,guide to ! ,,geologic ,,map ,,( ,,ill9ois ,ill9ois ,/ate ,geological ,survey ,educational ,s]ies #g ,,/ate ( ,,ill9ois ,otto ,k]n]1 ,gov]nor ,illu/ration3 ,,seal ,,( ,,! ,,/ate ,,( ,,ill9ois ,,dep>tm5t ( ,,regi/ration & ,,education ,william ,sylve/] ,:ite1 ,director #aifa ,,ill9ois ,,/ate ,,geological ,,survey ,john ,c4 ,frye1 ,*ief ,,urbana1 ,,ill9ois ,,pr9t$ ,,by ,,au?ority ,,( ,,! ,,/ate ,,( ,,ill9ois #dbeag-bj,m #b 7#ghghc7 ,guide to ! ,,geologic ,,map ,,( ,,ill9ois ,,glacial ,,geology ,illu/ration3 ,decorative capital ,al?\gh ! age ( ! ,e>? is measur$ 9 billions ( ye>s1 ! face ( ,ill9ois is "y--a m]e #ae1jjj ye>s old4 ,dur+ ! ,ice ,age1 mo/ ( ,ill9ois 0 repeat$ly invad$ by huge glaci]s1 sometimes t[]+ a mile or m high1 t c>ri$ emb$d$ 9 !m gr\nd up rock mat]ials !y _h g\g$ out ( ! b$rock to ! nor? z !y pond]\sly pu%$ s\?4 ,:5 ! la/ ( ! glaci]s melt$ f ,ill9ois1 ab\t #ae1jjj ye>s ago1 ! c\ntry t em]g$ look$ f> diff]5t f ! preglacial l&4 ,old hills & valleys _h vani%$1 new ones _h =m$1 & a mantle ( unconsolidat$ rock mat]ial1 ! burd5 c>ri$ by ! ice & dropp$ z ! ice melt$1 lay ov] mo/ ( ! region4 ,mo/ ( ?is mat]ial1 call$ glacial drift1 0 br\ght 9 by ! ice dur+ ! la/ two ( ! f\r major p]iods ( glaciation--! ,ill9oian p]iod #ajj1jjj to #aej1jjj ye>s ago & ! ,wiscons9an #e1jjj to #ej1jjj ye>s ago4 ,! old] drift introduc$ dur+ ! ,kansan & ,nebraskan glacial p]iods is almo/ entirely buri$ b5ea? ! lat] drifts4 ,! glaci]s cov]$ all ( ,ill9ois except ! nor?we/]n corn]1 ! s\?we/]n edge along ! ,mississippi ,riv]1 & extreme s\!rn ,ill9ois1 z %[n 9 figure #a4 ,9 ^? areas ! l& is mu* z x 0 be=e ! glaci]s came4 ,9 ! glaciat$ portion ( ! /ate1 h[ev]1 ! b$rock g5]ally is cov]$ by ! rock debris ! ice c>ri$ f z f> away z ,canada4 ,z ! fr+es ( ! ice melt$1 ^! loads ( rock mat]ial 71 9 "s places1 dump$ z ridges 7mora9es7 :i* are ! hills & m\nds on ! flat prairies ( ! pres5t l&scape4 ,su* mat]ial also fill$ anci5t riv] valleys1 b new valleys 7 cut by torr5ts ( wat] releas$ by ! melt+ ice4 ,illu/ration3 ,figure #a--;,a mantle ( glacial drift cov]s ! b$rock 9 mu* ( ,ill9ois4 ,,wiscons9an ,,glacial ,,drift ,,kansan ,,glacial ,,drift ,,ill9oian ,,glacial ,,drift ,! glacial drift belongs to ! y\nge/ 7topmo/ lay]7 ( ! major divisions ( our rocks1 :i* geologi/s h nam$ ! ,plei/oc5e 7sci5tific "n = ,ice ,age deposits74 ,mo/ ( ! drift is an unsort$ mixture ( clay1 pebbles1 & b\ld]s call$ 8till10 b "s glacial deposits consi/ ( wat]-sort$ s& & gravel c>ri$ & deposit$ by meltwat] f ! glaci]s4 ,o!r mat]ials 7 deposit$ by ! w9d--s& 0 pil$ into %ift+ dunes & f9e silts 7 spread l a blanket ov] ! l&4 ,?is mantle ( silt is call$ loess4 ,! glacial deposits conta9 a wide v>iety ( rocks1 "s br\ght f regions to ! nor?1 o!rs sc\r$ f ! lay]s ( native rock 9 ,ill9ois4 ,! limits ( ! ,ill9oian1 ! ,wiscons9an1 & ! ,kansan glaciations are %[n 9 figure #a4 ,"s ( ! m prom95t mora9es are sket*$ ) d>k gray l9es on plate #a4 ,)9 ?is area1 glacial drift cov]s ! b$rock except along valleys :]e /reams h cut ?r\gh & remov$ x4 ,,b$rock ,,geology ,b5ea? ! glacial drift ( ,ill9ois _m lay]s ( rocks ov]lie a base ( anci5t cry/all9e rocks t 9 ,ill9ois occur at dep?s ( #b1jjj to z mu* z #ae1jjj feet4 ,! geologic map 7plate #a1 9 pocket7 is drawn z if ! mantle ( glacial drift _h be5 remov$ to expose ! lay]s ( b$rock1 :i* are l>gely lime/one1 %ale1 & s&/one4 ,! key on ! map %[s ! age sequ5ce ( ! rocks1 arrang$ ) ! y\nge/ at ! top1 & gives ! names t geologi/s h assign$ to ! v>i\s sy/ems ( rocks4 ,ea* sy/em consi/s ( rocks t 7 deposit$ dur+ a long p]iod ( "t4 ,! complete sequ5ce ( rocks might be lik5$ to a book ( e>? hi/ory1 & ea* sy/em lik5$ to a *apt]4 ,sy/ems are divid$ into =mations1 :i* might be reg>d$ z pages 9 ! book4 ,z %[n on ! g5]aliz$ rock column 9 figure #b1 ! rocks next old] ?an ! glacial drift 7,plei/oc5e7 are ! ,t]ti>y & ,cretace\s s&s1 gravels1 & clays1 mo/ly unconsolidat$4 ,!y occur only at ! extreme s\!rn tip ( ,ill9ois & 7 deposit$ :5 t area 0 cov]$ by a nor?w>d ext5sion ( ! ,gulf ( ,mexico4 ,! ,t]ti>y rocks are %[n on ! map 9 gray$ p9k 7,t7 & ! ,cretace\s 9 r$-violet 7,k74 ,next old] ?an ! ,cretace\s are ! ,p5nsylvanian rocks1 nam$ = ! /ate ( ,p5nsylvania :]e !y are well expos$ & 7 fir/ /udi$4 ,! ,p5nsylvanian ,sy/em is divid$ into two areas on ! map 7,p & ,p74 ,! rocks %[n 9 lighte/ gray 7,p7 lie above ! ,no4 #f ,coal 9 ! sequ5ce & ^? 9 m$ium gray 7,p7 lie bel[ x4 ,! ,no4 #f ,coal is "o ( ! ?icke/1 mo/ valuable coals 9 ! /ate4 ,p5nsylvanian rocks occur "u ! glacial drift1 & _! ?ickness ranges f a few feet to z mu* z #c1jjj feet4 ,illu/ration3 ,figure #b--;,diagram ( lay]s ( rocks 9 ,ill9ois4 ,! olde/ rocks are at ! bottom1 ! y\nge/ at ! top4 ,names are ! /&>d ones appli$ by geologi/s to ! subdivisions ( ! geologic eras4 ,era ,g5]al ,types ( ,rocks ,p]iod or ,sy/em & ,?ickness ,epo* ,,c5ozoic 8,rec5t ,life0 ,age ( ,mammals ,quat]n>y #j-ejj ,plei/oc5e or ,glacial ,age ,rec5t--alluvium 9 riv] valleys ,glacial till1 glacial outwa%1 gravel1 s&1 silt lake deposits ( clay & silt1 loess & s& dunes2 cov]s ne>ly all ( /ate except nor?we/ corn] & s\!rn tip ,t]ti>y #j-ejj ,plioc5e ,*]t gravel2 pres5t 9 nor!rn1 s\!rn1 & we/]n ,ill9ois ,eoc5e ,mo/ly micace\s s& ) "s silt & clay2 pres5t only 9 s\!rn ,ill9ois ,paleoc5e ,mo/ly clay1 little s&2 pres5t only 9 s\!rn ,ill9ois ,,mesozoic 8,middle ,life0 ,age ( ,reptiles ,cretace\s ,mo/ly s&1 "s ?9 b$s ( clay &1 #j-cjj' locally1 gravel2 pres5t only 9 s\!rn ,ill9ois ,,paleozoic 8,anci5t ,life0 ,age ( ,amphibians & ,e>ly ,plants ,p5nsylvanian ,l>gely %ale & s&/one ) b$s ( coal1 #j-c1jjj lime/one1 & clay 78,coal ,measures07 ,mississippian ,black & gray %ale at base2 middle zone ( #j-c1ejj' ?ick lime/one t grades to silt/one1 *]t1 & %ale2 upp] zone ( int]b$d$ s&/one1 %ale & lime/one ,age ( ,fi%es ,devonian ,?ick lime/one1 m9or s&/ones & %ales2 #j-a1ejj' l>gely *]t & *]ty lime/one 9 s\!rn ,ill9ois ,age ( ,inv]tebrates ,silurian ,pr9cipally dolomite & lime/one #j-a1jjj' ,ordovician ,l>gely dolomite & lime/one b conta9s #ejj-b1jjj' s&/one1 %ale1 & silt/one =mations ,cambrian ,*iefly s&/ones ) "s dolomite & %ale2 #a1ejj-c1jjj' expos$ only 9 small areas 9 nor?-c5tral ,ill9ois ,,ar*eozoic & ,,prot]ozoic ,igne\s & metamorphic rocks2 kn[n 9 ,ill9ois only f deep wells ,! ,p5nsylvanian ,sy/em conta9s _m diff]5t k9ds ( rocks1 includ+ all ( our m9able coals4 ,x also conta9s important deposits ( lime/one1 %ale1 & clay1 & at places oil & gas4 ,next bel[ ! ,p5nsylvanian are ! rocks ( ! ,mississippian ,sy/em1 %[n 9 blue on ! map 7,m & ,m74 ,! l[] & middle ,mississippian rocks 7,m7 are l>gely lime/one 9 & ne> ! areas mapp$1 b 9 ! c5tral & ea/]n "p ( ! /ate :]e !y are buri$ "u ,p5nsylvanian rocks !y conta9 mu* silt/one & *]ty lime/one4 ,! upp] ,mississippian rocks 7,m7 consi/ ( a succession ( s&/one1 %ale1 & lime/one =mations4 ,?is sy/em ( rocks takes its "n f ! ,mississippi ,riv] because !re are excell5t exposures ( ^! /rata along ! ,mississippi ,valley 9 we/]n ,ill9ois1 s\!a/]n ,i[a1 & ea/]n ,miss\ri4 ,! ,mississippian rocks are a s\rce ( lime/one1 fluorsp>1 z9c1 & gani/]1 & are ( greate/ economic significance 9 s\!a/]n ,ill9ois :]e !y are ! mo/ important ( our oil-produc+ rocks4 ,! ,devonian 7,d1 d>k gray on ! map71 ,silurian1 7,s1 violet71 ,ordovician 7,o1 light p9k71 & ,cambrian 7,c1 deep p9k7 rocks1 9 ! ord] nam$1 are old] ?an ! ,mississippian /rata4 ,9 g5]al1 !y include dolomite1 lime/one1 %ale1 & s&/one4 ,except = small areas along ! ,mississippi & ,ill9ois ,riv] ,valleys1 ^! old] rocks are f\nd at ! surface only 9 ! nor!rn qu>t] ( ! /ate & locally 9 ,alex&]1 ,h>d91 ,jackson1 ,monroe1 ,pike1 & ,union ,c\nties4 ,!y are nev]!less economically important because !y yield lime/one1 dolomite1 silica s&1 oil1 z9c & lead1 tripoli1 novaculite1 & novaculite gravel4 ,! rocks ( ! ,cambrian ?r\gh ,p5nsylvanian ,sy/ems belong to ! ,paleozoic ,era4 ,! ,paleozoic rocks ov]lie cry/all9e rocks1 su* z granites1 t ext5d to unkn[n dep?s 9 ! cru/ ( ! e>?4 ,! cry/all9e rocks are n expos$ 9 ,ill9ois b are enc\nt]$ 9 ! drill+ ( "s deep wells & may be se5 9 ! ne>by ,miss\ri ,oz>ks & 9 c5tral ,wiscons94 ,,/ructural ,,geology ,! rock =mations appe> to lie flat 9 mo/ ( ,ill9ois1 b !y are slightly incl9$ 9 mo/ places4 ,9 "s areas !y are d[n-w>p$ into bas9s & tr\ghs 7syncl9es71 upfold$ into domes & ar*es 7anticl9es71 or brok5 by faults4 ,! l>ge/ /ructural feature 9 ,ill9ois is a great spoon-%ap$ bas9--! ,ill9ois ,bas9--t ext5ds s\!a/w>d into ,indiana & ,k5tucky4 ,! deepe/ "p ( ! bas9 is 9 s\!a/]n ,ill9ois4 ,illu/ration3 ,figure #c--,:5 rocks are d[n-w>p$ & ! surface is level$ by erosion1 ! y\nge/ rocks are pres]v$ 9 ! c5t] & ! old] rocks are expos$ at ! m>g9s4 ,because ! entire region1 includ+ ! bas91 has be5 erod$ by ra91 ice1 w9d1 & _m riv]s & /reams1 ! y\nge/ ,paleozoic rocks 7top-mo/ lay]s7 are pres]v$ only 9 ! middle ( ! bas91 z %[n 9 figures #c1 #f1 & #g4 ,?is is :y ! map %[s ! coal-be>+ rocks ( ,p5nsylvanian age 9 ! c5t] ( ! /ate & ! old] rocks cropp+ out 9 successive b&s ar\nd ! m>g9s ( ! bas9 9 s\!rn1 we/]n1 & nor!rn ,ill9ois4 ,di/ribution ( b$rock 9 nor!rn ,ill9ois is influ5c$ by a broad upfold or ar* 7see figures #d1 #f1 & #g74 ,! map 7plate #a7 %[s ! old] rocks 7,cambrian & ,ordovician7 expos$ at ! c5t] ( ! ar* & surr\nd$ by y\ng] ,silurian & ,devonian rocks4 ,ano!r elongat$ upfold 7anticl9al belt7 ext5ds f ! vic9ity ( ,dixon s\!a/w>d into ,indiana4 ,! cre/ ( ! upfold is indicat$ on ! map by pat*es ( ,silurian & ,devonian rocks 9 ,*ampaign & ,d\glas ,c\nties4 ,illu/ration3 ,figure #d--,:5 rocks are upfold$ & ! surface is erod$1 ! old] rocks are expos$ at ! cre/ ( ! dome or anticl9e4 ,9 extreme s\!rn ,ill9ois & 9 nor?-c5tral ,ill9ois1 ! rock lay]s are brok5 by great faults 7see figures #e & #f7 :i* displace ! lay]s ( rocks by z little z a few in*es to z mu* z #c1jjj feet4 ,! /ructural map ( ,ill9ois 7figure #f7 %[s ! position ( ! major geologic /ructures4 ,! big bas9 is indicat$ by %ad+1 ) ! d>ke/ patt]n %[+ :]e ! bas9 is deepe/4 ,! same /rata t lie at sea level at ! bas9's out] edge are d[nw>p$ to #f1jjj feet bel[ sea level 9 its deepe/ "p4 ,axes ( "s small anticl9es & locations ( major fault zones also are %[n4 ,illu/ration3 ,figure #e--,:5 rocks are fault$ by e>? /resses1 ! lay]s ( rock are displac$ or (fset4 ,illu/ration3 ,figure #f--,major /ructural features ( ,ill9ois--! ,ill9ois ,bas91 anticl9es1 & faults4 ,! increas+ dep? ( ! bas9 is %[n by progressively d>k] patt]ns4 ,,kankakee ,,ar* ,,mississippi ,r4 ,,ar* ,,la ,,salle ,,anticl9al ,,belt ,,oz>k ,,uplift ,,key ,position ( major anticl9e ,major faults ,illu/ration3 ,figure #g--,! cross section f nor? to s\? ?r\gh ,ill9ois %[s ! /rata d[n-w>p$ into ! bas94 ,,hi/orical ,,geology ,read+ ! hi/ory ( ! e>?'s cru/ is l read+ a my/]y /ory4 ,! geologi/ mu/ exam9e1 or read1 ea* rock lay]1 f ! y\nge/ at ! top to ! olde/ at ! bottom1 se>*+ = clues to its orig91 age1 & developm5t f :i* he c recon/ruct ! pa/4 ,"o ( ! clues to ! pa/ is ! fossil rema9s ( plants & animals f\nd 9 ! rocks4 ,= in/ance1 if a c]ta9 coral is kn[n to h liv$ only dur+ "o span ( "t1 all rocks conta9+ t coral fossil mu/ h be5 =m$ )9 t span4 ,records ( wells 7well logs7 & rock cores or samples collect$ :5 te/ holes are drill$ into ! b$rock also reveal mu* ab\t ! sequ5ce ( rock /rata b5ea? ! surface4 ,! k9ds ( rocks enc\nt]$ tell1 9 addition1 some?+ ab\t anci5t geography1 = "s 7 =m$ on l& & o!rs 7 deposit$ 9 long-dep>t$ seas4 ,su* k is extremely important 9 f9d+ & develop+ m9]al res\rces su* z coal & oil4 ,,economic ,,geology ,m9]als produc$ comm]cially 9 ,ill9ois include crude oil1 coal1 lime/one1 dolomite1 clay1 s&1 gravel1 fluorsp>1 tripoli1 gani/]1 novaculite gravel1 silica s&1 & ! metals z9c & lead4 ,! di/ribution ( m9]al indu/ries1 %[n 9 ! sev]al maps ( figures #h ?r\gh #ab1 is1 ( c\rse1 relat$ to ! di/ribution ( ! rocks 7plate #a74 ,= example1 ! coal m9es are scatt]$ along ! m>g9 ( ! area ( ,p5nsylvanian rocks :]e ! coals are at relatively %all[ dep?s4 ,! m9]al fuels1 coal & petroleum1 are ! lead+ m9]al products ( ,ill9ois1 mak+ up ab\t #gj p]c5t ( ! annual value ( all m9]als produc$ 9 ! /ate4 ,= _m ye>s coal 0 at ! top ( ! li/1 b petroleum n[ holds fir/ place4 ,petroleum ,9 rec5t ye>s production ( petroleum has av]ag$ ab\t #gh million b>rels ea* ye>1 mak+ ,ill9ois ! eigh? l>ge/ petroleum produc+ /ate4 ,! major oil area is ! deep "p ( ! ,ill9ois ,bas9 9 ! s\?c5tral & s\!a/]n p>ts ( ! /ate1 b significant discov]ies h be5 made rec5tly 9 c5tral & we/]n ,ill9ois4 ,!re are ab\t #dij oil fields 9 ,ill9ois1 rang+ f a few to sev]al ?\s& acres 9 size4 ,oil has be5 discov]$ 9 rocks ( ! ,p5nsylvanian1 ,mississippian1 ,devonian1 ,silurian1 & ,ordovician ,sy/ems1 b ! ,mississippian are ! mo/ productive & acc\nt = ab\t #gf p]c5t ( our total oil production4 ,illu/ration3 ,figure #h--,oil pools 9 ,ill9ois z ( ,janu>y #a1 #aifa4 ,! pools are conc5trat$ ma9ly 9 ! ,ill9ois ,bas9 & along ! ,la,salle ,anticl9al ,belt4 ,illu/ration3 ,figure #i--;,active coal m9es are scatt]$ ar\nd ! m>g9 ( ! bas9 :]e ! coals are at relatively %all[ dep?s4 ,,key ,,%ipp+ ,,m9es ,und]gr\nd ,/rip ,slope ,,local ,,m9es ,,ov] #be1jjj ,,tons ,und]gr\nd ,/rip ,coal ,ill9ois ranks f\r? 9 ! nation among /ates t produce bitum9\s coal1 ! type ( coal mo/ widely m9$ 9 ! ,unit$ ,/ates4 ,coal is us$ by _m manufactur+ indu/ries1 by public utilities companies t burn coal to g5]ate electricity1 & by individuals = heat+ homes4 ,all ,ill9ois coal deposits are f\nd 9 ! ,p5nsylvanian ,sy/em4 ,( ! _m coals1 only a few are ?ick en\gh to be m9$ pr(itably4 ,! coal is ( bitum9\s rank1 b x v>ies 9 quality4 ,ill9ois coal res]ves 9 /rata m ?an #bh in*es ?ick are e/imat$ at #acg billion tons & are l>g] ?an ^? ( any o!r /ate4 ,ar\nd ! edge ( ! coal bas9 :]e ! coal lies at %all[ dep?s1 x is commonly m9$ 9 op5 pits 7/rip m9es74 ,h[ev]1 9 ! pa/1 mo/ coal has be5 m9$ und]gr\nd1 & m ?an half ( ,ill9ois coal is /ill produc$ f su* m9es4 ,lime/one & ,dolomite ,!re are two types ( c>bonate rocks 9 ,ill9ois1 lime/one & dolomite4 ,9 appe>ance !y are almo/ indi/+ui%able1 al?\gh !y are diff]5t *emically4 ,lime/one is compos$ ma9ly ( calcium c>bonate 7! m9]al calcite71 :]eas dolomite is calcium magnesium c>bonate 7! m9]al dolomite74 ,lime/one deposits are f\nd at _m places 9 ! we/]n1 s\?we/]n1 & s\!rn m>g9al portions ( ! /ate4 ,!y are l>gely ( ,mississippian & ,ordovician age4 ,less] deposits ( ,p5nsylvanian lime/one are f\nd 9 ! c5tral portion ( ! /ate4 ,9 ! nor!rn fif? ( ! /ate1 dolomites ( ,silurian & ,ordovician age are expos$ at _m places4 ,lime/one & dolomite are qu>ri$ = a v>iety ( uses1 includ+ aggregate = concrete1 agricultural lime/one1 railroad balla/1 *ips = bitum9\s roads1 & = use 9 metallurgical & *emical processes4 ,!y also are qu>ri$ = build+ /one at "s places1 & m>ble is produc$ 9 s\!rn ,ill9ois4 ,illu/ration3 ,figure #aj--,lime/one & dolomite are qu>ri$ at _m places1 b fluorsp>1 z9c1 & lead are produc$ 9 re/rict$ m9]aliz$ areas4 ,,key ,qu>ry1 ,lime/one or ,dolomite ,cem5t or ,lime ,fluorsp> ,z9c & ,lead ,lime/one & %ale or clay are burn$ toge!r 9 kilns to produce portl& cem5t4 ,portl& cem5t is manufactur$ f a ,p5nsylvanian lime/one 9 ,la,salle ,c\nty & f an ,ordovician lime/one 9 ,lee ,c\nty4 ,lime/one or dolomite also is burn$ 9 kilns to make lime4 ,mississippian lime/one is us$ 9 ,adams ,c\nty & ,silurian dolomite is us$ 9 ,cook ,c\nty = lime mak+4 ,clay & ,clay ,products ,ill9ois comm]cial clays are f\nd 9 glacial1 ,cretace\s1 ,t]ti>y1 & ,p5nsylvanian deposits4 ,p5nsylvanian %ales also are s\rces ( clays4 ,glacial clays1 :i* occur z loess 7w9d-bl[n mat]ials71 alluvial 7wat]-deposit$7 s$im5ts1 & glacial till1 are widespread 9 ! /ate4 ,cretace\s & ,t]ti>y clays1 at ! extreme s\!rn tip ( ! /ate1 are valuable = ! manufacture ( heat-resi/ant bricks & coat+s & = floor-sweep+ comp\nds4 ,p5nsylvanian clays & %ales are ! mo/ important s\rce ( clay = manufactur+ su* products z pott]y1 /onew>e1 dra9 tile1 sew] pipe1 flue tile1 build+ tile1 brick1 & special heat-resi/ant fire-brick4 ,s& & ,gravel ,deposits ( s& & gravel1 f\nd 9 _m p>ts ( ,ill9ois1 provide l>ge quantities ( mat]ial = concrete1 railroad balla/1 road gravel1 build+ s&1 mold+ s&1 & o!r uses4 ,glacial deposits are ! pr9cipal s\rces ( s& & gravel1 b 9 extreme s\!rn ,ill9ois :]e !re is no glacial drift ! ma9 s\rce ( supply is ,t]ti>y gravel & ,devonian *]t gravel4 ,illu/ration3 ,figure #aa--,! clay indu/ry is scatt]$ widely 9 ,ill9ois4 ,_m manufactur+ plants are locat$ at ! clay pits4 ,,key ,pit or ,plant ,almo/ e c\nty has "s s& & gravel1 b ! major areas ( production are nor!a/]n ,ill9ois & "s ( ! major riv]s4 ,consid]able tonnages ( s& & gravel are dr$g$ f b>s 9 ! *annels ( ! ,mississippi1 ,ohio1 & ,waba% ,riv]s4 ,silica ,s& ,silica s& is us$ 9 mak+ glass1 = s& bla/+1 z gr9d+ s&1 z mold+ s& = ca/+ /eel1 & 9 ! fracture treatm5t ( oil wells to increase oil production4 ,"s ( ! s& is f9ely pulv]iz$ into a p[d] t is us$ z a fill]1 a f9e abrasive1 z a c]amic mat]ial1 & = _m o!r purposes4 ,?is special s&1 compos$ ( gra9s ( ! m9]al qu>tz 7silica71 comes f a s&/one ( ,ordovician age t is m9$ 9 ,la,salle & ,ogle ,c\nties4 ,tripoli & ,gani/] ,tripoli1 or 8amorph\s0 silica1 is m9$ f ,devonian rocks 9 ,alex&] ,c\nty4 ,! silica is f9ely gr\nd = use z a poli%+ ag5t1 z a fill]1 9 buff+ comp\nds1 & = o!r purposes4 ,gani/]1 a granul> mat]ial ) a high silica cont5t1 also is m9$ 9 extreme s\!rn ,ill9ois4 ,x is us$ 9 mak+ products t c )/& high temp]atures4 ,fluorsp> ,= _m ye>s ,ill9ois has l$ ! nation 9 ! production ( fluorsp>1 acc\nt+ annually = ab\t half ! total ,unit$ ,/ates output4 ,! indu/ry is c5t]$ 9 ,h>d9 & ,pope ,c\nties :]e ! deposits occur 9 ve9s & b$s 9 rocks ( ! ,mississippian ,sy/em4 ,res]ves ( fluorsp> are adequate to supply ! indu/ry = _m ye>s4 ,illu/ration3 ,figure #ab--,s& & gravel is produc$ at _m places 9 ! /ate4 ,silica s& is produc$ only f a s&/one 9 nor!rn ,ill9ois4 ,tripoli is f\nd only 9 s\!rn ,ill9ois4 ,,key ,s& & ,gravel ,silica ,s& ,mold+ ,s& ,tripoli ,fluorsp> is us$ 9 ! manufacture ( hydr(luoric acid1 z a flux 9 ! manufacture ( /eel1 9 ! ref9+ ( alum9um1 = ! manufacture ( fluor9e comp\nds us$ 9 a v>iety ( products1 9 c]amic glazes1 & = o!r special purposes4 ,lead & ,z9c ,lead & z9c are ! only metallic m9]als m9$ 9 ,ill9ois4 ,deposits are f\nd 9 ,jo ,daviess ,c\nty 9 nor?we/]n ,ill9ois & 9 ! fluorsp> area ( ,h>d9 & ,pope ,c\nties 9 extreme s\!rn ,ill9ois4 ,9 nor?we/]n ,ill9ois ! ore occurs 9 rocks ( ,ordovician age1 b 9 s\!a/]n ,ill9ois x is associat$ ) fluorsp> 9 rocks ( ,mississippian age4 ,betwe5 #ahbj & #ahfe1 ! m9+ area ( :i* nor?we/]n ,ill9ois is a "p 0 ! nation's pr9cipal produc] ( lead ore4 ,9 rec5t ye>s production ( z9c has increas$ & t ( lead has decreas$4 ,wat] ,supplies ,wat]1 too1 is a m9]al res\rce1 & our mo/ necess>y "o4 ,! s\rce ( ne>ly all wat] is ra9 & sn[1 :i* collect 9 lakes & /reams or seep into ! gr\nd to =m our two types ( wat] supplies--surface wat] & gr\nd wat]4 ,gr\nd wat] 9 ,ill9ois collects und]gr\nd 9 deposits ( s& & gravel or 9 ! por\s s&/one or lime/one lay]s ( b$rock4 ,^! rock mat]ials are call$ 8aquif]s0 because ( _! ability to hold wat] & to all[ x to fl[ into wells t are drill$ into !m4 ,! aquif]s are n equally di/ribut$ ?r\gh\t ,ill9ois1 s gr\nd-wat] supplies are abundant 9 "s p>ts ( ! /ate b are sc>ce 9 o!rs4 ,"s ,ill9ois cities dep5d :olly or p>tly on surface supplies f lakes & riv]s4 ,! s& & gravel aquif]s yield m gr\nd wat] ?an any o!rs 9 ,ill9ois4 ,! major s& & gravel aquif]s 7 deposit$ by /reams & lie along riv] valleys4 ,"s ( ^! riv] valleys are no long] visible to u because !y 7 buri$ by glacial drift4 ,!y are recogniz$1 h[ev]1 f well records or drill+ records4 ,! nor!rn ?ird ( ,ill9ois has ! mo/ abundant supplies ( gr\nd wat]4 ,b$rock =mations ( ,devonian ?r\gh ,cambrian age are favorable aquif]s & supply dr9kable 7potable7 wat] at dep?s ( f #bjj to #b1jjj feet4 ,^! =mations1 h[ev]1 lie mu* deep] 9 ! ,ill9ois ,bas91 :]e ! wat] !y furni% is too salty = mo/ uses4 ,we/ ( ! ,ill9ois ,riv] & at ! s\!rn tip ( ! /ate1 ! ,mississippian1 ,devonian1 & ,silurian lime/ones are ! *ief aquif]s4 ,_! yield1 h[ev]1 is small4 ,9 ! ,ill9ois ,bas9 all ^! =mations are ov]la9 by ,p5nsylvanian rocks :i* (f] only small1 scatt]$ supplies ( gr\nd wat]4 ,,ill9ois ,,/ate ,,geological ,,survey ,a city or f>m] ne$s a new wat] supply4 ,:]e c suitable wat]-be>+ =mations be f\nd8 ,a new lime/one qu>ry is consid]$4 ,:]e are ! mo/ suitable lime/one deposits8 ,a coal m9e is be+ plann$4 ,h[ deep mu/ a %aft be sunk to rea* ! ne>e/ m9able coal & :at w ! m9+ conditions be8 ,a l& own] has a clay deposit on 8 l&4 ,:at uses c be made ( x8 ,a road is to be con/ruct$4 ,are s& & gravel or lime/one deposits available ne>by = con/ruction mat]ials8 ,a f>m] wants to "k :e!r !re might be oil on 8 prop]ty4 ,are oil-be>+ /ructures pres5t &1 if s1 at :at dep?8 ,^! are typical que/ions br\ght to ! ,ill9ois ,/ate ,geological ,survey by ! indu/ries & p ( ,ill9ois4 ,f its accumulat$ /ore ( in=mation & exp]i5ce1 ! ,survey provides answ]s4 ,?is /oreh\se ( k is ! result ( ! ,survey's cont9u\s program ( geologic exploration1 mapp+1 rese>*1 & organization & int]pretation ( data4 ,! ,survey explores & maps ! geology & m9]al res\rces ( ! /ate1 does rese>* to f9d new & improv$ uses = our m9]al res\rces1 & organizes & int]prets basic geologic in=mation ga!r$ f well logs1 rock samples1 & field /udies1 putt+ !m all into usable =m4 ,su* k is %>$ ) ! public ?r\gh publications1 maps1 lectures1 & p]sonal consultations ) indu/ries1 drill]s1 eng9e]s1 l& own]s1 tea*]s1 & o!rs 9 ne$ ( geologic in=mation4 ,! discov]y ( facts ab\t ! ri* m9]al res\rces ( ,ill9ois has1 9 effect1 only begun1 & x is ! task ( ! ,geological ,survey to cont9ue to collect & apply new in=mation s t our res\rces c be us$ to ! be/ advantage4 ,,educational ,,ext5sion ,,program ,! ,educational ,ext5sion ,section ( ! ,geological ,survey conducts six field trips ea* ye>1 9 v>i\s p>ts ( ! /ate1 = tea*]s1 /ud5ts1 & laym54 ,x also assembles & di/ributes rock & m9]al collections = ,ill9ois educational gr\ps1 gives lectures1 prep>es exhibits1 & id5tifies rocks & m9]als = ! public4 ,educational ,ext5sion publications1 su* z ?is book1 are simplifi$ discussions ( geological subjects4 ,available = #be c5ts ea*1 ^! include3 ,educational ,s]ies #d3 ,guide = ,beg9n+ ,fossil ,hunt]s1 by ,*>les ,w4 ,coll9son4 ,educational ,s]ies #e3 ,guide to ,rocks & ,m9]als ( ,ill9ois4 ,educational ,s]ies #f3 ,field ,book ( ,p5nsylvanian ,plant ,fossils ( ,ill9ois1 by ,*>les ,coll9son & ,romayne ,sk>tv$t4 ,_m te*nical discussions ( ! v>i\s phases ( ,ill9ois geology also are publi%$ by ! ,geological ,survey4 ,regional reports on ! geology & m9]al res\rces ( "s areas are available 9 _m s*ool & public libr>ies or !y may be pur*as$ f ! ,survey4 ,"s ( ! regional reports include3 ,be>d/[n1 ,glas=d1 ,havana1 & ,v]mont ,quadrangles1 ,bullet9 #hb1 #a4jj4 ,buda ,quadrangle1 ,circul> #bge1 no *>ge4 ,c>l9ville ,quadrangle1 ,bullet9 #gg1 #a4jj ,*icago ,region1 ,bullet9 #fe1 ,"p #a1 #ej c5ts4 ,m>seilles1 ,ottawa1 & ,/reator ,quadrangles1 ,bullet9 #ff1 #a4jj4 8,m9]al ,production 9 ,ill9ois 9 #aiei10 ,circul> #cjj 7no *>ge71 is "o ( a s]ies ( annual economic summ>ies4 8,caves ( ,ill9ois10 ,report ( ,inve/igations #bae1 price #ej c5ts1 w be available by ,septemb] #aifa4 ,ill9ois ,/ate ,geological ,survey ,educational ,s]ies #g #bd pages1 #a plate1 #ab figures1 #aifa ,illu/ration3 ,ill9ois ,/ate ,geological ,survey1 ,urbana ,educational ,s]ies #g--,plate #a--,nor? ,illu/ration3 ,ill9ois ,/ate ,geological ,survey1 ,urbana ,educational ,s]ies #g--,plate #a--;,c5tral ,illu/ration3 ,ill9ois ,/ate ,geological ,survey1 ,urbana ,educational ,s]ies #g--,plate #a--,s\? ,,geologic ,,map ,,( ,,ill9ois %[+ ,,b$rock ,,bel[ ,,! ,,glacial ,,drift #aifa ,,key ,t ,t]ti>y 7,plioc5e omitt$7 ,k ,cretace\s ,p ,p5nsylvanian 7,above ,no4 #f ,coal7 ,p ,p5nsylvanian 7,bel[ ,no4 #f ,coal7 ,p ,p5nsylvanian 7,above ,no4 #f ,coal7 ,m ,mississippian 7,upp]7 ,m ,mississippian 7,middle & ,l[]7 ,d ,devonian ,,sd ,silurian & ,devonian ,s ,silurian ,o ,ordovician ,c ,cambrian ,f ,fault ,,osdm ,complex fault$ area ,physiographic base map by ,james ,a4 ,bi] ,price1 #be c5ts ,illu/ration3 ,,p5nsylvanian ,,coal-,,be>+ ,,rocks ,transcrib]'s ,notes --,sil5tly correct$ a few typos4 --,reta9$ publication in=mation f ! pr9t$ edition3 ?is e,book is public-doma9 9 ! c\ntry ( publication4 --,9 ! text v]sions only1 text 9 italics is delimit$ by und]scores4