* a reciprocal relation exi/s betwe5 ! effects ( heat & pressure4 ,= all rocks are believ$ to exp& by heat+1 up to ! po9t ( fusion2 & x is a recogniz$ physical law t 9 all bodies :i* heat exp&s1 ! effects ( heat are oppos$ by pressure4 ,h5ce we _c say1 8,! heavi] ! load :i* /rata be> ! l[] ! temp]ature necess>y to prev5t fracture01 nor c we say1 8,! high] ! temp]ature ( /rata ! less ! load necess>y to prev5t fracture04 ,,! ,,"q ,,( ,,cov] ,,& ,,! ,,"q ,,( ,,age4 ,x is evid5t t ! laccolites ( ! ,h5ry ,m\nta9s 7 =m$ b5ea? ! surface ( ! e>?'s cru/1 b at :at dep? is n s evid5t4 ,! problem is involv$ ) ! problem ( ! age ( ! laccolites1 & ! two are connect$ ) ! g5]al hi/ory ( ! ,bas9 ( ! ,colorado4 ,nei!r problem c be call$1 = ! pres5t at lea/1 det]m9ate1 b x is possible to n>r[ !m d[n by ! indication ( limits :i* _! solutions w n exce$4 ,s mu* ( ! ,colorado ,plateau region z lies )9 ,colorado & ,utah 0 cov]$ dur+ a geological age :i* x is conv5i5t to call ,cretace\s1 by a sea1 ! wat]s ( :i* appe> to h become fre% t[>d ! la/4 ,!n came elevation bo? g5]al & diff]5tial4 ,a great "p ( ! sea b$ became dry l&1 & ! accumulat$ s$im5ts toge!r ) _m :i* und]lay !m 7 b5t into great waves ?\s&s ( feet 9 altitude4 ,! cre/s ( ! waves 7 subject$ to erosion & truncat$4 ,!n came a second subm]g5ce :i* 0 purely lacu/r9e4 ,9 "s way t has n be5 asc]ta9$ a lake bas9 0 =m$1 & ! region receiv$ a new sy/em ( s$im5ts :i* x is conv5i5t to call ,t]ti>y1 & :i* n m]ely fill$ ! tr\ghs betwe5 ! great rock-waves b cov]$ ! truncat$ summits ( ! waves !mselves4 ,!n foll[$ ! desiccation ( ! bas9 by ! cutt+ d[n ( its rim :]e ! wat] ov]fl[$4 ,! ov]fl[+ riv] z x deep5$ its *annel & gradually l[]$ ! lake1 /eadily ext5d$ its upp] c\rse to foll[ ! rec$+ %ore2 & f9ally :5 ! bas9 0 completely dra9$ ! riv] rema9$1 its *annel lead+ ?r\gh :at _h be5 ! deepe/ "p ( ! ,t]ti>y sea4 ,t riv] is ! ,colorado4 ,z portions ( ! lake bottom 7 successively dra9$ !y began at once to be erod$1 & f t "t to ?is !re has be5 progressive degradation4 ,! regions ne>e/ to ! c5tral riv] 7 r$uc$ mo/ rapidly & h be5 completely /ripp$ ( _! ,t]ti>y /rata1 b broad areas ( ! latt] rema9 at ! we/1 & nor?1 & ea/4 7,! read] w und]/& t ?is succ9ct hi/ory is %orn = ! sake ( cle>ness ( all details & qualifications4 ,!re h be5 complicat+ eruptions & displacem5ts or oscillations at e /age1 & if ! full /ory c\ld be told1 x w\ld n be by a s+le p>agraph nor by a s+le *apt]47 ,:5 ! ,cretace\s /rata 7 ?r[n into waves ! site ( ! ,h5ry ,m\nta9s rema9$ 9 a tr\gh1 & x probably 0 n dri$1 b cont9u$ ! sc5e ( s$im5tation :ile ! cre/s ( ! surr\nd+ rock-waves 7 worn away4 ,c]ta9ly x 0 n greatly erod$ at t "t2 & :5 ! ,t]ti>y lake b$s 7 ?r[n d[n x 0 favorably dispos$ = a heavy deposit4 ,x is n extravagant to assume t f\r ?\s& feet ( lake b$s re/$ on ! ,masuk s&/one at ! beg9n+ ( ! f9al desiccation4 ,9 brief !re may be di/+ui%$-- #a4 ,! deposition ( ! ,cretace\s4 #b4 ,! fold+ & erosion ( ! ,cretace\s4 #c4 ,! deposition ( ! ,t]ti>y4 #d4 ,! desiccation ( ! ,t]ti>y lake bas94 #e4 ,! erosion :i* is /ill 9 progress4 ,x is evid5t t ! laccolites 7 n =m$ until ! ,cretace\s /rata _h be5 deposit$2 = _! uplifts h b5t & tilt$ all ,cretace\s rocks up to & includ+ ! ,masuk s&/one4 ,!y 7 n =m$ at any late /age ( ! f9al erosion1 = !y cons]ve tables along _! we/]n base1 :i* b = _! %elt] w\ld long s9ce h disappe>$4 ,f ! end ( ! ,cretace\s p]iod to ! end ( ! desiccation ( ! bas9 !re is no ev5t ) :i* ! laccolites c be directly connect$4 ,!re is h[ev] a consid]ation :i* 9 an indirect way sanctions ! op9ion t ! epo* ( igne\s activity 0 aft] ! deposition ( ! ,t]ti>ies & be=e _! erosion4 ,! ,masuk ,s&/one is at once ! summit ( ! ,cretace\s & ! highe/ b$ 9 ! pres5t ,h5ry ,m\nta9 section4 ,if x 7 re/or$ ov] ! entire range1 ! laccolites ( ! upp] zone w\ld h on ! av]age ?irty-five hundr$ feet ( cov]1 & ^? ( ! l[] zone ne>ly sev5 ?\s& feet4 ,?is 0 ! dep? ( _! orig9al cov]1 if !y 7 intrud$ at ! close ( ! ,cretace\s age4 ,dur+ ! epo* ( ,t]ti>y deposition & ! subsequ5t epo* ( erosion1 ! cov] fir/ increas$ 9 dep? & !n dim9i%$1 hav+ its maximum at ! end ( ! ,t]ti>y deposition4 ,if x c be %[n t ! orig9al cov] ( ! upp] laccolites exce$$ ?irty-five hundr$ feet1 ! "q ( age w be r$uc$ to comp>atively n>r[ limits4 ,9 ord] to discuss ! problem ( ! orig9al dep? ( cov] x w be necess>y to consid] ano!r matt]1 ( :i* ! connection w n at fir/ be app>5t4 ,! size ( laccolites4--,x is a matt] wor?y ( note t no laccolite ( inconsid]able ext5t is kn[n 9 ! ,h5ry ,m\nta9s4 ,! smalle/ :i* has be5 measur$ is m ?an half a mile 9 diamet]1 & ! l>ge/ ab\t f\r miles4 ,! ph5om5on does n occur ^u a small scale1 b has a def9ite inf]ior limit to its magnitude4 ,let u seek an explanation ( ?is limit4 ,! dome ( /rata :i* cov]s a laccolite has = its pr(ile on e side a monocl9al curve4 ,9 ,figure #eb ! section ( a dome exhibits a monocl9al flexure 9 s a & aga9 9 s b2 & ! dome be+ approximately circul> ?is flexure completely surr\nds x4 ,we may ev5 describe or def9e ! dome z a monocl9al flexure encircl+ a po9t or a space4 ,consid]+ n[ t :5 ! laccolite 0 inject$ ! ov]ly+ /rata 7 lift$1 & t ?is di/urbance 0 communicat$ upw>d to ! !n exi/+ surface ( ! e>?1 we may prop]ly speak ( ! lift$ body ( rock z a cyl9d] b\nd$ on e side by a monocl9al flexure4 ,fur!rmore1 s9ce ! monocl9al flexure is ! /ructural equival5t ( ! fault#d1 we may r5d] our conception /ill simpl] by replac+ 9 imag9ation ! encircl+ flexure by an encircl+ fault1 & pictur+ to ourselves ! uplift$ rock mass z a simple cyl9d]1 p]fectly divid$ f ! surr\nd+ rock & slidd5 upw>d s z to project above ! surface an am\nt equal to ! dep? ( ! laccolite4 ,footnote #d3 ,exploration ( ! ,colorado1 pp4 #ahb-ahd4 ,explorations ,we/ ( ! #ajj? ,m]idian1 ,vol4 ,,iii1 p4 #dh4 ,am]ican ,j\rnal ( ,sci5ce1 ,july1 #ahgf1 p4 #ba4 ,x is possible to give a ma!matical expression to ! =ce necess>y to produce su* a circul> fault4 ,disreg>d+ li?ologic diff]5ces1 ! resi/ance to ! rupture is measur$ by ! area ( ! fault$ surface1 or :at is ! same ?+1 ! area ( ! convex surface ( ! cyl9d]4 ,repres5t+ ! resi/ance to be ov]come by r1 ! height ( ! cyl9d] 7equal to ! dep? ( ! cov] ( ! laccolite7 by d1 & its circumf]5ce by c1 we h r dc,c 7#a71 9 :i* ,c is a function ( ! cohesion ( ! mat]ial & is con/ant4 ,! =ce by :i* ! cyl9d] is lift$ & by :i* x is assum$ t ! fault+ is accompli%$1 is communicat$ ?r\gh ! molt5 lava ( ! =m+ laccolite4 ,be+ ?us communicat$ x is appli$ equally to all p>ts ( ! base ( ! cyl9d]1 & its effici5t total is measur$ by ! area ( t base4 ,a "p ( x is devot$ to lift+ ! weight ( ! cyl9d]1 & ! rema9d] is devot$ to ! mak+ ( ! fault4 ,ea* ( ^! p>ts is proportion$1 l ! :ole1 to ! area ( ! base ( ! cyl9d]1 or to ! area ( ! laccolite4 ,repres5t+ ! portion appli$ to ! fault+ by f1 & ! area ( ! laccolite by a1 we h f a ,cl 9 :i* ,cl1 is a con/ant1 & a function ( ! pressure "u :i* ! lava is inject$4 ,sub/itut+ = a its equival5t1 c f c#b ,cl_/#d & sub/itut+ ,cll = ! con/ant t]m ,cl_/#d f c#b ,cll 7#b7 ,equation #a gives an expression = ! resi/ance :i* cohesion c oppose to ! uplift ( ! cyl9d]4 ,equation #b gives an expression = ! =ce ex]t$ by ! fluid laccolite t[>d ov]com+ ! resi/ance ( cohesion4 ,x is evid5t t = a giv5 value ( d x is possible to assign a value ( ,c s l>ge t f w be great] ?an r1 or s small t f w be less ?an r4 ,t is to say1 at a giv5 dep? b5ea? ! surface a laccolite ( a c]ta9 circumf]5ce w be able to =ce upw>d ! sup]jac5t cyl9d] ( rock1 :ile a laccolite ( a c]ta9 small] circumf]5ce w be unable to lift its cov]4 ,or 9 o!r words1 !re is a limit 9 size b5ea? :i* a laccolite _c be =m$4 ,:5 a lava =c$ upw>d ?r\gh ! /rata rea*es ! level at :i* "u ! law ( hydro/atic equilibrium x mu/ /op1 we may conceive t x exp&s along "s plane ( b$d+ 9 a ?9 %eet1 until its horizontal ext5t becomes s great t x ov]comes ! resi/ance (f]$ by ! rigidity ( its cov]1 & x beg9s to uplift x4 ,! direction ( lea/ resi/ance is n[ upw>d1 & ! res]voir ( lava increases 9 dep? in/ead ( wid?4 ,! area ( a laccolite ?us t5ds to rema9 at its m9imum limit1 & may be reg>d$ z m or less p]fectly an index ( t limit4 ,9 equations #a & #b1 if f r1 !n c#b ,cll d c ,c or c d7,c_/,cll7 7#c7 ,t is to say1 if ! =ce ex]t$ by ! lava is b>ely suffici5t to ov]come ! resi/ance to uplift1 !n ! circumf]5ce ( ! laccolite is proportional to ! dep? ( its cov]4 ,or 9 o!r words1 ! 7l9e>7 size ( a laccolite is proportion$ to its dep? b5ea? ! surface4 ,if n[ we return f ! fault$ cyl9d] :i* = simplicity's sake has be5 hypo!cat$1 to ! actual cyl9d] :i* is surr\nd$ by a flexure in/ead ( a fault1 c we reta9 our conclusions8 ,) c]ta9 modifications ,i ?9k we c4 ,! /ra9s develop$ 9 de=mation by flexure are less easy ( analysis ?an ^? :i* arise 9 fault+1 b ! two cases are 9 "s degree analog\s4 ,! expression 7equation #b7 = ! =ce :i* ! lava applies to de=mation is unaffect$ by ! mann] 9 :i* ! /rata yield4 ,! expression 7equation #a7 = ! resi/ance to de=mation by fault+ involves two t]ms1 ea* 9 its simple/ relations2 ! resi/ance v>ies directly z ! circumf]5ce ( ! laccolite1 & x v>ies directly z ! dep? ( ! cov]4 ,9 ord] to pass to an expression = ! resi/ance to de=mation by flexure1 only "o ( ^! t]ms ne$ be *ang$4 ,! resi/ance be>s ! same relation to ! circumf]5ce ( ! laccolite2 b x is no long] simply proportional to ! dep? ( ! cov]4 ,x v>ies m rapidly4 ,if ! cov]+ /rata 7 all ( a giv5 ?ickness1 7 id5tical 9 k9d1 & 7 free to slide ^u ea* o!r )\t friction1 _! total resi/ance to de=mation w\ld be equal to ! resi/ance ( a s+le /ratum multipli$ by ! numb] ( /rata4 ,b s9ce !y are n free to slide "o ^u ano!r1 !y su/a9 ea* o!r1 & ! resi/ance (f]$ by ! comb9ation is great] ?an t product4 ,i am l$ by ! analogy ( alli$ problems 9 me*anics to assume t ! resi/ance ( ! body ( /rata v>ies ) "s p[] ( its dep?1 b ,i am unable to say :at p[]4 ,s f> z ,i am aw>e1 nei!r ma!matical analysis nor exp]im5tation has be5 direct$ to ! problem 9 "q4 ,accord+ to ,rank9e 8! resi/ances ( flexure ( simil> cross-sections ( ela/ic beams are z _! bread?s & z ! squ>es ( _! dep?s0 78,appli$ ,me*anics01 page #caf71 & x is possible t ! same law applies to ! resi/ances :i* cont9u\s /rata oppose to ! uplifts ( domes4 ,b x appe>s m probable t ! great] complexity ( ! /ra9s develop$ 9 ! =mation ( domes causes ! dep? to ent] into ! =mula ) a high] p[] ?an ! second4 ,on ! o!r h&1 "s all[ance %\ld be made = ! fact t ! ela/icity ( ! resi/+ /rata is imp]fect4 ,if we call ! p[] ) :i* ! dep? ent]s ! =mula a1 equation #a becomes r da c ,clll 7#d74 & equation #c becomes c da 7,clll_/,cll7 7#e74 ,x is probable t ! true value ( a is n less ?an #b1 nor m ?an #c4 ,int]pret+ ^! equations 9 ! same mann] z ^? apply+ to de=mation by fault+1 we rea* ! foll[+ conclusions3 #a/4 ,at a giv5 dep? b5ea? ! surface1 lava inject$ "u a giv5 pressure _c =m a laccolite ( less ?an a c]ta9 area4 ,?is may be call$ its limital area4 #b;d4 ,! pressure ( injection rema9+ con/ant1 ! limital area ( a laccolite is a direct function ( its dep? b5ea? ! surface4 ,! limital area is great] :5 ! dep? is great]1 & less :5 ! dep? is less4 #c;d4 ,a laccolite ( small volume w n exce$ ! limital area1 b w gr[ by lift+ its cov]4 ,if h[ev] ! volume ( intrud$ lava be great1 its own weight becomes a factor 9 ! equilibrium ( =ces & modifies ! di/ribution ( ! pressures4 ,z ! rock bubble rises1 ! weight ( ! conta9$ fluid is progressively subtract$ f ! pressure aga9/ its top1 & ?is proce$s until ! upw>d & lat]al pressures become proportional to ! resi/ances :i* sev]ally oppose !m4 ,fur!r expansion is !n bo? upw>d & outw>d4 #d?4 ,!re is a limit to upw>d expansion1 dep5d5t on ! fact t ! pressure due to ! comb9$ weight ( ! laccolite & cov] _c exce$ ! pressure ( ! intrusive lava4 ,reg>d+ ! intrusive pressure z con/ant1 x is divisible into ?ree p>ts1 ( :i* "o su/a9s ! weight ( ! cov]1 also con/ant2 ano!r su/a9s ! weight ( ! fluid laccolite1 & is measur$ by its ?ickness or dep?2 & ! ?ird produces de=mation4 ,:5 ! sum ( ! weights ( ! cov] & laccolite equals ! total pressure ( ! intrusive lava1 uplift ceases1 & ! maximum dep? or ?ickness is atta9$4 ,we may call ?is ! limital ?ickness4 ,) reg>d to simple laccolites ! limit is absolute1 b x applies only to ! di/9ct lay]s ( ^? :i* are composite2 = a composite laccolite1 built by successive intrusions at wide int]vals ( "t1 may be reliev$ ( "p ( its load by ! erosion ( ! m\nd :i* its expansion causes at ! surface ( ! l&4 ,a laccolite =m$ b5ea? ! bottom ( a sea has a great] limital ?ickness ?an "o =m$ b5ea? a l& surface2 = ! sup]jac5t wat] be+ displac$ & ?ru/ aside1 is to t ext5t subtract$ f ! load to be lift$4 #e?4 ,! laccolite 9 its =mation is con/antly solv+ a problem ( 8lea/ =ce01 & its =m is ! result4 ,bel[1 above1 & on all sides its expansion is resi/$1 & :]e ! resi/ance is greate/ its cont\r is lea/ convex4 ,! floor ( its *amb] is unyield+1 & ! bottom ( ! laccolite is flat4 ,! ro( & walls alike yield reluctantly to ! pressure1 b ! weight ( ! lava dim9i%es its pressure on ! ro(4 ,h5ce ! top ( ! laccolite becomes broadly convex1 & its edges acutely4 ,local accid5ts except$1 ! walls oppose an equal resi/ance on e side2 & ! base ( ! laccolite is r5d]$ circul>4 ,! second ( ! conclusions enunciat$ above is susceptible ( te/ by obs]vation4 ,by select+ ^? laccolites ( :i* ! dim5sions are kn[n ) ! be/ degree ( approximation1 ! foll[+ table has be5 =m$3 ,=mations4 ,titles ( ,laccolites4,diamet]s,means4 9 miles4 ,upp] ,zone ,blue ,gate ,%ale ,s5t9el 4#g 4#ga4b ,tununk ,%ale ,geikie 4#ha4b ,a 4#i ,m>v9e #a4j ,jukes #a4d ,peale #a4h ,flam+ ,gorge ,%ale,/ew>d #a4ja4d ,b #a4a ,newb]ry #a4h ,c #a4i ,l[] ,zone ,dana #b4j #b4f ,great] ,holmes #b4a ,less] ,holmes #b4a ,ellswor? #b4c ,pulpit #b4c ,maze #b4h ,cresc5t #c4f ,hill]s #c4i ,!re is no laccolite ( ! upp] zone s l>ge z ! smalle/ 9 ! l[] zone2 & ! mean diamet] ( ^? 9 ! l[] zone is d\ble ! mean ( ^? 9 ! upp]4 ,! measurem5ts d n give ! diamet]s ( limital areas1 b x is presumable t ! actual areas be> sub/antially ! same relation to ! limital 9 ! two zones4 ,if we select ! smalle/ laccolites 9 ea* gr\p z ^? mo/ likely to express ! limital areas1 ! result is practically ! same4 ,=mations4 ,diamet]s4 ,means4 ,upp] ,zone ,tununk ,%ale 4#h 4#i #a4j 4#i #a4j ,flam+ ,gorge ,%ale #a4ja4je #a4a ,l[] ,zone #b4j #b4a #b4a #b4a ,! mean = ! l[] zone is /ill d\ble ! mean = ! upp]4 ,! confirmation ( ! conclusion is z ne>ly p]fect z c\ld h be5 anticipat$4 ,!re is no room to d\bt t a relation exi/s betwe5 ! diamet]s ( laccolites & ! dep?s ( _! intrusion4 ,hav+ det]m9$ by obs]vation ! mean size ( ! laccolites 9 ! upp] & l[] zones1 z well z ! int]val :i* sep>ates ! two zones1 & kn[+ approximately ! law :i* b9ds ! size ( ! laccolite to its dep? ( intrusion1 we c compute ! dep? ( intrusion ( ea* zone4 ,our result w d\btless h a l>ge probable error1 b x w n be entirely )\t value4 ,let x repres5t ! ?ickness 9 feet ( ! orig9al cov] ( ! laccolites ( ! upp] zone2 & x #ccjj ! ?ickness ( ! cov] ( ! laccolites ( ! l[] zone4 ,! mean circumf]5ce 9 feet ( ! upp] laccolites is #a4b #ebhj #fccf 4 ,! mean circumf]5ce ( ! l[] laccolites is #b4f #ebhj #acgbh 4 ,sub/itut+ ^! values 9 equation #e1 we obta9 #fccf xa7,clll_/,cll7 & #acgbh 7x #ccjj7;a7,clll_/,cll7 ,divid+ ! second equation by ! fir/ & r$uc+1 #ccjj x #ccjj_/7 #a7 7#f74 ,to obta9 a m9imum result1 assume a #b2 !n x #ccjj_/7 #a7 #gjjj feet1 & x #ccjj #ajcjj feet4 ,! summit ( ! ,masuk s&/one is #c1ejj feet above ! mean level ( ! upp] laccolites2 subtract+ ?is f ! value ( x gives #c1ejj feet z ! dep? ( ,t]ti>y /rata :i* ov]lay ! ,masuk b$s dur+ ! epo* ( laccolitic intrusion4 ,to obta9 a maximum result1 assume a #c2 !n x #ccjj_/7 #a7 #aabjj feet1 x #ccjj #adejj feet1 & ! result = ! dep? ( ! ,t]ti>y /rata is #g1gjj feet4 ,i am f> f atta*+ great weight to ?is speculation 9 reg>d to ! orig9al dep?s ( ! laccolite cov]s4 ,x is always haz>d\s to attempt ! quantitative discussion ( geological problems1 = ! reason t ! conditions are apt to be bo? complex & imp]fectly kn[n2 & 9 ?is case an unc]ta9ty atta*es to ! law ( relation1 z well z to ! quantities to :i* x is appli$4 ,nev]!less aft] mak+ e all[ance !re rema9s a presumption t ! cov] ( ! laccolites includ$ "s ?\s&s ( feet ( ,t]ti>y s$im5ts4 ,:at evid5ce we h !n1 indicates t ! epo* ( laccolitic intrusion 0 aft] ! accumulation ( deep ,t]ti>y deposits & be=e ! subsequ5t degradation _h made great progress--t x 0 at or ne> ! close ( ! epo* ( local ,t]ti>y s$im5tation4 ,if ! read] w\ld realize ! relation betwe5 ! erod$ mat]ial & ! surviv+ m\nta9s1 let him turn to ! ,frontispiece4 ,a p]spective view is !re giv5 ( a tract t5 miles squ>e1 ) ,m\nt ,ellswor? 9 ! c5t]4 ,x is repres5t$ z cut out f all surr\nd+s by v]tical planes :i* desc5d to ! level ( ! ocean4 ,! s\!rn or ne>] half ( ! block %[s ! pres5t aspect ( ! c\ntry2 ! remote half %[s ! =m x is suppos$ to h _h if ! uplift 0 complet$ be=e ! erosion began1 or :at is ! same ?+1 ! =m x w\ld h1 _h !re be5 no erosion4 ,! diff]5ce betwe5 ! two repres5ts ! total am\nt ( ! mat]ial t has be5 wa%$ away s9ce ! completion ( ! ,t]ti>y s$im5ts4 ,p>tly 9 review1 let u n[ sket* ! ,,hi/ory ,,( ,,! ,,laccolite4 ,:5 lavas =c$ upw>d f l[]-ly+ res]voirs rea* ! zone 9 :i* !re is ! lea/ hydro/atic resi/ance to _! accumulation1 !y cease to rise4 ,if ?is zone is at ! top ( ! e>?'s cru/ !y build volcanoes2 if x is b5ea?1 !y build laccolites4 ,light lavas are m apt to produce volcanoes2 heavy1 laccolites4 ,! porphyritic tra*ytes ( ! ,plateau ,prov9ce produc$ laccolites4 ,! /ation ( ! laccolite be+ decid$1 ! fir/ /ep 9 its =mation is ! intrusion along a p>t+ ( /rata1 ( a ?9 %eet ( lava1 :i* spreads until x has an area adequate1 on ! pr9ciple ( ! hydro/atic press1 to ! de=mation ( ! cov]+ /rata4 ,! spread+ %eet always ext5ds itself 9 ! direction ( lea/ resi/ance1 & if ! resi/ances are equal on all sides1 takes a circul> =m4 ,s soon z ! lava c up>* ! /rata x does s1 & ! %eet becomes a laccolite4 ,) ! cont9u$ addition ( lava ! laccolite gr[s 9 height & wid?1 until f9ally ! supply ( mat]ial or ! propell+ =ce s f> dim9i%es t ! lava clogs by congelation 9 its conduit & ! infl[ /ops4 ,an irruption is !n complete1 & ! progress ( ! laccolite is comp>able ) t ( a volcano at ! end ( its fir/ eruption4 ,dur+ ! irruption & aft] its completion1 !re is an int]*ange ( temp]atures4 ,! laccolite cools & solidifies2 its walls are heat$ & metamorphos$4 ,at ! edges1 :]e ! surface ( ! laccolite is mo/ convex1 ! heat is mo/ rapidly dissipat$1 & its effect 9 metamorphism is lea/4 ,a second irruption may take place ei!r be=e or aft] ! fir/ is solidifi$4 ,x may intrude above or x may intrude b5ea? x2 & obs]vation has n yet di/+ui%$ ! "o case f ! o!r4 ,9 any case x c>ries =w>d ! de=mation ( cov] t 0 begun by ! fir/1 & comb9es ) x 9 su* way t ! comp\nd =m is symmetric1 & is sub/antially ! same t w\ld h be5 produc$ if ! two irruptions 7 comb9$ 9 "o4 ,?us ! laccolite gr[s by successive accretions until at l5g? its cool$ mass1 heavi] & /rong] ?an ! surr\nd+ rocks1 proves a suffici5t ob/acle to intrusion4 ,! next irruption !n avoids x1 op5s a new conduit1 & builds a new laccolite at its side4 ,by successive %ift+s ( ! conduit a gr\p ( laccolites is =m$1 j z by ! %ift+ ( v5ts eruptive cones are gr\p$4 ,ea* laccolite is a subt]ranean volcano4 ,illu/ration3 ,,fig4 #ec4--;,diagram to illu/rate ! relation ( ,dikes & ,%eets to ! ,/ra9s :i* are develop$ 9 ! uplift+ ( laccolitic ar*es4 ,! /rata above ! laccolite are b5t in/ead ( brok51 because _! mat]ial is subject$ to s great a pressure by sup]9cumb5t /rata t x _c hold an op5 fissure & is quasi-pla/ic4 ,b al?\gh quasi-pla/ic x is none ! less solid1 & c be crack$ op5 if ! gap is in/antane\sly fill$1 ! crack+ & ! fill+ be+ "o ev5t4 ,?is happ5s 9 ! imm$iate walls ( ! laccolite1 & !y are inject$ by dikes & %eets ( ! lava4 ,! directions ( ! cracks are normal to ! directions ( ! ext5sive /ra9s 7/ra9s t5d+ to ext5d7 :]e !y occur4 ,f ! top ( ! laccolite dikes run upw>d into ! ro(1 m>k+ horizontal /ra9s 7a a74 ,f ! sides small] v]tical dikes run outw>d1 m>k+ horizontal1 tang5tial /ra9s4 ,& p>allel to ! sides ne> ! base ( ! laccolite1 are num]\s %eets1 m>k+ /ra9s direct$ outw>d & upw>d 7c c74 ,^! la/ especially s]ve to %[ t ! rigidity ( ! /rata is n aboli%$1 al?\gh x is ov]p[]$1 by ! pressure :i* w>ps !m4 ,"h we are br\ght face to face ) a great fact ( dynamic geology :i* ?\gh well kn[n is too (t5 ignor$4 ,! solid cru/ ( ! e>?1 & ! solid e>? if x be solid1 are z pla/ic 9 great masses z wax is 9 small4 ,solidity is n absolute b relative4 ,x is only a l[ grade ( pla/icity4 ,! rigidity or /r5g? ( a body is measur$ by ! squ>e ( its l9e> dim5sions1 :ile its weight is measur$ by ! cube4 ,h5ce ) increase 9 magnitude1 ! weight increases m rapidly ?an ! /r5g?2 & no v l>ge body is /rong en\gh to )/& ! pressure ( its own weight4 ,h[ev] solid x may be1 x mu/ succumb & be flatt5$4 ,:5 we speak ( rock masses :i* are measur$ by feet1 we may reg>d !m z solid2 b :5 we consid] masses :i* are measur$ by miles1 we %\ld reg>d !m z pla/ic4 ,! same pr9ciple is illu/rat$ by ! limital area ( laccolites4 ,a small laccolite _c lift its small cov]1 b a l>ge laccolite c lift its correspond+ly l>ge cov]4 ,! /r5g? or rigidity :i* resi/s de=mation is ov]come by magnitude4 ,laccolites ( ,o!r ,regions4--,9 _m l&s geologi/s h obs]v$ intrusive rocks occurr+ 9 great bodies1 b ,i am n aw>e t su* a sy/em z t ( ! ,h5ry ,m\nta9s has ev] be5 describ$4 ,d\btless all su* bodies are laccolitic1 b ! comb9ation ( conditions :i* ?is field pres5ts c r>ely be repeat$4 ,9 ! fir/ place ! /rata :i* "h conta9 ! laccolites lay level4 ,!y _h suff]$ no displacem5t be=e ! epo* ( irruption1 & !y h suff]$ none s9ce4 ,! laccolitic ph5om5a /& by !mselves1 ) no?+ to m> _! symmetry or complicate _! /udy4 ,9 ! next place ! laccolites are "h assembl$ 9 su* numb] & ) su* v>iety ( size1 =m1 & horizon t !re is little dang] ( mi/ak+ accid5tal features = ess5tial4 ,aga91 ! region hav+ be5 rec5tly elevat$ is ! sc5e ( rapid degradation4 ,wat]ways are deeply corrad$1 slopes are /eep1 & esc>pm5ts ab\nd4 ,& f9ally ! climate is s arid t vegetation is exce$+ly scant4 ,! rocks are = ! mo/ "p b>e & _! exam9ation is unob/ruct$4 ,if ! conditions ( erosion & climate _h be5 unfavorable 9 ! ,h5ry ,m\nta9s1 !y c\ld n h yield$ ! key to ! laccolitic /ructure2 b ! key once f\nd1 x is to be anticipat$ t ! /ructure w be recogniz$ 9 o!r laccolites ( :i* ! exposures are less p]fect4 ,if ! /rata _h exp]i5c$ ant]ior displacem5ts s z to be incl9$1 fold$1 & fault$1 a symmetrical gr[? ( laccolites w\ld h be5 impossible1 & ! m\nta9s w\ld n h yield$ a k ( ! type =m4 ,b ! type =m be+ kn[n1 x is to be anticipat$ t 9 di/urb$ regions ab]rant =ms w be recogniz$ & ref]r$ to ! type4 ,possible ,analogues ( ! ,laccolite4--,all ! ar*es ( ! ,h5ry ,m\nta9s h be5 ascrib$ to laccolites1 :e!r _! nuclei 7 visible or conceal$1 & ! evid5ce ^u :i* ! latt] 7 includ$ appe>s to admit ( no controv]sy4 ,! "q arises :e!r ! great flexures ( ! ,plateau region may n be alli$ 9 /ructure4 ,! volcano hav+ its homologue 9 ! laccolite1 may n broad lava fields h _! homologues b5ea? displacem5ts ( ! ,kaibab type8 ,! idea is naturally attractive to "o :o has made a special /udy ( laccolites1 b x is h>dly t5able4 ,!re are inde$ _m po9ts ( resemblance betwe5 su* flexures z ! ,wat]pocket1 & ! uplifts ( ! ,h5ry ,m\nta9s2 b ! po9ts ( contra/ are equally conspicu\s1 & seem to m>k a radical diff]5ce4 ,!re is a c]ta9 symmetry ( =m :i* is *>act]i/ic ( ! laccolitic ar*es1 b :i* is r>ely se5 9 ! great flexures4 ,& !re is a l9e> elem5t :i* is *>act]i/ic ( ! latt]1 b n ( ! =m]4 ,! great flexures always h direction or tr5d1 & (t5 exhibit p>allelism2 ! laccolitic ar*es betray no tr5d ei!r individually or collectively4 ,^! features are well %[n 9 ,plate ,,ii1 :]e ! ,wat]pocket flexure is contra/$ ) ! ,h5ry ,m\nta9 ar*es4 ,,*apt] ,v4 ,,l& ,,sculpture4 ,! ,bas9 ( ! ,colorado (f]s peculi> facilities = ! /udy ( ! orig9 ( topographic =ms1 & its m>vel\s sculpture has excit$ ! int]e/ ( e obs]v]4 ,x has already made notable contributions to ! pr9ciples ( e>? sculpture#e1 & its res\rces are f> f exhau/$4 ,! /udy ( ! ,h5ry ,m\nta9s has n prov$ entirely unfruitful1 & = ! sake ( %[+ ! be>+ ( its peculi> features ^u ! g5]al subject1 ,i %all take ! lib]ty to re/ate c]ta9 pr9ciples ( erosion :i* h be5 d]iv$ or en=c$ by ! /udy ( ! ,colorado ,plateaus4 ,footnote #e3 ,geology ( ! 8,colorado ,explor+ ,exp$ition01 by ,j4 ,s4 ,newb]ry1 p4 #de4 8,exploration ( ! ,colorado ,riv] ( ! ,we/01 by ,j4 ,w4 ,p[ell1 p4 #aeb4 8,geology ( ! ,u9ta ,m\nta9s01 by ,j4 ,w4 ,p[ell1 p4 #aha4 8,explorations ,we/ ( ! #ajj? ,m]idian01 ,vol4 ,,iii1 ,"p ,i1 by ,g4 ,k4 ,gilb]t1 pp4 #fg & #eed4 8,! ,colorado ,plateau ,region0 9 ,am]ican ,j\rnal ( ,sci5ce = ,augu/1 #ahgf1 by ,g4 ,k4 ,gilb]t4 ,a portion ( ! la/ pap] is repeat$1 aft] modification1 9 ! fir/ section ( ?is *apt]4 ,i4--,,erosion4 ,! sculpture & degradation ( ! l& are p]=m$ p>tly by %ore waves1 p>tly by glaci]s1 p>tly by w9d2 b *iefly by ra9 & runn+ wat]4 ,! la/ m5tion$ ag5cies only w be "h discuss$4 ,! erosion :i* !y accompli% w be consid]$ 7,a7 z consi/+ ( p>ts1 & 7,b7 z modifi$ by conditions4 ,a4 ,,processes ,,( ,,erosion4 ,all indurat$ rocks & mo/ e>?s are b\nd toge!r by a =ce ( cohesion :i* mu/ be ov]come be=e !y c be divid$ & remov$4 ,! natural processes by :i* ! division & removal are accompli%$ make up erosion4 ,!y are call$ dis9tegration & transportation4 ,transportation is *iefly p]=m$ by runn+ wat]4 ,dis9tegration is naturally divid$ into two p>ts4 ,s mu* ( x z is accompli%$ by runn+ wat] is call$ corrasion1 & t :i* is n1 is call$ wea!r+4 ,/at$ 9 _! natural ord]1 ! ?ree g5]al divisions ( ! process ( erosion are 7#a7 wea!r+1 7#b7 transportation1 & 7#c7 corrasion4 ,! rocks ( ! g5]al surface ( ! l& are dis9tegrat$ by wea!r+4 ,! mat]ial ?us loos5$ is transport$ by /reams to ! ocean or o!r receptacle4 ,9 transit x helps to corrade f ! *annels ( ! /reams o!r mat]ial1 :i* jo9s ) x to be transport$ to ! same goal4 ,wea!r+4 ,9 wea!r+ ! *ief ag5ts ( dis9tegration are solution1 *ange ( temp]ature1 ! beat+ ( ra91 gravity1 & vegetation4 ,! great solv5t ( rocks is wat]1 b x receives aid f "s o!r sub/ances ( :i* x becomes ! vehicle4 ,^! sub/ances are *iefly products ( ! =mation & decomposition ( vegetable tissues4 ,"s rocks are dis9tegrat$ by _! complete solution1 b ! great majority are divid$ into gra9s by ! solution ( a portion2 & fragm5tal rocks usually lose by solution ! cem5t m]ely1 & are ?us r$uc$ to _! orig9al incoh]5t condition4 ,! mo/ rigid rocks are crack$ by sudd5 *anges ( temp]ature2 & ! crevices ?us begun are op5$ by ! freez+ ( ! wat] )9 !m4 ,! coh]5ce ( ! m por\s rocks is impair$ & (t5 de/roy$ by ! same expansive =ce ( freez+ wat]4 ,! beat+ ( ! ra9 ov]comes ! feeble coh]5ce ( e>?s1 & assi/s solution & fro/ by deta*+ ! p>ticles :i* !y h p>tially loos5$4 ,:5 ! base ( a cliff is erod$ s z to remove or dim9i% ! support ( ! upp] "p1 ! rock ?us depriv$ ( support is brok5 (f 9 blocks by gravity4 ,! process ( :i* ?is is a "p is call$ cliff erosion or sapp+4 ,plants (t5 pry ap>t rocks by ! gr[? ( _! roots1 b _! *ief aid to erosion is by increas+ ! solv5t p[] ( p]colat+ wat]4 ,9 g5]al s(t rocks wea!r m rapidly ?an h>d4 ,transportation4 ,a portion ( ! wat] ( ra9s fl[s ov] ! surface & is quickly ga!r$ into /reams4 ,a second portion is absorb$ by ! e>? or rock on :i* x falls1 & aft] a sl[ und]gr\nd circulation reissues 9 spr+s4 ,bo? transport ! products ( wea!r+1 ! latt] c>ry+ dissolv$ m9]als & ! =m] *iefly undissolv$4 ,transportation is also p]=m$ by ! direct action ( gravity4 ,9 sapp+1 ! blocks :i* are deta*$ by gravity are by ! same ag5cy c>ri$ to ! base ( ! cliff4 ,corrasion4 ,9 corrasion ! ag5ts ( dis9tegration are solution & me*anical we>4 ,:]ev] ! two are comb9$1 ! sup]ior effici5cy ( ! latt] is evid5t2 & 9 all fields ( rapid corrasion ! "p play$ by solution is s small t x may be disreg>d$4 ,! me*anical we> ( /reams is p]=m$ by ! aid ( h>d m9]al fragm5ts :i* are c>ri$ along by ! curr5t4 ,! effective =ce is t ( ! curr5t2 ! tools are mud1 s&1 & b[ld]s4 ,! mo/ important ( !m is s&2 x is *iefly by ! impact & friction ( gra9s ( s& t ! rocky b$s ( /reams are dis9tegrat$4 ,/reams ( cle> wat] corrade _! b$s by solution4 ,muddy /reams act p>tly by solution1 b *iefly by attrition4 ,/reams transport ! comb9$ products ( corrasion & wea!r+4 ,a "p ( ! dbris is c>ri$ 9 solution1 & a "p me*anically4 ,! f9e/ ( ! undissolv$ detritus is held 9 susp5sion2 ! co>se/ is roll$ along ! bottom2 & !re is a gradation betwe5 ! two modes4 ,!re is a con/ant comm9ution ( all ! mat]ial z x moves1 & ! "w ( transportation is !reby accel]at$4 ,b[ld]s & pebbles1 :ile !y we> ! /ream b$ by p\nd+ & rubb+1 are worn /ill m rapidly !mselves4 ,s& gra9s are worn & brok5 by ! cont9u$ jo/l+1 & _! fragm5ts jo9 ! susp5d$ mud4 ,f9ally ! detritus is all m or less dissolv$ by ! wat]1 ! f9e/ ! mo/ rapidly4 ,9 brief1 wea!r+ is p]=m$ by solution2 by *ange ( temp]ature1 includ+ fro/2 by ra9 beat+2 by gravity2 & by vegetation4 ,transportation is p]=m$ *iefly by runn+ wat]4 ,corrasion is p]=m$ by solution1 & by me*anical we>4 ,corrasion is di/+ui%$ f wea!r+ *iefly by includ+ me*anical we> among its ag5cies1 & ! importance ( ! di/9ction w be app>5t :5 we come to consid] h[ greatly & peculi>ly ?is process is affect$ by modify+ conditions4 ,b4 ,,conditions ,,controll+ ,,erosion4 ,! *ief conditions :i* affect ! rapidity ( erosion are 7#a7 declivity1 7#b7 "* ( rock1 & 7#c7 climate4 ,rate ( ,erosion & ,declivity4 ,9 g5]al erosion is mo/ rapid :]e ! slope is /eepe/2 b wea!r+1 transportation1 & corrasion are affect$ 9 diff]5t ways & 9 diff]5t degrees4 ,) increase ( slope goes increase 9 ! velocity ( runn+ wat]1 & ) t goes increase 9 its p[] to transport undissolv$ detritus4 ,! ability ( a /ream to corrade by solution is n notably enhanc$ by great velocity2 b its ability to corrade by me*anical we> keeps pace ) its ability to transport1 or may ev5 increase m rapidly4 ,= n only does ! bottom receive m bl[s 9 proportion z ! quantity ( transi5t detritus increases1 b ! bl[s acquire great] =ce f ! accel]at$ curr5t1 & f ! great] size ( ! mov+ fragm5ts4 ,x is necess>y h[ev] to di/+ui% ! ability to corrade f ! rate ( corrasion1 :i* w be se5 fur!r on to dep5d l>gely on o!r conditions4 ,wea!r+ is n directly influ5c$ by slope1 b x is rea*$ indirectly ?r\gh transportation4 ,solution & fro/1 ! *ief ag5ts ( rock decay1 are bo? ret>d$ by ! excessive accumulation ( dis9tegrat$ rock4 ,fro/ action ceases altoge!r at a few feet bel[ ! surface1 & solution gradually decreases z ! zone ( its activity desc5ds & ! circulation on :i* x dep5ds becomes m sluggi%4 ,h5ce ! rapid removal ( ! products ( wea!r+ /imulates its action1 & especially t portion ( its action :i* dep5ds ^u fro/4 ,if h[ev] ! p[] ( transportation is s great z to remove completely ! products ( wea!r+1 ! "w ( dis9tegration is !reby *eck$2 = ! soil :i* wea!r+ t5ds to accumulate is a res]voir to cat* ra9 z x rea*es ! e>? & /ore x up = ! "w ( solution & fro/1 in/ead ( lett+ x run (f at once unus$4 ,sapp+ is directly favor$ by great declivity4 ,9 brief1 a /eep declivity favors transportation & !reby favors corrasion4 ,! rapid1 b p>tial1 transportation ( wea!r$ rock accel]ates wea!r+2 b ! complete removal ( its products ret>ds wea!r+4 ,rate ( ,erosion & ,rock ,texture4 ,o!r ?+s be+ equal1 erosion is mo/ rapid :5 ! erod$ rock (f]s lea/ resi/ance2 b ! rocks :i* are mo/ favorable to "o portion ( ! process ( erosion d n necess>ily /& 9 ! same relation to ! o!rs4 ,dis9tegration by solution dep5ds 9 l>ge "p on ! solubility ( ! rocks1 b x proce$s mo/ rapidly ) ^? fragm5tal rocks ( :i* ! cem5t is soluble1 & ( :i* ! texture is op54 ,dis9tegration by fro/ is mo/ rapid 9 rocks :i* absorb a l>ge p]c5tage ( wat] & are feebly coh]5t4 ,dis9tegration by me*anical we> is mo/ rapid 9 s(t rocks4 ,transportation is mo/ favor$ by ^? rocks :i* yield by dis9tegration ! mo/ f9ely comm9ut$ dbris4 ,rate ( ,erosion & ,climate4 ,! influ5ce ( climate ^u erosion is less easy to =mulate4 ,! direct influ5ces ( temp]ature & ra9fall are comp>atively simple1 b _! indirect influ5ce ?r\gh vegetation is complex1 & is 9 "p oppos$ to ! direct4 ,temp]ature affects erosion *iefly by its *anges4 ,:]e ! range ( temp]ature includes ! freez+ po9t ( wat]1 fro/ contributes its p[]ful aid to wea!r+2 & x is only :]e *anges are great & sudd5 t rocks are crack$ by _! unequal expansion or contraction4 ,all ! processes ( erosion are affect$ directly by ! am\nt ( ra9fall1 & by its di/ribution ?r\gh ! ye>4 ,all are accel]at$ by its increase & ret>d$ by its dim9ution4 ,:5 x is conc5trat$ 9 "o "p ( ! ye> at ! exp5se ( ! rema9d]1 transportation & corrasion are accel]at$1 & wea!r+ is ret>d$4 ,wea!r+ is favor$ by abundance ( moi/ure4 ,fro/ accompli%es mo/ :5 ! rocks are saturat$2 & solution :5 !re is ! free/ subt]ranean circulation4 ,b :5 ! annual ra9fall is conc5trat$ into a limit$ season1 a l>g] %>e ( ! wat] fails to p5etrate1 & ! ga9 f tempor>y flood+ does n comp5sate = ! *eck+ ( all solution by a long dry season4 ,transportation is favor$ by increas+ wat] supply z greatly z by increas+ declivity4 ,:5 ! volume ( a /ream increases1 x becomes at ! same "t m rapid1 & its transport+ capacity ga9s by ! increm5t to velocity z well z by ! increm5t to volume4 ,h5ce ! increase 9 p[] ( transportation is m ?an proportional to ! increase ( volume4 ,x is due to ?is fact *iefly t ! transportation ( a /ream :i* is subject to floods is great] ?an x w\ld be if its total wat] supply 7 ev5ly di/ribut$ 9 "t4 ,! indirect influ5ce ( ra9fall & temp]ature1 by means ( vegetation1 has diff]5t laws4 ,vegetation is intimately relat$ to wat] supply4 ,!re is little or none :]e ! annual precipitation is small1 & x is pr(use :]e ! latt] is great--especially :]e ! temp]ature is at ! same "t high4 ,9 proportion z vegetation is pr(use ! solv5t p[] ( p]colat+ wat] is increas$1 & on ! o!r h& ! gr\nd is %elt]$ f ! me*anical action ( ra9s & rills4 ,! removal ( dis9tegrat$ rock is greatly imp$$ by ! cons]vative p[] ( roots & fall5 leaves1 & a soil is ?us pres]v$4 ,transportation is ret>d$4 ,wea!r+ by solution is accel]at$ up to a c]ta9 po9t1 b 9 ! end x suff]s by ! clogg+ ( transportation4 ,! "w ( fro/ is ne>ly /opp$ z soon z ! dep? ( soil exce$s ! limit ( fro/ action4 ,! =ce ( ra9 drops is exp5d$ on foliage4 ,moreov] a deep soil acts z a di/ribut+ res]voir = ! wat] ( ra9s1 & t5ds to equalize ! fl[ ( /reams4 ,h5ce ! g5]al effect ( vegetation is to ret>d erosion2 & s9ce ! direct effect ( great ra9fall is ! accel]ation ( erosion1 x results t its direct & indirect t5d5cies are 9 opposite directions4 ,9 arid regions ( :i* ! declivities are suffici5t to give ?or\gh dra9age1 ! abs5ce ( vegetation is accompani$ by abs5ce ( soil4 ,:5 a %[] falls1 ne>ly all ! wat] runs (f f ! b>e rock1 & ! little t is absorb$ is rapidly r$uc$ by evaporation4 ,solution becomes a sl[ process = lack ( a cont9u\s supply ( wat]1 & fro/ accompli%es its "w only :5 x closely foll[s ! infrequ5t ra94 ,?us wea!r+ is ret>d$4 ,transportation has its "w s conc5trat$ by ! quick ga!r+ ( %[]s into floods1 z to comp5sate1 9 "p at lea/1 = ! smallness ( ! total ra9fall f :i* !y d]ive _! p[]4 ,h5ce 9 regions ( small ra9fall1 surface degradation is usually limit$ by ! sl[ rate ( dis9tegration2 :ile 9 regions ( great ra9fall x is limit$ by ! rate ( transportation4 ,!re is probably an int]m$iate condition ) mod]ate ra9fall1 9 :i* a rate ( dis9tegration great] ?an t ( an arid climate is balanc$ by a m rapid transportation ?an consi/s ) a v moi/ climate1 & 9 :i* ! rate ( degradation atta9s its maximum4 ,ov] ne>ly ! :ole ( ! e>?'s surface !re is a soil1 & :]ev] ?is exi/s we "k t ! conditions are m favorable to wea!r+ ?an to transportation4 ,h5ce x is true 9 g5]al t ! conditions :i* limit transportation are ^? :i* limit ! g5]al degradation ( ! surface4 ,to und]/& ! mann] 9 :i* ?is limit is rea*$ x is necess>y to look at ! process by :i* ! "w is accompli%$4 ,transportation & ,comm9ution4 ,a /ream ( wat] fl[+ d[n its b$ exp5ds an am\nt ( en]gy t is measur$ by ! quantity ( wat] & ! v]tical di/ance ?r\gh :i* x desc5ds4 ,if !re 7 no friction ( ! wat] ^u its *annel ! velocity ( ! curr5t w\ld cont9ually increase2 b if1 z is ! usual case1 !re is no increase ( velocity1 !n ! :ole ( ! en]gy is consum$ 9 friction4 ,! friction produces inequalities 9 ! motion ( ! wat]1 & especially induces subsidi>y curr5ts m or less oblique to ! g5]al onw>d movem5t4 ,"s ( ^! subsidi>y curr5ts h an upw>d t5d5cy1 & by !m is p]=m$ ! *ief "w ( transportation4 ,!y lift small p>ticles f ! bottom & hold !m 9 susp5sion :ile !y move =w>d ) ! g5]al curr5t4 ,! f9e/ p>ticles s9k mo/ sl[ly & are c>ri$ f>!/ be=e !y fall4 ,l>g] ones are b>ely lift$1 & are dropp$ at once4 ,/ill l>g] are only half lift$2 t is1 !y are lift$ on ! side ( ! curr5t & roll$ ov] )\t quitt+ ! bottom4 ,& f9ally !re is a limit to ! p[] ( e curr5t1 & ! l>ge/ fragm5ts ( its b$ are n mov$ at all4 ,!re is a def9ite relation betwe5 ! velocity ( a curr5t & ! size ( ! l>ge/ b[ld] x w roll4 ,x has be5 %[n by ,hopk9s t ! weight ( ! b[ld] is proportion$ to ! six? p[] ( ! velocity4 ,x is easily %[n also t ! weight ( a susp5d$ p>ticle is proportion$ to ! six? p[] ( ! velocity ( ! upw>d curr5t t w prev5t its s9k+4 ,b x mu/ n be inf]r$ t ! total load ( detritus t a /ream w transport be>s any su* relation to ! rapidity ( its curr5t4 ,! true inf]5ce is1 t ! velocity det]m9es ! size-limit ( ! detritus t a /ream c move by roll+1 or c hold 9 susp5sion4 ,e p>ticle :i* a /ream lifts & su/a9s is a draft ^u its en]gy1 & ! measure ( ! draft is ! weight 7weigh$ 9 wat]7 ( ! p>ticle1 multipli$ by ! di/ance x w\ld s9k 9 /ill wat] 9 ! "t dur+ :i* x is susp5d$4 ,if = ! sake ( simplicity we suppose ! :ole load ( a /ream to be ( uni=m p>ticles1 !n ! measure ( ! en]gy consum$ 9 _! transportation is _! total weight multipli$ by ! di/ance "o ( !m w\ld s9k 9 ! "t occupi$ 9 _! transportation4 ,s9ce f9e p>ticles s9k m sl[ly ?an co>se1 ! same consumption ( en]gy w convey a great] load ( f9e ?an ( co>se4 ,aga91 ! en]gy ( a cle> /ream is entirely consum$ 9 ! friction ( fl[2 & ! friction be>s a direct relation to its velocity4 ,b if detritus be add$ to ! wat]1 !n a portion ( its en]gy is div]t$ to ! transportation ( ! load2 & ?is is done at ! exp5se ( ! friction ( fl[1 & h5ce at ! exp5se ( velocity4 ,z ! en]gy exp5d$ 9 transportation increases1 ! velocity dim9i%es4 ,if ! detritus be compos$ ( uni=m p>ticles1 !n we may also say t z ! load increases ! velocity dim9i%es4 ,b ! dim9i%+ velocity w f9ally rea* a po9t at :i* x c b>ely transport p>ticles ( ! giv5 size1 & :5 ?is po9t is atta9$1 ! /ream has its maximum load ( detritus ( ! giv5 size4 ,b f9e detritus requires less velocity = its transportation ?an co>se1 & w n s soon r$uce ! curr5t to ! limit ( its effici5cy4 ,a great] p]c5tage ( ! total en]gy ( ! /ream c h5ce be employ$ by f9e detritus ?an by co>se4 7,x %\ld be expla9$ t ! friction ( fl[ is 9 itself a complex affair4 ,! wat] 9 contact ) ! bottom & walls ( ! *annel develops friction by fl[+ pa/ !m1 & t :i* is f>!r away by fl[+ pa/ t :i* is ne>4 ,! inequality ( motion gives rise to cross curr5ts & !re is a friction ( ^! ^u ea* o!r4 ,! ratio or coeffici5t ( friction ( wat] aga9/ ! sub/ance ( ! b$1 ! coeffici5t ( friction ( wat] aga9/ wat]1 or ! viscosity ( wat]1 & ! =m ( ! b$1 all conspire to det]m9e ! resi/ance ( fl[ & toge!r make up :at may be call$ ! coeffici5t ( ! friction ( fl[4 ,! friction dep5ds on its coeffici5t & on ! velocity47 ,?us ! capacity ( a /ream = transportation is enhanc$ by comm9ution 9 two ways4 ,f9e detritus1 on ! "o h&1 consumes less en]gy = ! transportation ( ! same weight1 & on ! o!r1 x c utilize a great] portion ( ! /ream's en]gy4 ,x foll[s1 z a coroll>y1 t ! velocity ( a fully load$ /ream dep5ds 7cet]is p>ibus7 on ! comm9ution ( ! mat]ial ( ! load4 ,:5 a /ream has its maximum load ( f9e detritus1 its velocity w be less ?an :5 c>ry+ its maximum load ( co>se detritus2 & ! great] load corresponds to ! less velocity4 ,x foll[s also t a /ream :i* is suppli$ ) het]og5e\s dbris w select ! f9e/4 ,if ! f9e/ is suffici5t 9 quantity ! curr5t w be s *eck$ by x t ! co>s] _c be mov$4 ,if ! f9e/ is n suffici5t ! next grade w be tak51 & s on4 ,transportation & ,declivity4 ,to consid] n[ ! relation ( declivity to transportation we w assume all o!r conditions to be con/ant4 ,let u suppose t two /reams h ! same l5g?1 ! same quantity ( wat]1 fl[ ov] b$s ( ! same "*1 & are suppli$ to _! full capacities ) detritus ( ! same k9d2 b diff] 9 ! total am\nt ( fall4 ,_! declivities or rates ( fall are proportional to _! falls4 ,s9ce ! en]gy ( a /ream is measur$ by ! product ( its volume & its fall1 ! relative en]gies ( ! two /reams are proportional to _! falls1 & h5ce proportional to _! declivities4 ,! velocities ( ! two /reams1 dep5d+1 z we h se5 above1 on ! "* ( ! detritus :i* loads !m1 are ! same2 & h5ce ! same am\nt ( en]gy is consum$ by ea* 9 ! friction ( fl[4 ,& s9ce ! en]gy :i* ea* /ream exp5ds 9 transportation is ! residual aft] d$uct+ :at x sp5ds 9 friction f its total en]gy1 x is evid5t t ! /ream ) ! great] declivity w n m]ely h ! great] en]gy1 b w exp5d a less p]c5tage ( x 9 friction & a great] p]c5tage 9 transportation4 ,h5ce declivity favors transportation 9 a degree t is great] ?an its simple ratio4 ,!re are two elem5ts ( :i* no acc\nt is tak5 9 ! prec$+ discussion1 b :i* ne$ to be m5tion$ to prev5t misappreh5sion1 al?\gh !y detract 9 no way f ! conclusions4 ,! fir/ is ! addition :i* ! transport$ detritus makes to ! en]gy ( ! /ream4 ,a /ream ( wat] *>g$ ) detritus is at once a comp\nd & an un/able fluid4 ,x has be5 treat$ m]ely z an un/able fluid requir+ a con/ant exp5diture ( en]gy to ma9ta9 its con/itution2 b look+ at x z a comp\nd fluid1 x is pla9 t ! en]gy x develops by its desc5t is great] ?an ! en]gy p]ta9+ to ! wat] alone1 9 ! precise ratio ( ! mass ( ! mixture to ! mass ( ! simple wat]4 ,! second elem5t is ! addition :i* ! detritus makes to ! friction ( fl[4 ,! coeffici5t ( friction ( ! comp\nd /ream ^u its bottom w always be great] ?an t ( ! simple /ream ( wat]1 & ! coeffici5t ( int]nal friction or ! viscosity w be great] ?an t ( pure wat]1 & h5ce = ! same velocity a great] am\nt ( en]gy w be consum$4 ,x may be not$ 9 pass+1 t ! en]gy :i* is consum$ 9 ! friction ( ! detritus on ! /ream b$1 accompli%es z "p ( its "w ! me*anical corrasion ( ! b$4 ,transportation & ,quantity ( ,wat]4 ,a /ream's friction ( fl[ dep5ds ma9ly on ! "* ( ! b$1 on ! area ( ! surface ( contact1 & on ! velocity ( ! curr5t4 ,:5 ! o!r elem5ts are con/ant1 ! friction v>ies approximately ) ! area ( contact4 ,! area ( contact dep5ds on ! l5g? & =m ( ! *annel1 & on ! quantity ( wat]4 ,= /reams ( ! same l5g? & same =m ( cross-section1 b diff]+ 9 size ( cross-section1 ! area ( contact v>ies directly z ! squ>e root ( ! quantity ( wat]4 ,h5ce1 cet]is p>ibus1 ! friction ( a /ream on its b$ is proportion$ to ! squ>e root ( ! quantity ( wat]4 ,b z /at$ above1 ! total en]gy ( a /ream is proportion$ directly to ! quantity ( wat]2 & ! total en]gy is equal to ! en]gy sp5t 9 friction1 plus ! en]gy sp5t 9 transportation4 ,:5ce x foll[s t if a /ream *ange its quantity ( wat] )\t *ang+ its velocity or o!r accid5ts1 ! total en]gy w *ange at ! same rate z ! quantity ( wat]2 ! en]gy sp5t 9 friction w *ange at a less rate1 & ! en]gy rema9+ = transportation w *ange at a great] rate4 ,h5ce increase 9 quantity ( wat] favors transportation 9 a degree t is great] ?an its simple ratio4 ,x foll[s z a coroll>y t ! runn+ wat] :i* c>ries ! dbris ( a di/rict loses p[] by subdivision t[>d its s\rces2 & t1 unless !re is a comp5sat+ increm5t ( declivity1 ! tribut>ies ( a riv] w fail to supply x ) ! full load x is able to c>ry4 ,x is notewor?y also t ! ob/ruction :i* vegetation opposes to transportation is especially effective 9 t x is appli$ at ! inf9itesimal s\rces ( /reams1 :]e ! =ce ( ! runn+ wat] is lea/4 ,a /ream :i* c transport dbris ( a giv5 size1 may be said to be compet5t to su* dbris4 ,s9ce ! maximum p>ticles :i* /reams are able to move are proportion$ to ! six? p[]s ( _! velocities1 compet5ce dep5ds on velocity4 ,velocity1 9 turn1 dep5ds on declivity & volume1 & 7inv]sely7 on load4 ,9 brief1 ! capacity ( a /ream = transportation is great] = f9e dbris ?an = co>se4 ,its capacity = ! transportation ( a giv5 k9d ( dbris is enl>g$ 9 m ?an simple ratio by increase ( declivity2 & x is enl>g$ 9 m ?an simple ratio by increase ( volume4 ,! compet5ce ( a /ream = ! transport ( dbris ( a giv5 f95ess1 is limit$ by a correspond+ velocity4 ,! rate ( transportation ( dbris ( a giv5 f95ess may equal ! capacity ( ! transport+ /ream1 or x may be less4 ,:5 x is less1 x is always f ! insuffici5cy ( supply4 ,! supply furni%$ by wea!r+ is nev] available unless ! degree ( f95ess ( ! dbris br+s x )9 ! compet5ce ( ! /ream at ! po9t ( supply4 ,! *ief po9t ( supply is at ! v head ( ! fl[+ wat]4 ,! ra9 :i* falls on mat]ial t has be5 dis9tegrat$ by wea!r+1 beg9s aft] x has saturat$ ! imm$iate surface to fl[ (f4 ,b x =ms a v ?9 %eet2 its friction is great2 its velocity is small2 & x is compet5t to pick up only p>ticles ( exce$+ f95ess4 ,if ! mat]ial is het]og5e\s1 x discrim9ates & leaves ! co>s] p>ticles4 ,z ! %eet moves on x becomes deep] & soon beg9s to ga!r itself into rills4 ,z ! deep5+ & conc5tration ( wat] progresses1 ei!r its capacity increases & ! load ( f9e p>ticles is augm5t$1 or1 if f9e p>ticles are n 9 suffici5t =ce1 its compet5ce increases1 & l>g] ones are lift$4 ,9 ei!r case ! load is augm5t$1 & z rill jo9s rill x /eadily gr[s1 until ! accumulat$ wat] f9ally passes beyond ! zone ( dis9tegrat$ mat]ial4 ,! p>ticles :i* ! feeble initial curr5ts are n compet5t to move1 h to wait ei!r until !y are subdivid$ by ! ag5cies ( wea!r+1 or until ! deep5+ ( ! *annels ( ! rills s f> increases ! declivities t ! curr5ts acquire ! requisite velocity1 or until "s fi]c] /orm floods ! gr\nd ) a deep] %eet ( wat]4 ,?us rate ( transportation1 z well z capacity = transportation1 is favor$ by f95ess ( dbris1 by declivity1 & by quantity ( wat]4 ,x is oppos$ *iefly by vegetation1 :i* holds toge!r t :i* is loos5$ by wea!r+1 & %ields x f ! ag5t ( transportation 9 ! v place :]e t ag5t is weake/4 ,:5 ! curr5t ( a /ream gradually dim9i%es 9 its c\rse--z = example 9 approa*+ ! ocean--! capacity = transportation also dim9i%es2 & s soon z ! capacity becomes less ?an ! load1 precipitation beg9s--! co>s] p>ticles be+ deposit$ fir/4 ,corrasion & ,transportation4 ,:]e a /ream has all ! load ( a giv5 degree ( comm9ution :i* x is capable ( c>ry+1 ! entire en]gy ( ! desc5d+ wat] & load is consum$ 9 ! translation ( ! wat] & load & !re is none appli$ to corrasion4 ,if x has an excess ( load its velocity is !reby dim9i%$ s z to less5 its compet5ce & a portion is dropp$4 ,if x has less ?an a full load x is 9 condition to receive m & x corrades its bottom4 ,a fully load$ /ream is on ! v]ge betwe5 corrasion & deposition4 ,z w be expla9$ 9 ano!r place1 x may we> ! walls ( its *annel1 b its we> ( "o wall w be accompani$ by an addition to ! opposite wall4 ,! "w ( transportation may ?us monopolize a /ream to ! exclusion ( corrasion1 or ! two works may be c>ri$ =w>d at ! same "t4 ,corrasion & ,declivity4 ,! rapidity ( me*anical corrasion dep5ds on ! h>dness1 size1 & numb] ( ! transi5t fragm5ts1 on ! h>dness ( ! rock-b$1 & on ! velocity ( ! /ream4 ,! bl[s :i* ! mov+ fragm5ts deal ^u ! /ream b$ are h>d 9 proportion z ! fragm5ts are l>ge & ! curr5t is swift4 ,!y are mo/ effective :5 ! fragm5ts are h>d & ! b$-rock is s(t4 ,!y are m num]\s & h>d] ^u ! bottom ( ! *annel ?an ^u ! sides because ( ! con/ant t5d5cy ( ! p>ticles to s9k 9 wat]4 ,_! numb] is increas$ up to a c]ta9 limit by ! increase ( ! load ( ! /ream2 b :5 ! fragm5ts become greatly cr[d$ at ! bottom ( a /ream _! =ce is p>tially sp5t among !mselves1 & ! b$-rock is 9 ! same degree protect$4 ,= ?is reason1 & because increase ( load causes ret>dation ( curr5t1 x is probable t ! maximum "w ( corrasion is p]=m$ :5 ! load is f> )9 ! transport+ capacity4 ,! elem5t ( velocity is ( d\ble importance s9ce x det]m9es n only ! spe$1 b to a great ext5t ! size ( ! pe/les :i* gr9d ! rocks4 ,! coeffici5ts ^u :i* x 9 turn dep5ds1 namely1 declivity & quantity ( wat]1 h ! same importance 9 corrasion t !y h 9 transportation4 ,let u suppose t a /ream end[$ ) a con/ant volume ( wat]1 is at "s po9t cont9u\sly suppli$ ) z great a load z x is capable ( c>ry+4 ,= s great a di/ance z its velocity rema9s ! same1 x w nei!r corrade 7d[nw>d7 nor deposit1 b w leave ! grade ( its b$ un*ang$4 ,b if 9 its progress x rea*es a place :]e a less declivity ( b$ gives a dim9i%$ velocity1 its capacity = transportation w become less ?an ! load & "p ( ! load w be deposit$4 ,or if 9 its progress x rea*es a place :]e a great] declivity ( b$ gives an increas$ velocity1 ! capacity = transportation w become great] ?an ! load & !re w be corrasion ( ! b$4 ,9 ?is way a /ream :i* has a supply ( dbris equal to its capacity1 t5ds to build up ! g5tl] slopes ( its b$ & cut away ! /eep]4 ,x t5ds to e/abli% a s+le1 uni=m grade4 ,let u n[ suppose t ! /ream aft] hav+ oblit]at$ all ! inequalities ( ! grade ( its b$ loses ne>ly ! :ole ( its load4 ,its velocity is at once accel]at$ & v]tical corrasion beg9s ?r\gh its :ole l5g?4 ,s9ce ! /ream has ! same declivity & consequ5tly ! same velocity at all po9ts1 its capacity = corrasion is ev]y:]e ! same4 ,its rate ( corrasion h[ev] w dep5d on ! "* ( its b$4 ,:]e ! rock is h>d corrasion w be less rapid ?an :]e x is s(t1 & !re w result inequalities ( grade4 ,b s soon z !re is inequality ( grade !re is inequality ( velocity1 & inequality ( capacity = corrasion2 & :]e h>d rocks h produc$ declivities1 !re ! capacity = corrasion w be increas$4 ,! diff]5tiation w proce$ until ! capacity = corrasion is ev]y:]e proportion$ to ! resi/ance1 & no fur!r1--t is1 until !re is an equilibrium ( action4 ,9 g5]al1 we may say t a /ream t5ds to equalize its "w 9 all p>ts ( its c\rse4 ,its p[] inh]es 9 its fall1 & ea* foot ( fall has ! same p[]4 ,:5 its "w is to corrade & ! resi/ance is unequal1 x conc5trates its en]gy :]e ! resi/ance is great by cr[d+ _m feet ( desc5t into a small space1 & diffuses x :]e ! resi/ance is small by us+ b a small fall 9 a long di/ance4 ,:5 its "w is to transport1 ! resi/ance is con/ant & ! fall is ev5ly di/ribut$ by a uni=m grade4 ,:5 its "w includes bo? transportation & corrasion1 z 9 ! usual case1 its grades are some:at unequal2 & ! inequality is greate/ :5 ! load is lea/4 ,x is to be rem>k$ t 9 ! case ( mo/ /reams x is ! flood /age :i* det]m9es ! grades ( ! *annel4 ,! load ( detritus is usually greate/ dur+ ! highe/ floods1 & p[] is conf]r$ s rapidly ) increase ( quantity ( wat]1 t 9 any ev5t ! influ5ce ( ! /ream dur+ its high /age w ov]p[] any influ5ce :i* may h be5 ex]t$ at a l[ /age4 ,t relation ( transportation to corrasion :i* subsi/s :5 ! wat] is high w det]m9e ! grades ( ! wat]way4 ,declivity & ,quantity ( ,wat]4 ,! conclusions rea*$ 9 reg>d to ! relations ( corrasion & declivity dep5d on ! assumption t ! volume ( ! /ream is ! same ?r\gh\t its :ole c\rse1 & !y consequ5tly apply directly to su* portions only ( /reams z are n increas$ by tribut>ies4 ,a simple modification w include ! m g5]al case ( bran*+ /reams4 ,let u suppose t two equal /reams :i* jo91 h ! same declivity1 & are bo? fully load$ ) detritus ( ! same k9d4 ,if ! *annel d[n :i* !y fl[ aft] union has also ! same declivity1 !n ! jo9t /ream w h a great] velocity ?an its bran*es1 its capacity = transportation w be m ?an adequate = ! jo9t load1 & x w corrade its bottom4 ,by its corrasion x w dim9i% ! declivity ( its b$1 & consequ5tly its velocity & capacity = transportation1 until its capacity is equal to ! total capacity ( its tribut>ies4 ,:5 an equilibrium ( action is rea*$1 ! declivity ( ! ma9 /ream w be less ?an ! declivities ( its bran*es4 ,?is result does n dep5d on ! assum$ equality ( ! bran*es1 nor ^u _! numb]4 ,x is equally true t 9 any riv] sy/em :i* is fully suppli$ ) mat]ial = transportation & :i* has atta9$ a condition ( equal action1 ! declivity ( ! small] /reams is great] ?an t ( ! l>g]4 ,let u fur!r suppose t two equal /reams :i* jo91 are only p>tially load$1 & are corrad+ at a common rate a common rock4 ,if ! *annel d[n :i* !y fl[ aft] union is 9 ! same rock & has ! same declivity1 !n ! jo9t riv] w h a great] velocity1 & w corrade m rapidly ?an its bran*es4 ,by its m rapid corrasion x w dim9i% ! declivity ( its b$1 until z be=e !re is an equilibrium ( action1--! bran* hav+ a great] declivity ?an ! ma94 ,?is result also is indep5d5t ( ! numb] & equality ( ! bran*es2 & x is equally true t 9 any riv] sy/em :i* trav]ses & corrades rock ( equal resi/ance ?r\gh\t1 & :i* has rea*$ a condition ( equal action1 ! declivity ( ! small] /reams is great] ?an t ( ! l>g]4 ,9 g5]al we may say t1 cet]is p>ibus1 declivity he>s an inv]se relation to quantity ( wat]4 7,!re is an app>5t exception to ?is law1 :i* is specially notewor?y 9 ! sculpture ( bad-l&s1 & w be describ$ 9 ano!r place74 ,,ii4 ,,sculpture4 ,erosion may be reg>d$ f sev]al po9ts ( view4 ,x lays b>e rocks :i* 7 be=e cov]$ & conceal$1 & is !nce call$ d5udation4 ,x r$uces ! surfaces ( m\nta9s1 plateaus1 & cont95ts1 & is !nce call$ degradation4 ,x c>ves new =ms ( l& f ^? :i* be=e exi/$1 & is !nce call$ l& sculpture4 ,9 ! foll[+ pages x w be consid]$ z l& sculpture1 & att5tion w be call$ to c]ta9 pr9ciples ( erosion :i* are conc]n$ 9 ! production ( topographic =ms4 ,sculpture & ,declivity4 ,we h already se5 t erosion is favor$ by declivity4 ,:]e ! declivity is great ! ag5ts ( erosion are p[]ful2 :]e x is small !y are weak2 :]e !re is no declivity !y are p[]less4 ,moreov] x has be5 %[n t _! p[] increases ) ! declivity 9 m ?an simple ratio4 ,x is evid5t t if /eep slopes are worn m rapidly ?an g5tle1 ! t5d5cy is to aboli% all diff]5ces ( slope & produce uni=mity4 ,! law ( uni=m slope ?us opposes div]sity ( topography1 & if n complem5t$ by o!r laws1 w\ld r$uce all dra9age bas9s to pla9s4 ,b 9 reality x is nev] free to "w out its full results2 = x dem&s a uni=mity ( conditions :i* n[h]e exi/s4 ,only a wat] %eet ( uni=m dep?1 fl[+ ov] a surface ( homog5e\s mat]ial1 w\ld suffice2 & e inequality ( wat] dep? or ( rock texture produces a correspond+ inequality ( slope & div]sity ( =m4 ,! reliefs ( ! l&scape exemplify o!r laws1 & ! law ( uni=m slopes is m]ely ! cons]vative elem5t :i* limits _! results4 ,sculpture & ,/ructure2 ! ,law ( ,/ructure4 ,we h already se5 t erosion is influ5c$ by rock "*4 ,c]ta9 rocks1 ( :i* ! h>d are mo/ conspicu\s1 oppose a /ubborn resi/ance to erosive ag5cies2 c]ta9 o!rs1 ( :i* ! s(t are mo/ conspicu\s1 oppose a feeble resi/ance4 ,erosion is mo/ rapid :]e ! resi/ance is lea/1 & h5ce z ! s(t rocks are worn away ! h>d are left prom95t4 ,! diff]5tiation cont9ues until an equilibrium is rea*$ ?r\gh ! law ( declivities4 ,:5 ! ratio ( erosive action z dep5d5t on declivities becomes equal to ! ratio ( resi/ances z dep5d5t on rock "*1 !re is equality ( action4 ,9 ! /ructure ( ! e>?'s cru/ h>d & s(t rocks are gr\p$ ) inf9ite div]sity ( arrangem5t4 ,!y are 9 masses ( all =ms1 & dim5sions1 & positions2 & f ^! =ms are c>v$ an inf9ite v>iety ( topographic reliefs4 ,9 s f> z ! law ( /ructure controls sculpture1 h>d masses /& z em95ces & s(t are c>v$ 9 valleys4 ,! ,law ( ,divides4 ,we h se5 t ! declivity ov] :i* wat] fl[s be>s an inv]se relation to ! quantity ( wat]4 ,if we foll[ a /ream f its m\? upw>d & pass successively ! m\?s ( its tribut>ies1 we f9d its volume gradually less & less & its grade /eep] & /eep]1 until f9ally at its head we rea* ! /eepe/ grade ( all4 ,if we draw ! pr(ile ( ! riv] on pap]1 we produce a curve concave upw>d & ) ! greate/ curvature at ! upp] end4 ,! same law applies to e tribut>y & ev5 to ! slopes ov] :i* ! fre%ly fall5 ra9 fl[s 9 a %eet be=e x is ga!r$ into rills4 ,! ne>] ! wat]%$ or divide ! /eep] ! slope2 ! f>!r away ! less ! slope4 ,x is 9 accordance ) ?is law t m\nta9s are /eepe/ at _! cre/s4 ,! pr(ile ( a m\nta9 if tak5 along dra9age l9es is concave outw>d z repres5t$ 9 ! diagram2 & ?is is purely a matt] ( sculpture1 ! uplifts f :i* m\nta9s are c>v$ r>ely if ev] assum+ ?is =m4 ,illu/ration3 ,,fig4 #ed4--,typical pr(ile ( ! ,dra9age ,slopes ( ,m\nta9s4 ,"u ! law ( ,/ructure & ! law ( ,divides comb9$1 ! features ( ! e>? are c>v$4 ,declivities are /eep 9 proportion z _! mat]ial is h>d2 & !y are /eep 9 proportion z !y are ne> divides4 ,! di/ribution ( h>d & s(t rocks1 or ! geological /ructure1 & ! di/ribution ( dra9age l9es & wat]%$s1 are coeffici5t conditions on :i* dep5ds ! sculpture ( ! l&4 ,9 ! sequel x w be %[n t ! di/ribution ( dra9age l9es & wat]%$s dep5ds 9 "p on t ( h>d & s(t rocks4 ,9 "s places ! fir/ ( ! two conditions is ! m important1 9 o!rs ! second4 ,9 ! b$ ( a /ream )\t tribut>ies ! grade dep5ds on ! /ructure ( ! und]ly+ rocks4 ,9 rock :i* is homog5e\s & /ructureless all slopes dep5d on ! di/ribution ( divides & dra9age l9es4 ,! relative importance ( ! two conditions is especially affect$ by climate1 & ! influ5ce ( ?is factor is s great t x may claim rank z a ?ird condition ( sculpture4 ,sculpture & ,climate4 ,! ,h5ry ,m\nta9s consi/ topographically ( five individuals1 sep>at$ by l[ passes1 & practically indep5d5t 9 climate4 ,at ! same "t !y are all ( "o type ( /ructure1 be+ con/itut$ by simil> aggregation ( h>d & s(t rocks4 ,_! altitudes appe> 9 ! foll[+ table4 ,altitude above ! sea4 ,m\nt ,ell5 #aa1bej feet4 ,m\nt ,p5nell #aa1aej feet4 ,m\nt ,hill]s #aj1ejj feet4 ,m\nt ,ellswor? #h1jjj feet4 ,m\nt ,holmes #g1gge feet4 ,! pla9 on :i* !y /& has a mean altitude ( #e1ejj feet1 & is a des]t4 ,a l>ge proportion ( ! ra9 :i* falls 9 ! region is caught by ! m\nta9s1 & especially by ! high] m\nta9s4 ,( ?is !re is abundant pro( 9 ! di/ribution ( vegetation & ( spr+s4 ,! vegetation ( ! pla9 is exce$+ly meag]1 compris+ only sp>sely set grasses & %rubs1 & 9 favor$ spots ! dw>f c$> ( ! ,we/ 7,junip]us occid5talis74 ,m\nt ,ell51 :i* has a cont9u\s ridge two miles long & m ?an #aa1jjj feet high1 be>s c$> ab\t its base1 m+l$ high] up ) pion 7,p9us edulis71 & succe$$ above by ! yell[ p9e 7,p4 pond]osa71 spruce 7,abies ,d\glasii71 fir 7,a4 ,engelmanni71 & asp5 7,populus tremuloides74 ,! p9es are scatt]+1 b ! c$>s are close set1 & ! firs are 9 d5se groves4 ,! upp] slopes :]e n timb]$ are matt$ ) luxuriant grasses & h]bs4 ,! summits are nak$4 ,m\nt ,p5nell s5ds a s+le peak only to ! height ( ! ,ell5 ridge4 ,its vegetation is ne>ly ! same1 b ! timb] ext5ds almo/ to ! summit4 ,m\nt ,hill]s is #fej feet l[]4 ,its timb] rea*es to ! pr9cipal summit1 b is less d5se ?an on ! high] m\nta9s4 ,! range ( trees is ! same4 ,m\nt ,ellswor?1 #b1ejj feet l[] ?an ,m\nt ,hill]s1 be>s nei!r fir1 spruce1 p9e nor asp54 ,c$> & pion climb to ! summit1 b are n s ?ickly set z on ! l[] slopes ( ! l>g] m\nta9s4 ,! grasses are less rank & gr[ 9 scatt]$ bun*es4 ,m\nt ,holmes1 a few feet l[]1 has ! same flora1 ) ! addition ( a score ( spruce trees1 high up on ! nor!rn flank4 ,its summits are b>e4 ,9 a ^w1 ! luxuriance ( vegetation1 & ! annual ra9fall1 ( :i* x is ! index1 are proportion$ to ! altitude4 ,consid] n[ ! =ms ( ! m\nta9 tops4 ,9 ,figure #ee are pictur$ ! summit =ms ( ,m\nt ,ell54 ,! cre/s are r\nd$2 ! slopes are uni=m & smoo?4 ,exam9ation has %[n t ! con/itu5t rocks are ( v>y+ degrees ( h>dness1 tra*yte dikes alt]nat+ ) s&/ones & %ales2 b ^! v>iations r>ely f9d expression 9 ! sculptur$ =ms4 ,9 ,figure #ef are ! summit crags ( ,m\nt ,holmes4 ,!y are dikes ( tra*yte d5ud$ by a discrim9at+ erosion ( _! encasem5ts ( s&/one1 & c>v$ 9 bold relief4 ,9 virtue ( _! sup]ior h>dness !y survive ! g5]al degradation4 ,illu/ration3 ,,fig4 #ee4--,! ,cre/ ( ,m\nt ,ell51 z se5 f ,ell5 ,peak4 ,illu/ration3 ,,fig4 #ef4--,! ,cre/ ( ,m\nt ,holmes4 ,! o!r m\nta9s are int]m$iate 9 ! "* ( _! sculpture4 ,m\nt ,p5nell is ne>ly z smoo? z ,m\nt ,ell54 ,m\nt ,ellswor? is ne>ly z rugg$ z ,m\nt ,holmes4 ,"o may ride to ! cre/ ( ,m\nt ,ell5 & to ! summit ( ,m\nt ,p5nell2 he may lead 8 sure-foot$ cayuse to ! top ( ,m\nt ,hill]s2 b ,m\nts ,ellswor? & ,holmes are n to be scal$ by horses4 ,! m\nta9e] mu/ climb to rea* _! summits1 & = "p ( ! way use h&s z well z feet4 ,9 a ^w1 ! rugg$ness ( ! summits or ! diff]5tiation ( h>d & s(t by sculpture1 is proportion$ inv]sely to ! altitude4 ,& ra9fall1 :i* 9 ^! m\nta9s dep5ds directly on altitude1 is proportion$ inv]sely to rugg$ness4 ,! explanation ( ?is co9cid5ce dep5ds on ! g5]al relations ( vegetation to erosion4 ,we h se5 t vegetation favors ! dis9tegration ( rocks & ret>ds ! transportation ( ! dis9tegrat$ mat]ial4 ,:]e vegetation is pr(use !re is always an excess ( mat]ial await+ transportation1 & ! limit to ! rate ( erosion comes to be m]ely ! limit to ! rate ( transportation4 ,& s9ce ! div]sities ( rock texture1 su* z h>dness & s(tness1 affect only ! rate ( dis9tegration 7wea!r+ & corrasion7 & n ! rate ( transportation1 ^! div]sities d n affect ! rate ( erosion 9 regions ( pr(use vegetation1 & d n produce correspond+ div]sities ( =m4 ,on ! o!r h&1 :]e vegetation is scant or abs5t1 transportation & corrasion are favor$1 :ile wea!r+ is ret>d$4 ,!re is no accumulation ( dis9tegrat$ mat]ial4 ,! rate ( erosion is limit$ by ! rate ( wea!r+1 & t v>ies ) ! div]sity ( rock texture4 ,! s(t are eat5 away fa/] ?an ! h>d2 & ! /ructure is embodi$ 9 ! topographic =ms4 ,?us a moi/ climate by /imulat+ vegetation produces a sculpture indep5d5t ( div]sities ( rock texture1 & a dry climate by repress+ vegetation produces a sculpture dep5d5t on ^? div]sities4 ,) great moi/ure ! law ( divides is supreme2 ) aridity1 ! law ( /ructure4 ,h5ce x is t ! upp] slopes ( ! l(ti] ( ! ,h5ry ,m\nta9s are s c>v$ z to conceal ! /ructure1 :ile ! l[] slopes ( ! same m\nta9s & ! entire =ms ( ! less l(ty m\nta9s are s c>v$ z to reveal ! /ructure2 & h5ce too x is t ! arid plateaus ( ! ,colorado ,bas9 ab\nd 9 cliffs & caons1 & (f] facilities to ! /ud5t ( geological /ructure :i* no humid region c af=d4 ,"h too is ! answ] to ! "q s (t5 ask$1 8:e!r ! ra9s & riv]s :i* excavat$ ! caons & c>v$ ! cliffs 7 n mighti] ?an ! ra9s & riv]s ( to-day40 ,aridity be+ an ess5tial condition ( ?is peculi> type ( sculpture1 we may be sure t ?r\gh long ages x has *>act]iz$ ! climate ( ! ,colorado ,bas94 ,a climate ( great ra9fall1 z ,pr(essor ,p[ell has already po9t$ out 9 8 8,exploration ( ! ,colorado10 w\ld h produc$ curves & g5tle slopes 9 place ( ! actual angles & cliffs4 ,bad-l&s4 ,m\nta9 =ms 9 g5]al dep5d m on ! law ( divides ?an on ! law ( /ructure1 b _! indep5d5ce ( /ructure is r>ely p]fect1 & x is difficult to discrim9ate ! results ( ! two pr9ciples4 ,= ! inve/igation ( ! work+s ( ! law ( divides x is bett] to select examples f regions :i* af=d no v>iety ( rock texture & are h5ce unaffect$ 9 _! erosion by ! law ( /ructure4 ,su* examples are f\nd 9 bad-l&s4 ,:]e a homog5e\s1 s(t rock is subject$ to rapid degradation 9 an arid climate1 its surface becomes absolutely b>e ( vegetation & is c>v$ into =ms ( great regul>ity & beauty4 ,9 ! neighborhood ( ! ,h5ry ,m\nta9s1 ! ,blue ,gate & ,tununk %ales are ( ?is "*1 & _! exposures af=d _m opportunities = ! /udy ( ! pr9ciples ( sculpture4 ,i 0 able to devote no "t to !m1 b 9 rid+ across !m my att5tion 0 attract$ by "s ( ! m /rik+ features1 & ^! ,i w v5ture to pres5t1 al?\gh ,i am consci\s t !y =m b a small "p ( ! :ole mat]ial :i* ! bad-l&s may be made to yield4 ,if we exam9e a bad-l& ridge1 sep>at+ two dra9age l9es & =m+ a divide betwe5 !m1 we f9d an arrangem5t ( second>y ridges & second>y dra9age l9es1 simil> to t repres5t$ 9 ! diagram1 7,figure #eh47 ,illu/ration3 ,,fig4 #eg4--;,g5]al view ( ! ,plateaus ly+ ,ea/ ( ! ,h5ry ,m\nta9s4 ,! g5]al c\rse ( ! ma9 ridge be+ /raight1 its c\rse 9 detail is f\nd to be> a simple relation to ! second>y ridges4 ,:]ev] a second>y jo9s1 ! ma9 ridge turns1 its angle be+ directly t[>d ! second>y4 ,! divide ?us foll[s a zigzag c\rse1 be+ deflect$ to ! "r or left by ea* lat]al spur4 ,! altitude ( ! ma9 ridge is correspond+ly relat$ to ! second>y ridges4 ,at e po9t ( union !re is a maximum1 & 9 ! int]vals are saddles4 ,! maxima are n all equal1 b be> "s relation to ! magnitudes ( ! correspond+ second>y ridges1 & are especially acc5t$ :]e two or m second>ies jo9 at ! same po9t4 7,see pr(ile 9 ,figure #ei47 ,i conceive t ! explanation ( ^! ph5om5a is z foll[s3 ,! heads ( ! second>y dra9age l9es laid d[n 9 ! diagram are 9 nature tol]ably def9ite po9ts4 ,! wat] :i* dur+ ra9 conv]ges at "o ( ^! po9ts is !re abruptly conc5trat$ 9 volume4 ,above ! po9t x is a %eet1 or at lea/ is divid$ into _m rills4 ,bel[ x1 x is a s+le /ream ) greatly increas$ p[] ( transportation & corrasion4 ,! pr9ciple ( equal action gives to ! conc5trat$ /ream a less declivity ?an to ! diffus$ %eet1 &--:at is especially important--x t5ds to produce an equal grade 9 all directions upw>d f ! po9t ( conv]g5ce4 ,! conv]g+ surface becomes hopp]-%ap$ or funnel-%ap$2 & z ! po9t ( conv]g5ce is l[]$ by corrasion1 ! walls ( ! funnel are eat5 back equally 9 all directions--except ( c\rse ! direction ( ! /ream4 ,! influ5ce ( ! /ream 9 /imulat+ erosion above its head is ?us ext5d$ radially & equally ?r\gh an arc ( #ahj1 ( :i* ! c5t] is at ! po9t ( conv]g5ce4 ,:]e two /reams head ne> ea* o!r1 ! influ5ce ( ea* t5ds to p>e away ! divide betwe5 !m1 & by p>+ to c>ry x f>!r back4 ,! position ( ! divide is det]m9$ by ! two influ5ces comb9$ & repres5ts ! l9e ( equilibrium betwe5 !m4 ,! influ5ces be+ radial f ! po9ts ( conv]g5ce1 ! l9e ( equilibrium is tang5tial1 & is consequ5tly at "r angles to a l9e connect+ ! two po9ts4 ,?us1 = example1 if a1 b1 & c 7,figure #eh7 are ! po9ts ( conv]g5ce at ! heads ( ?ree dra9age l9es1 ! divide l9e ed is at "r angles to a l9e connect+ a & b1 & ! divides fd & gd are simil>ly det]m9$4 ,! po9t d is simultane\sly det]m9$ by ! int]section ( ! ?ree divide l9es4 ,illu/ration3 ,,fig4 #eh4--;,gr\nd plan ( a ,bad-l& ,ridge1 %[+ its relation to ,wat]ways4 ,! smoo? l9es repres5t ,divides4 ,,fig4 #ei4--,pr(ile ( ! same ridge4 ,fur!rmore1 s9ce t po9t ( ! l9e ed :i* lies directly betwe5 a & b is ne>e/ to ^? po9ts1 x is ! po9t ( ! divide mo/ subject to ! erosive influ5ces :i* radiate f a & b1 & x is consequ5tly degrad$ l[] ?an ! contigu\s portions ( ! divide4 ,! po9ts d & e are less r$uc$2 & d1 :i* c be %[n by simil> reason+ to /& high] ?an ! adjac5t portion ( ei!r ( ! ?ree ridges :i* !re unite1 is a local maximum4 ,!re is "o o!r peculi>ity ( bad-l& =ms :i* is ( great significance1 b :i* ,i %all nev]!less n und]take to expla94 ,accord+ to ! law ( divides1 z /at$ 9 a previ\s p>agraph1 ! pr(ile ( any slope 9 bad-l&s %\ld be concave upw>d1 & ! slope %\ld be /eepe/ at ! divide4 ,! union or int]section ( two slopes on a divide %\ld produce an angle4 ,b 9 po9t ( fact ! slopes d n unite 9 an angle4 ,!y unite 9 a curve1 & ! pr(ile ( a dra9age slope in/ead ( be+ concave all ! way to its summit1 *anges its curvature & becomes convex4 ,figure #fj repres5ts a pr(ile f a to b ( ,figure #eh4 ,f a to m & f b to n ! slopes are concave1 b f m to n !re is a convex curvature4 ,:]e ! flank+ slopes are z /eep z repres5t$ 9 ! diagram1 ! convexity on ! cre/ ( a ridge has a bread? ( only two or ?ree y>ds1 b :]e ! flank+ slopes are g5tle1 its bread? is sev]al times z great4 ,x is nev] abs5t4 ,?us 9 ! sculpture ( ! bad-l&s !re is reveal$ an exception to ! law ( divides1--an exception :i* _c be ref]r$ to accid5ts ( /ructure1 & :i* is z p]si/5t 9 its recurr5ce z are ! features :i* con=m to ! law1--an exception :i* 9 "s unexpla9$ way is "p ( ! law4 ,our analysis ( ! ag5cies & conditions ( erosion1 on ! "o h&1 has l$ to ! conclusion t 7:]e /ructure does n prev5t7 ! declivities ( a cont9u\s dra9age slope increase z ! quantities ( wat] fl[+ ov] !m decrease2 & t !y are great 9 proportion z !y are ne> divides4 ,our obs]vation1 on ! o!r h&1 %[s t ! declivities increase z ! quantities ( wat] dim9i%1 up to a c]ta9 po9t :]e ! quantity is v small1 & !n decrease2 & t declivities are great 9 proportion z !y are ne> divides1 unless !y are v ne> divides4 ,evid5tly "s factor has be5 ov]look$ 9 ! analysis1--a factor :i* 9 ! ma9 is less important ?an ! fl[ ( wat]1 b :i* ass]ts its exi/5ce at ^? po9ts :]e ! fl[ ( wat] is exce$+ly small1 & is !re supreme4 ,illu/ration3 ,,fig4 #fj4--;,cross-pr(ile ( a ,bad-l& ,divide4 ,equal ,action & ,int]dep5d5ce4 ,! t5d5cy to equality ( action1 or to ! e/abli%m5t ( a dynamic equilibrium1 has already be5 po9t$ out 9 ! discussion ( ! pr9ciples ( erosion & ( sculpture1 b "o ( its mo/ important results has n be5 notic$4 ,( ! ma9 conditions :i* det]m9e ! rate ( erosion1 namely1 quantity ( runn+ wat]1 vegetation1 texture ( rock1 & declivity1 only ! la/ is reciprocally det]m9$ by rate ( erosion4 ,declivity orig9ates 9 upheaval1 or 9 ! displacem5ts ( ! e>?'s cru/ by :i* m\nta9s & cont95ts are =m$2 b x receives its di/ribution 9 detail 9 accordance ) ! laws ( erosion4 ,:]ev] by reason ( *ange 9 any ( ! conditions ! erosive ag5ts come to h locally exceptional p[]1 t p[] is /eadily dim9i%$ by ! reaction ( rate ( erosion ^u declivity4 ,e slope is a memb] ( a s]ies1 receiv+ ! wat] & ! wa/e ( ! slope above x1 & dis*>g+ its own wat] & wa/e ^u ! slope bel[4 ,if "o memb] ( ! s]ies is erod$ ) exceptional rapidity1 two ?+s imm$iately result3 fir/1 ! memb] above has its level ( dis*>ge l[]$1 & its rate ( erosion is !reby increas$2 & second1 ! memb] bel[1 be+ clogg$ by an exceptional load ( detritus1 has its rate ( erosion dim9i%$4 ,! accel]ation above & ! ret>dation bel[1 dim9i% ! declivity ( ! memb] 9 :i* ! di/urbance orig9at$2 & z ! declivity is r$uc$ ! rate ( erosion is likewise r$uc$4 ,b ! effect does n /op "h4 ,! di/urbance :i* has be5 transf]r$ f "o memb] ( ! s]ies to ! two :i* adjo9 x1 is by !m transmitt$ to o!rs1 & does n cease until x has rea*$ ! conf9es ( ! dra9age bas94 ,= 9 ea* bas9 all l9es ( dra9age unite 9 a ma9 l9e1 & a di/urbance ^u any l9e is communicat$ ?r\gh x to ! ma9 l9e & !nce to e tribut>y4 ,& z any memb] ( ! sy/em may influ5ce all ! o!rs1 s ea* memb] is influ5c$ by e o!r4 ,!re is an int]dep5d5ce ?r\gh\t ! sy/em4 ,,iii4--,,sy/ems ,,( ,,dra9age4 ,to "k well ! dra9age ( a region two sy/ems ( l9es mu/ be asc]ta9$--! dra9age l9es & ! divides4 ,! maxima ( surface on :i* wat]s "p1 & ! m9ima ( surface 9 :i* wat]s jo91 are alike intimately associat$ ) ! sculpture ( ! e>? & ) ! hi/ory ( ! e>?'s /ructure2 & ! /ud5t ( ei!r sculpture or hi/ory c well af=d to /udy !m4 ,9 ! foll[+ pages c]ta9 conditions :i* affect _! p]man5ce & trans=mations are discuss$4 ,,! ,,/ability ,,( ,,dra9age ,,l9es4 ,9 corrasion ! *ief "w is p]=m$ by ! impact & friction ( h>d & heavy p>ticles mov$ =w>d by runn+ wat]4 ,!y are driv5 aga9/ all sides ( ! *annel1 b _! t5d5cy to s9k 9 wat] br+s !m aga9/ ! bottom ) great] frequ5cy & =ce ?an aga9/ ! walls4 ,if ! rate ( we> be rapid1 by f> ! great] "p ( x is appli$ to ! bottom1 & ! d[nw>d corrasion is s mu* m p[]ful ?an ! lat]al t ! effect ( ! latt] is practically lo/1 & ! *annel ( ! /ream1 )\t v>y+ ! position ( its banks1 c>ves its way v]tically into ! rock b5ea?4 ,x is only :5 corrasion is exce$+ly sl[ t ! lat]al we> becomes ( importance2 & h5ce z a rule ! position ( a /ream b$ is p]man5t4 ,! /ability ( dra9age l9es is especially illu/rat$ 9 regions ( displacem5t4 ,if a m\nta9 is sl[ly lift$ a?w>t ! c\rse ( a /ream1 ! corrasion ( ! latt] is accel]at$ by ! increase ( declivity1 & in/ead ( be+ turn$ aside by ! uplift1 x p]si/5tly holds its place & c>ves a *annel into ! m\nta9 z ! m\nta9 rises4 ,= example ! deep clefts :i* int]sect ! ,wasat* range owe _! exi/5ce to ! fact t at ! "t ( ! beg9n+ ( ! uplift :i* has made ! range1 !re 7 /reams fl[+ across ! l9e ( its tr5d :i* 7 too p[]ful to be turn$ back by ! gr[+ ridge4 ,! same relation has be5 %[n by ,pr(essor ,p[ell :]e ! ,gre5 ,riv] crosses ! uplift ( ! ,u9ta ,m\nta9s1 & 9 _m in/ances ?r\gh\t ! ,rocky ,m\nta9 region x may be said t riv]s h cut _! way ?r\gh m\nta9s m]ely because !y _h e/abli%$ _! c\rses be=e ! inception ( ! displacem5t1 & c\ld n be div]t$ by an ob/ruction :i* 0 ?r[n up ) ! sl[ness ( m\nta9 uplift4 ,,! ,,in/ability ,,( ,,dra9age ,,l9es4 ,! /ability ( wat]ways be+ ! rule1 e case ( in/ability requires an explanation2 & 9 ! /udy ( su* exceptional cases !re h be5 f\nd a numb] ( diff]5t me?ods by :i* ! c\rses ( /reams are %ift$4 ,! m important w be not$4 ,pond+4 ,:5 a m\nta9 uplift crosses ! c\rse ( a /ream1 x (t5 happ5s t ! rate ( uplift is too rapid to be equal$ by ! corrasion ( ! /ream1 & ! upris+ rock becomes a dam ov] :i* ! wat] /ill runs1 b above :i* !re is accumulat$ a pond or lake4 ,:5ev] ?is takes place1 ! pond cat*es all ! dbris ( ! upp] c\rse ( ! /ream1 & ! wat] :i* ov]fl[s at ! outlet hav+ be5 reliev$ ( its load is almo/ p[]less = corrasion1 & _c cont9ue its conte/ ) ! uplift unless ! pond is silt$ up ) detritus4 ,z ! uplift progresses ! level ( ! pond is rais$ high] & high]1 until f9ally x f9ds a new outlet at "s o!r po9t4 ,! orig9al outlet is at once ab&on$1 & ! new "o becomes a p]man5t "p ( ! c\rse ( ! /ream4 ,z a rule x is only l>ge /reams :i* hold _! c\rses :ile m\nta9s rise2 ! small] are turn$ back by pond+1 & are usually div]t$ s z to jo9 ! l>g]4 ,! di/urbances :i* div]t dra9age l9es are n always ( ! sort :i* produce m\nta9s4 ,! same results may foll[ ! mo/ g5tle undulations ( pla9s4 ,x requir$ a movem5t ( a few feet only to *ange ! outlet ( ,lakes ,mi*igan1 ,huron1 & ,sup]ior f ! ,ill9ois ,riv] to ! ,/4 ,clair2 & 9 ! tilt+ :i* turn$ ,lake ,w9ipeg f ! ,mississippi to ! ,nelson no abrupt slopes 7 produc$4 ,if ! entire hi/ory ( ! latt] case 7 work$ out1 x w\ld probably appe> t ! ,saskat*ewan ,riv] :i* rises 9 ! ,rocky ,m\nta9s beyond our nor!rn b\nd>y1 0 =m]ly ! upp] c\rse ( ! ,mississippi1 & t :51 by ! ris+ ( l& 9 ,m9nesota or its s9k+ at ! nor?1 a b>ri] 0 =m$1 ! wat] 0 pond$ & ,lake ,w9ipeg came into exi/5ce4 ,by ! cont9uance ( ! movem5t ( ! l& ! lake 0 increas$ until x ov]fl[$ into ,hudson's ,bay2 & by its fur!r cont9uance1 comb9$ ) ! corrasion ( ! outlet1 ! lake has be5 aga9 dim9i%$4 ,:5 ev5tually ! lake disappe>s ! revolution w be complete1 & ! ,saskat*ewan w fl[ directly to ,hudson's ,bay1 z x once fl[$ directly to ! ,gulf ( ,mexico4 7,see ! 8,physical ,features ( ! ,valley ( ! ,m9nesota ,riv]10 by ,g5]al ,g4 ,k4 ,w>r547 ,planation4 ,x has be5 %[n 9 ! discussion ( ! relations ( transportation & corrasion t d[nw>d we> ceases :5 ! load equals ! capacity = transportation4 ,:5ev] ! load r$uces ! d[nw>d corrasion to little or no?+1 lat]al corrasion becomes relatively & actually ( importance4 ,! fir/ result ( ! we>+ ( ! walls ( a /ream's *annel is ! =mation ( a flood-pla94 ,z an effect ( mom5tum ! curr5t is always swifte/ along ! outside ( a curve ( ! *annel1 & x is !re t ! we>+ is p]=m$2 :ile at ! inn] side ( ! curve ! curr5t is s sl[ t "p ( ! load is deposit$4 ,9 ?is way ! wid? ( ! *annel rema9s ! same :ile its position is %ift$1 & e "p ( ! valley :i* x has cross$ 9 its %ift+s comes to be cov]$ by a deposit :i* does n rise above ! highe/ level ( ! wat]4 ,! surface ( ?is deposit is h5ce appropriately call$ ! flood-pla9 ( ! /ream4 ,! deposit is ( ne>ly uni=m dep?1 desc5d+ no l[] ?an ! bottom ( ! wat]-*annel1 & x re/s ^u a tol]ably ev5 surface ( ! rock or o!r mat]ial :i* is corrad$ by ! /ream4 ,! process ( c>v+ away ! rock s z to produce an ev5 surface1 & at ! same "t cov]+ x ) an alluvial deposit1 is ! process ( planation4 ,x sometimes happ5s t two adjac5t /reams by ext5d+ _! areas ( planation eat ?r\gh ! divid+ ridge & jo9 _! *annels4 ,! /ream :i* has ! high] surface at ! po9t ( contact1 quickly ab&ons ! l[] "p ( its *annel & becomes a bran* ( ! o!r1 hav+ %ift$ its c\rse by planation4 ,! slopes ( ! ,h5ry ,m\nta9s illu/rate ! process 9 a peculi>ly /rik+ mann]4 ,! /reams :i* fl[ d[n !m are limit$ 9 _! rate ( degradation at bo? ends4 ,at _! s\rces1 erosion is oppos$ by ! h>dness ( ! rocks2 ! tra*ytes & metamorphics ( ! m\nta9 tops are c>v$ v sl[ly4 ,at _! m\?s1 !y dis*>ge into ! ,colorado & ! ,dirty ,devil1 & _c s9k _! *annels m rapidly ?an d ^? riv]s4 ,betwe5 ! m\nta9s & ! riv]s1 !y cross rocks :i* are s(t 9 comp>ison ) ! tra*yte1 b !y c deep5 _! *annels ) no great] rapidity ?an at _! ends4 ,! grades h adju/$ !mselves accord+ly4 ,among ! h>d rocks ( ! m\nta9s ! declivities are great1 s z to give effici5cy to ! erod+ wat]4 ,among ! s$im5t>y rocks ( ! base !y are small 9 comp>ison1 ! *ief "w ( ! /reams be+ ! transportation ( ! tra*yte dbris4 ,s greatly are ! /reams conc]n$ 9 transportation1 & s little 9 d[nw>d corrasion 7outside ! tra*yte region71 t _! grades are almo/ unaffect$ by ! diff]5ces ( rock texture1 & !y pass ?r\gh s&/one & %ale ) ne>ly ! same declivity4 ,! rate ( d[nw>d corrasion be+ ?us limit$ by extrane\s conditions1 & ! in/rum5t ( corrasion--! dbris ( ! h>d tra*yte--be+ effici5t1 lat]al corrasion is limit$ only by ! resi/ance :i* ! banks ( ! /reams oppose4 ,:]e ! mat]ial ( ! banks is a firm s&/one1 n>r[ flood-pla9s are =m$2 & :]e x is a %ale1 broad ones4 ,9 ! ,gray ,cliff & ,v]milion ,cliff s&/ones flat-bottom$ caons are excavat$2 b 9 ! great %ale b$s broad valleys are op5$1 & ! flood-pla9s ( adjac5t /reams coalesce to =m cont9u\s pla9s4 ,! broade/ pla9s are z a rule c>v$ f ! ?icke/ b$s ( %ale1 & ^! are f\nd at ! top ( ! ,jura-,trias & ne> ! base ( ! ,cretace\s4 ,:]e ! /reams f ! m\nta9s cross ! ,blue ,gate1 ! ,tununk1 or ! ,flam+ ,gorge %ale at a favorable angle1 a pla9 is ! result4 ,! pla9 :i* lies at ! s\!rn & we/]n bases ( ,m\nt ,hill]s is c>v$ *iefly f ! ,tununk %ale 7see ,figure #bg74 ,! pla9 slop+ ea/w>d f ,m\nt ,p5nell 7,figure #cf7 is c>v$ f ! ,blue ,gate & ,tununk %ales4 ,! ,lewis ,creek pla91 :i* lies at ! we/]n base ( ,m\nt ,ell51 is =m$ f ! ,blue ,gate1 ,tununk1 & ,masuk %ales1 & ! planation :i* produc$ x has s p]fectly truncat$ ! ,tununk & ,blue ,gate s&/ones t _! outcrops _c be trac$ 7,figures #fa1 #ci1 & #db74 ,! pla9 :i* truncates ! ,cresc5t ar* 7,figure #di7 is c>v$ 9 *ief "p f ! ,flam+ ,gorge %ale4 ,t[>d ! ea/ x is limit$ by ! outcrops ( ! ,h5ry's ,=k conglom]ate1 b t[>d ! m\nta9 x cuts across ! edge ( ! same conglom]ate & ext5ds ov] ,tununk %ale to ! m>g9 ( ! tra*yte4 ,illu/ration3 ,,fig4 #fa4--;,cross-section ( ! ,lewis ,creek ,pla94 ,m1 ,masuk ,%ale4 ,,bg1 ,blue ,gate ,gr\p4 ,t1 ,tununk ,gr\p4 ,,hf1 ,h5ry's ,=k conglom]ate4 ,scale1 #a in* #d1jjj feet4 ,! /reams :i* made ^! pla9s & :i* ma9ta9 !m1 accompli% _! "w by a cont9ual %ift+ ( _! *annels2 & :]e ! pla9s are be/ develop$ !y employ ano!r me?od ( %ift+--a me?od :i* 9 its prop] logical ord] mu/ be treat$ 9 ! discussion ( alluvial cones1 b :i* is practically comb9$ 9 ! ,h5ry ,m\nta9s ) ! me?od ( planation4 ,! supply ( detritus d]iv$ f ! erosion ( ! tra*yte is n entirely con/ant4 ,n only is m c>ri$ out 9 "o season ?an ano!r & 9 "o ye> ?an ano!r1 b ! "w is accompli%$ 9 "p by sudd5 /orms :i* create great floods & z sudd5ly cease4 ,x results f ?is irregul>ity t ! *annels are sometimes *ok$ by dbris1 & t by ! *ok+ ( ! *annels ! /reams are turn$ aside to seek new c\rses ^u ! g5]al pla94 ,! ab&on$ c\rses rema9 pla9ly m>k$1 & "o :o looks d[n on !m f "s comm&+ em95ce c (t5 trace out _m /ages 9 ! hi/ory ( ! dra9age4 ,:]e a s]ies ( /reams em]ge f adjac5t m\nta9 gorges ^u a common pla91 _! %ift+s br+ ab\t frequ5t unions & sep>ations1 & produce a v>iety ( comb9ations4 ,illu/ration3 ,,fig4 #fb4--;,ideal sket* to illu/rate ! ,%ift+ ( wat]ways on a slope ( ,planation4 ,! accompany+ sket*1 ,figure #fb1 is n f nature1 b x s]ves to illu/rate ! "* ( ! *anges4 ,! /reams :i* issue f ! m\nta9 gorges a & b jo9 & fl[ to z2 :ile t :i* issues at c fl[s alone to x4 ,an ab&on$ *annel1 n1 %[s t ! /ream f b 0 =m]ly unit$ ) t f c1 & fl[$ to x2 & ano!r *annel1 m1 %[s t x has at "s "t ma9ta9$ an indep5d5t c\rse to y4 ,by su* %ift+s /reams are sometimes *ang$ f "o dra9age sy/em to ano!r2 ! hypo!tical c\rses1 x1 y1 & z1 may lead to diff]5t riv]s1 & to diff]5t oceans4 ,an in/ance occurs on ! we/]n flank ( ! m\nta9s4 ,"o ( ! pr9cipal heads ( ,p9e ,alcove ,creek rises on ! s\? slope ( ,m\nt ,ell5 & ano!r on ! nor?we/ slope ( ,m\nt ,p5nell4 ,! two unite & fl[ s\?w>d to ! ,colorado ,riv]4 ,!y d n n[ cross an area ( planation1 b at an e>li] /age ( ! degradation !y did2 & ! portions ( t pla9 :i* survive1 indicate by ! direction ( _! slopes t "o or bo? ( ! /reams may h !n dis*>g$ its wat] into ,lewis ,creek1 :i* runs nor?w>d to ! ,dirty ,devil ,riv]4 ,z ! g5]al degradation ( ! region progresses ! /reams & _! pla9s s9k l[]1 & ev5tually ea* pla9 is sunk completely ?r\gh ! %ale ^: s(tness made x possible4 ,s soon z ! /reams rea* h>d] rock _! lat]al corrasion is *eck$1 & !y are no long] free to *ange _! ways4 ,:]ev] !y *ance to run at t "t1 !re !y /ay & c>ve = !mselves caons4 ,portions ( ! des]t$ pla9s rema9 betwe5 ! caons1 & hav+ a durable capp+ ( tra*yte gravel are long pres]v$4 ,su* /r&$ fragm5ts ab\nd on ! slopes ( ! m\nta9s1 & 9 !m "o may read _m pages ( ! hi/ory ( ! degradation4 ,!y =m tabul> hills ) slop+ tops & ev5 pr(iles4 ,! top ( ea* hill is cov]$ ) a uni=m lay] ( gravel1 b5ea? :i* ! solid rock is smoo?ly truncat$4 ,! slope ( ! hill dep5ds on ! grade ( ! anci5t /ream1 & is indep5d5t ( ! h>dness & dip ( ! /rata4 ,! illu/ration repres5ts a hill ( planation on ! nor? slope ( ,m\nt ,ellswor?4 ,x is built ( ! ,gray ,cliff s&/one & ,flam+ ,gorge %ale1 incl9$ at angles v>y+ f #be to #de2 b not)/&+ _! v>iety ( texture & dip ! edges ( ! /rata are ev5ly cut away1 s t _! upp] surface con/itutes a plane4 ,! /ream :i* p]=m$ ?is truncation aft]w>d cut deep] into ! /rata & c>v$ ! l[] table :i* =ms ! =egr\nd ( ! sket*4 ,x has n[ ab&on$ ?is pla9 also & fl[s ?r\gh a /ill deep] *annel on ! opposite side ( ! hill4 ,illu/ration3 ,,fig4 #fc4--;,a ,hill ( ,planation4 ,! ph5om5a ( planation are fur!r illu/rat$ 9 ! region :i* lies to ! nor?we/ ( ! ,h5ry ,m\nta9s4 ,tantalus & ,temple ,creeks1 ris+ "u ! edge ( ! ,aqu>ius ,plateau1 transport ! tra*yte ( ! plateau across ! region ( ! ,wat]pocket flexure to ! ,dirty ,devil ,riv]4 ,_! flood-pla9s are n n[ ( great ext5t1 b :5 _! dra9age l9es ran a few hundr$ feet high] !y appe> to h c>v$ into a s+le pla9 a broad exposure ( ! ,flam+ ,gorge %ale1 :i* !n lay betwe5 ! ,wat]pocket & ,blue ,gate flexures4 ,at ! ,r$ ,gate :]e ! ,dirty ,devil ,riv] passes f a di/rict ( tra*yte plateaus to ! di/rict ( ! ,great ,flexures1 x foll[s = a few miles ! outcrop ( ! ,%9>ump %ale1 & ! remnants ( its ab&on$ flood-pla9s =m a s]ies ( t]races ^u ea* bank4 ,small /reams f ! sides h cut across ! b5*es & display$ _! /ructure4 ,ea* "o is c>v$ f ! rock 9 situ1 b ea* is cov]$ by a lay] ( ! r\nd$ riv] gravel4 ,! :ole are results ( planation2 & !y s]ve to connect ! some:at peculi> features ( ! m\nta9 slopes ) ! ord9>y t]races ( riv]s4 ,illu/ration3 ,,fig4 #fd4--;,ideal cross-section ( a ,t]rac$ ,riv] ,valley1 aft] ,hit*cock4 ,a1 ,b1 ,c1 ,d1 ,e1 & ,f1 ,alluvial deposits4 ,g1 ,indurat$ rock1 9 situ4 ,riv] t]races z a rule are c>v$ out1 & n built up4 ,!y are always ! ve/iges ( flood-pla9s1 & flood-pla9s are usually produc$ by lat]al corrasion4 ,!re are in/ances1 especially ne> ! sea-coa/1 ( riv]-pla9s :i* h orig9at$ by ! silt+ up ( valleys1 & h be5 aft]w>d p>tially de/roy$ by ! same riv]s :5 "s *ange ( level p]mitt$ !m to cut _! *annels deep]2 & ^! in/ances1 conspir+ ) ! fact t ! surfaces ( flood-pla9s are alluvial1 & ) ! fact t _m t]races 9 glacial regions are c>v$ f unconsolidat$ drift1 h l$ "s ,am]ican geologi/s into ! error ( suppos+ t riv] t]races 9 g5]al are ! records ( s$im5tation1 :5 9 fact !y record ! /ages ( a progressive corrasion4 ,! ideal section ( a t]rac$ riv] valley :i* ,i reproduce f ,hit*cock 7,surface ,geology1 ,plate ,,xii1 figure #a7 reg>ds ea* t]race z ! remnant ( a sep>ate deposit1 built up f ! bottom ( ! valley4 ,to illu/rate my own idea ,i h copi$ 8 pr(ile 7,figure #fe7 & int]pret$ its features z ! results ( lat]al corrasion or planation1 giv+ ea* b5* a capp+ ( alluvium1 b con/itut+ x o!rwise ( ! prexi/5t mat]ial ( ! valley4 ,! prexi/5t mat]ial 9 ! region ( ! ,h5ry ,m\nta9s is always rock 9 situ1 b 9 ! ,nor!rn ,/ates x (t5 includes glacial drift1 modifi$ or unmodifi$4 ,!re is a k9dr$ error1 z ,i conceive1 involv$ 9 ! assumption t ! /reams :i* occupi$ ! upp] & broad] flood-pla9s ( a valley 7 great] ?an ^? :i* h succe$$ !m4 ,!y may h be51 or !y may n4 ,9 ! process ( lat]al corrasion all ! mat]ial t is worn f ! bank has to be transport$ by ! wat]1 & :]e ! bank is high ! "w proce$s less rapidly ?an :]e x is l[4 ,a /ream :i* degrades its imm$iate valley m rapidly ?an ! surr\nd+ c\ntry is degrad$ 7& ! /reams :i* ab\nd 9 t]races are ( ?is "*7 /eadily increases ! height ( ! banks :i* mu/ be excavat$ 9 planation & dim9i%es ! ext5t ( its flood-pla92 & ?is might occur ev5 if ! volume ( ! /ream 0 progressively increas+ in/ead ( dim9i%+4 ,illu/ration3 ,,fig4 #fe4--;,ideal cross-section ( a ,t]rac$ ,riv] ,valley1 reg>d$ z a result ( ,planation4 ,a1 ,b1 ,c1 c41 ,alluvial deposits4 ,g1 ,prexi/5t mat]ial f :i* ! valley 0 excavat$4 ,( ! same ord] also is ! mi/ake1 occasionally made ( ignor+ ! excavation :i* a /ream has p]=m$1 & assum+ t :5 ! upp] t]races 7 made ! valley 0 z op5 z at pres5t1 & ! volume ( fl[+ wat] 0 great en\gh to fill x4 ,alluvial ,cones4 ,:]ev] a /ream is engag$ 9 deposition in/ead ( corrasion--:]ev] x deposits its load--!re is a %ift+ ( *annel by a ?ird process4 ,! deposition ( s$im5t takes place ^u ! bottom ( ! *annel & ^u its imm$iate banks1 & ?is cont9ues until ! *annel bottom is high] ?an ! adjac5t c\ntry4 ,! wall ( ! *annel is !n brok5 ?r\gh at "s po9t1 & ! wat] ab&ons its old b$ = "o :i* is l[]4 ,su* occurr5ces belong to ! hi/ories ( all riv] deltas1 & ! deva/ation !y h wr\ght at ! m\?s ( l>ge riv]s has en=c$ att5tion to _! ph5om5a & /imulat$ a /udy ( _! causes4 ,! same ?+ happ5s among ! m\nta9s4 ,:]ev]1 z 9 ,nevada & ,we/]n ,utah1 ! valleys are ! receptacles ( ! detritus wa%$ out f ! m\nta9s1 ! foot-slopes ( ! m\nta9s consi/ ( a s]ies ( alluvial cones4 ,f ea* m\nta9 gorge ! products ( its erosion are dis*>g$ into ! valley4 ,! /ream :i* be>s ! dbris builds up ! b$ ( its *annel until x is high] ?an ! adjac5t l& & !n ab&ons x1 & by ! repetition ( ?is process accumulates a conical hill ( detritus :i* slopes equally 9 all directions f ! m\? ( ! m\nta9 gorge4 ,at "o "t or ano!r ! wat] runs ov] e "p ( ! cone & leaves x by e "p ( its base2 & x sometimes happ5s t ! opposite slopes ( ! cone lead to diff]5t dra9age sy/ems4 ,an illu/ration may be se5 9 ,r$ ,rock ,pass at ! nor? end ( ,ca*e ,valley1 ,idaho4 ,lake ,bonneville1 ! anci5t expansion ( ,great ,salt ,lake1#f "h f\nd outlet to ! bas9 ( ! ,columbia1 & ! *annel c>v$ by its wat] is pla9ly m>k$4 ,= a di/ance ( twelve miles ! b$ ( ! *annel is ne>ly level1 ) a wid? ( a ?\s& feet4 ,midway1 ,m>% ,creek ent]s x f ! ea/1 & has built an alluvial cone :i* ext5ds to ! opposite bank & divides x into two p>ts4 ,9 ! con/ruction ( ! cone ,m>% ,creek has fl[$ alt]nately to ! nor? & to ! s\?1 be+ 9 "o case a tribut>y to ! ,snake & ,columbia ,riv]s & to ! ,pacific ,ocean1 & 9 ! o!r to ! ,be> ,riv] & ,great ,salt ,lake4 ,s f> z ! creek is kn[n to :ite m5 x is a tribut>y ( ! ,snake1 b an irrigat+ dit* t has be5 dug ^u its cone c>ries "p ( its wat] to ! ,be>4 ,footnote #f3 ,lake ,bonneville is describ$ 9 volume ,,iii 7,geology7 ( ! 8,u4 ,s4 ,geog4 ,surveys ,we/ ( ! #ajj? ,m]idian10 pp4 #hh-ajd2 & less fully 9 ! ,am]ican ,naturali/ = ,novemb]1 #ahgf1 & ! ,am]ican ,j\rnal ( ,sci5ce = ,m>*1 #ahgf1 p4 #bbh4 ,see also ,johnson's ,cyclop$ia1 article 8,sevi] ,lake40 ,ano!r illu/ration exi/s at ! m\? ( ! ,colorado ,riv]4 ,z has be5 %[n by ,blake 9 ! fif? volume ( ! ,pacific ,railroad ,reports 7p4 #bcf71 ! delta ( ! ,colorado--or 9 o!r words ! alluvial cone :i* is built at its m\?--has ext5d$ itself completely across ! ,gulf ( ,cali=nia1 sev]+ ! upp] end f ! l[] & f ! ocean1 & conv]t+ x into a lake4 ,9 cont9u+ ! upbuild+ ( ! delta ! riv] has fl[$ alt]nately into ! l[] gulf & into its sev]$ segm5t4 ,at ! pres5t day its m\? op5s to ! l[] gulf2 b at r>e int]vals a portion ( its wat] runs by ! *annel kn[n z 8,new ,riv]0 to ! opposite side ( ! delta4 ,:ile x is ab&on$ by ! riv] ! lake bas9 is dry1 & x is kn[n to human hi/ory only z ! ,colorado ,des]t4 ,its bottom1 :i* is l[] ?an ! surface ( ! ocean1 is /rewn ) ! rema9s ( ! life its wat]s su/a9$1 & its bea*es are pati5tly await+ ! cycle ( *ange :i* is sl[ly b surely prep>+ to re/ore to !m _! p>5t waves4 ,illu/ration3 ,,fig4 #ff4--;,cross-section ( incl9$ /rata1 to illu/rate ,monocl9al ,%ift+ ( wat]ways4 ,monocl9al ,%ift+4 ,9 a f\r? mann] dra9age l9es are un/able4 ,9 a region ( incl9$ /rata !re is a t5d5cy on ! "p ( /reams :i* trav]se s(t b$s to cont9ue !re91 & !re is a t5d5cy to elim9ate dra9age l9es f h>d b$s4 ,9 ,figure #ff1 ,s repres5ts a homog5e\s s(t b$1 & ,h & ,k1 homog5e\s h>d b$s4 ,a & ,b are /reams fl[+ ?r\gh *annels op5$ 9 ! s(t rock1 & 9 ! h>d4 ,z ! g5]al degradation progresses ! /ream at a abrades bo? sides ( its *annel ) equal =ce2 b x fails to corrade !m at equal rates because ( ! inequality ( ! resi/ance4 ,x results t ! *annel does n cut its way v]tically into ! h>d rock1 b works obliquely d[nw>d )\t *ang+ its relation to ! two b$s2 s t :5 ! degradation has rea*$ ! /age indicat$ by ! dott$ l9e1 ! /ream fl[s at a1 hav+ be5 %ift$ horizontally by circum/ances dep5d5t on ! dip & ord] ( ! /rata4 ,at ! same "t ! /ream at ,b1 enc\nt]+ homog5e\s mat]ial1 cuts its way v]tically d[nw>d to b2 & a cont9uance ( ! process c>ries x completely ?r\gh ! h>d rock & into ! s(t4 ,once 9 ! s(t x t5ds l ! o!r /reams to rema9 !re2 & 9 ! c\rse ( "t x f9ds its way to ! l[] edge & e/abli%es a *annel l t at ,a4 ,illu/ration3 ,,fig4 #fg4--;,gr\nd plan ( outcrops ( incl9$ /rata1 to illu/rate ! results ( ,monocl9al ,%ift+4 ,! effect ( ?is process on ! c\rse ( a /ream :i* runs obliquely across incl9$ b$s is %[n 9 ,figure #fg4 ,! outcrops ( a s]ies ( h>d & s(t /rata1 ,h1 ,h1 ,h & ,s1 ,s1 are repres5t$ 9 gr\nd plan1 & ! direction ( _! dip is indicat$ by ! arr[4 ,suppos+ t a /ream is ?r[n across !m 9 ! direction ( ! dott$ l9es & t ! l& is !n degrad$1 ! foll[+ *anges w take place4 ,! portion ( ! /ream f c to d w s9k ?r\gh ! s(t rock d[n to ! surface ( ! h>d1 & !n foll[ d[n ! slope ( ! h>d1 until at la/ its :ole c\rse w be transf]r$ to ! l9e ( sep>ation betwe5 ! two1 & its position 7) ref]5ce to ! outcrops :i* w !n h succe$$ ! orig9al7 w be repres5t$ by ! l9e g c4 ,! portion f e to d s9k+ fir/ ?r\gh ! h>d b$ & !n ?r\gh ! s(t1 w be deflect$ 9 ! same mann] to ! position e h g4 ,! po9ts e & c w reta9 _! orig9al relations to ! /rata4 ,! same *anges w affect ! portion f e to f2 & ! orig9al oblique c\rse w be conv]t$ into two sets ( c\rses1 ( :i* "o w foll[ ! /rike ( ! /rata & ! o!r w cross ! /rike at "r angles4 ,! "* ( ^! *anges is indep5d5t ( ! direction ( ! curr5t4 ,!y are n individually ( great am\nt1 & !y d n (t5 div]t /reams f "o dra9age sy/em to ano!r nor *ange _! g5]al directions4 ,_! *ief effects are se5 9 ! details ( dra9age sy/ems & 9 ! production ( topographic =ms4 ,! t5d5cy ( h>d /rata to rid !mselves ( wat]ways & ( s(t /rata to accumulate !m1 is a prime elem5t ( ! process :i* c>ves hills f ! h>d & valleys f ! s(t4 ,:]e h>d rocks are cross$ by wat]ways !y _c /& high] ?an ! adjac5t p>ts ( ! wat]ways2 b :]e !y are n s cross$ !y become divides1 & ! 8law ( divides0 conspires ) ! 8law ( /ructure0 to c>ve em95ces f !m4 ,! t5d5cy ( wat]ways to escape f h>d /rata & to abide 9 s(t1 & _! t5d5cy to foll[ ! /rike ( s(t /rata & to cross h>d at "r angles1 are t5d5cies only & d n always prevail4 ,!y are oppos$ by ! t5d5cy ( dra9age l9es to /ability4 ,if ! dip ( ! /rata is small1 or if ! diff]5ces ( h>dness are slight1 or if ! *anges ( texture are gradual in/ead ( abrupt1 monocl9al %ift+ is greatly r$uc$4 ,wat]pocket ,caon is "o ( ! mo/ rem>kable ( monocl9al valleys2 & x s]ves to illu/rate bo? ! rule ( monocl9al %ift+ & its exception4 ,! pr9cipal b$ ( s(t rock :i* outcrops along ! l9e ( ! ,wat]pocket flexure is ! ,flam+ ,gorge %ale1 hav+ a ?ickness ( m ?an "o ?\s& feet4 ,?r\gh ne>ly ! :ole ext5t ( ! outcrop a valley is c>v$ f x1 b ! valley is n a unit 9 dra9age4 ,at ! nor? x is cross$ by ! ,dirty ,devil ,riv] & by ,temple & ,tantalus ,creeks1 & ! adjac5t portions slope t[>d ^? /reams4 ,at ! s\? x is occupi$ = ?irty miles by a s+le wat]way--! longe/ monocl9al dra9age l9e ) :i* ,i am acqua9t$4 ,! valley "h be>s ! "n ( ,wat]pocket ,caon1 & desc5ds all ! way f ! ,masuk ,plateau to ! ,colorado ,riv]4 ,! upp] "p ( ! caon is dry except 9 "t ( ra91 b ! l[] c>ries a p]petual /ream kn[n z ,hoxie ,creek4 ,:atev] may h be5 ! orig9al me&]+s ( ! latt] !y are n[ re/ra9$1 & x is limit$ to ! n>r[ belt 9 :i* ! %ale outcrops4 ,z ! caon is worn deep] ! *annel /eadily %ifts its position d[n ! slope ( ! und]ly+ ,gray ,cliff s&/one1 & c>ves away ! %ale4 ,b !re is "o exceptional po9t :]e x has n done ?is4 ,:5 ! bottom ( ! caon 0 a ?\s& feet high] ! creek fail$1 at a place :]e ! dip ( ! /rata 0 comp>atively small1 to %ift its *annel z x deep5$ x1 & began to cut its way into ! massive s&/one4 ,hav+ once ent]$ ! h>d rock x c\ld n retreat b sank deep] & deep]1 c>v+ a n>r[ gorge ?r\gh :i* x /ill runs mak+ a det\r f ! ma9 valley4 ,! travel] :o foll[s d[n ,wat]pocket ,caon n[ comes to a place :]e ! creek turns f ! op5 caon ( ! %ale & ent]s a d>k cleft 9 ! s&/one4 ,he c foll[ ! c\rse ( ! wat] 7on foot71 & w be repaid = ! wett+ ( 8 feet by ! /range beauty ( ! defile4 ,= ne>ly ?ree miles he w ?read 8 way ?r\gh a gorge wall$ 9 by ! smoo?1 curv$ faces ( ! massive s&/one1 & s n>r[ & devi\s t x is gloomy = lack ( sunlight2 & !n he w em]ge once m into ! op5 caon4 ,or if he pref] he c keep to 8 saddle1 to ! op5 daylight1 & to ! outcrop ( ! %ale1 & rid+ ov] a l[ divide c rea* ! m\? ( ! gorge 9 half ! di/ance4 ,illu/ration3 ,,fig4 #fh4--,wat]pocket ,caon & ! ,horse%oe ,b5d ( ,hoxie ,creek4 ,,! ,,/ability ,,( ,,divides4 ,! ra9 drops :i* fall ^u ! two sides ( a divide fl[ 9 opposite directions4 ,h[ev] ne> to ! divid+ l9e !y rea* ! e>? ! "w ( ea* is apportion$ to its own slope4 ,x dis9tegrates & transports ! mat]ial ( its own dra9age slope only4 ,! divide is ! l9e across :i* no wat] fl[s--across :i* !re is no transportation4 ,x receives ! m9imum ( wat]1 = x has only t :i* falls directly ^u x1 & e o!r po9t receives 9 addition t :i* fl[s f high] po9ts4 ,x is high] ?an ! surfaces :i* adjo9 x1 & s9ce less wat] is appli$ to its degradation x t5ds to rema9 high]4 ,x t5ds to ma9ta9 its position4 ,oppos$ to ?is t5d5cy !re are o!rs :i* lead to ,,! ,,in/ability ,,( ,,divides1 & :i* w n[ be consid]$4 ,pond+1 ,planation1 & ,alluviation4 ,:5ev] by pond+1 a /ream or a sy/em ( /reams :i* h belong$ to "o dra9age sy/em are div]t$ s z to jo9 ano!r !re is co9cid5tly a *ange ( divides4 ,! g5]al divide betwe5 ! two sy/ems is %ift$ f "o side to ! o!r ( ! area :i* *anges its allegiance4 ,! l9e :i* 0 =m]ly ! ma9 divide becomes in/ead a subord9ate divide sep>at+ portions ( ! dra9age sy/em :i* has increas$ its area2 & on ! o!r h& a l9e :i* _h be5 a subord9ate divide is promot$ to ! rank ( a ma9 divide4 ,9 l mann] ! %ift+ ( /reams f "o sy/em ( dra9age to ano!r by ! ext5sion ( flood-pla9s1 or by ! build+ ( alluvial cones or deltas1 involves a simultane\s %ift+ ( ! divides :i* b\nd ! dra9age sy/ems4 ,! *anges :i* are produc$ by ^! me?ods are p] saltum4 ,:5 a pond or lake op5s a new outlet & ab&ons its old "o !re is a %ort int]regnum dur+ :i* ! dra9age is divid$ betwe5 ! two outlets1 & ! wat]%$ sep>at+ ! dra9age sy/ems is d\ble4 ,b 9 no o!r s5se is ! *ange gradual4 ,! divide occupies no int]m$iate positions betwe5 its orig9al & its f9al4 ,& ! same may be said ( ! *anges by planation & alluviation4 ,9 ea* case a tract ( c\ntry is transf]r$ bodily f "o riv] sy/em to ano!r1 & 9 ea* case ! wat]%$ makes a leap4 ,b !re are o!r me?ods ( *ange1 by :i* divid+ l9es move sl[ly across ! l&2 & to ^! we w proce$4 ,monocl9al ,%ift+4 ,9 regions ( incl9$ /rata1 ! same process :i* ga!rs ! wat]ways into ! outcrops ( ! s(t] b$s conv]ts ! outcrops ( ! h>d] into divides4 ,z ! degradation progresses ! wat]ways & divides desc5d obliquely & reta9 ! same relations to ! b$s4 ,! wat]ways cont9u\sly select ! s(t because !y resi/ erosion feebly1 & ! wat]%$s z cont9u\sly select ! h>d because !y resi/ erosion /rongly4 ,if ! incl9ation ( ! /rata is g5tle1 ea* h>d b$ becomes ! cap ( a slop+ table b\nd$ by a cliff1 & ! erosion ( ! cliff is by sapp+4 ,! divide is at ! br[ ( ! cliff1 & z successive fragm5ts ( ! h>d rock break away & roll d[n ! slope ! divide is %ift$4 ,! process is illu/rat$ 9 ! ,p9k ,cliffs ( ,s\!rn ,utah4 ,!y face to ! s\?1 & _! esc>pm5t is dra9$ by /reams fl[+ to ! ,colorado4 ,! table :i* !y limit incl9es to ! nor? & be>s ! headwat]s ( ! ,sevi]4 ,z ! erosion ( ! cliffs /eadily c>ries !m back & re/ricts ! table1 ! dra9age area ( ! ,colorado is increas$ & t ( ! 8,great ,bas901 to :i* ! ,sevi] ,riv] is tribut>y1 is dim9i%$4 ,illu/ration3 ,,fig4 #fi4--;,ideal cross-section ( incl9$ /rata1 to %[ ! ,%ift+ ( ,divides 9 ,cliff ,erosion4 ,successive positions ( a divide are indicat$ at a1 b1 & c4 ,unequal & ,equal ,declivities4 ,illu/ration3 ,,fig4 #gj4--;,cross-pr(ile ( a bad-l& divide sep>at+ slopes ( ,unequal ,declivity4 ,two /ages ( erosion are indicat$1 to illu/rate ! horizontal %ift+ ( ! divide4 ,9 homog5e\s mat]ial1 & ) equal quantities ( wat]1 ! rate ( erosion ( two slopes dep5ds ^u _! declivities4 ,! /eep] is degrad$ ! fa/]4 ,x is evid5t t :5 ! two slopes are ^u opposite sides ( a divide ! m rapid we>+ ( ! /eep] c>ries ! divide t[>d ! side ( ! g5tl]4 ,! action ceases & ! divide becomes /ation>y only :5 ! pr(ile ( ! divide has be5 r5d]$ symmetric4 ,x is to ?is law t bad-l&s owe mu* ( _! beauty4 ,!y acquire _! smoo? curves "u :at ,i h call$ ! 8law ( divides01 b ! symmetry ( ea* ridge & ea* spur is due to ! law ( equal declivities4 ,by ! law ( divides all ! slopes ^u "o side ( a ridge are made int]dep5d5t4 ,by ! law ( equal declivities a relation is e/abli%$ betwe5 ! slopes :i* adjo9 ! cre/ on opposite sides1 & by ?is means ! slopes ( ! :ole ridge1 f base to base1 are r5d]$ int]dep5d5t4 ,"o result ( ! int]dep5d5ce ( slopes is t a bad-l& ridge sep>at+ two wat]ways :i* h ! same level1 /&s midway betwe5 !m2 :ile a ridge sep>at+ two wat]ways :i* h diff]5t levels1 /&s ne>] to ! "o :i* is high]4 ,x results also t if "o ( ! wat]ways is corrad$ m rapidly ?an ! o!r ! divide moves /eadily t[>d ! latt]1 & ev5tually1 if ! process cont9ues1 rea*es x4 ,:5 ?is occurs1 ! /ream ) ! high] valley ab&ons ! l[] "p ( its c\rse & jo9s its wat] to t ( ! l[] /ream4 ,?us f ! %ift+ ( divides !re arises yet ano!r me?od ( ! %ift+ ( wat]ways1 a me?od :i* x w be conv5i5t to *>act]ize z t ( ab/raction4 ,a /ream :i* = any reason is able to corrade its bottom m rapidly ?an d its neighbors1 exp&s its valley at _! exp5se1 & ev5tually 8ab/racts0 !m4 ,& conv]sely1 a /ream :i* = any reason is able to corrade its bottom less rapidly ?an its neighbors1 has its valley contract$ by _! encroa*m5ts & is ev5tually 8ab/ract$0 by "o or ! o!r4 ,! div]se circum/ances :i* may lead to ^! results ne$ n be enum]at$1 b !re is "o case :i* is specially notewor?y on acc\nt ( its relation to ! pr9ciples ( sculpture4 ,suppose t two /reams :i* run p>allel & ne> to ea* o!r corrade ! same mat]ial & degrade _! *annels at ! same rate4 ,_! divide w run midway4 ,b if 9 ! c\rse ( "t "o ( ! /reams enc\nt]s a peculi>ly h>d mass ( rock :ile ! o!r does n1 its rate ( corrasion above ! ob/ruction w be *eck$4 ,! unob/ruct$ /ream w out/rip x1 w encroa* ^u its valley1 & w at la/ ab/ract x2 & ! incipi5t corrasion ( ! h>d mass w be /opp$4 ,?us by ab/raction z well z by monocl9al %ift+1 /reams are elim9at$ f h>d rocks4 ,rsum4--,!re is a t5d5cy to p]man5ce on ! "p ( dra9age l9es & divides1 & !y are n displac$ )\t adequate cause4 ,h5ce e *ange :i* is kn[n to occur dem&s & admits ( an explanation4 7a7 ,!re are f\r ways 9 :i* abrupt *anges are made4 ,/reams are div]t$ f "o dra9age sy/em to ano!r1 & ! wat]%$s :i* sep>ate ! sy/ems are re>rang$1 7#a7 by pond+1 due to ! elevation or depression ( portions ( ! l&2 7#b7 by planation1 or ! ext5sion ( flood-pla9s by lat]al corrasion2 7#c7 by alluviation1 or 9 ! process ( build+ alluvial cones & deltas2 & 7#d7 by ab/raction4 7b7 ,!re are two ways 9 :i* gradual *anges are effect$3 7#a7 ,:5 ! rock texture is v>iable1 x modifies & controls by monocl9al %ift+ ! di/ribution 9 detail ( divides & wat]ways4 7#b7 ,:5 ! rock texture is uni=m1 ! positions ( divides are adju/$ 9 accordance ) ! pr9ciple ( equal declivities4 ,! abrupt *anges are ( geographic import2 ! gradual1 ( topographic4 ,! me?ods :i* h be5 enum]at$ are n ! only ones by :i* dra9age sy/ems are modifi$1 b !y are ! *ief4 ,v r>ely /reams are 8pond$0 & div]t$ to new c\rses ?r\gh ! damm+ ( _! valleys by glaci]s or by volcanic ejecta or by l&-slips4 ,m frequ5tly !y are ob/ruct$ by ! gr[+ alluvial cones ( /rong] /reams1 b only ! smalle/ /reams w yield _! 8"r ( way0 = su* cause1 & ! results are insignificant4 ,! rotation ( ! e>?1 j z x gives direction to ! trade-w9ds & to ocean curr5ts1 t5ds to deflect riv]s4 ,9 ! s\!rn hemisph]e /reams are cr[d$ aga9/ _! left banks & 9 nor!rn aga9/ ! "r4 ,b ?is influ5ce is exce$+ly small4 ,mr4 ,f]rel's inve/igations %[ t 9 latitude #de & = a curr5t velocity ( t5 miles an h\r1 x is measur$ by less ?an "o tw5ty-?\s&? "p ( ! weight ( ! wat] 7,am]ican ,j\rnal ( ,sci5ce1 ,janu>y1 #ahfa74 ,if its effects are ev] appreciable x mu/ be :]e lat]al corrasion is rapid2 & ev5 !re x is probable t ! *ief result is an incl9ation ( ! flood-pla9 t[>d "o bank or ! o!r1 am\nt+ at mo/ to two or ?ree m9utes4 ,,consequ5t ,,& ,,inconsequ5t ,,dra9age4 ,if a s]ies ( s$im5ts accumulat$ 9 an ocean or lake be subject$ to a sy/em ( displacem5ts :ile /ill "u wat]1 & !n be conv]t$ to dry l& by elevation en masse or by ! retirem5t ( ! wat]1 ! ra9s :i* fall on !m w inaugurate a dra9age sy/em p]fectly con=mable ) ! sy/em ( displacem5ts4 ,/reams w rise along ! cre/ ( ea* anticl9al1 w fl[ f x 9 ! direction ( ! /eepe/ dip1 w unite 9 ! syncl9als1 & w foll[ !m l5g?wise4 ,! axis ( ea* syncl9al w be m>k$ by a wat]c\rse2 ! axis ( ea* anticl9al by a wat]%$4 ,su* a sy/em is said to be consequ5t on ! /ructure4 ,if h[ev] a rock s]ies is affect$ by a sy/em ( displacem5ts aft] ! s]ies has become cont95tal1 x w h already acquir$ a sy/em ( wat]ways1 & provid$ ! displacem5ts are produc$ sl[ly ! wat]s w n be div]t$ f _! accu/om$ ways4 ,! effect ( local elevation w be to /imulate local corrasion1 & ea* riv] t crosses a l9e ( uplift w in* by in* z ! l& rises deep5 its *annel & valor\sly ma9ta9 its orig9al c\rse4 ,x w result t ! directions ( ! dra9age l9es w be indep5d5t ( ! displacem5ts4 ,su* a dra9age sy/em is said to be antec$5t to ! /ructure4 ,b if 9 ! latt] case ! displacem5ts are produc$ rapidly ! dra9age sy/em w be re>rang$ & w become consequ5t to ! /ructure4 ,x has frequ5tly happ5$ t displacem5ts =m$ ) mod]ate rapidity h giv5 rise to a dra9age sy/em ( mix$ "* 9 :i* ! c\rses ( ! l>g] /reams are antec$5t & ^? ( ! small] are consequ5t4 ,!re is a f\r? case4 ,suppose a rock s]ies t has be5 fold$ & erod$ to be aga9 subm]g$1 & to receive a new accumulation ( uncon=m+ s$im5ts4 ,suppose fur!r t x once m em]ges & t ! new s$im5ts are erod$ f its surface4 ,!n ! dra9age sy/em w h be5 giv5 by ! =m ( ! upp] surface ( ! sup]ior /rata1 b w be indep5d5t ( ! /ructure ( ! inf]ior s]ies1 into :i* x w desc5d v]tically z ! degradation progresses4 ,su* a dra9age sy/em is said to be sup]impos$ by s$im5tation ^u ! /ructure ( ! old] s]ies ( /rata4 ,fif?4 ,! dra9age ( an alluvial cone or ( a delta is indep5d5t ( ! /ructure ( ! b$-rock b5ea?2 & if 9 ! c\rse ( "t erosion takes ! place ( deposition & ! alluvial =mation is cut ?r\gh1 ! dra9age sy/em :i* is acquir$ by ! rocks b5ea? is n consequ5t ^u _! /ructure b is sup]impos$ by alluviation4 ,six?4 ,! dra9age ( a di/rict ( planation is indep5d5t ( ! /ructure ( ! rock f :i* x is c>v$2 & :5 9 ! progress ( degradation ! b$s favorable to lat]al corrasion are de/roy$ & ! wat]ways become p]man5t1 _! sy/em may be said to be sup]impos$ by planation4 ,9 brief1 sy/ems ( dra9age1 9 _! relation to /ructure1 are 7,a7 consequ5t 7a7 by em]g5ce1 :5 ! displacem5ts are subaque\s1 & 7b7 by sudd5 displacem5t2 7,b7 antec$5t2 & 7,c7 sup]impos$ 7a7 by s$im5tation1 or subaque\s deposition1 7b7 by alluviation1 or subarial deposition1 & 7c7 by planation4 ,,! ,,dra9age ,,( ,,! ,,h5ry ,,m\nta9s is consequ5t on ! laccolitic displacem5ts4 ,! uplift+ ( a laccolite1 l ! upbuild+ ( a volcanic cone1 is an ev5t ( s rapid progress t ! corrasion ( a /ream b$ _c keep pace ) x4 ,we d n "k t ! site ( ! m\nta9s 0 dry l& at ! "t ( _! elevation2 b if x 01 !n :atev] /reams cross$ x 7 ob/ruct$ & turn$ f _! c\rses4 ,if x 0 n1 !re 7 no prexi/5t wat]ways1 & ! new ones1 =m$ by ! fir/ ra9 :i* fell ^u ! domes ( /rata1 radiat$ f ! cre/s 9 all directions4 ,! result 9 ei!r case w\ld be ! same1 & we _c det]m9e f ! pres5t dra9age sy/em :e!r ! domes 7 lift$ f ! b$ ( ! ,t]ti>y lake or arose aft] its subsid5ce4 ,b :ile ! dra9age ( ! ,h5ry ,m\nta9s is consequ5t z a :ole1 x is n consequ5t 9 all its details1 & ! "* ( its p>tial inconsequ5ce is wor?y ( exam9ation4 ,let u beg9 ) ! simple/ case4 ,! dra9age sy/em ( ,m\nt ,ellswor? is m purely consequ5t ?an any o!r ) :i* ,i am acqua9t$4 ,9 ! accompany+ *>t ! po9t c m>ks ! cre/ ( ! ,ellswor? dome2 ! inn] circle repres5ts ! l9e ( maximum dip ( ! ar*+ /rata & ! out] circle ! limit ( ! di/urbance4 ,x w be se5 t all ! wat]ways radiate f ! cre/ & foll[ closely ! directions 9 :i* ! /rata incl9e4 ,at a ! ,ellswor? ar* t\*es t ( ,m\nt ,holmes & at b t ( ,m\nt ,hill]s2 & ! effect ( ! comp\nd incl9ation is to modify ! directions ( a few ( ! wat]ways4 ,illu/ration3 ,,fig4 #ga4--;,dra9age sy/em ( ! ,ellswor? ,ar*4 ,turn+ n[ to ,m\nt ,holmes1 we f9d t its two domes are n equally respect$ by ! dra9age l9es4 ,! cre/ ( ! ,great] ar* 7see ,figure #gb7 is ! c5t] ( a radiat+ sy/em1 b ! cre/ ( ! ,less] ar* is n2 & wat]ways aris+ on ! ,great] trav]se ! ,less] f side to side4 ,m ?an ?is1 a wat]way aft] foll[+ ! m>g9 ( ! ,less] ar* turns t[>d x & p5etrates ! flank ( ! ar* = "s di/ance4 ,9 a ^w1 ! dra9age ( ! ,great] ar* is consequ5t on ! /ructure1 :ile ! dra9age ( ! ,less] ar* is inconsequ5t4 ,illu/ration3 ,,fig4 #gb4--;,dra9age sy/em ( ! ,holmes ,ar*es4 ,!re are at lea/ two ways 9 :i* ?is /ate ( affairs may h aris54 ,fir/1 ! ,great] ar* may h be5 lift$ s long be=e ! ,less] t its wat]ways 7 c>v$ too deeply to be div]t$ by ! g5tle flexure ( ! latt]4 ,! dra9age ( ! ,less] w\ld 9 t case be class$ z antec$5t4 ,if ! ,less] ar* 7 fir/ =m$ & c>v$1 ! lift+ ( ! ,great] might ?r[ a /ream across its summit2 b x c\ld n initiate ! wat]ways :i* skirt ! slopes ( ! ,less]1 especially if ^? slopes 7 already furr[$ by /reams :i* desc5d$ !m4 ,if ! e/abli%m5t ( ! dra9age sy/em dep5d$ on ! ord] ( uplift1 ! ,great] ar* is surely ! old]4 ,second1 ! dra9age ( ! ,less] ar* may h be5 impos$ ^u x by planation at a v late /age ( ! degradation4 ,:atev] 0 ! orig9 ( ! ar*es1 & :atev] 0 ! dep? ( cov] :i* !y su/a9$1 ! ,great] is c]ta9 to h be5 a c5t] ( dra9age f ! "t ( its =mation4 ,:5 x 0 fir/ lift$ x became a dra9age c5t] because x 0 an em95ce2 & aft]w>d x rema9$ an em95ce because x 0 a dra9age c5t]4 ,:5 9 ! progress ( ! d5udation its dikes 7 expos$1 _! h>dness *eck$ ! we> ( ! summit & its em95ce became m pron\nc$4 ,x 0 p]haps at ab\t ?is "t t ! la/ ( ! ,cretace\s rocks 7 remov$ f ! summits & slopes ( ! two ar*es & ! ,flam+ ,gorge %ale 0 laid b>e1 & s soon z ?is occurr$ ! conditions = lat]al corrasion 7 complete4 ,) tra*yte 9 ! peaks & %ale ^u ! slopes planation w\ld naturally result1 & a dra9age sy/em w\ld be arrang$ ab\t ! dikes z a c5t] )\t reg>d to ! curves ( ! /rata4 ,! subsequ5t removal ( ! %ale w\ld imp>t its dra9age to ! und]ly+ s&/ones4 ,ei!r hypo!sis is compet5t to expla9 ! facts1 b ! data d n w>rant ! adoption ( "o to ! exclusion ( ! o!r4 ,! wat]ways ( ! ,less] ar* may be ei!r antec$5t1 or sup]impos$ by planation4 ,! ,great] ar* may h be5 ! fir/ to rise or ! la/4 ,! dra9age ( ,m\nt ,hill]s is consequ5t to ! ma9 uplift & to ! majority ( ! m9or1 b to ! ,pulpit ar* x is inconsequ5t4 ,9 ?is case !re is no "q t ! ar* has be5 truncat$ by planation4 7,figure #gc47 ,! ,hill]s dome1 ris+ five times z high z ! ,pulpit1 became ! c5t] ( dra9age = ! clu/]1 & ! tra*yte-lad5 /reams :i* x s5t =? 7 able to p>e away completely ! l[] ar* :ile x 0 /ill unprotect$ by ! h>dness ( its nucleus4 ,! foot-pla9 ( ,m\nt ,hill]s1 :i* ext5ds unbrok5 to ! outcrop ( ! ,h5ry's ,=k conglom]ate1 is cont9u$ on sev]al l9es across ! ,pulpit ar*1 al?\gh 9 ! int]vals ! c5tral area is deeply excavat$4 ,! planation /age is j complet$1 & an epo* ( fix$ wat]ways is inaugurat$4 ,illu/ration3 ,,fig4 #gc4--;,cross-section ( ! ,pulpit ,ar*1 %[+ its truncation4 ,! dra9age ( ,m\nt ,p5nell is consequ5t 9 reg>d to ! ma9 uplift1 b inconsequ5t to "s ( ! m9or4 ,a /ream :i* rises on ! nor? flank n m]ely runs across "o ( ! upp] s]ies ( laccolites1--a companion to ! ,s5t9el1--b has cut into x & divid$ x ne>ly to ! base4 ,x is probable t ! position ( ! wat]way 0 fix$ by planation1 b no remnant ( ! pla9 0 se54 ,too little is kn[n ( ! /ructure ( ! c5tral area ( ,m\nt ,ell5 to ass]t its relation to ! dra9age4 ,ab\t its base !re are five laccolites :i* h lo/ all or ne>ly all _! cov]1 & ea* ( ^! is a local c5t] ( dra9age1 avoid$ by ! /reams :i* head 9 ! m\nta9 cre/4 ,f\r o!rs h be5 laid b>e at a few po9ts only1 & ^! are ea* cross$ by "o or two /reams f high] levels4 ,! rema9d] are n expos$ at all1 & _! ar*es are cross$ by num]\s p>allel /reams4 ,! ,cresc5t ar* is fre%ly truncat$ by planation1 & ! ,dana & ,maze be> pro( t !y h at "s "t be5 truncat$4 ,! laccolites :i* /& highe/ ) ref]5ce to ! g5]al surface are exempt f cross-dra9age1 & ! ar*es :i* lie l[ are completely ov]run4 ,if we g back 9 imag9ation to a "t :5 ! erosion ( ! m\nta9 0 s little advanc$ t ! /ream b$s 7 ?ree ?\s& feet high] ?an !y n[ are1 we may suppose t v little tra*yte 0 laid b>e4 ,z ! surface 0 degrad$ & a few laccolites 7 expos$1 x w\ld probably happ5 t "s ( ! !n exi/+ /reams w\ld be s plac$ z to run across ! tra*yte4 ,b be+ un>m$ z yet by ! dbris ( simil> mat]ial !y w\ld corrade x v sl[ly2 & ! adjo9+ /reams hav+ only %ale to enc\nt]1 w\ld s f> out/rip !m z ev5tually to div]t !m by ! process ( 8ab/raction04 ,9 ?is way ! fir/-b>$ laccolites might be fre$ f cross-dra9age & p]mitt$ to acquire su* radiat+ sy/ems ( wat]ways z we f9d !m to possess4 ,at a lat] /age :5 tra*yte 0 expos$ at _m po9ts & all /reams 7 load$ ) its wa/e1 ! p[] to corrade 0 increas$1 & ! l[]-ly+ laccolites c\ld n turn aside ! /reams :i* ov]ran !m4 ,! "w ( planation is s frequ5tly se5 ab\t ! flanks ( ! ,h5ry ,m\nta9s t !re seems no viol5ce 9 ref]r+ all ! cross-dra9age ( lat]al ar*es to its action2 & if t is done ! hi/ory ( ! erosion ( ! m\nta9s takes ! foll[+ =m3 ,:5 ! laccolites 7 intrud$1 ! m\nds :i* !y uplift$ ei!r rose f ! b$ ( a lake or else turn$ back all /reams :i* cross$ _! sites2 & 9 ei!r case !y e/abli%$ ^u _! flanks a new & 8consequ5t0 set ( wat]ways4 ,! highe/ m\nds became c5t]s ( dra9age1 & s5t _! /reams ei!r across or betwe5 ! l[]4 ,all ! /reams ( ! di/urb$ region rose )9 x & fl[$ outw>d4 ,! degradation ( ! m\nds probably began be=e ! uplift 0 complete1 b ( ?is !re is no evid5ce4 ,z x proce$$ ! convex =ms ( ! m\nds 7 quickly oblit]at$ & concave pr(iles 7 sub/itut$4 ,! rocks :i* 7 fir/ excavat$ 7 n uni=m 9 texture1 b !y 7 all s$im5t>y & 7 s(t z comp>$ to ! tra*yte4 ,! ,t]ti>y & probably ! ,upp] ,cretace\s 7 remov$ f ! summits be=e any ( ! igne\s rocks 7 br\ght to light1 & dur+ _! removal ! t5d5cy ( divides to p]man5ce kept ! dra9age c5t]s or maxima ( surface at sub/antially ! same po9ts4 ,:5 at l5g? ! tra*yte 0 rea*$ its h>dness introduc$ a new factor4 ,! em95ces :i* conta9$ x 7 e/abli%$ m firmly z maxima1 & _! rate ( degradation 0 *eck$4 ,) ! *eck+ ( summit degradation & ! addition ( tra*yte to ! transport$ mat]ial1 planation began ^u ! flanks1 & by its action ! :ole dra9age has be5 re=m$4 ,"o by "o ! l[] laccolites are une>!d1 & ea* "o adds to ! complexity & to ! p]man5ce ( ! dra9age4 ,if ! displacem5ts 7 complet$ be=e ! erosion began1 ! m\nta9s 7 !n ( great] magnitude ?an at any lat] date4 ,be=e ! igne\s nuclei 7 laid b>e & :ile s$im5t>y rocks only 7 subject to erosion1 ! rate ( degradation 0 m rapid ?an x has be5 s9ce ! h>dness & t\ghness ( ! tra*yte h oppos$ x4 ,if ! surr\nd+ pla9 has be5 worn away at a uni=m rate1 ! height ( ! m\nta9s 7above ! pla97 mu/ h fir/ dim9i%$ to a m9imum & aft]w>d increas$4 ,! m9imum occurr$ at ! beg9n+ ( ! erosion ( ! tra*yte1 & at t "t ! m\nta9s may ev5 h be5 r$uc$ to ! rank ( hills4 ,!y owe _! pres5t magnitude1 n to ! uplift+ ( ! l& 9 ,middle ,t]ti>y "t1 b to ! contra/ betwe5 ! incoh]5ce ( ! s&/ones & %ales ( ! ,mesozoic s]ies & ! extreme durability ( ! laccolites :i* _! de/ruction has laid b>e4 ,& if ! wa/e ( ! pla9 %all cont9ue at a l uni=m rate 9 ! future1 x is safe to prophesy t ! m\nta9s w = a :ile cont9ue to increase 9 relative altitude4 ,! phase :i* w give ! maximum resi/ance to degradation has be5 rea*$ 9 none ( ! m\nta9s1 except p]haps ,m\nt ,hill]s4 ,9 ,m\nt ,ell5 ! laccolites ( ! upp] zone only h be5 d5ud$2 ! great] masses :i* und]lie !m w hold _! place m /ubbornly4 ,! ma9 bodies ( ,m\nts ,ellswor?1 ,holmes1 & ,p5nell are unassail$1 & ! pres5t prom95ce ( _! =ms has be5 accompli%$ simply by ! valor ( _! skirmi% l9es ( dikes & spurs4 ,9 atta*+ to ! lea/ ( ! peaks ! "n ( my fri5d ,mr4 ,holmes1 ,i am confid5t t ,i commemorate 8 atta9m5ts by a monum5t :i* w be m conspicu\s to future g5]ations & races ?an x is to ! pres5t4 ,,*apt] ,,vi4 ,,economic4 ,!re is little to add to :at has already be5 said ( ! economic value ( ! m\nta9s1 & ?is *apt] is h>dly m ?an a regr\p+ ( facts scatt]$ ?r\gh ^? t prec$e4 ,coal4--,possibly "s valuable ?\gh re/rict$ deposit 0 ov]look$2 b x is safe to say t no ?ick & cont9u\s b$ w be f\nd4 ,! ,cretace\s s&/ones all conta9 ?9 & local b$s--en\gh to m>k !m z coal-be>+ rocks--b !re are no seams ( value4 ,! be/ outcrop 0 se5 9 ! bank ( ! s\? bran* ( ,lewis ,creek :]e x crosses ! upturn$ edge ( ! ,blue ,gate s&/one4 ,! seam has a ?ickness ( f\r feet only1 & is n well dispos$ = m9+4 ,b if ! ,cretace\s coals 7 well develop$ x is to be d\bt$ if !y w\ld ev] be us$4 ,!y c\ld h no local m>ket4 ,!y c\ld n be c>ri$ to ! ea/ or s\? on acc\nt ( ! caons4 ,if tak5 nor?w>d !y w\ld h to compete ) ! coal ( ,ca/le ,valley1 :i* is m conv5i5t & v abundant4 ,if tak5 we/w>d to ! metal m9es ( ,nevada & ,we/]n ,utah !y w\ld be und]sold by ! m accessible coals f\nd on ! headwat]s ( ! ,virg9 ,riv] & ,kanab ,creek1 & ev5 by ^? ( ! ,kaip>[its ,plateau4 ,! ,gypsum & ,build+ ,/ones ( ! region ne$ n be describ$4 ,!y are pl5tiful 9 _m p>ts ( ,utah1 & h[ev] abundant 9 ?is remote place c nev] be 9 dem&4 ,gold1 ,silv]1 etc4--,?ree p>ties ( 8prospectors0 h at diff]5t times made unsuccessful se>* = metallif]\s ve9s4 ,9 ! c\rse ( my survey ,i sp5t m ?an a mon?'s "t among ! cry/all9e & metamorphic =mations ( ! m\nta9 tops1 & al?\gh direct+ my att5tion con/antly to ! rocks1 did n discov] a fissure ve94 ,comb9+ ^! negative data ) c]ta9 !oretic consid]ations :i* are set =? 9 ! f\r? *apt]1 ,i am l$ to ! v confid5t op9ion t ! ess5tial conditions = ! production ( fissure ve9s h n exi/$ 9 ! ,h5ry ,m\nta9s1 & h5ce t !re are no valuable deposits ( ! preci\s metals4 ,! same !oretic consid]ations apply to o!r m\nta9s ( ! same "*1 & ,i v5ture to pr$ict t gold & silv] w n be f\nd 9 pay+ quantity 9 ,navajo ,m\nta91 ! ,si]ra la ,sal1 ! ,si]ra ,abajo1 ! ,si]ra ,c>isso1 or ! ,si]ra ,la ,lata4 ,agricultural ,l&4--,b[l ,creek1 bo? bran*es ( ,lewis ,creek1 & ! s\? bran* ( ,tra*yte ,creek c readily be l$ to tracts ( l& suffici5tly level = f>m+1 & ea* furni%es en\gh wat] to irrigate sev]al hundr$ acres4 ,x is possible t ^! tracts w prove useful = f>m+1 b !y lie a little too high to be assur$ ( a favorable climate4 ,! l[e/ has an altitude ( #f1jjj1 & ! highe/ ( #f1hjj feet4 ,graz+ ,l&4--,above ! altitude ( #g1ejj feet !re are _m tracts ( good grass1 available = graz+ ?r\gh ! great] "p ( ! ye> b cov]$ by sn[ 9 ! w9t]4 ,bel[ t level !re is a great] area ( inf]ior grass1 available ?r\gh ! :ole ye>4 ,by us+ "o portion 9 summ] & ! o!r 9 w9t] ! m\nta9s c\ld be made to give p]man5t support to a h]d ( #c1jjj or #d1jjj cattle4 ,) su* ov]/ock+ z is (t5 practic$ 9 ,utah !y may subsi/ #aj1jjj animals = "o or two ye>s4 ,timb]4--,! trees wor?y to be class$ z timb] are ( ?ree species--fir 7,abies ,engelmanni71 ,d\glass ,spruce 7,a4 ,d\glasii71 & yell[ p9e 7,p9us pond]osa74 ,! p9e is ! mo/ valuable & ! fir ! mo/ abundant4 ,! fir gr[s ^u ! m\nta9 slopes1 above ! level ( #g1ejj feet & =ms ?ick-set =e/s4 ,! total area :i* x cov]s is n f> f tw5ty-five squ>e miles4 ,! spruce m+les ) ! fir at ! l[] edges ( ! =e/s2 & ! p9e =ms a few op5 groves a little l[] d[n ! slopes4 ,x is to be d\bt$ if ! trees w ev] be cut4 ,o!r timb] ( ! same quality & sup]ior 9 quantity lies betwe5 x & ! settlem5ts1 & nei!r railroad nor m9e nor t[n is likely to create a local dem&4 ,coal1 build+ /one1 gypsum1 & timb] h no value = lack ( a m>ket1 ei!r pres5t or prospective2 gold & silv] are n f\nd2 & !re is little or no l& t c be successfully f>m$4 ,only = graz+ h ! m\nta9s a money value4 ,,index4 ,abajo ,m\nta9s1 #fg1 #fi1 #aeb ,agricultural l&s1 #aeb ,alluvial cones & alluviation1 #acc1 #aci ,alp9e sculpture1 #cf1 #ch ,altitudes ( peaks & passes1 #c1 #aag ,analogues ( ! laccolite1 #ih ,anci5t riv]s no l>g] ?an mod]n1 #acc ,antec$5t dra9age1 #adc ,ar*1 ,b[l ,creek1 #de 1 ,cresc5t1 #dd 1 ,dana1 #dc 1 ,g1 #dc 1 ,maze1 #dd 1 ,pulpit1 #cc1 #adg ,ar*es1 ,=ces :i* produc$ laccolitic1 #hg ,aridity favorable to geological exam9ation1 #b1 #ih ( ! ,colorado ,bas9 9 =m] times1 #abj ,aubrey ,s&/one1 #h ,bad-l&s1 ,sculpture (1 #abj1 #adj ,bis*(1 on contraction ( igne\s rocks 9 cool+1 #gf ,blue ,gate flexure1 #ac ,s&/one1 #d ,%ale1 #d ,bonneville1 ,outlet ( ,lake1 #acd ,b[l ,creek ar*1 #de ,caons ( ! ,colorado z ob/ructions to travel1 #a1 #aea z evid5ce ( arid climate1 #abj ,c>bonif]\s /rata1 #h ,c>riso ,m\nta9s1 #fi1 #aeb ,circle ,cliffs1 #ad ,cleavage1 ,slaty1 n f\nd1 #ff 1 ,v]tical1 produc$ by sapp+1 #ee ,cliffs1 ,circle1 #ad ,climate1 ,arid1 favorable to geological exam9ation1 #b1 #ih 1 ,g5]al influ5ce (1 on erosion1 #ajc 1 ,influ5ce (1 on sculpture1 #aag ,coal1 #e1 #aea ,colorado ,bas91 ,hi/ory ( !1 #hd ,des]t1 #acd ,riv]1 ,orig9 ( !1 #he ,colors ( s&/ones1 ,local v>iation (1 #g ,comm9ution ( detritus aids transportation1 #ajf ,compet5ce1 #aaj ,conditions ( rock flexure1 #hc ,cones1 ,alluvial1 #acc ,consequ5t dra9age1 #adc ,contact ph5om5a1 #fe ,contraction ( igne\s rocks by cool+1 #ge1 #hj ,corrasion1 #ajj1 #aja 1 ,relation (1 to declivity1 #aab 1 to friction ( fl[1 #aji 1 to transportation1 #aaa ,cov] ( ! laccolites1 ,dep? ( !1 #hf1 #id ,cresc5t ar*1 #dd ,cotta1 ,pr(4 ,b]nh>d von1 cit$1 #ge ,cretace\s p]iod1 ,di/urbance at ! close ( !1 #aj1 #he rock s]ies1 #d ,cross-lam9ation1 ,incl9ation (1 #g ,dana ar*1 #dc ,declivity1 ,g5]al influ5ce (1 ^u erosion1 #ajb ( /ream b$s1 relation to corrasion1 #aab 1 relation to transportation1 #ajh 1 ,relation (1 to quantity ( wat]1 #aac ,declivities1 ,influ5ce ( unequal1 on divides1 #adj ,degradation 7see ,erosion71 #ii1 #aae ,delesse on contraction ( igne\s rocks 9 cool+1 #gf ,d5sities ( igne\s rocks1 #ge ( s$im5t>y rocks1 #gg ,d5sity a condition ( laccolitic intrusion1 #gc1 #gd ( porphyritic tra*yte1 #gg ,d5udation 7see ,erosion71 #ii1 #aae ( laccolites1 #ba ,deposition by runn+ wat]1 #aaa ,diamet]s ( laccolites1 #ib ,dike ne> ,m\nt ,ellswor?1 #ei ,dikes & %eets def9$1 #bj 1 ,flat-topp$1 #bh ( ,m\nt ,ellswor?1 #bc ( ,m\nt ,holmes1 #bh 1 ,relation (1 to /ra9s1 #if ,d9ah ,creek ,pass1 #c ,dirty ,devil ,riv]1 ,flood-pla9s (1 #aca ,di/ances1 ,table (1 #ag ,di/ribution ( laccolites1 ,horizontal1 #bj1 #cj 1 ,v]tical1 #ba1 #ef ,divides 9 bad-l&s1 ,r\nd+ (1 #abb 1 ,in/ability (1 #aci 1 ,law (1 #aaf 1 ,/ability (1 #ach ,dra9age l9es1 ,in/ability (1 #abe 1 ,/ability (1 #abd 1 ,sy/ems (1 #abd1 #adc ,dutton1 ,capt4 ,c4 ,e41 on ! intrusive rocks1 #fa ,economic geology1 #aea ,elk ,m\nta9s1 #fi ,ell5 ,m\nt 7see ,m\nt ,ell574 ,ellswor? ,m\nt 7see ,m\nt ,ellswor?74 ,en]gy ( muddy /reams1 #ajh /reams1 h[ measur$1 #ajf ,equal action1 ,pr9ciple (1 #abc ,erosion1 ,conditions :i* control1 #ajb 1 ,influ5ce ( climate ^u1 #ajc 1 ,influ5ce ( declivity ^u1 #ajb ,erosion1 ,influ5ce ( rock texture ^u1 #ajc 1 ,influ5ce ( vegetation ^u1 #ajd ( ,m\nt ,ellswor?1 #be 1 ,pr9ciples (1 #ii 1 ,processes (1 #ii ,f>m+ l&s1 #aeb ,faults on ,m\nt ,ellswor?1 #bc ,m\nt ,holmes1 #bh 1 ,region (1 #ab1 #ae ,fi% ,lake ,valley1 ,/ructure (1 #ad ,fissure ve9s limit$ 9 dep?1 #hb n f\nd 9 ! ,h5ry ,m\nta9s1 #hc1 #aea ,flam+ ,gorge ,gr\p1 #f ,flat-topp$ dikes1 #bh ,flexure ( rocks1 ,conditions (1 #hc ,flood-pla9 def9$1 #abg ,fl[ ( /reams1 ,friction (1 #ajg1 #aji ,folds1 ,! ,great1 #aj1 #aa1 #he ,=ces :i* produce laccolitic ar*es1 #hg ,=m ( laccolites1 #ee ,fro/1 #ajd ,friction ( fl[ ( /reams1 #ajg1 #aji ,geikie laccolite1 #da ,gold & silv]1 #aea ,granite1 ,eruptive1 #gj ,graves1 ,mr4 ,walt] ,h41 #a ,gray ,cliff ,gr\p1 #f ,graz+ l&s1 #aeb ,heights1 #c1 #aag ,h5ry1 ,pr(4 ,joseph1 #a ,h5ry ,m\nta9s1 ,altitudes ( !1 #b1 #aag caus$ by resi/ance ( tra*yte to erosion1 #be1 #ce 1 ,contributions ( !1 to ! pr9ciples ( erosion1 #ii 1 ,detail$ description ( !1 #bb 1 ,dra9age ( !1 #add 1 ,economic value ( !1 #aeb 1 ,planation 9 !1 #abg1 #adi 1 ,relation ( vegetation to type ( sculpture 9 !1 #aah 1 ,r\te ( travel to !1 #ad2 _! /ructure laccolitic1 #ai1 #ec ,h5ry's ,=k ,gr\p1 #d ,hill]s1 ,m\nt 7see ,m\nt ,hill]s74 ,hills ( planation1 #acj ,hi/orical note1 #ff ,hi/ory ( ! ,colorado ,bas91 #hd ,holmes1 ,m\nt 7see ,m\nt ,holmes74 ,holmes1 ,mr4 ,w4 ,h41 on ! ,elk ,m\nta9s1 #gj ,la ,lata & ,c>riso ,m\nta9s1 #fi ,hopk9s on ! p[] ( curr5ts1 #ajf ,h[ell laccolite1 #cd 1 ,mr4 ,edw9 ,e41 ,fossils discov]$ by1 #e2 obs]vation ( ! ,h5ry ,m\nta9s1 #ff2 obs]vation ( ! ,navajo ,m\nta91 #fi ,hydro/atic equilibrium1 ,law (1 #gb ,igne\s m\nta9s ( ! ,plateau ,prov9ce1 #fg ,igne\s rocks1 ,contraction (1 by cool+1 #ge1 #hj ,inconsequ5t dra9age1 #adc ,in/ability ( divides1 #aci dra9age l9es1 #abe ,int]dep5d5ce ( dra9age slopes1 #abc1 #ada ,int]nal /ructure ( laccolites1 #ee ,intrusive rocks ( ! ,h5ry ,m\nta9s1 #ei1 #fa ,isolation ( ! ,h5ry ,m\nta9s1 #b1 #ah ,j]ry ,butte1 #cd ,jukes ,butte1 #df ,jukes1 ,pr(4 ,j4 ,beete1 on prismatic /ructure1 #gf ,jura-,trias rock s]ies1 #e ,kaibab /ructure1 #aa ,laccolite ,a1 #cb ,b1 #cb ,c1 #cb ,d1 #ce ,e1 #da ,f1 #db 1 ,geikie1 #da ,h1 #df 1 ,hill]s1 #cj 1 ,hi/ory ( !1 #ie 1 ,h[ell1 #cd 1 ,jukes1 #df 1 ,m>v9e1 #db 1 ,newb]ry1 #da ( ,m\nt ,ellswor?1 #bg ( ,m\nt ,p5nell1 #cf ( ! we/]n base ( ,m\nt ,ell51 #dj 1 ,peale1 #dg 1 ,possible analogues ( !1 #ih 1 ,scrope1 #dg 1 ,s5t9el1 #ch 1 ,%\ld]1 #db 1 ,/ew>d1 #cb 1 ,!1 def9$1 #ai ,laccolites1 ,age ( !1 discuss$1 #hd 1 ,composite1 #ee 1 ,d5udation (1 #ba 1 ,dep? ( cov] (1 #hf1 #id 1 ,detail$ description (1 #bb 1 ,diamet]s (1 #ib 1 ,=m (1 #ee1 #ia 1 ,holmes1 #bg 1 ,horizontal1 di/ribution (1 #bj intrud$ 9 s(t b$s1 #eh 1 ,limital area (1 #ij1 #ig ?ickness (1 #ia 1 ,mat]ial (1 #ei n prismatic1 #ee ( ! ,elk ,m\nta9s1 #gj ( o!r regions1 #ig2 size limit$1 #hf subsequ5t to ! /rata :i* inclose !m1 #ea 1 ,v]tical di/ribution (1 #ba1 #ef1 #fe ,laccolitic m\nta9s ( ! ,plateau ,prov9ce1 #fg1 #fi /ructure *>act]i/ic ( ! ,h5ry ,m\nta9s1 #ai1 #ec ,si]ra ,la ,sal1 etc41 #fi condition$ by d5sities1 #gd correlat$ ) acidic lavas1 #ga 1 ,discussion ( ! orig9 (1 #gb ,lake ,bonneville1 ,outlet (1 #acd 1 ,great ,salt1 ,outlet (1 #acd ,w9ipeg1 ,orig9 (1 #abf ,l&1 ,agricultural1 #aeb 1 ,graz+1 #aeb sculpture1 ,pr9ciples (1 #ii1 #aae 1 ,timb]1 #aeb ,la ,lata ,m\nta9s1 #fh1 #fi1 #aeb ,la ,sal ,m\nta9s1 #fh1 #fi1 #aeb ,law ( divides1 #aaf 1 ,exception to !1 #abb ,lewis ,creek pla91 #abh ,limital area ( laccolites1 #ij1 #ig ?ickness ( laccolites1 #ia ,load1 ,relation (1 to comm9ution1 #ajg ,mallet1 ,rob]t1 ,c4 ,e41 on contraction ( igne\s rocks 9 cool+1 #gf ,m>v9e laccolite1 #db ,ma-suk' ,plateau1 #ac ,s&/one1 #d ,%ale1 #d ,maze ar*1 #dd ,metamorphism 9 ! ,h5ry ,m\nta9s1 #fe on ,m\nt ,ell51 #ch ,ellswor?1 #bd ,hill]s1 #ca ,holmes1 #bh ,m9]als ( ! ,h5ry ,m\nta9s1 #fa1 #fd ,monocl9al %ift+1 #ace1 #adj ,m\nt ,ell51 ,"* ( sculpture (1 #aah 1 ,dra9age (1 #adh 1 ,/ructure (1 #ch 1 ,topography (1 #c 1 ,vegetation (1 #aah ,ellswor?1 ,"* ( sculpture (1 #be1 #aah 1 ,dra9age (1 #ade 1 ,/]eogram (1 #bc1 #ie 1 ,/ructure (1 #bb 1 ,topography (1 #c 1 ,vegetation (1 #aah ,hill]s1 ,"* ( sculpture (1 #aai 1 ,dra9age (1 #adg 1 ,/ructure (1 #cj 1 ,topography (1 #c 1 ,vegetation (1 #aah ,holmes1 ,"* ( sculpture (1 #aah 1 ,dra9age (1 #adf 1 ,/ructure (1 #bg 1 ,topography (1 #c ,m\nt ,holmes1 ,vegetation (1 #aah ,p5nell1 ,"* ( sculpture (1 #aai 1 ,dra9age (1 #adh 1 ,/ructure (1 #ce 1 ,topography (1 #c 1 ,vegetation (1 #aah ,m\nt ,taylor1 #ga ,mud-cracks1 ,fossil1 #i ,navajo ,m\nta91 #fi1 #aeb ,newb]ry1 ,dr4 ,j4 ,s41 on ! ,si]ra ,abajo1 #fg ,la ,sal1 #fh laccolite1 #da ,oblique lam9ation1 ,incl9ation (1 #g ,peale1 ,dr4 ,a4 ,c41 on igne\s m\nta9s ( ,colorado1 #fi on ! ,elk ,m\nta9s1 #gj ,peale laccolite1 #dg ,p5nell1 ,m\nt 7see ,m\nt ,p5nell74 ,p5nell5 ,pass1 #c ,p9e ,alcove ,creek1 ,=m] c\rse (1 #acj ,planation1 #abf1 #aci 1 ,hills (1 #acj ,pla/icity ( solids1 #hb1 #hc1 #ig ,plateaus enum]at$1 #ac ,precipitation f runn+ wat]1 #aaa ,pressure a condition = rock flexure1 #ha1 #hc1 #if ,prismatic /ructure1 ,abs5ce (1 #ee1 #gf def9$1 #ee ,pond+1 #abe1 #aci ,porphyritic tra*yte1 #fj1 #fd ,porphyry2 use ( t]m discuss$1 #fc ,p[ell1 ,pr(4 ,j4 ,w41 on ! climate ( ! ,colorado ,bas91 #abj ,pulpit ar*1 #cc1 #adg ,rank9e on flexure ( beams1 #ij ,r$ ,gate flexure1 #ac 1 ,flood-pla9s (1 #aca 1 ,!1 #af ,revet-crags def9$1 #be ( ,m\nt ,hill]s1 #ca ( ,m\nt ,holmes1 #bi ( ,m\nt ,p5nell1 #cg ,ripple-m>ks1 ,fossil1 #af ,riv] t]races produc$ by planation1 #acb ,riv]s1 ,anci5t1 no great] ?an mod]n1 #acc ,rock texture1 ,influ5ce (1 on sculpture1 #aae1 #ace1 #adj 1 ,g5]al influ5ce (1 on erosion1 #ajc ,rocks ( ! ,h5ry ,m\nta9s1 ,intrusive1 #ei1 #fa 1 ,s$im5t>y1 #c ,rotation ( ! e>?1 #adb ,r\te to ! ,h5ry ,m\nta9s1 #ad ,san ,rafael fold1 #af1 #ah ,scrope laccolite1 #dg ,sculpture1 ,alp9e1 #cf1 #ch influ5c$ by climate1 #aag di/ribution ( divides1 #aaf rock /ructure1 #aae1 #ace1 #adj ,sculpture ( bad-l&s1 #abj ( ,m\nt ,ellswor?1 #be 1 ,pr9ciples (1 #ii1 #aae ,s5t9el ,butte1 #ch ,%eets & dikes def9$1 #bj ( ,m\nt ,ellswor?1 #bd ( ,m\nt ,holmes1 #bh 1 ,relation (1 to /ra9s1 #if ,%9-ar'-ump ,gr\p1 #f ,%\ld] laccolite1 #db ,si]ra ,abajo1 #fg1 #fi1 #aeb ,c>riso1 #gi1 #aeb ,la ,lata1 #fh1 #fi1 #aeb ,la ,sal1 #fh1 #fi1 #aeb ,solidity ( rocks n absolute1 #hb1 #hc1 #ig ,specific gravities 7see ,d5sities74 ,specim5s ( ,h5ry ,m\nta9 tra*yte1 #fj ,spr+s2 relation to s(t /rata expla9$1 #hb ,/ability ( divides1 #ach ( dra9age l9es1 #abd ,/]eogram1 h[ made1 #aa1 #di ( ,m\nt ,ellswor?1 #bc1 #ie ( ! ,h5ry ,m\nta9s1 #di & ,wat]pocket flexure1 #aa ,/ew>d laccolite1 #cb 1 ,mr4 ,john ,f41 cit$1 #ff ,/ra9s %[n by dikes & %eets1 #if ,/ret*+ ( /rata1 #hj ,/ructure1 ,law (1 #aae ,suncracks1 ,fossil1 #i ,sup]impos$ dra9age1 #add ,sy/ems ( dra9age1 #abd1 #adc ,table ( altitudes1 #aag d5sities ( s$im5t>y rocks1 #gh 9 ord] ( sup]position1 #gi tra*ytes1 #gg diamet]s ( laccolites1 #ib di/ances1 #ag mean d5sities ( c]ta9 rock s]ies1 #hj ,tantalus ,creek1 #ag 1 ,flood-pla9s (1 #aca ,taylor1 ,m\nt1 #ga ,temple ,creek1 #af 1 ,flood-pla9s (1 #aca ,t]races1 ,riv]1 produc$ by planation1 #acb ,t]ti>y /rata protect$ by lava1 #ab ,?icknesses ( individual /rata1 #g ,?ompson1 ,pr(4 ,a4 ,h41 #a1 #ff ,?\s& ,lake ,m\nta91 ,view f1 #ae ,timb] l&1 #aeb ,tra*yte1 ,porphyritic1 #fj1 #fd ,tra*ytes ( ! ,h5ry ,m\nta9s n vesicul>1 #ea1 #fd ,transportation1 #ajj1 #aja by /reams1 analyz$1 #ajf ,conditions :i* det]m9e rate (1 #aaj favor$ by comm9ution ( mat]ial1 #ajf declivity1 #ajh quantity ( wat]1 #aji 1 ,relation (1 to corrasion1 #aaa ,tr5d1 ,abs5ce (1 #b1 #cj1 #ih ,tu-nunk' ,s&/one1 #d ,%ale1 #d ,uncon=mities1 #h1 #he ,uncon=mity at ,sal9a1 #ad ,vegetation1 ,g5]al influ5ce (1 on erosion1 #ajd ,ve9s1 ,abs5ce ( fissure1 #hc1 #aea 1 ,fissure1 limit$ 9 dep?1 #hb ,v]milion ,cliff ,gr\p1 #f ,v]tical cleavage by sapp+1 #ee ,volcanoes ( ! ,plateau ,prov9ce1 ,ext9ct1 #fg1 #gj ,volume ( /reams1 ,influ5ce (1 on erosion1 #ajd transportation1 #aji 1 ,relation (1 to declivity1 #aac ,w>r51 ,g5]al ,g4 ,k41 on ! valley ( ! ,m9nesota ,riv]1 #abf ,wat]pocket ,caon1 #acg flexure1 describ$1 #ab 1 ,passes across !1 #af ,wat]%$s 7see ,divides74 ,wea!r+1 #ajj ,:ite1 ,dr4 ,c4 ,a42 id5tification ( ,h5ry's ,=k ,gr\p1 #d ,:itney1 ,pr( ,j4 ,d41 on incl9ation ( b$d+1 #eb ,w9ipeg1 ,orig9 ( ,lake1 #abf ,zones ( laccolites1 #eg1 #eh1 #gd ,illu/ration3 ,plate ,i4 ,,map ( ! ,,h5ry ,,m\nta9s ,,& ,,vic9ity4 ,photograph$ f a model 9 relief4 ,triangulation by ,a4 ,h4 ,?ompson4 ,topography by ,w4 ,h4 ,graves4 ,illu/ration3 ,plate ,,ii4 ,,/]eogram ( ! ,,h5ry ,,m\nta9s ,,& ,,wat]pocket ,,fold4 ,includ+ ! same area z ,plate ,i4 ,illu/ration3 ,plate ,,iii4 ,,map ( ! ,,h5ry ,,m\nta9s4 by ,g4 ,k4 ,gilb]t4 ,photograph$ f a model 9 relief4 ,illu/ration3 ,plate ,,iv4 ,,/]eogram ( ! ,,displacem5ts ( ! ,,h5ry ,,m\nta9s includ+ ! same area z ,plate ,,iii4 ,! ,blue ,gate ,s&/one is re/or$ s z to exhibit ! =m x receiv$ by ! uplift ( ! laccolitic domes4 ,illu/ration3 ,plate ,v4 ,,map ( ! ,,h5ry ,,m\nta9s by ,g4,k4 ,gilb]t4 ,f a model 9 relief4 ---------------------------------------- -------------------------------- ,,transcrib]',s ,,notes ,page ,*ang$ f ,*ang$ to #cj degradation1 less ?an "o-half degradation1 less ?an "o-half has be5 /ripp$ ( its cov] has be5 /ripp$ ( its cov] ( ar*-ar*+ ( ov]>*+ ,typos fix$2 non-/&>d spell+ & dialect reta9$4 ,us$ numb]s = footnotes4 ,enclos$ italics font 9 und]scores4 ,! 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