,! ,geological ,society ( ,am]ica ,special ,pap] #fe ,,! ,,floors ,,( ,,! ,,oceans ,i4 ,,! ,,nor? ,,atlantic ,text to ,accompany ! ,physiographic ,diagram ( ! ,nor? ,atlantic ,,by ,,bruce ,c4 ,,heez51 ,,m>ie ,,?>p1 ,,& ,,maurice ,,ew+ ,lamont ,geological ,obs]vatory 7,columbia ,univ]sity7 ,palisades1 ,new ,york ,illu/ration ,april #aa1 #aiei ,made 9 ! ,unit$ ,/ates ( ,am]ica ,,text ,,pages ,,compos$ ,,& ,,pr9t$ ,,by ,,! ,,william ,,byrd ,,press ,,collotype ,,plates ,,pr9t$ ,,by ,,! ,,m]id5 ,,gravure ,,company ,,l9e ,,plates ,,pr9t$ ,,by ,,williams ,,& ,,he9tz ,,b\nd ,,by ,,russell-,,rutt] ,,company ,,publi%$ ,,by ,,! ,,geological ,,society ,,( ,,am]ica ,,address ,,all ,,communications ,,to ,,! ,,geological ,,society ,,( ,,am]ica #dai ,,we/ #aag ,,/reet1 ,,new ,,york #bg1 ,n4 ,y4 ,! ,special ,pap]s ,s]ies ,( ,! ,geological ,society ( ,am]ica is made possible ?r\gh ! beque/ ( ,ri*>d ,alex&] ,full]ton ,p5rose1 ,jr4 ,c\ld ! wat]s ( ! ,atlantic be drawn (f1 s z to expose to view ?is great sea-ga%1 :i* sep>ates cont95ts1 & ext5ds f ! ,arctic to ! ,ant>ctic1 x w\ld pres5t a sc5e ! mo/ rugg$1 gr&1 & impos+4 ,! v ribs ( ! solid e>?1 ) ! f\ndations ( ! sea1 w\ld be br\ght to light1 & we %\ld h pres5t$ to u at "o view ! empty cradle ( ! ocean4444 7,m4 ,f4 ,maury1 ,! ,physical ,geography ( ! ,sea1 #ahee47 ,,=eword ,! diagrammatic portrayal ( ! relief ( cont95tal l& areas ( ! _w has be5 complet$ by bo? ! late ,a4 ,k4 ,lobeck & ,erw9 ,raisz1 ^: magnific5t diagrams are famili> to all geologi/s & geograph]s4 ,! au?ors ( ! pres5t %eet are prep>+ a simil> s]ies ( m>9e physiographic diagrams4 ,! ,physiographic ,diagram3 ,atlantic ,ocean2 ,%eet #a is ! fir/ ( ?is project$ s]ies4 ,! ,atlantic ,ocean diagram w consi/ ( five %eets at a scale ( ab\t #a3e million4 ,a diagram ( ! ,s\? ,atlantic ,ocean at a scale ( ab\t #a3aa million n[ ne>ly complet$ w =m ! fir/ ( a g5]al s]ies plann$ to portray ! _w oceans4 ,9 addition1 diagrams ( select$ areas well cov]$ by s\nd+ pr(iles w be prep>$ at scales ( ab\t #a3b million4 ,ea* %eet or s]ies ( %eets w be accompani$ by descriptive notes treat+ ! nom5clature1 morphological1 geological1 & geophysical *>act]i/ics ( ea* ( ! physiographic prov9ces4 ,lamont ,geological ,obs]vatory ,contribution #cjh ,,note ,physiographic ,diagram3 ,atlantic ,ocean1 ,%eet #a 7,plate #a7 ,copies ( ! ,physiographic ,diagram3 ,atlantic ,ocean1 ,%eet #a are available unfold$ s t ea* w be suitable = wall m\nt+4 ,! diagram is !re=e n physically ins]t$ or atta*$ to ?is volume al?\gh x =ms ! basic "p ( ! pap]4 ,,ackn[l$gem5ts ,! /udies ( subm>9e topography at ! ,lamont ,geological ,obs]vatory h be5 support$ by ! ,unit$ ,/ates ,navy ,bureau ( ,%ips "u ,contract ,n,obsr #fdedg4 ,! exp$itions :i* obta9$ topographic data 7 support$ by ! ,(fice ( ,naval ,rese>* "u ,contracts ,n#f onr #bgabd & ,n#f onr #bgaac & ! ,bureau ( ,%ips "u ,contract ,n,obsr #fdedg4 ,?ree cruises 7 support$ by ! ,national ,geographic ,society1 ! ,woods ,hole ,oceanographic ,in/itution1 & ,columbia ,univ]sity4 ,f9ancial support has be5 receiv$ f ,! ,geological ,society ( ,am]ica 7,grant #fce-ed74 ,! prep>ation ( ?is pap] 0 support$ 9 "p by ! ,bell ,telephone ,laboratories4 ,! /udies t l$ to ! pres5t pap] began at ! ,woods ,hole ,oceanographic ,in/itution j aft] ,_w ,w> ,,ii4 ,) ! f\nd+ ( ! ,lamont ,geological ,obs]vatory 9 #aidi ! "w 0 transf]r$ to t obs]vatory at ,palisades1 ,new ,york4 ,topographic data f ,woods ,hole cruises 7 incorporat$ ) ,lamont data until #aiec1 :5 a sep>ate program 0 e/abli%$ at ,woods ,hole by ,j4 ,b4 ,h]sey1 & ,columbia ,univ]sity acquir$ ! ,,vema z its own rese>* vessel4 ,al?\gh ,woods ,hole data obta9$ betwe5 #aiec & #aieg h n be5 us$ 9 prep>+ %eet #a1 arrangem5ts rec5tly conclud$ provide = ! incorporation ( pa/ & future ,woods ,hole data 9 subsequ5t %eets ( ?is s]ies4 ,! s\nd+s 7 read1 compil$1 & plott$ by ,morris ,wir%up1 ! late ,&rew ,nelson1 ,ivan ,tol/oy1 ,g4 ,leon>d ,johnson1 ,,iii1 ! au?ors1 & sev]al o!rs4 ,! pr(iles 7 plott$ by ,m4 ,wir%up1 ,he/] ,h>+1 ! au?ors1 & sev]al o!rs4 ,! s\nd+s 7 tak5 prim>ily on bo>d ! ,rese>* ,vessels ,,vema & ,,atlantis 7,woods ,hole ,oceanographic ,in/itution71 b important s\nd+ l9es 7 obta9$ by ! ,r_/,v ,,albatross 7,woods ,hole ,oceanographic ,in/itution71 ,m_/,v ,,!ta1 & ,r_/,v ,,c>yn 7,woods ,hole ,oceanographic ,in/itution7 & 9 ! ea/]n ,atlantic by ! ,r4,r4,s4 ,,discov]y 7,national ,in/itute ( ,oceanography74 ,! foll[+ (fic]s made out/&+ contributions to ! navigational plott+3 ,a4 ,k4 ,lane1 ! late ,a4 ,k>lson1 ,j4 ,pike1 ,r_/,v ,,atlantis2 ,d4 ,g\ld1 ! late ,f4 ,s4 ,u%]1 ,d4 ,smi?1 ,v4 ,s9clair1 ,h4 ,kohl]1 & ,k4 ,simonson1 ,r_/,v ,,vema2 & ! late ,a4 ,nelson1 ,r_/,v ,,vema & ,m_/,v ,,!ta4 ,! e*o s\nd]s h be5 in/all$1 ma9ta9$1 & improv$ by ,b4 ,lusk91 ,h4 ,r4 ,johnson1 ,a4 ,rob]ts1 ,m4 ,l&isman1 ,c4 ,hubb>d1 ,h4 ,van ,sant=d1 ,m4 ,langse?1 ,g4 ,sutton1 & _m o!rs4 ,! entire sci5tific p>ty ( ea* ( ! m ?an #ej exp$itions repres5t$ 9 ! data ( ?is pap] took turns m>k+ & adju/+ ! e*o s\nd]1 & all navigational (fic]s on ^! exp$itions took ! fixes & kept ! logs4 ,to ^! sea-go+ sci5ti/s & m>9]s too num]\s to li/ ! au?ors are extremely grateful4 ,s\nd+s 9 ! nor!a/ ,atlantic compil$ by ! ,briti% ,admiralty ,hydrographic ,dep>tm5t 7 k9dly provid$ by ,cmdr4 ,j4 ,s4 ,n4 ,pryor ( t organization4 ,dr4 ,m4 ,n4 ,hill ( ,cambridge & ,dr4 ,g4 ,e4 ,r4 ,deacon ( ! 7,briti%7 ,national ,in/itute ( ,oceanography 7 in/rum5tal 9 obta9+ _m ( ^! valuable deep-sea s\nd+s4 ,orig9al s\nd+ %eets ( _m areas 7 provid$ by ! ,coa/ & ,geodetic ,survey ?r\gh ! c\rtesy ( ,admiral ,a4 ,k>o & ,mr4 ,g4 ,f4 ,jordan4 ,b4 ,lusk9's developm5t ( ! ,precision ,dep? ,record] & 8 cont9u$ rese>* & developm5t 9 e*o-s\nd+ equipm5t made x possible to obta9 _m ( ! detail$ data ( ?is pap]4 ,! foll[+ exp$ition *ief sci5ti/s conduct$ s\nd+ surveys :i* h be5 incorporat$ 9 ?is pap]3 ,m4 ,ew+1 ,j4 ,l4 ,worzel1 ,j4 ,e4 ,nafe1 ,i4 ,tol/oy1 ,r4 ,s4 ,edw>ds1 ,g4 ,r4 ,hamilton1 ,c4 ,l4 ,drake1 ,b4 ,lusk91 ,w4 ,c4 ,beckmann1 ,f4 ,press1 ,j4 ,nor?rop1 ,j4 ,hir%man1 ,m4 ,j4 ,davidson1 ,r4 ,j4 ,m5zies1 ,f4 ,c4 ,fugli/]1 ,e4 ,t4 ,mill]1 & ,b4 ,c4 ,heez54 ,! writ]s are grateful to ! great numb] ( sci5ti/s :o enc\rag$ !m 9 ?is "w & especially to ^? :o (f]$ sugge/ions & discuss$ ! data & conclusions4 ,we are p>ticul>ly indebt$ to ,w4 ,h4 ,bu*] = discussions relative to tectonics1 to ,david ,b4 ,ericson = problems relat+ to s$im5t di/ribution & analysis1 & to ,c4 ,o',d4 ,isel9 & ,c4 ,h4 ,elm5dorf = g5]al enc\ragem5t & support dur+ ! sev]al ye>s ( ?is /udy4 ,,cont5ts ,,page ,,ab/ract #a ,,"p #a4 ,,prep>ation ,,( ,,! ,,physiographic ,,diagram #c ,,"p #b4 ,,physiographic ,,prov9ces #aa ,introduction #aa ,nom5clature & classification ( deep-sea relief #aa ,units ( dep? & slope #ab ,cont95t & ocean #af ,cont95tal m>g9 #ag ,def9ition & g5]al categories #ag ,g5]al categories #ag ,category ,i prov9ces #ag ,category ,,ii prov9ces #ah ,category ,,iii prov9ces #ai ,regional description ( cont95tal m>g9 #ba ,b5*es & t]races ( ! cont95tal m>g9 #da ,geology & geophysics ( cont95tal-m>g9 physiographic prov9ces #ea ,seismicity ( ! cont95tal-m>g9 prov9ces #ea ,magnetic anomalies & cont95tal-m>g9 physiographic prov9ces #ea ,cru/al /ructures & cont95tal-m>g9 prov9ces #eb ,s$im5t di/ribution & physiographic prov9ces ( ! cont95tal m>g9 #ec ,pa/1 pres5t1 & future ( ! cont95tal-m>g9 prov9ces #ec ,ocean-bas9 floor #ee ,g5]al description #ee ,abyssal pla9s #ee ,g5]al discussion #ee ,regional description #eg ,abyssal hills #fa ,def9ition & di/ribution #fa ,regional description #fc ,orig9 ( abyssal-hills topography #fe ,o!r major features ( ! abyssal floor #ff ,abyssal gaps #ff ,mid-ocean canyons #ff ,regional description #ff ,orig9 ( abyssal-floor topography #gd ,oceanic rises #gd ,def9ition & di/ribution #gd ,regional description #gd ,seam\nts ( ! ocean-bas9 floor #gh ,seismicity ( ! ocean-bas9 floor #hj ,ocean-bas9 floor prov9ces & cru/al /ructure #hj ,mid-oceanic ridges #hc ,def9ition #hc ,mid-,atlantic ,ridge #hc ,prov9ces ( ! ,mid-,atlantic ,ridge #hd ,g5]al /atem5t #hd ,cre/ prov9ces #hd ,flank prov9ces #ie ,azores ,plateau #ig ,azores-,gibralt> ,ridge #ih ,atlantis-,plato-,cruis]-,great ,meteor ,seam\nt ,*a9 #ih ,geology & geophysics ( ,mid-,atlantic ,ridge physiographic prov9ces #ih ,seismicity ( ! ,mid-,atlantic ,ridge #ih ,s$im5ts & physiographic prov9ces ( ! ,mid-,atlantic ,ridge #ii ,rocks ( ! ,mid-,atlantic ,ridge #ii ,cru/al /ructure ( ! ,mid-,atlantic ,ridge prov9ces #ajj ,orig9 ( ! ,mid-,atlantic ,ridge #ajc ,sub-bottom reflections record$ on ,,pdr records & physiographic prov9ces #je ,summ>y ( prov9ce *>act]i/ics #ajg ,,bibliography #aji ,,index #aae ,,illu/rations ,,plates ,,foll[+ ,,plate ,,page #a4 ,physiographic diagram3 ,atlantic ,ocean1 ,%eet #a 7,9 sep>ate tube7 #b4 ,prelim9>y *>t ( ,hudson ,subm>9e ,canyon #bj #c4 ,repres5tative ,,pdr records f cont95tal rise ( nor!a/]n ,unit$ ,/ates #cb #d4 ,,pdr records f cont95tal slope & ,blake ,plateau #cb #e4 ,,pdr records f out] ridge ea/ ( ! ,blake ,plateau & f ! ,blake-,bahama ,abyssal ,pla9 #cb #f4 ,,pdr record ( out] ridge %[+ sub-bottom horizon #cb #g4 ,trac+s ( ,,pdr records across cont95tal slope & "p ( ! ,blake ,plateau #cf #h4 ,,pdr records ,european cont95tal rise & ,biscay ,abyssal ,pla9 #ch #i4 ,repres5tative ,,pdr records ( cont95tal m>g9 & abyssal floor s\?we/ ( ,can>y ,isl&s #ch #aj4 ,,pdr record ( abyssal hills1 s\!a/ ( ,b]muda ,rise #ch #aa4 ,ocean bottom photographs ( ! cont95tal m>g9 & ocean bas9 floor #ch #ab4 ,,pdr record ( ,biscay ,abyssal ,pla9 #eb #ac4 ,,pdr records ( ,madeira ,abyssal ,pla9 & ! ,madeira ,rise #eb #ad4 ,,pdr records ( ,mid-,ocean ,canyon ,no4 #b & canyons at ,vema ,gap #eh #ae4 ,ocean-bottom photographs ( seam\nts #eh #af4 ,repres5tative ,,pdr records f ,b]muda ,rise #gh #ag4 ,,pdr record1 ,b]muda ,sc>p ,zone #gh #ah4 ,,pdr record1 ,upp] ,/ep ,mid-,atlantic ,ridge #gh #ai4 ,ocean-bottom photographs2 ,mid-,atlantic ,ridge #gh #bj4 ,physiographic prov9ces1 ,atlantic ,ocean #abb #ba4 ,control *>t #abb #bb4 ,six trans-,atlantic topographic pr(iles #abb #bc4 ,index *>t %[+ locations ( pr(iles ( ,plates #bd1 #be1 #bf & ,figure #de #abb #bd4 ,?irty-f\r pr(iles ( ! cont95tal m>g93 we/]n ,nor? ,atlantic #abb #be4 ,tw5ty-?ree pr(iles ( ! cont95tal m>g9 ( ,europe & ,africa #abb #bf4 ,cru/al /ructure & cont95tal-m>g9 prov9ces #abb #bg4 ,five topographic pr(iles1 we/]n ,nor? ,atlantic #abb #bh4 ,di/ribution ( deep-sea s&s 9 relation to physiographic prov9ces #abb #bi4 ,e>?quake epic5t]s1 ,nor? ,atlantic #abb #cj4 ,location ( ,,pdr records & bottom photographs reproduc$ z illu/rations4 #abb ,,figures ,,page ,,figure #a4 ,me?od ( prep>ation ( physiographic diagram #d #b4 ,precision dep? record] 7,,pdr7 s\nd+ l9es obta9$ by rese>* vessels #f #c4 ,good1 b nonprecision s\nd+ l9es obta9$ by rese>* vessels #g #d4 ,major bas9s ( ! ,nor? ,atlantic1 aft] ,w/ 7#aidj7 #ab #e4 ,s\nd-velocity corrections = e*o s\nd+s #ac #f4 ,conv]sion diagram = degrees1 p] c5t grade1 feet p] /atute mile1 & gradi5t #ad #g4 ,gradi5ts f #a3e to #a3hjjj %[n at #dj3a v]tical exagg]ation #ae #h4 ,outl9e ( subm>9e topography #ae #i4 ,major morphologic divisions3 ,nor? ,atlantic ,ocean #af #aj4 ,?ree categories ( cont95tal-m>g9 prov9ces #ag #aa4 ,two ea/-we/ pr(iles ( ,s\!a/ ,newf\ndl& ,ridge #bb #ab4 ,laur5tian ,*annel #bc #ac4 ,ea/]n ,*annel1 ,gulf ( ,ma9e #bc #ad4 ,subm>9e canyons (f ! ,scotian ,%elf #bd #ae4 ,cont95tal-m>g9 prov9ces3 ,type pr(ile (f nor!a/]n ,unit$ ,/ates #bf #af4 ,trac+s ( ,,pdr records ( cont95tal & insul> slopes #bh #ag4 ,cross sections ( ,hudson ,subm>9e ,canyon #cb #ah4 ,trac+ ( ,,pdr record ( ,blake ,esc>pm5t #cd #ai4 ,cont95tal-m>g9 prov9ces3 ,type pr(iles (f nor?we/ ,africa #dj #bj4 ,georges ,bank canyons #dd #ba4 ,two project$ pr(iles ( ,georges ,bank canyons #de #bb4 ,geologic section at ,cape ,hatt]as1 ,virg9ia #df #bc4 ,correlation ( /ructural b5*es (f nor!a/ ,unit$ ,/ates #dh #bd4 ,geologic section3 ,we/]n ,europe bas$ on refraction measurem5ts #di #be4 ,index *>t1 location ( abyssal hill pr(iles illu/rat$ 9 ,figures #bf & #bg #fb #bf4 ,elev5 pr(iles1 ,abyssal ,hills ,prov9ce1 we/]n ,atlantic #fb #bg4 ,eight pr(iles1 ,abyssal ,hills ,prov9ce1 ea/]n ,atlantic #fc #bh4 ,trac+ ( ,,pdr record1 abyssal hills1 s\!a/ ( ,b]muda ,rise #fd #bi4 ,nor?we/ ,atlantic ,mid-,ocean ,canyon #fg #cj4 ,eight ea/-we/ pr(iles %[+ ,nor?we/ ,atlantic ,mid-,ocean ,canyon #fh #ca4 ,=ty-eight cross sections ( ,nor?we/ ,atlantic ,mid-,ocean ,canyon #fi #cb4 ,long pr(ile ( ,nor?we/ ,atlantic ,mid-,ocean ,canyon #gj #cc4 ,trac+ ( ,,pdr record across ,!ta ,gap #gc #cd4 ,natural scale pr(ile1 ,kelv9 ,seam\nts #gg #ce4 ,cru/al sections 9 v>i\s physiographic prov9ces1 det]m9$ by seismic-refraction measurem5ts #ha #cf4 ,index to natural-scale ,mid-,atlantic ,ridge pr(iles reproduc$ 9 ,figures #cg-da #hd #cg4 ,natural-scale ,mid-,atlantic ,ridge pr(ile #a;,a #he #ch4 ,natural-scale ,mid-,atlantic ,ridge pr(ile #a;,b #hf #ci4 ,natural-scale ,mid-,atlantic ,ridge pr(ile #a;,c #hg #dj4 ,natural-scale ,mid-,atlantic ,ridge pr(ile #b;,a #hh #da4 ,natural-scale ,mid-,atlantic ,ridge pr(ile #b;,b #hi #db4 ,type pr(ile1 prov9ces ( ! ,mid-,atlantic ,ridge #ij #dc4 ,trac+ ( ,,pdr record1 ,rift ,valley1 ,rift ,m\nta9s1 ,high ,fractur$ ,plateau1 & ,upp] ,/ep #ia #dd4 ,trac+ ( ,,pdr record1 ,we/]n ,rift ,m\nta9s #ib #de4 ,tw5ty-six rift valley pr(iles1 ,mid-,atlantic ,ridge #ic #df4 ,five repres5tative pr(iles1 cre/ & we/]n flank ( ,mid-,atlantic ,ridge #id #dg4 ,axial pr(ile ( ! ,mid-,atlantic ,ridge #if #dh4 ,pr(ile ( total magnetic int5sity & topography1 ,mid-,atlantic ,ridge #aja #di4 ,physiographic prov9ces & trans-,atlantic /ructure #ajb ,,tables ,,table ,,page #a4 ,*>act]i/ics ( cont95tal rise1 nor!a/]n ,unit$ ,/ates #bg #b4 ,*>act]i/ics ( cont95tal rise1 nor?we/ ,africa #da #c4 ,dep?s ( prom95t cont95tal-%elf t]races #db ,,ab/ract ,! ,physiographic ,diagram3 ,atlantic ,ocean1 ,%eet #a1 :i* portrays ! ,nor? ,atlantic betwe5 #ag & #ej ,nor? ,latitude1 is ! fir/ ( a project$ s]ies ( diagrams4 ,! diagram is bas$ on cont9u\s e*o-s\nd+ trav]ses made by rese>* vessels4 ,! relief %[n on ! pr(iles 0 sket*$ 9 p]spective us+ ! te*nique introduc$ by ,lobeck4 ,betwe5 s\nd+ pr(iles ! relief is speculative1 bas$ on extrapolation ( tr5ds not$ 9 ! pr(iles4 ,! area ( ! diagram is divid$ into ?ree major physiographic regions :i* are 9 turn subdivid$ into ! foll[+ categories ( prov9ces4 ,,cont95tal ,,m>g9 ,category ,i ,cont95tal ,%elf ,epicont95tal ,seas ,m>g9al ,plateaus ,category ,,ii ,cont95tal ,slope ,m>g9al ,esc>pm5ts ,l&w>d ,slopes ( ,tr5*es ,category ,,iii ,cont95tal ,rise ,m>g9al ,tr5*-,out] ,ridge ,complex ,m>g9al ,bas9-,out] ,ridge ,complex ,,ocean ,,bas9 ,,floor ,abyssal ,floor ,abyssal ,pla9s ,abyssal ,hills ,abyssal ,gaps & ,mid-,ocean ,canyons ,oceanic ,rises ,seam\nt ,gr\ps ,,mid-,,oceanic ,,ridge ,cre/ ,prov9ces ,rift ,valley ,rift ,m\nta9s ,high ,fractur$ ,plateau ,flank ,prov9ces ,upp] ,/ep ,middle ,/ep ,l[] ,/ep ,ea* prov9ce is def9$1 briefly describ$1 & illu/rat$ ) pr(iles & photographs ( e*o-s\nd+ records4 ,! b\nd>ies ( ! physiographic prov9ces1 def9$ solely by bottom topography1 %[ good correlation ) v>iations 9 cru/al /ructure z det]m9$ by seismic-refraction measurem5ts & ) anomalies ( ! gravity & magnetic fields4 ,9 addition1 ! prov9ce b\nd>ies correlate well ) di/ribution patt]ns ( bottom s$im5ts4 ,! physiographic prov9ces are ?us really morpho-tectonic prov9ces4 ,! precise correlation ( topographic prov9ces & /ructure obs]v$ 9 specific sections c ?us be extrapolat$ along prov9ce b\nd>ies to d$uce ! geology 9 l>ge areas :]e no geophysical "w has be5 done4 ,! tectonic map ( ! ,atlantic prep>$ 9 ?is mann] w be pres5t$ 9 a subsequ5t publication4 ,,"p #a4 ,,prep>ation ,,( ,,! ,,physiographic ,,diagram ,sev]al /eps are involv$ 9 ! prep>ation ( a m>9e physiographic diagram4 ,! raw data consi/ ( cont9u\sly record$ e*ograms & li/s ( positions ( ! rese>* %ip4 ,e*ograms are pr(iles ( ocean dep?1 automatically plott$ aga9/ "t 7,lusk9 et al41 #aied74 ,! fir/ /ep is to read & tabulate ! dep? at ea* peak1 tr\gh1 or *ange ( slope4 ,^! read+s are plott$ on a *>t 7#a3a1jjj1jjj7 z a s]ies ( closely spac$ s\nd+s4 ,dep? pr(iles are plott$ aga9/ di/ance at a /&>d v]tical exagg]ation ( #dj3a4 ,! s\nd+ l9es are also plott$ on a *>t ( small scale 7#a3e1jjj1jjj7 :i* is at ! same scale z ! f9al physiographic diagram4 ,! subsequ5t /eps 9 ! prep>ation ( ! diagram are illu/rat$ by ,figures #a;a-d4 ,! exagg]at$ pr(iles 7#a;b7 along ! tracks 7#a;a7 %[ a succession ( peaks & valleys4 ,^! features are sket*$ 9 along ! tracks 7#a;c74 ,aft] all ! tracks 9 a l>ge area are sket*$ 9 ?is way1 ! major tr5ds are e/imat$1 & ! diagram is complet$ by int]polation & extrapolation 7,fig4 #a;d2 ,pl4 #a74 ,! v]tical scale ( ! diagram is #a in* #ejjj fa?oms :i* is an effective v]tical exagg]ation ( #bj to #a4 ,! f9al diagram z pr9t$ is at a scale ( #a3e million at #dj ,n4 on a ,m]cator projection4 ,!re is a fundam5tal diff]5ce betwe5 ! prep>ation ( a t]re/rial & a m>9e physiographic diagram4 ,9 ! =m] ! major problem is to select f m-detail$ maps ! features to be repres5t$4 ,except 9 unexplor$1 inaccessible areas1 ! %ape ( all l& features is a matt] ( record$ fact2 ! problem is to ab/ract & artfully draw ! features 9 "q4 ,9 contra/1 ! prep>ation ( a m>9e physiographic diagram requires ! au?or to po/ulate ! patt]ns & tr5ds ( ! relief on ! basis ( cross sections & !n to portray ?is int]pretation 9 ! diagram4 ,,physiographic ,,prov9ce ,,*>t3 ,a /udy ( ! exagg]at$ pr(iles plott$ dur+ ! prep>ation ( ! physiographic diagram reveal$ ! exi/5ce ( morphological features & morphological prov9ces n previ\sly del9eat$4 ,! limits ( areas ( contra/+ morphology 7 not$ on ! pr(iles1 & ^! po9ts 7 plott$ on a *>t ( small scale 7also ab\t #a3e million at #dj ,n47 7,pl4 #bj74 ,,control3 ,almo/ all ! e*o-s\nd+ pr(iles us$ 9 ! prep>ation ( ! physiographic diagram 7,pl4 #a7 & ! physiographic prov9ce *>t 7,pl4 #bj7 7 obta9$ by exp$itions ( ! ,lamont ,geological ,obs]vatory & ! ,woods ,hole ,oceanographic ,in/itution 7,pl4 #ba74 ,"s s\nd+s 7 provid$ by ! ,hydrographic ,dep>tm5t1 ,briti% ,admiralty 7,pl4 #ba7 & ! ,int]national ,hydrographic ,bureau 7,monaco74 ,illu/ration3 ,,figure #a4--,me?od ( prep>ation ( physiographic diagram 7a7 ,positions ( s\nd+ l9es 7,a1 ,b7 are plott$ on *>t2 7b7 ,s\nd+s are plott$ z pr(iles 7,a1 ,b7 at #dj3a v]tical exagg]ation2 7c7 ,features %[n on pr(iles 7,a1 ,b7 are sket*$ on *>t along tracks2 7d7 ,aft] all available s\nd+ pr(iles are sket*$ ! rema9+ uns\nd$ areas are fill$ 9 by extrapolat+ & int]polat+ tr5ds obs]v$ 9 a succession ( pr(iles4 ,! e*o s\nd+s made by rese>* vessels fall into ?ree classes3 7#a7 precision s\nd+s 7accuracy bett] ?an #a fa?om 9 #cjjj72 7#b7 nonprecision s\nd+s obta9$ by rese>* vessels us+ comm]cial e*o s\nd]s ) control or close *eck on "t /&>d2 7#c7 poor to bad s\nd+s made ) comm]cial e*o s\nd]s )\t tim+ control or adequate *ecks4 ,mo/ ( ! s\nd+s us$ 9 ?is pap] fall into ! fir/ two categories4 ,9 ,figure #b ! ,precision ,dep? ,record] 7,,pdr7 s\nd+ tracks are %[n4 ,9 ,figure #c ! good b nonprecision tracks are %[n4 ,! s\nd+s ( ! ?ird class are n %[n4 ,all tracks us$ 9 ! prep>ation ( ! diagram are %[n 9 ,plate #ba4 ,mo/ ( ! s\nd+ l9es 7 locat$ by /&>d dead-reckon+ proc$ures f a/ronomical fixes4 ,errors ( a few miles are probably common4 ,position errors d n s]i\sly affect ! "w describ$ "h s9ce we are deal+ l>gely ) texture read f pr(iles & plott$ on a small-scale %eet4 ,9 addition to ! s\nd+ tracks %[n 9 ! control *>t1 spot dep?s %[n on ,u4 ,s4 ,hydrographic ,(fice *>ts ,,ho #jiee;a1 #jiee;b1 #jief;a1 #jief;b1 & #edhg & on feuille ,a-#a ( ! ,c>te ,gnrale ,ba?ymtrique des ,ocans 7#aice7 7 us$ :]e pr(iles 7 lack+4 ,along ! ea/ coa/ ( ! ,unit$ ,/ates ! ,coa/ & ,geodetic ,survey s\nd+s publi%$ by ,veat* & ,smi? 7#aici7 7 us$ = ! cont95tal %elf & slope4 ,o!r important s\rces ( publi%$ s\nd+s include ,hill 7#aief71 ,de ,&rade 7#aicg71 ,dietri* 7#aici71 ,w/ 7#aidj;a71 ,em]y 7#aiej71 & ,tol/oy 7#aiea74 ,! l& areas ( ! diagram 7 sket*$ to ! same rigid v]tical scale z t us$ = ! deep sea4 ,elevations = ! ,unit$ ,/ates 7 tak5 f ,unit$ ,/ates ,geological ,survey & ,army ,map ,s]vice quadrangle maps2 elevations = ,europe & ,africa are f ,b>?olomew maps2 & elevations = ! isl&s f ,unit$ ,/ates ,navy ,hydrographic ,(fice *>ts4 ,,exagg]at$ ,,pr(iles3 ,! pr(iles plott$ at #dj3a v]tical exagg]ation are ! basis = ! topography sket*$ on ! physiographic diagram4 ,a selection ( ^! pr(iles is reproduc$ 9 ,plates #bb1 #bd1 #be1 & #bg1 & 9 ,figure #de4 ,all pr(iles f precision s\nd+s 7 orig9ally plott$ at a v]tical scale ( #b in*es equals #ajjj fa?oms & a horizontal scale ( #b in*es equals #dj miles4 ,nonprecision s\nd+s 7 plott$ at scales ( #a in* equals #ajjj fa?oms & #a in* equals #dj miles4 ,9 a typical area #dj to #fj s\nd+s 7 plott$ = ea* #fj miles ( pr(ile4 ,! po9ts 7 connect$ & !n qualitatively *eck$ aga9/ ! orig9al e*ogram4 ,al?\gh all ! l>g] features are repres5t$ on ^! pr(iles1 features ( less ?an a mile 9 wid? may be miss$4 ,! small scale ( ! physiographic diagram exclud$ ! possibility ( portray+ mo/ ( ! features less ?an #c-f miles 9 wid? & less ?an #bj fa?oms 9 height4 ,detail$ /udy ( ! small-scale features less ?an #b or #c miles 9 wid? is be/ accompli%$ by a /udy ( ! orig9al e*ograms4 ,! ,,pdr records are ideal = ?is purpose4 ,illu/ration3 ,,figure #b4--,precision dep? record] 7,,pdr7 s\nd+ l9es obta9$ by rese>* vessels ,mo/ ( s\nd+s %[n 7 obta9$ by ! ,lamont ,geological ,obs]vatory's ,r4 ,v4 ,,vema1 #aiec-aieg4 ,illu/ration3 ,,figure #c4--;,good1 b nonprecision s\nd+ l9es obta9$ by rese>* vessels ,mo/ s\nd+s obta9$ by ! ,woods ,hole ,oceanographic ,in/itution's ,r4 ,v4 ,,atlantis1 #aidf-aiec4 ,,nor? ,,atlantic ,,s\nd+s3 ,! /udy ( ! ,nor? ,atlantic deep-sea ba?ymetry began a little m ?an a c5tury ago ) ! tak+ ( ! fir/ deep-sea s\nd+s by lead l9e4 ,by #ahfj1 l>gely because ( ! great public int]e/ 9 ! propos$ trans-,atlantic cables & ! en?usia/ic enc\ragem5t ( ,mat!w ,f4 ,maury 7#ahee71 sev]al hundr$ s\nd+s _h be5 tak5 9 ! ,nor? ,atlantic 9 dep?s great] ?an #ajjj fa?oms4 ,mean:ile1 on ei!r side ( ! ,atlantic surveys ( coa/s1 h>bors1 (f%ore banks1 & ! cont95tal %elf 7 be+ made = navigational use4 ,! ,hudson ,subm>9e ,*annel & ! head ( ! ,hudson ,canyon 7 discov]$ by ! ,unit$ ,/ates ,coa/ ,survey dur+ ?is p]iod4 ,by #aiab m ?an #ahjj deep-sea s\nd+s _h be5 tak5 9 ! ,nor? ,atlantic by ! labori\s me?od ( us+ a lead l[]$ at fir/ by hemp l9e & lat] by wire4 ,betwe5 #aijj & #aibj ,fess5d5 9 ! ,unit$ ,/ates1 ,behm 9 ,g]many1 & ,langev9 & ,florisson 9 ,france e/abli%$ t ac\/ic e*o s\nd+ 0 possible & built ma*9es to take e*o s\nd+s4 ,9 #aibb1 e*o s\nd+ became a practical op]ation4 ,al?\gh _m ( ! e>ly e*o s\nd]s 7 fitt$ ) automatic record]s1 !y 7 9 g5]al suitable only = use 9 %all[ wat] 7less ?an #ejj fa?oms74 ,deep-sea e*o s\nd+s 7 obta9$ by li/5+ on e>phones = ! return+ e*o & tim+ ! int]val by eye ) a suitable clock4 ,! improvem5t ( s\nd+ ge> cont9u$1 & by ! mid #aicj's automatic record+ deep-sea e*o s\nd]s 7 manufactur$ & put into limit$ use1 al?\gh1 by & l>ge1 all pre-,_w ,w> ,,ii deep-sea 7 #ajjj fa?oms7 e*o s\nd+s 7 discrete obs]vations by ! e> & eye me?od4 ,a good review ( pre-,_w ,w> ,,ii e*o-s\nd+ app>atus is giv5 9 a publication ( ! ,int]national ,hydrographic ,bureau 7,anon41 #aici74 ,dur+ ! w> ! ,,nmc#a e*o s\nd] 0 develop$ & in/all$ on _m ,u4 ,s4 %ips4 ,x 0 adequate = deep-sea s\nd+ if 9 p]fect condition2 b ! design]s1 be+ cauti\s1 _h arrang$ = record+ only 9 ! dep? range ( #j-bjjj fa?oms4 ,! ,,nmc s\nd] on ,atlantis 0 modifi$ to record 9 great] dep?s 9 #aide1 & _m ?\s&s ( miles ( tracks 7 obta9$ ( ! deep sea ) ?is app>atus4 ,! ,,nmc _h a small record *>t 7#f in*es #bjjj fa?oms2 in* ab\t #c miles74 ,! precision 0 l[ s9ce ! app>atus dep5d$ on a %ip's regul> ,,ac p[] supply = its "t /&>d4 ,a new s\nd]1 ! ,,uqn-#a;,b1 0 develop$ 9 ! ,unit$ ,/ates foll[+ ,_w ,w> ,,ii4 ,! in/rum5t z manufactur$ record$ on an extremely small *>t 7#h in*es #fjjj fa?oms7 b c\ld be modifi$ = multiple #fjj-;fa?om scale record+ 7#h in*es #fjj fa?oms74 ,! tim+ function 0 usually accompli%$ by poorly regulat$ %ip's ,,ac p[] supply1 & errors 7 consequ5tly l>ge 7,dietz1 #aied2 ,heez51 #aied74 ,9 addition1 ! /ylus arrangem5t requir$ con/ant adju/m5t4 ,aft] only a few ?\s& miles 7 obta9$ by ! ,lamont ,obs]vatory exp$itions x became obvi\s t a new record] incorporat+ precision tim+ & l>ge record] pres5tation 0 necess>y = an adequate k ( topography4 #a ,u4 ,s4 ,navy designation4 ,b]n>d ,lusk9 ( ! ,lamont ,geological ,obs]vatory1 9 co-op]ation ) ! ,times ,facsimile ,company1 adapt$ ! ,times ,facsimile receiv] to d ! tim+ & record+ function ( ! e*o s\nd]1 us+ a /&>d ,,uqn receiv] & transmitt] 7)\t record]74 ,m ?an #bjj1jjj miles ( ,,pdr s\nd+s h n[ be5 obta9$ by exp$itions ( ! ,lamont ,geological ,obs]vatory4 ,! app>atus orig9ally describ$ by ,lusk9 et al4 7#aied7 has be5 ext5sively improv$ 7,lusk9 & ,israel1 #aief74 ,! ,times ,facsimile-,lamont ,,pdr p]=ms ! tim+ & record+ functions ) an accuracy ( bett] ?an #a fa?om 9 #cjjj4 ,?is 0 a consid]able improvem5t ov] old] app>atus4 ,! ,,pdr g5]ally uses multiple #djj-;fa?om scales 9 :i* #djj fa?oms is repres5t$ by #ah in*es ( record2 ! pap] is c>ri$ ?r\gh ! ma*9es at #bd in*es an h\r4 ,o!r v]tical scales 7i4 e41 #bjj1 #hjj1 #abjj7 c easily be provid$1 & ! pap] transport c be *ang$ by /eps f #ab to #if in*es p] h\r4 ,! lam9at$ record+ pap] consi/s ( two lay]s ( light gray & a c5t] lay] ( black4 ,! record is made by burn+ ! upp] gray lay] & ?us expos+ ! und]ly+ d>k lay]4 ,! facsimile record+ pap] diff]s f ! conv5tional e*o-s\nd] record pap] 9 t a great] range ( %ades c be reproduc$4 ,sev]al ,,pdr records are %[n 9 ! foll[+ text 7,pls4 #c1 #d1 #e1 #f1 #h1 #i1 #aj1 #ab1 #ac1 #ad1 #af1 #ag1 #ah74 ,effective /udy ( ! physiography ( ! deep-sea floor 0 made possible by introduction ( ! ,,pdr4 ,e*o s\nd+s obta9$ by ! ,engli% 9 ! area s\?we/ ( ,engl& h be5 us$ 9 ! pres5t /udy4 ,! accuracy ( _! equipm5t has n be5 adequately treat$ 9 ! lit]ature1 b x appe>s by comp>ison t mo/ s\nd+s are accurate to )9 at lea/ #a p] c5t4 ,,"p #b4 ,,physiographic ,,prov9ces ,,introduction ,descriptions ( physical features ( ! e>?'s surface are f\nd 9 ! e>lie/-kn[n writ+s4 ,h[ev]1 ! sy/ematic classification ( l& =ms is relatively rec5t & foll[$ ! developm5t ( ! sci5ce ( physical geology4 ,! natural topographic divisions ( ! cont95ts h be5 classifi$ into physiographic prov9ces accord+ to sev]al simil> sy/ems 7,lobeck1 #aici2 ,f5neman1 #aich2 ,atwood1 #aidj2 & o!rs74 ,^! sy/ems take into acc\nt =m & age ( ! relief1 z well z ! /ructure ( ! und]ly+ rocks4 ,descriptions are usually giv5 9 t]ms ( age1 process1 & /ructure1 ) ! ultimate aim ! und]/&+ ( ! orig9 & hi/ory ( topography4 ,detail$ topographic maps at #a3ej1jjj or l>g] are available & are us$ 9 conjunction ) direct field obs]vations4 ,m rec5tly a]ial photographs h greatly aid$ geomorphic /udies4 ,! oceans1 9 contra/1 h be5 subdivid$ by oceanograph]s m]ely into bas9s sep>at$ by ridges & swells4 ,?is 0 done on ! basis ( widely spac$ discrete s\nd+s %[n on *>ts r>ely ( l>g] scale ?an #a3aj million4 ,! bas9s 7 delimit$ by arbitr>ily *os5 & (t5 crudely controll$ isoba?s4 ,! developm5t & in/allation ( cont9u\sly record+ deep-sea e*o s\nd]s & _! ext5sive use 9 ! deep sea provide = ! fir/ "t detail$ topographic in=mation on ! deep-sea floor & ?us a new basis = description & classification4 ,x is p]haps presumptu\s at ?is "t to ref] to ! topographic divisions ( ! sea floor z physiographic prov9ces :5 we h only scant in=mation conc]n+ ! /ructure ( ea* prov9ce1 ! age1 ! physical processes1 &1 9 fact1 ! details ( topography4 ,!re=e1 ! classification describ$ 9 ! foll[+ pages is pres5t$ z a fir/ attempt1 ) ! full k t x w be modifi$ & exp&$ by subsequ5t exploration4 ,we are only beg9n+ to und]/& ! /ructural significance ( deep-sea physiographic prov9ces4 ,we n[ ?9k t ! correlation ( topography & /ructure w be bett] "u ! sea ?an on l& because ( less vigor\s erosion at dep? 9 ! sea4 ,if ?is is true1 deep-sea /ructural patt]ns may ev5tually be q simple to map4 ,,nom5clature ,,& ,,classification ,,( ,,deep-,,sea ,,relief ,be=e ! adv5t ( cont9u\sly record$ e*o-s\nd+ pr(iles1 & _! revelation ( ! texture ( ! sea-floor relief1 classification & nom5clature ( subm>9e topography 7 bas$ on broad clos$ isoba?s4 ,we c *>act]ize ! old] sy/em z ! ba?ymetric sy/em ( nom5clature 9 contra/ to t employ$ 9 ?is pap]1 :i* we c call a geomorphic or textural sy/em4 ,! t]ms bas9 & deep us$ 9 ! old] lit]ature are usually def9$ by clos$ #cjjj-1 #djjj-1 or #ejjj-met] cont\rs z repres5t$ on ! ,c>te ,gnrale ,ba?ymtrique des ,ocans 7,int]national ,hydrographic ,bureau74 ,= _m purposes ?is t]m9ology is useful1 p>ticul>ly 9 describ+ ! habitat ( a deep-sea fi% or ! locale ( a wat] mass4 ,consequ5tly "s su* sy/em %\ld be reta9$ ev5 ?\gh 9 _m areas bas9 b\nd>ies are difficult to def9e1 & reg>dless ( ! fact t _m b\nd>ies cut arbitr>ily ?r\gh physiographic prov9ces )\t reg>d = local prov9ce b\nd>ies4 ,! ,atlantic has be5 subdivid$ by ,w/ 7#aidj;b7 7,fig4 #d7 ^: sy/em is n[ 9 g5]al use4 ,illu/ration3 ,,figure #d4--,major bas9s ( ! ,nor? ,atlantic1 aft] ,w/ 7#aidj7 ,heavy solid l9es indicate b\nd>y =m$ by axis ( ,mid-,atlantic ,ridge4 ,light solid l9es indicate b\nd>y =m$ by %elf breaks & subm>9e ridges4 ,da%$ l9es indicate arbitr>y b\nd>ies4 ,! nom5clature ( deep-sea topography has be5 consid]$ by sev]al committees dur+ ! pa/ half c5tury4 ,! mo/ rec5t recomm5dations publi%$ by ,wiseman & ,ovey 7#aiec2 #aiee7 are foll[$ :]ev] applicable4 ,! old] sy/ems ( nom5clature1 h[ev]1 are n rigidly employ$ s9ce we are deal+ ) textural prov9ces bas$ on pr(iles obta9$ ) cont9u\sly record+ e*o s\nd]s r ?an ba?ymetric prov9ces def9$ by clos$ isoba?s4 ,,units ,,( ,,dep? ,,& ,,slope ,on ! pr(iles & e*ograms ! v]tical scale is 9 units ( e*o-s\nd+ "t r ?an 9 units ( true dep?4 ,9 o!r words1 all dep?s are calculat$ "u ! assumption t ! v]tical s\nd velocity is #hjj fa?oms p] second4 ,consid]+ t ! s\nd travels to ! bottom & back1 ! calculation is bas$ on #djj fa?oms p] second ( laps$ "t4 ,s9ce ! av]age v]tical velocity is1 )9 ! area cov]$1 always slightly less ?an #hjj fa?oms p] second1 ! true dep? is always slightly great] ?an ! e*o-"t dep? z express$ 9 nom9al fa?oms4 ,figure #e %[s ! range ( corrections :i* mu/ be appli$ 9 v>i\s p>ts ( ! area4 ,! spot dep?s indicat$ on ! physiographic diagram are 9 units ( true dep? correct$ accord+ to ,mat!ws' tables 7#aici7 = regional v>iations 9 ! av]age v]tical s\nd+ velocity4 ,illu/ration3 ,,figure #e4--,s\nd-velocity corrections = e*o s\nd+s ,add correction to uncorrect$ e*o s\nd+ to obta9 true dep?4 ,curves ,i & ,,ii are repres5tative ( ,nor? ,atlantic #ag-ej,n4 exclusive ( ! ,gr& ,banks region4 ,curves ,,iii & ,,iv are repres5tative ( ! deep-wat] areas ne> ! ,gr& ,banks4 ,curves are bas$ on ,mat!ws 7#aici7 & are = use only :]e assum$ s\nd+ velocity is #hjj fa?oms_/second4 ,all s\nd+s m5tion$ 9 ! text are uncorrect$ = s\nd velocity4 ,illu/ration3 ,,figure #f4--;,conv]sion diagram = degrees1 p] c5t grade1 feet p] /atute mile1 & gradi5t 7a7 ,values ( gradi5t f #a3aj-a3aejj2 7b7 ,values ( gradi5t f #a3ajj-a3ejjj ,! incl9ation ( ! bottom is giv5 z ! tang5t ( ! angle betwe5 ! slop+ plane & ! horizontal express$ z a ratio ( integ]s4 ,^! ratios are ref]r$ to z gradi5ts4 ,9 ,figure #f slope values express$ 9 degrees1 p] c5t grade1 feet p] /atute mile1 & gradi5t are comp>$4 ,) a few exceptions all pr(iles are repres5t$ ) a #dj3a v]tical exagg]ation4 ,to facilitate judg+ ! magnitude ( slopes on ^! pr(iles1 ,figure #g %[s v>i\s gradi5t ratios at a #dj3a v]tical exagg]ation4 ,slope corrections h n be5 made to ! s\nd+s4 ,except 9 special cases su* corrections w\ld make insignificant *anges 9 ! #dj3a pr(ile4 ,all di/ances are giv5 9 nautical or geographical miles 7#a nautical mile #fjhj feet74 ,illu/ration3 ,,figure #g4--;,gradi5ts f #a3e to #a3hjjj %[n at a #dj3a v]tical exagg]ation ,mo/ pr(iles reproduc$ 9 ?is pap] are at #dj3a v]tical exagg]ation4 ,?is template is provid$ to aid ! read] 9 judg+ slopes on ^! exagg]at$ pr(iles4 ,illu/ration3 ,,figure #h4--,outl9e ( subm>9e topography ,l9e #a1 fir/-ord] features ( ! cru/2 l9e #b1 major topographic features ( ! ocean2 l9e #c1 categories ( prov9ces & sup]-prov9ces2 l9e #d1 prov9ces2 l9e #e1 sub-prov9ces & o!r important features4 ,,cont95t ,,& ,,ocean ,! two fir/-ord] morphologic divisions ( ! e>?'s cru/ are cont95t & ocean4 ,! oceans c be divid$ into a few major divisions :i* are 9 turn subdivid$ into categories ( physiographic prov9ces & !n into individual prov9ces4 ,! area ( ! pres5t /udy is compos$ ( ! ?ree major divisions %[n 9 ,figure #i3 cont95tal m>g91 ocean-bas9 floor1 & mid-oceanic ridge4 ,! discussion & description ( ! physiographic prov9ces ( ! ,nor? ,atlantic w foll[ ! s*ematic outl9e %[n 9 ,figure #h4 ,illu/ration3 ,,figure #i4--,major morphologic divisions3 ,nor? ,atlantic ,ocean ,! pr(ile is a repres5tative pr(ile f ,new ,engl& to ! ,sah>a ,coa/4 ,,cont95tal ,,m>g9 ,,def9ition ,,& ,,g5]al ,,categories ,! cont95tal m>g9 includes ^? prov9ces ( ! cont95ts & ( ! oceans :i* are associat$ ) ! b\nd>y betwe5 ^! two fir/-ord] features ( ! e>?4 ,g5]al categories4--,9 mo/ areas ?ree p>allel categories ( prov9ces c be di/+ui%$ 9 ! cont95tal m>g9 7,fig4 #aj74 ,! relatively flat portions ( ! subm]g$ cont95tal plat=m con/itute category ,i4 ,^! prov9ces are3 cont95tal %elf1 epicont95tal m>g9al seas 7e4 g41 ,gulf ( ,ma9e71 & cont95tal-m>g9 plateaus 7e4 g41 ,blake ,plateau74 ,! prov9ces ( category ,,ii include ! cont95tal slope1 m>g9al esc>pm5ts 7e4 g41 ,blake ,esc>pm5t71 & ! l&w>d slopes ( tr5*es4 ,^! prov9ces m>k ! edge ( ! cont95tal block4 ,category ,,iii includes ! cont95tal rise1 m>g9al tr5*-out] ridge1 & m>g9al bas9-out] ridge complexes4 ,illu/ration3 ,,figure #aj4--,?ree categories ( cont95tal-m>g9 prov9ces ,category ,i prov9ces lie on ! cont95tal block1 ,category ,,ii prov9ces =m ! side ( ! cont95tal block1 & ,category ,,iii prov9ces are ! upturn$ or depress$ m>g9s ( ! oceanic depression4 ,! mo/ common type ( cont95tal m>g9 is made up ( cont95tal %elf 7,i71 cont95tal slope 7,,ii71 & cont95tal rise 7,,iii74 7,fig4 #aj1 ,sah>a & ,new ,york74 ,9 areas :]e ! cont95tal rise is well develop$ x is compos$ ( two p>ts1 ! upp] & ! l[] cont95tal rise 7,fig4 #ae74 ,9 "s areas ! l[] cont95tal rise is replac$ by an out] ridge1 & ! upp] cont95tal rise is replac$ by a m>g9al bas9 or m>g9al tr5*4 ,^! two latt] types are illu/rat$ 9 ,figure #aj by pr(iles m>k$ ,blake ,plateau & ,pu]to ,rico respectively4 ,seam\nts & isl&s occur 9 all ! cont95tal-m>g9 prov9ces4 99 99 99 99 99 ,category ,i prov9ces4--,! ocean ov]fl[s its bas9 onto ! edge ( ! cont95ts4 ,! pr9cipal physiographic prov9ce ( ?is subm]g$ portion ( ! cont95tal plat=m is ! cont95tal %elf :i* is pres5t (f all ! l&s ( ! _w4 ,! cont95tal %elf is a smoo? area ) v l[ relief & is ne>ly ev]y:]e limit$ to dep?s less ?an #bej fa?oms4 ,! cont95tal blocks are also flood$ by epicont95tal seas4 ,"s ( ^! h r\gh bottoms1 z ! ,gulf ( ,ma9e2 o!rs are relatively smoo?-floor$4 ,m>g9al plateaus1 :]e pres5t1 lie 9 dep?s ( #ejj-abjj fa?oms1 & _m are ne>ly z smoo? z ! cont95tal %elves4 ,,cont95tal ,,%elf3 ,! cont95tal %elf is a %all[ 7av]ag+ less ?an #ajj fa?oms71 g5tly slop+ 7less ?an #a3ajjj7 surface ( l[ local relief 7less ?an #aj fa?oms7 :i* ext5ds f ! %ore l9e to ! %elf break :]e ! seaw>d gradi5t %>ply increases to great] ?an #a3dj4 ,its wid? ranges f a few miles to m ?an #bjj miles4 ,cont95tal %elves bord] all l& areas4 ,because ( _! proximity to %ore1 _! %all[ dep?1 & _! importance 9 navigation ! cont95tal %elves are n[ ! be/-kn[n "p ( ! oceans 7,veat* & ,smi?1 #aici2 ,%ep>d1 #aidh74 ,! transition f ! cont95tal %elf to ! cont95tal slope is g5]ally abrupt & is kn[n z ! %elf break4 ,?is feature ranges 9 dep? f #bj to m ?an #ajj fa?oms & 9 =m f a %>p edge to a r\nd$ %\ld]4 ,! *ange 9 ! gradi5t is f less ?an #a3ajjj to great] ?an #a3dj4 ,,epicont95tal ,,m>g9al ,,seas3 ,! epicont95tal m>g9al seas are ^? %all[ seas 7less ?an #aejj fa?oms7 :i* lie on ! cont95tal block & c be di/+ui%$ f ! cont95tal %elves by _! great] dep? 7usually #ajj fa?oms7 & possibly great] topographic irregul>ity4 ,mo/ ( !m are enclos$ by %all[ banks 7 #ej fa?oms7 ( ! cont95tal %elf & by l&4 ,! ,gulf ( ,ma9e1 ! ,gulf ( ,/4 ,lawr5ce1 & ! *annels ( ! ,bahamas belong to ?is class4 ,,m>g9al ,,plateaus3 ,a m>g9al plateau is a %elflike feature :i* lies at great] dep?s ?an ! cont95tal %elf & is sep>at$ f ! cont95tal %elf by an incipi5t cont95tal slope4 ,^! features g5]ally lie at dep?s great] ?an #ajj fa?oms & less ?an #abjj fa?oms4 ,!y c be di/+ui%$ f epicont95tal m>g9al seas by _! lack ( a seaw>d b>ri] or sill4 ,! surface ( a m>g9al plateau is g5]ally q simil> to ! cont95tal %elf 9 slope & 9 ! frequ5cy & magnitude ( m9or relief features4 ,! ,blake ,plateau is ! only well-express$ repres5tative ( ?is morphologic type 9 ! area ( ! diagram4 ,well-develop$ m>g9al plateaus are also f\nd (f ! coa/ ( s\!rn ,arg5t9a & ea/ ( ,new ,zeal&4 99 99 99 99 99 ,category ,,ii prov9ces4--,! /eep slopes :i* bord] ! cont95tal block are gr\p$ into category ,,ii prov9ces4 ,loosely speak+1 we are ref]r+ to ! cont95tal slope b1 because ( ! complications impos$ by su* features z m>g9al plateaus & m>g9al tr5*es1 we di/+ui% ?ree prov9ce types4 ,,cont95tal ,,slope3 ,! cont95tal slope is t relatively /eep 7#c-f7 portion ( ! sea floor :i* lies at ! seaw>d bord] ( ! cont95tal %elf4 ,x typically drops f dep?s ( #ej-ajj fa?oms to dep?s ( #gej-agej fa?oms4 ,! top ( ! slope is usually well m>k$ by a relatively %>p %elf break4 ,! base ( ! slope1 al?\gh less def9ite1 is g5]ally abrupt4 ,z a basis ( classification 9 ^? few areas :]e no abrupt *ange is not$1 we h set ! gradi5t ( #a3dj z ! l[e/ gradi5t ( ! cont95tal slope4 ,! sett+ up ( a l[] limit = ! gradi5t m>ks a dep>ture f ! old] usage 9 :i* ! cont95tal slope 0 def9$ z ! slopes lead+ f ! out] edge ( ! cont95tal %elves d[n to ! great dep?s ( ! ocean 7,%ep>d1 #aidh74 ,?is old] def9ition includ$ ! cont95tal rise1 m>g9al plateaus1 & m>g9al esc>pm5ts4 ,! cont95tal slopes are a _w-wide ph5om5on4 ,! details ( _! regional di/ribution 9 ! ,nor? ,atlantic are cov]$ 9 a lat] section4 ,,m>g9al ,,esc>pm5ts3 ,a m>g9al esc>pm5t is a precipit\s esc>pm5t :i* =ms ! seaw>d slope ( a m>g9al plateau4 ,su* esc>pm5ts beg9 9 dep?s ( #ejj-aejj fa?oms & are #ajjj to #bjjj fa?oms high4 ,! base ( ! esc>pm5t is well m>k$ by an abrupt *ange 9 slope4 ,gradi5ts ( m>g9al esc>pm5ts exce$ #a3aj4 ,! ,blake ,esc>pm5t is a m>g9al esc>pm5t4 ,simil> features are f\nd 9 ! ,gulf ( ,mexico & (f ! s\!a/ coa/ ( ,arg5t9a4 ,,l&w>d ,,slopes ,,( ,,tr5*es3 ,?is t]m 0 introduc$ to set ap>t ! l&w>d slopes ( m>g9al tr5*es f ! usual cont95tal slopes f\nd (f tr5*-less coa/s4 ,^! /eep slopes 7 #a3dj7 drop f dep?s ( a few hundr$ fa?oms ne> a cont95t to a dep? ( a few ?\s& fa?oms 9 a m>g9al tr5*4 ,9 ! ,nor? ,atlantic ! "o example is nor? ( ,pu]to ,rico4 ,a l>ge "p ( ! circumf]5ce ( ! ,pacific is b\nd$ by su* features4 99 99 99 99 99 ,category ,,iii prov9ces4--,at ! base ( ! cont95tal slope a g5tle gradi5t cont9ues to ! local level ( ! abyssal floor4 ,?is seaw>d gradi5t ranges f #a3ajj to #a3gjj & ext5ds ov] a /rip f a few miles to a few hundr$ miles 9 wid?4 ,on _m topographic pr(iles made at "r angles to ! slope ( ! cont95tal m>g9 ?ree major breaks are visible3 ! %elf break1 ! base ( ! cont95tal slope1 & ! po9t :]e ! ne>-by level ( ! ocean-bas9 floor int]sects ! m /eeply slop+ cont95tal m>g94 ,s9ce we h limit$ ! cont95tal slope to gradi5ts great] ?an #a3dj1 we split (f ?is l[] portion ( ! cont95tal m>g9 into a sep>ate prov9ce1 ! cont95tal rise4 ,9 ! old] ba?ymetric classification ( relief ! ocean bas9--cont95tal slope b\nd>y 0 along ! #bjjj- or #bejj-;fa?om cont\r1 an arbitr>y division :i* cut across ! !n-unrecogniz$ cont95tal rise4 ,at ! base ( ! ,blake ,esc>pm5t lies an enclos$ bas91 & nor? ( ,pu]to ,rico ! sea floor drops almo/ directly to ! floor ( a m>g9al tr5*4 ,^! seem+ly div]se prov9ces ( cont95tal rise1 m>g9al esc>pm5ts1 enclos$ m>g9al bas9s1 m>g9al tr5*es1 & out] ridges are plac$ 9 category ,,iii because ( _! simil>ity 9 position ) respect to ! cont95ts & ocean floor & because ( o!r simil>ities %[n 9 ! deep] /ructure ( ! cont95tal rise4 ,,cont95tal ,,rise3 ,! cont95tal rise1 :]e pres5t1 lies at ! base ( ! cont95tal slope4 ,gradi5ts on ! cont95tal rise g5]ally range f #a3ajj to #a3gjj1 :ile ! wid? ranges f a few score to a few hundr$ miles4 ,h[ev]1 gradi5ts z high z #a3ej are obs]v$ 9 segm5t #c ( ! upp] cont95tal rise1 & gradi5ts z l[ z #a3bejj are locally pres5t 9 segm5t #b ( ! l[] cont95tal rise 7,tables #a & #b74 ,! seaw>d limit ( ! cont95tal rise is g5]ally abrupt1 & at ?is po9t regional gradi5ts decrease to less ?an #a3ajjj4 ,! dep? on ! cont95tal rise ranges f #gej to #bhjj fa?oms4 ,local relief is mod]ate to l[1 &1 except = infrequ5t seam\nts & fairly frequ5t subm>9e canyons1 ! local relief ( ! cont95tal rise r>ely exce$s #bj fa?oms4 ,! cont95tal rise is well develop$ ov] mo/ ( ! area cov]$ by ! physiographic diagram4 ,! major exceptions are nor? ( ! ,ib]ian ,p59sula :]e ! rise is pres5t1 b extremely n>r[1 & 9 ! s\?we/]n ?ird ( ! map 9 ! area s\? ( ,cape ,hatt]as1 :]e x is n pres5t4 ,9 ?is latt] area ! geographical position usually fill$ by ! cont95tal rise is occupi$ by ! l[1 broad out] ridge & ! enclos$ m>g9al bas9 & m>g9al tr5*4 ,,out] ,,ridge3 ,an out] ridge is a broad ridge g5]ally m ?an #ajj miles wide t rises f less ?an #ajj fa?oms to ab\t #ajjj fa?oms above ! adjac5t floor4 ,x lies p>allel to ! cont95tal m>g9 & may enclose a bas9 or tr5* on ! l&w>d side4 ,! local relief ( an out] ridge is g5]ally a little great] ?an t ( ! cont95tal rise b mu* m subdu$ ?an t on ! oceanic rises & mid-oceanic ridges4 ,,m>g9al ,,bas93 ,a m>g9al bas91 :]e pres5t1 lies at ! foot ( ! cont95tal slope or at ! base ( a m>g9al esc>pm5t4 ,x is slightly %all[] ?an ! g5]al level ( ! ocean bas9s & is b\nd$ on ! seaw>d side by an out] ridge4 ,"p ( its floor is g5]ally occupi$ by an abyssal pla94 ,,m>g9al ,,tr5*3 ,a m>g9al tr5* is a n>r[1 /eep-sid$ feature runn+ closely p>allel to ! tr5d ( ! cont95tal m>g92 x is g5]ally at lea/ #ajjj fa?oms bel[ ! g5]al level ( ! adjac5t ocean floor4 ,x is sep>at$ f ! ocean floor by a l[ out] ridge :i* rises #ajj-ejj fa?oms above ! level ( ! adjac5t ocean floor4 ,! bottom ( a tr5* is g5]ally rugg$ except ne> ! deepe/ spots :]e x is flat4 ,! comb9ation ( m>g9al bas9 & out] ridge replaces ! cont95tal rise ea/ ( ! ,blake ,plateau4 ,nor? ( ,pu]to ,rico ?is comb9ation is replac$ by a m>g9al tr5*-out] ridge complex4 ,! reason = ?is gr\p+ is discuss$ 9 a lat] section4 ,subm>9e canyons cut across all ! cont95tal-m>g9 prov9ces except isolat$ portions ( ! out] ridge4 ,subm>9e canyons range f less ?an a mile to m ?an #aj miles 9 wid? & f less ?an #aj to ne>ly #ajjj fa?oms 9 dep?4 ,canyons are mo/ abundant on ! cont95tal slope4 ,h[ev]1 a small] numb] p]si/ across ! cont95tal rise4 ,!y are also f\nd on ! m>g9al esc>pm5ts & on ! l&w>d slopes ( tr5*es4 ,%ep>d 7#aidh71 ,ku55 7#aiej71 ,veat* & ,smi? 7#aici71 ,de ,&rade 7#aicg71 ,johnson 7#aici71 & o!rs h discuss$ ! cont95tal-slope canyons at great l5g?4 ,canyons 9 ! cont95tal rise ( ! ,nor? ,atlantic 7 discov]$ & mapp$ by ,ericson1 ,ew+1 & ,heez5 7#aiea74 ,,regional ,,description ,,( ,,cont95tal ,,m>g9 ,?is discussion is bas$ on cont9u\sly record$ e*o-s\nd+ trav]ses made by ,lamont ,geological ,obs]vatory exp$itions4 ,pr(iles approximately p]p5dicul> to ! cont95tal m>g9 are reproduc$ 9 ,plates #bd & #be4 ,none is precisely p]p5dicul>1 & ?us slight di/ortions ( slopes & wid?s ( ! features are unavoidable4 ,,ea/]n ,,nor? ,,am]ica3 ,?irty-f\r pr(iles ( ! cont95tal m>g9 ( ea/]n ,nor? ,am]ica are pres5t$ 9 ,plate #bd4 ,! positions ( ! pr(iles are indicat$ on ! index *>t 9 ,plate #bc4 ,all pr(iles %[ ! ?ree categories ( cont95tal-m>g9 prov9ces4 ,pr(iles ,w-#a to ,w-#ba ,plate #bd %[ ! m g5]al succession ( %elf1 slope1 & rise1 :ile pr(iles ,w-#bb to ,w-#cd %[ ! out] ridge-m>g9al bas9 & out] ridge-m>g9al tr5* complexes4 ,ea* ( ! #cd pr(iles exhibits a cont95tal %elf al?\gh x may range f #bj to #cjj miles 9 wid?4 ,on ea* a %elf break is pres5t at dep?s ( #bj-aej fa?oms4 ,ea* pr(ile %[s a cont95tal slope1 ! base ( :i* may be f #cjj to #aijj fa?oms deep4 ,nor!rn ,gr& ,banks ,sector4--,on pr(iles ,w-#a to ,w-#f 7,pl4 #bd71 across ! ,gr& ,banks ( ,newf\ndl&1 ! %elf ranges f #abj to #bhe miles 9 wid?4 ,exceptionally /rong local relief ( #ej-ajj fa?oms is f\nd on ! %elf 9 pr(ile ,w-#a nor!a/w>d f ,newf\ndl&4 ,! %elf break1 :i* occurs at #aej fa?oms1 is abnormally deep--m ?an twice ! dep?s f\nd (f ,new ,engl&4 ,! cont95tal slope has a typical gradi5t ( #a3bj b is unusually %ort z ! cont95tal rise is rea*$ at #gbe fa?oms4 ,f ?is dep? ! cont95tal rise desc5ds to ! #agjj-;fa?om curve at a gradi5t ( #a3adj4 ,?is g5tle slope is int]rupt$ by a gr\p ( exceptionally rugg$ l[] cont95tal rise hills :i* rise to #abej fa?oms4 ,nor!a/ ( ! hills ! #bbjj-;fa?om l9e m>ks ! r abrupt beg9n+ ( ! abyssal pla9 :i* slopes seaw>d at a gradi5t ( #a3aajj4 ,flemi% ,cap4--,pr(ile ,w-#b crosses ! ,gr& ,banks1 along its wide/ ea/-we/ axis1 & also ! semideta*$ bank call$ ,flemi% ,cap4 ,! %elf is mu* smoo!r ?an 9 pr(ile ,w-#a1 except = a small deep ( ab\t #ajj fa?oms imm$iately ea/ ( ,newf\ndl&4 ,! %elf break at #aej fa?oms is foll[$ by a cont95tal slope #aej to #ejj fa?oms deep :i* has a gradi5t ( #a3bj4 ,! ,flemi% ,cap is a difficult feature to classify4 ,x is too l>ge to be a seam\nt & too %all[ to be a m>g9al plateau4 ,we mu/ treat x z a "p ( ! cont95tal %elf1 semideta*$ f ! re/ by a #fej-;fa?om-deep *annel4 ,! ea/]n flank ( ! ,flemi% ,cap slopes (f at gradi5ts ( #a3ajj & #a3fj until at a dep? ( #fej fa?oms ! bottom drops precipit\sly to #agej fa?oms at a gradi5t ( #a3aj4 ,seaw>d ( ?is po9t an #he-mile-wide cont95tal rise has a gradi5t ( #a3fe & #a3bej d[n to ! ,newf\ndl& ,abyssal ,pla9 :i* is at a dep? ( #bdjj fa?oms4 ,tw5ty miles ea/ ( ! cont95tal rise ?is pr(ile crosses ! ,nor?we/ ,atlantic ,mid-,ocean ,canyon4 ,on pr(ile ,w-#c ! %elf is q smoo?1 & ! %elf break is rea*$ at #fj fa?oms4 ,! pr(ile runs slightly oblique to ! cont95tal slope & reveals a s]ies ( subm>9e canyons4 ,! base ( ! slope is at #agjj fa?oms :]e ! gradi5t drops to less ?an #a3bjj4 ,illu/ration3 ,,figure #aa4--,two ea/-we/ pr(iles ( ,s\!a/ ,newf\ndl& ,ridge ,positions ( pr(iles are index$ on ,plate #bc4 ,bo? pr(iles plott$ f nonprecision s\nd+s 7,,nmc74 ,s\!a/ ,newf\ndl& ,ridge4--,f ! s\!rn tip ( ! ,gr& ,banks a broad ridge runs s\!a/]ly t[>d ! ,mid-,atlantic ,ridge & =ms a natural b>ri] betwe5 ! ,newf\ndl& ,bas9 & ! ,nor? ,am]ica ,bas9 to ! s\?4 ,s9ce x is almo/ impossible to def9e a b\nd>y betwe5 ! cont95tal rise & ! ridge1 we consid] ! ,s\!a/ ,newf\ndl& ,ridge an ext5sion ( ! cont95tal rise4 ,! ridge is #fj-ajj miles wide1 & its cre/ plunges s\!a/w>d f dep?s ( #aejj fa?oms ne> #ej ,w4 to dep?s ( #bbjj fa?oms ne> #de ,w4 ,pr(iles ,n-#a & ,n-#b 7,fig4 #aa7 cross ! ,s\!a/ ,newf\ndl& ,ridge at ab\t #da4e ,n4 & #ci4e ,n4 respectively4 ,pr(ile ,n-#a is ( poor quality1 :i* probably acc\nts = ! lack ( f9e-textur$ relief4 ,! ,mid-,ocean ,canyon is aga9 se5 at ! ea/]n end ( ,pr(ile ,n-#b4 ,pr(ile ,w-#e 7,pl4 #bd7 crosses ! ,s\!a/ ,newf\ndl& ,ridge f nor? to s\?4 ,! simil>ity ( pr(iles ,w-#e & ,w-#bc sugge/s t ! ,s\!a/ ,newf\ndl& ,ridge is an out] ridge ( ! same k9d z ! "o ea/ ( ! ,blake-,bahama region4 ,! nor!rn "o is n s long1 & x does n totally enclose a bas94 ,o!rwise1 x is q simil> to ! out] ridge ea/ ( ! ,bahamas 9 relative position1 size1 & surface features4 ,! t]m ,s\!a/ ,newf\ndl& ,ridge 0 propos$ by ,w/ 7#aidj;b2 #aidc7 & ! feature has be5 %[n on ba?ymetric *>ts 7,tol/oy1 #aiea7 & pr(iles 7,em]y1 #aiej74 ,?is ridge w be discuss$ aga9 9 connection ) ! ,mid-,ocean ,canyon & ! ocean-bas9 floor4 ,s\!rn ,gr& ,banks ,sector4--,pr(iles ,w-#d & ,w-#e cross ! s\!rn tip ( ! ,gr& ,banks4 ,! %elf break is at #ej fa?oms on bo? pr(iles4 ,on ,pr(ile ,w-#d an app>5t gradi5t ( #a3be ext5ds f #bjj to ab\t #ajjj fa?oms :]e1 aft] "s irregul>ities probably associat$ ) subm>9e canyons1 ! gradi5t drops to #a3dj4 ,?is l[] gradi5t ext5ds to #agej fa?oms4 ,pr(ile ,w-#e is q simil> to ,w-#d except t a /eep initial slope ( #a3e1 f ab\t #bjj fa?oms to #fej fa?oms1 is foll[$ by a gradi5t ( #a3hj :i* cont9ues to #ajjj fa?oms4 ,?is same t]racelike feature is also se5 on ,w-#c1 ,w-#d1 ,w-#e1 ,w-#f1 ,w-#g1 & ,w-#h4 ,bel[ #ajjj fa?oms a gradi5t ( ab\t #a3ej is f\nd on pr(iles ,w-#d1 ,w-#e1 ,w-#f1 ,w-#g1 & ,w-#h4 ,pr(ile ,w-#f runs s\? ( ! ,gr& ,banks ?r\gh ! epic5t] ( ! #aibi ,gr& ,banks e>?quake & !n s\? ?r\gh ! area pass$ ov] by ! #aibi ,gr& ,banks turbidity curr5t 7,heez5 & ,ew+1 #aieb74 ,! depression m>k$ by ! #aaej-;fa?om s\nd+ on ! cont95tal slope 9 ,pr(ile ,w-#f is a canyon runn+ s\? f ! ,laur5tian ,*annel4 ,! cont95tal rise is #bej miles wide & has an av]age gradi5t ( #a3djj ov] its deepe/ ?ird4 ,at a dep? ( #bgej fa?oms ! gradi5t abruptly drops to #a3bjjj1 & ?is m>ks ! nor!rn edge ( ! ,sohm ,abyssal ,pla94 ,illu/ration3 ,,figure #ab4--,laur5tian ,*annel ,pr(ile replott$ f ,,nmc e*ogram ,illu/ration3 ,,figure #ac4--;,ea/]n ,*annel1 ,gulf ( ,ma9e ,pr(ile replott$ f ,,nmc e*ogram ,laur5tian ,*annel4--,betwe5 ,nova ,scotia & ,newf\ndl& a #fj-mile-wide1 /eep-sid$1 flat-floor$ *annel cuts across ! cont95tal %elf connect+ ! ,gulf ( ,/4 ,lawr5ce & ! op5 ocean4 ,! ne>ly flat1 smoo? floor ( ?is *annel lies at ab\t #bcj fa?oms dep?4 ,figure #ab %[s a cross-section ( ! ,laur5tian ,*annel ne> its seaw>d end4 ,! orig9 & physiography ( ! *annel has be5 treat$ by ,%ep>d 7#aica2 #aidh72 its /ructure has be5 report$ by ,press & ,beckmann 7#aied74 ,! ,laur5tian ,*annel cont9ues z a /eep-sid$1 box-%ap$ feature = m ?an #ejj miles into ! ,gulf ( ,/4 ,lawr5ce4 ,scotian ,%elf ,sector4--,! t]m ,scotian ,%elf 0 introduc$ by ,canadian oceanograph]s & ref]s to ! cont95tal %elf s\!a/ ( ,nova ,scotia f ! ,laur5tian ,*annel to ! ,gulf ( ,ma9e4 ,?is region is illu/rat$ by ,pr(iles ,w-#g1 ,w-#h1 ,w-#i1 ,w-#aj1 & ,w-#aa :i* run at slightly diff]5t directions1 all />t+ 9 ! vic9ity ( ,halifax1 ,nova ,scotia4 ,along ! entire ,scotian ,%elf a s]ies ( #abj-;fa?om depressions are locat$ #aj to #hj miles (f %ore4 ,a ne>ly cont9u\s bank #bj-fj fa?oms deep & #aj-be miles wide lies along ! seaw>d edge ( ! ,scotian ,%elf4 ,f nor!a/ to s\?we/ ?is feature is divid$ by l[ saddles into ,banqu]eau ,bank 7#bj-dj fa?oms71 ,sable ,isl& ,bank 7#j-bj fa?oms71 ,em]ald ,bank 7#dj-fj fa?oms71 ,lahave ,bank 7#ej-fj fa?oms71 & ,br[ns ,bank 7#bj-fj fa?oms74 ,^! %elf-edge banks culm9ate 9 ! l[1 s&y ,sable ,isl& :i* /ret*es = ab\t #be miles along ! out] edge ( ! %elf4 ,9 pr(ile ,w-#g ! break f ! ne>ly flat %elf to a gradi5t ( #a3ej occurs at #ej fa?oms2 a second break occurs at #hj fa?oms4 ,a gradi5t ( #a3aj is rea*$ at ! #aej-;fa?om curve4 ,pr(ile ,w-#aa is some:at simil> to ,w-#g 9 ! =m ( ! %elf break4 ,pr(iles ,w-#h1 ,w-#i1 & ,w-#aj %[ %elf breaks at #ej1 #fj1 & #gj fa?oms respectively4 ,! gradi5t ( ! cont95tal slope (f ! ,scotian ,%elf ranges f #a3aj to #a3be along ! pr(iles4 ,9 pr(iles ,w-#g1 ,w-#h1 ,w-#aj1 & ,w-#aa ! #a3be gradi5t abruptly decreases to #a3gj at ab\t #gjj fa?oms2 9 ,w-#i ! #a3be gradi5t cont9ues to almo/ #bjjj fa?oms4 ,x is difficult to decide :e!r to include ! #a3dj to #a3fj segm5ts ) ! cont95tal slope or ) ! cont95tal rise4 ,h[ev]1 s9ce we h pick$ ! gradi5t ( #a3dj z ! m9imum gradi5t = true cont95tal slopes1 ^! segm5ts fall )9 ! cont95tal rise4 ,! cont95tal rise ?us def9$ av]ages #afj miles 9 wid? (f ! ,scotian ,%elf4 ,gradi5ts are g5]ally great] "h ?an 9 ! cont95tal rise f>!r s\?4 ,! ,gully1 a l>ge subm>9e canyon %[n on navigational *>ts1 lies ab\t #be miles ea/ ( ,sable ,isl&4 ,! subm>9e canyons ( ! ,scotian ,%elf h n be5 accurately mapp$1 b ! exi/5ce ( _m canyons 9 ?is area has be5 %[n by sev]al fa?ograms obta9$ 9 ?is vic9ity4 ,figure #ad illu/rates "o s\nd+ pr(ile ne>ly p>allel to ! %elf ne> ! ,gully4 ,sev]al small canyons ab\t #ajj fa?oms deep occur betwe5 #ajj & #gjj fa?oms4 ,sev]al l>g] canyons #cjj-ejj fa?oms deep & #g-aj miles wide are cross$ on ! l[] cont95tal slope & upp] cont95tal rise4 ,illu/ration3 ,,figure #ad4--,subm>9e canyons (f ! ,scotian ,%elf ,pr(ile replott$ f ,,nmc e*ogram runs ne>ly p>allel to tr5d ( cont95tal slope ne> ,sable ,isl&4 ,on navigational *>ts l>ge/ canyon is kn[n z ! ,gully4 ,gulf ( ,ma9e ,entrance4--,s\?we/ ( ! ,scotian ,%elf !re is a n>r[ gap 9 ! cont95tal %elf simil> to ! ,laur5tian ,*annel4 ,?is feature1 call$ ei!r ! ,nor!a/ ,tr\gh 7,%ep>d1 #aidh7 or ,ea/]n ,*annel ( ! ,gulf ( ,ma9e1 is #ae miles wide & ab\t #aej fa?oms deep2 x provides a deep-wat] entrance to ! ,gulf ( ,ma9e 7,fig4 #ac74 ,! ,gulf ( ,ma9e is enclos$ by ,georges ,bank (f ! ,new ,engl& %elf1 ,cape ,cod1 & s\!rn ,nova ,scotia4 ,?is entrance has rec5tly be5 describ$ by ,torphy & ,zeigl] 7#aieg74 ,gulf ( ,ma9e ,int]ior4--,mu* ( ! int]ior ( ! ,gulf ( ,ma9e has be5 survey$ 9 exceptional detail by ! ,coa/ & ,geodetic ,survey4 ,! read] is ref]r$ to ,murray's pap] 7#aidg7 = a ?or\gh description ( ! floor ( ! ,gulf ( ,ma9e4 ,9 g5]al ! floor is extremely irregul> ) sev]al #bj- to #dj-;fa?om hills p] mile4 ,! floor is cov]$ by s$im5t :i* transmits s\nd s readily t ! area is not$ = exceptionally pron\nc$ sub-bottom reflections f ! rock lay]s b5ea? ! s$im5t4 ,nor!a/]n ,unit$ ,/ates ,sector4--,f ! nor!a/ tip ( ,georges ,bank to ,cape ,hatt]as ! cont95tal m>g9 is rem>kably uni=m 9 morphologic detail4 ,pr(iles ,w-#ab to ,w-#ai diff] v little f ! type pr(ile (f nor!a/]n ,unit$ ,/ates 7,fig4 #ae74 ,! cont95tal %elf & slope 9 ?is area are bett] survey$ ?an 9 any o!r area 9 ! ,atlantic4 ,! surveys ( ! ,coa/ & ,geodetic ,survey 7 cont\r$ & describ$ by ,veat* & ,smi? 7#aici74 ,! s$im5t /udies ( ,/etson 7#aicf2 #aich2 #aidi7 & ! seismic /udies ( ,ew+ & o!rs 7#aicg et seq47 make ?is geologically ! be/-kn[n %elf & slope 9 ! _w4 ,_m l>ge & well-mapp$ canyons cut ! cont95tal slope f ,georges ,bank to ,cape ,hatt]as4 ,! l>ge subm>9e canyons (f ,georges ,bank h attract$ great int]e/ because ( _! remot5ess f riv]s & associat$ dis*>ges ( riv] s$im5ts4 ,! cont95tal %elf is #ej to #ajj miles wide 9 ?is sector4 ,t[>d ,cape ,hatt]as ! coa/al pla9 wid5s z ! %elf n>r[s4 ,! comb9$ features are call$ ! em]g$ & subm]g$ coa/al pla94 ,! gradi5t ( ! cont95tal slope ranges f #a3h to #a3ae & ! base ( ! slope ) "o exception is at #aaej #ajj fa?oms4 ,! %elf break is at ab\t #ej fa?oms on all pr(iles4 ,on pr(iles ,w-#ab1 ,w-#ac1 ,w-#ad1 ,w-#ae1 ,w-#ah1 & ,figure #a ( ,plate #d !re is a second break at #ge-ajj fa?oms4 ,! break betwe5 ! cont95tal slope & ! upp] cont95tal rise is abrupt at "s places & occupies a di/ance ( #e to #aj miles 9 o!r places 7,fig4 #af74 ,9 ea* case ! gradi5t ( ! next l[] #cj- to #ej-mile segm5t is #a3ajj4 ,all pr(iles f ,georges ,bank to ,cape ,hatt]as1 a span ( m ?an #ejj miles1 %[ bo? an upp] & a l[] cont95tal rise 7,pr(iles ,w-#ac1 ,w-#ai1 & ,fig4 #ae74 ,! uni=mity 9 ! cont95tal slope gradi5t c>ries ov] into ! cont95tal rise4 ,bo? ! upp] cont95tal rise & ! l[] cont95tal rise are divid$ into ?ree segm5ts4 ,! wid?1 gradi5t1 & dep?s ( ea* ( ! slope segm5ts are rem>kably simil>4 ,repres5tative values bas$ on pr(iles ,w-#ac to ,w-#ai & ,figure #ae are %[n 9 ,table #a4 ,illu/ration3 ,,figure #ae4--;,cont95tal m>g9 prov9ces3 ,type pr(ile (f nor!a/]n ,unit$ ,/ates4 ,pr(ile plott$ f ,,pdr records4 ,?is pr(ile is repres5tative ( ! sector f ,georges ,bank to ,cape ,hatt]as4 ,,table #a4--;,*>act]i/ics ( ! cont95tal rise1 nor!a/]n ,unit$ ,/ates sector3 repres5tative values ( gradi5t1 dep?1 & wid? ( slope segm5ts ,values measur$ f pr(iles ,w-#ac to ,w-#ai ,dep? ,segm5t ,upp] ,l[] ,gradi5t ,wid? edge edge ,upp] cont95tal rise #a #aaej #aej #adej #bjj #a3ajj #bj #cj #e #b #adej #bjj #afej #aej #a3bge #be #dj #ae #c #afej #aej #baej #bjj #a3ij #cj #cj #ae ,l[] cont95tal rise #a #baej #bjj #bcej #ajj #a3bej #ej #dj #aj #b #bcej #ajj #bcej #ajj #a3adjj #ajjj #ej #bj #c #bcej #ajj #bgbe #ajj #a3aej #cj #fj #bj ---------------------------------------- ------------------ ,! upp] cont95tal rise & ! l[] cont95tal rise are ess5tially t]race or %elflike features4 ,ea* has a relatively /eep 7#a3ej-a3bjj7 out] face 7segm5t #c7 & a relatively g5tle 7#a3bej-a3bjjj7 %elflike surface 7segm5t #b74 ,9 ea* case a slope ( int]m$iate gradi5t 7#a3hj-a3cjj7 7segm5t #a7 connects ! upp] %elflike surface ) ! next high] face4 ,9 ! case ( ! upp] cont95tal rise ! next high] face is ! cont95tal slope4 ,o!r small]-scale t]racelike features may ev5tually be correlat$ along ! /rike :5 m data are available4 ,! local relief exce$s #bj fa?oms 9 ! deep] p>ts ( segm5t #c ( ! l[] cont95tal rise4 ,a range ( hills ext5ds = a few hundr$ miles along ! base ( ! cont95tal rise z indicat$ on ! physiographic prov9ce *>t 7,pl4 #bj74 ,^! hills1 kn[n z ! l[] cont95tal rise hills1 are #cj-ajj fa?oms high & ea* is #a to #c miles wide4 ,an e*ogram 7,pl4 #c1 fig4 #d7 %[s ?ree cont95tal rise hills4 ,! only o!r "p ( ! cont95tal rise :]e relief ( m ?an #bj fa?oms is g5]ally enc\nt]$ is 9 segm5t #a ( ! upp] cont95tal rise4 ,! irregul>ity 9 ?is case is probably relat$ to ! ext5sions ( num]\s cont95tal-slope canyons onto ! cont95tal rise4 ,relief ( #e-aj fa?oms is almo/ univ]sal 9 segm5ts #a & #b ( ! upp] cont95tal rise4 ,! e*ogram reproduc$ 9 ,figure #a ( ,plate #c %[s typical m9or-relief features ( ! upp] cont95tal rise4 ,an oblique cross+ ( a subm>9e canyon on ! upp] cont95tal rise is %[n 9 ,figure #b ( ,plate #c4 ,! smoo? topography typical ( mo/ ( ! rema9d] ( ! cont95tal rise is well illu/rat$ by ! e*ogram %[n 9 ,figure #c ( ,plate #c4 ,! ,hudson ,subm>9e ,canyon cuts across ! cont95tal rise 9 ?is sector4 ,a *>t cont\r$ by ,ivan ,tol/oy & ! au?ors f surveys made 9 #aidi is %[n 9 ,plate #b 7,ericson1 ,ew+1 & ,heez51 #aiea74 ,a s]ies ( #cj cross pr(iles is %[n 9 ,figure #ag4 ,illu/ration3 ,,figure #af4--,trac+s ( ,,pdr records ( cont95tal & insul> slopes 7a74 ,insul> slope ( ,madeira s\?we/ ( ,fun*al4 7b74 ,cont95tal slope ( ,europe4 7c74 ,cont95tal slope (f nor!a/]n ,unit$ ,/ates4 ,! ,hudson ,canyon1 :i* is m ?an #ejj fa?oms deep & #e miles wide 9 ! cont95tal slope 7,upp] ,gorge71 n>r[s to less ?an #b miles & %all[s to #ej fa?oms at ! base ( ! cont95tal slope4 ,z x cuts across segm5t #b ( ! upp] cont95tal rise ! canyon gradually deep5s4 ,:5 x cuts into ! upp] "p ( segm5t #c ! canyon deep5s to #cjj fa?oms1 wid5s to #c miles1 & =ms ! ,l[] ,gorge4 ,! canyon gradually n>r[s & %all[s z x cuts across ! l[] cont95tal rise4 ,x ends ne> ,c>yn ,peak :]e s$im5t cores indicate an ext5sive delta or subm>9e alluvial cone4 ,! upp] cont95tal rise & ! l[] cont95tal rise c be t5tatively trac$ nor!a/w>d ?r\gh ! ,scotian ,%elf & ,gr& ,banks sectors4 ,! irregul> b5* at #bbej-bdej fa?oms on ,w-#f & ! b5* at #bcjj fa?oms on ,w-#h & ,w-#aa c probably be ref]r$ to segm5t #b ( ! l[] cont95tal rise4 ,illu/ration ,ne> ,cape ,hatt]as ! entire "* ( ! cont95tal m>g9 *anges4 ,b5*es :i* 7 b>ely disc]nible f>!r nor? wid5 to =m a s]ies ( broad /eps :i* resemble a giant /aircase desc5d+ to ! dep?s ( ! ,atlantic4 ,^! b5*es appe> to m]ge ) ! b5*es ( ! ,blake ,plateau & ,esc>pm5t f>!r s\?4 ,h[ev]1 insuffici5t pr(iles exi/ to p]mit a firm correlation4 ,illu/ration3 ,,figure #ag4--;,cross sections ( ,hudson ,subm>9e ,canyon ,replott$ f nonprecision s\nd+s 7,,nmc7 made #aidi-aiej ,blake ,plateau ,sector4--,?is sector is divid$ into two p>ts1 ! nor!rn "p f ,cape ,hatt]as to #bi ,n4 7ess5tially a transition zone7 & ! s\!rn or ma9 ,blake ,plateau betwe5 #bi ,n4 & ! nor!rn edge ( ! ,bahamas at #bf ,n4 ,! %elf break lies p>allel to ! coa/1 ab\t #fj miles (f%ore1 f j s\? ( ,cape ,hatt]as to ,cape ,canav]al4 ,! cont95tal slope ext5ds 7at a gradi5t ( #a3dj7 only to dep?s ( #cjj-djj fa?oms :]e ! l[] gradi5ts 7ca4 #a3ajjj7 ( ! ,blake ,plateau are f\nd4 ,! ma9 or s\!rn ,blake ,plateau is #agj miles wide 7ea/-we/7 & ext5ds f ! latitude ( ,gr& ,bahama ,isl& to #cj ,n4 ,f ?is po9t to ,cape ,hatt]as ! ,blake ,plateau n>r[s & disappe>s4 ,! ,blake ,esc>pm5t =ms a precipit\s drop to abyssal dep?s along ! ea/]n edge ( ! plateau4 ,! top ( ! ,blake ,esc>pm5t lies at ab\t #eej fa?oms1 & its base at ab\t #bfjj fa?oms4 ,! ,esc>pm5t is typically =m$ by two or ?ree di/9ct slope segm5ts4 ,an e*ogram obta9$ along a track runn+ s\!a/ f ,*>le/on1 ,s\? ,c>ol9a1 is reproduc$ 9 ,figure #a ( ,plate #g4 ,! cont95tal %elf ext5ds f ! %ore at an extremely l[ gradi5t to ! #be-;fa?om isoba? :]e a small def9ite not* m>ks an increase 9 gradi5t to #a3ajjj4 ,?is gradi5t cont9ues to ! #ej-;fa?om isoba? :]e x *anges to #a3dj4 ,at ! #ij-;fa?om curve ! gradi5t increases to #a3abj & cont9ues to #afj fa?oms :]e x f9ally increases to #a3dj4 ,?is cont95tal slope drops f #afj fa?oms to #bhj fa?oms :]e ! gradi5t flatt5s1 & ! surface *anges f smoo? to r\gh1 ) hills #aj to #bj fa?oms high & half a mile to #a- miles wide4 ,^! hills1 :i* ext5d = #d-f miles along ! pr(ile1 directly und]lie ! ,gulf ,/ream4 ,= #ej miles seaw>d ( ^! hills ! ocean floor is irregul> betwe5 #bcj & #cjj fa?oms4 ,at #ij miles f %ore five ea/w>d-fac+ sc>ps #aj-bj fa?oms high =m a /rik+ contra/ to ! g5]ally smoo?1 g5tly roll+ topography4 ,at #cjj fa?oms ! gradi5t increases to #a3bjj1 & ! sea floor drops = ! next #bd miles to #djj fa?oms :]e a few small hills are associat$ ) a drop 9 ! gradi5t to #a3ajjj4 ,s\!a/ ( ?is po9t ! bottom is smoo? until at a dep? ( #dcj fa?oms a /eep sc>p drops abruptly #cj fa?oms to =m a mile-wide depression #bj-cj fa?oms deep4 ,! s\!a/ side ( ?is feature rises to #dde fa?oms1 & s\!a/w>d ( a few #e-;fa?om sc>ps ! surface ( ! ,blake ,plateau becomes smoo?4 ,illu/ration3 ,,pl4 #c ,,figure #a4 ,,upp] ,,cont95tal ,,rise ,,figure #b4 ,,oblique ,,cross+ ,,( ,,subm>9e ,,canyon ,,figure #c4 ,,smoo? ,,bottom ,,( ,,l[] ,,cont95tal ,,rise ,,figure #d4 ,,l[] ,,cont95tal ,,hills ,,repres5tative ,,pdr ,,records ,,f ,,cont95tal ,,rise ,,( ,,nor!a/]n ,,unit$ ,,/ates ,illu/ration3 ,,pl4 #d ,,figure #a4 ,,%elf ,,break ,,& ,,cont95tal ,,slope ,,(f ,,new ,,york ,,figure #b4 ,,small ,,hills ,,on ,,cont95tal ,,slope ,,(f ,,daytona ,,bea*1 ,,florida ,,figure #c4 ,,small ,,hills ,,9 ,,! ,,/raits ,,( ,,florida ,,figure #d4 ,,small ,,abrupt ,,depressions ,,on ,,! ,,inn] ,,"p ,,( ,,! ,,blake ,,plateau ,,pdr ,,records ,,f ,,cont95tal ,,slope ,,& ,,blake ,,plateau ,! positions ( all e*o-s\nd+ records are %[n 9 ,plate #cj4 ,dep? 9 fa?oms4 ,illu/ration3 ,,pl4 #e ,,figure #a4 ,,we/ ,,( ,,! ,,cre/ ,,( ,,! ,,out] ,,ridge ,,figure #b4 ,,we/]n ,,side ,,( ,,out] ,,ridge ,,ne> ,,abyssal ,,pla9 ,,figure #c4 ,,blake-,,bahama ,,abyssal ,,pla9 ,,pdr ,,records ,,f ,,out] ,,ridge ,,ea/ ,,( ,,! ,,blake ,,plateau ,,& ,,f ,,! ,,blake-,,bahama ,,abyssal ,,pla9 ,dep? 9 fa?oms3 ,! outgo+ p+s z well z scatt]+ lay]s are record$ 9 ! #j-djj fa?om scale range2 ! bottom topography may lie )9 ! range ( any multiple ( #djj fa?oms4 ,! dep? scales indicat$ on ! plates ref] to ! pr(iles ( bottom topography4 ,= example--,figure #a ( ,plate #e %[s a #cjj fa?om deep scatt]+ lay] ov] :i* ! bottom pr(ile has be5 sup]impos$4 ,illu/ration3 ,heez5 et al41 ,,pl4 #f ,,pdr ,,record ,,( ,,out] ,,ridge ,,%[+ ,,sub-,,bottom ,,horizon ,"o #c millisecond p+ 0 transmitt$ & receiv$ once ea* second4 ,dep? 9 fa?oms4 ,! same g5]al succession ( topographic features is %[n 9 a e*ogram 7,pl4 #g1 fig4 #b7 tak5 along a s\!a/-nor?we/ l9e ea/ ( ,daytona ,bea*1 ,florida4 ,! small def9ite not* at #bf fa?oms is pres5t1 b a significant diff]5ce betwe5 ! two e*ograms is se5 betwe5 #ij & #cjj fa?oms4 ,on ! ,*>le/on pr(ile a /eep #a3dj gradi5t slope m>ks ?is dep? range1 :ile1 on ! ,daytona ,bea* pr(ile1 ! gradi5t is relatively g5tle 7#a3ahj72 small b probably significant b5*es are f\nd at #bbe1 #bgj1 #bij1 #cge1 & #che fa?oms4 ,bo? pr(iles h ! same *>act]i/ic rugg$ #e- to #ae-;fa?om hills at #djj fa?oms at a po9t und]ly+ ! ,gulf ,/ream4 ,on ! ,*>le/on pr(ile a broad1 g5tly fractur$ ar* sep>ates ! cont95tal slope f ! smoo? out] "p ( ! ,blake ,plateau4 ,! small1 %>p-cre/$ hills not$ on ! ,daytona ,bea* & ,*>le/on pr(iles are also f\nd at ! nor? end ( ! ,/raits ( ,florida 7,pl4 #d1 fig4 #b74 ,blake ,esc>pm5t4--,pr(iles ,w-#bc1 ,w-#bd1 & ,w-#be & ,figure #ah illu/rate ! =m ( ! ,blake ,esc>pm5t4 ,! out] edge ( ! ,blake ,plateau abruptly breaks (f at ab\t #fjj fa?oms4 ,"h gradi5ts increase to #a3cj4 ,?is segm5t cont9ues ) a few m9or breaks to a dep? ( #abjj to #aejj fa?oms :]e a n>r[ b5* or at lea/ a major break 9 slope occurs4 ,bel[ ?is b5* ! esc>pm5t drops s /eeply t only a few side e*oes are record$4 ,! gradi5t "h exce$s #a3b 9 sev]al pr(iles4 ,at #bdjj fa?oms !re is 9 places ano!r n>r[ b5*1 b on o!r pr(iles ! abyssal pla9 ( ! floor ( ! ,blake-,bahama ,bas9 lies directly at ! foot ( ! /eepe/ segm5t4 ,a peculi> fact is t along _m ea/-we/ cross sections ! deepe/ po9t 9 ! bas9 lies directly at ! foot ( ! esc>pm5t4 ,a simil> deep5+ adjac5t to ! ,campe*e & ,we/ ,florida esc>pm5ts 9 ! ,gulf ( ,mexico has be5 report$ 7,ew+1 ,ericson1 ,heez51 #aieh74 ,antilles ,out] ,ridge4--,s\? ( ,cape ,hatt]as a ridge rang+ 9 wid? f #fj to #bjj miles lies ab\t #ajj miles ea/ ( ! ,blake ,esc>pm5t & ! ,bahama ,banks4 ,! ridge has two p>allel cre/s #ajj miles ap>t :i* bo? plunge to ! s\?4 ,at #cj,n4 ! cre/s av]age ab\t #afjj fa?oms 9 dep?1 b at #be,n4 !y are #bgej fa?oms1 a drop ( ne>ly #ajjj fa?oms 9 #cjj miles4 ,! smoo? roll+ topography ( ! ridge betwe5 ,cape ,hatt]as & #bd,n4 resembles ! cont95tal rise (f ,new ,york or1 9 "s areas1 ! some:at /rong] relief ( ! ,b]muda ,plateau ( ! c5tral ,b]muda ,rise 7,pl4 #e1 figs4 #a1 #b74 ,s\? ( #bd,n4 & 9 ! vic9ity ( ,hispaniola ! ridge is poorly kn[n & difficult to /udy because ( its l[ relief & ! l>ge errors 9 mo/ nonprecision s\nd+s tak5 9 su* a great dep? ( wat]4 ,nor? ( ,pu]to ,rico ! out] ridge appe>s z a cle>ly def9$ feature betwe5 ! ,pu]to ,rico ,tr5* on ! s\? & ! ,n>es ,abyssal ,pla9 on ! nor?4 ,aga9 !re are two p>allel cre/s #fj miles ap>t m>k$ by l[ relief ( #bj to #ajj fa?oms at a dep? ( #bgej fa?oms4 ,! ,antilles ,out] ,ridge1 cont9u+ to ! ea/1 m]ges ) ! ,l[] ,/ep ( ! ,mid-,atlantic ,ridge4 ,b m probably x skirts ! ,less] ,antilles to jo9 ! cont95tal rise (f ,s\? ,am]ica4 ,! cre/ zone is cov]$ by ,globig]9a ooze 9 ! nor? & r$ clay 9 ! s\?2 x is isolat$ f ! silty clays ( ! cont95tal slope except on its nor?we/ flank4 ,sub-bottom e*oes appe> on fa?ograms tak5 across ! out] ridge4 ,data sugge/ t a prom95t #h- to #aj-;fa?om sub-bottom int]face ext5ds ov] ! out] ridge betwe5 ,san ,salvador & #cj,n4 7,pl4 #f74 ,bahamas ,sector4--,! ,bahamas sector c be divid$ into two p>ts3 7#a7 ! broad 7#bjj miles wide7 nor!rn area dom9at$ by broad1 %all[ banks brok5 by relatively n>r[1 deep 7ca4 #ajjj fa?oms7 tongues or *annels2 7#b7 ! n>r[ s\!a/]n "p :]e ! banks decrease 9 area & ! tongues deep5 7to #bbjj fa?oms7 & wid54 ,?is s\!a/]n "p tap]s to ! ea/ 9 ! direction ( ! ,pu]to ,rico ,tr5*4 ,! s\!a/ tip ( ?is area is =m$ by ,navidad ,bank1 ^: ea/]n slopes drop to ! floor ( ! ,pu]to ,rico ,tr5*4 ,illu/ration3 ,,figure #ah4--,trac+ ( ,,pdr record ( ,blake ,esc>pm5t ,no s\nd+s 7 record$ betwe5 #afjj & #bdjj fa?oms1 a common difficulty on ?is precipit\s esc>pm5t4 ,note h[ ,blake-,bahama ,abyssal ,pla9 slopes t[>d ! base ( ! esc>pm5t4 ,illu/ration ,! ,bahama ,banks appe> to consi/ ( a slab sup]impos$ on ! same surface :i* =ms ! ,blake ,plateau4 ,! ,blake ,esc>pm5t m]ges ) ! l[] "p ( ! ea/]n slope ( ! ,bahamas4 ,! slopes ( ! ,bahamas are precipit\s2 gradi5ts are ( ! ord] ( #a3d to #a3h4 ,v]tical cliffs1 :i* lie j bel[ ! #ej-;fa?om curve1 h be5 report$ by lead s\nd+s 7,arm/rong1 #aiec74 ,! ,tongue ( ! ,ocean & ! ,nor!a/ & ,nor?we/ ,provid5ce *annels =m a network ( subm>9e canyons 7,hess1 #aicc74 ,! floor ( ?is canyon sy/em has a cont9u\s d[n-slope gradi5t to ! floor ( ! ,blake-,bahama ,bas94 ,s$im5t cores f ! floor ( ! ,blake-,bahama ,bas9 7#bebe fa?oms7 7,ericson1 ,ew+1 & ,heez51 #aieb7 conta9$ ?ick 7#a-c m7 b$s ( grad$ calc>e\s s&4 ,! /eep slopes ( ! ,bahamas are g5]ally rocky1 & cores "h reveal a v>iety ( ,t]ti>y & ,cretace\s s$im5ts4 ,exuma ,s\nd also is l9k$ by subm>9e canyons to ! ,blake-,bahama ,bas94 ,! grad$ calc>e\s s&s ( ! ,blake-,bahama ,bas9 7 probably c>ri$ ?r\gh ?is subm>9e canyon sy/em by turbidity curr5ts4 ,! topographic b5*es ( ,exuma ,s\nd h be5 describ$ by ,lee 7#aiea74 ,! s\!a/]n ,bahamas f ,great ,inagua to ,navidad ,bank consi/ ( m num]\s isolat$ banks & great] expanses ( ocean floor 9 ! dep? range ( #agjj-bdjj fa?oms4 ,! bas9s beh9d ! s\!rn ,bahamas lie bel[ ! sill dep? betwe5 ! l9e ( banks4 ,?us an abyssal pla9 lies entrapp$ 9 ! ,hispaniola-,caicos ,*annel & ! s\!a/]n portion ( ! ,old ,bahama ,*annel4 ,pr(ile ,w-#bi 7,pl4 #bd7 %[s mu* irregul> relief betwe5 #ajjj & #aejj fa?oms4 ,pu]to ,rico ,tr5* ,sector4--,) ! disappe>ance ( ! ,bahama ,banks at ! ea/]n edge ( ,navidad ,bank1 ! cont95tal m>g9 assumes its ?ird mode ( expression3 ! m>g9al tr5*-out] ridge complex4 ,! out] ridge1 :i* ne>ly disappe>$ 9 ! s\!a/]n ,bahama sector1 aga9 becomes a prom95t feature4 ,! la/ traces ( ! m>g9al plateau m]ge ) ! cont95tal slope ( ,hispaniola & ,pu]to ,rico4 ,! ,pu]to ,rico ,tr5* develops rapidly ea/ ( ,navidad ,bank2 x lies betwe5 ! out] ridge & ! cont95tal slope or l&w>d tr5* slope ( ! ,great] ,antilles4 ,! relief ( ! out] ridge is some:at great] ?an t obs]v$ on ! out] ridge f>!r nor?we/ ne> ! ,blake ,plateau4 ,! floor ( ! ,pu]to ,rico ,tr5* is divid$ into two p>ts by a longitud9al ridge4 ,! deepe/ p>ts ( bo? are floor$ by ne>ly level tr5* pla9s4 ,! deep] "o on ! out] or nor!rn side ma9ta9s a ne>ly con/ant dep? at #dceh fa?oms 7#dehe fa?oms correct$7 = #aej miles 7,ew+ & ,heez51 #aiee74 ,! s\!rn or inn] tr5* is m v>iable 9 dep?1 & ! tr5* pla9 lies int]mitt5tly along its l5g?4 ,its dep? ranges f #cfjj to #dcjj fa?oms 7uncorrect$74 ,! walls ( ! ,pu]to ,rico ,tr5* are =m$ by a s]ies ( extremely /eep segm5ts :i* %[ a rem>kable p]si/5ce along ! tr5*4 ,pr(iles ,w-#cb & ,w-#cc illu/rate ! typical tr5* pr(ile nor? ( ,pu]to ,rico4 ,breaks 9 slope are obs]v$ at #gjj fa?oms & at #aejj fa?oms2 at #bjjj fa?oms ! gradi5t /eep5s to #a3f4 ,9 ?is region all s\nd+s are side e*oes4 ,! out] or seaw>d wall ( ! tr5* is also *>act]iz$ by a succession ( lat]ally p]si/5t slope segm5ts4 ,a b5* at #chjj fa?oms at ! top ( a sc>p :i* drops to ! bottom ( ! tr5* is *>act]i/ic ( sev]al pr(iles4 ,anegada ,passage4--,! ,virg9 ,isl&s ,bank ext5ds #cj miles ea/ ( ,pu]to ,rico along ! s\? side ( ! ,pu]to ,rico ,tr5*4 ,betwe5 ! ,virg9 ,isl&s ,bank & ,/4 ,croix a deep passage cuts ?r\gh f ! ,atlantic to ! ,c>ibbean4 ,?is deep passage is #acj miles long & runs along an e-ne-w-sw l9e4 ,its walls are extremely /eep 7#i-dc7 7,frassetto & ,nor?rop1 #aieg74 ,! /ructure ( ?is feature has be5 /udi$ by ,%urbet & ,worzel 7#aieg7 & by ,j4 ,ew+ et al4 7#aieg74 ,,s\?we/]n ,,europe ,,& ,,nor?we/ ,,africa3 ,! cont95tal m>g9 ( ,europe & ,africa is illu/rat$ 9 ,plate #be by only #bc pr(iles1 & !re=e our description ( ?is area _c be z detail$ z t = ,nor? ,am]ica4 ,= purposes ( description we h brok5 ! area into f\r sectors ( contra/+ type3 7#a7 ! ,anglo-,fr5* sector3 7#b7 ! ,ib]ian sector2 7#c7 ! ,gibralt> sector2 & 7#d7 ! ,nor? ,african sector4 ,9 all b ! ?ree pr(iles 9 ! ,gibralt> sector !re is a well-def9$ cont95tal %elf4 ,! cont95tal slope is ev]y:]e pres5t b ranges widely 9 height & gradi5t4 ,! cont95tal rise is extremely well develop$ (f ,africa b virtually abs5t 9 ! ,bay ( ,biscay4 ,abyssal pla9s are %[n on almo/ e pr(ile1 b _! dep? ranges f #beej to #cjge fa?oms1 & _! wid? f #ej to #bej miles4 ,anglo ,fr5* ,sector4--,pr(iles ,e-#a1 ,e-#b1 & ,e-#c are repres5tative ( ! ,anglo-,fr5* sector :i* ext5ds f #de ,n4 to #fj ,n4 ,only ! s\!rn "p ( ?is sector is %[n on ! physiographic diagram4 ,! cont95tal slope is brok5 by a prom95t b5* or m>g9al plateau at #ajjj-abjj fa?oms4 ,! nor?we/ corn] ( ! physiographic diagram s\? to #db ,n4 is includ$ 9 ,hill's 7#aief7 cont\r *>t4 ,accord+ to ?is *>t ! prom95t #abjj-;fa?om b5* ext5ds = m ?an #ijj miles along ! cont95tal m>g9 f #de to #fj ,nor? ,latitude4 ,! cont95tal slope f ! %elf break to ! prom95t b5* exhibits small] b5*es & *anges 9 slope1 _m ( :i* probably w be correlatable :5 m pr(iles are obta9$ 9 ?is region4 ,! g5]al gradi5t ( ?is portion ( ! slope ranges f #a3aj to #a3cj4 ,on ! b5* individual slope segm5ts range f #a3dj to #a3hj4 ,bel[ ! b5* ! sea floor drops f #aejj to #bajj fa?oms at gradi5ts ( #a3ae to #a3cj4 ,9 pr(iles ,e-#a & ,e-#c a n>r[ cont95tal rise ab\t #gj miles wide ) gradi5ts ( #a3bej to #a3hjj lies at ! foot ( ! cont95tal slope4 ,?is n>r[ cont95tal rise 7,pl4 #h1 fig4 #a7 gives away to a #fj-mile-wide abyssal pla9 at ab\t #bejj fa?oms dep? 7,pl4 #h1 fig4 #c74 ,abyssal-pla9 gradi5ts are ab\t #a3bjjj 9 ?is region4 ,t[>d ! s\!a/ corn] ( ! ,bay ( ,biscay ! #ajjj- to #abjj-;fa?om b5* disappe>s 7,fig4 #af;b72 ! cont95tal rise & cont95tal %elf n>r[ to #cj miles4 ,we h only two pr(iles (f ! nor? coa/ ( ,ib]ia1 b ,hill's 7#aief7 *>t sugge/s t ! slope is relatively /eep ) "s prom95t b5*es1 & t ! cont95tal %elf & cont95tal rise n>r[ to #aj to #ae miles 9 wid?4 ,! prom95t ,cape ,breton ,subm>9e ,canyon lies at ! s\!a/ corn] ( ! ,bay ( ,biscay 7,b\rc>t1 #aidi74 ,ib]ian ,sector4--,?is sector 0 describ$ by ,de ,&rade 7#aicg7 on ! basis ( a l>ge numb] ( discrete s\nd+s by ! ,portuguese ,hydrographic ,s]vice4 ,relatively few e*o-s\nd+ pr(iles are available = ! area1 & little m c be add$ to ,de ,&rade's description4 ,! %elf 9 mo/ places is less ?an #bj miles 9 wid?4 ,! few e*o-s\nd+ pr(iles available indicate sev]al prom95t b5*es on ! cont95tal slope4 ,exceptionally l>ge subm>9e canyons occur (f ,cape ,/4 ,v9c5t1 ,setbal1 ,lisbon 7#b71 & ,naz>4 ,prelim9>y inve/igations by ! ,lamont ,geological ,obs]vatory indicate t ,t]ti>y s$im5ts outcrop on ! walls ( ,lisbon & ,setbal canyons 7,sutton et al41 #aieg74 ,t]ti>y s$im5ts h also be5 obta9$ by dr$g+ & cable grappl+ along ! cont95tal slope ( nor?we/ ,ib]ia 7,wiseman & ,ovey1 #aiej74 ,gibralt> ,sector4--,! cont95tal m>g9 9 ?is sector is unique4 ,! /raits cut ?r\gh at ab\t #bjj fa?oms s t pr(iles ?r\gh ! /raits %[ no cont95tal %elf4 ,a typical abrupt cont95tal slope is also abs5t s9ce only locally d slope segm5ts h gradi5ts exce$+ #a3de4 ,a s]ies ( prom95t b5*es is se5 9 ! sector f pr(ile ,e-#g to ,e-#aj4 ,! dom9ant b5* levels 9 ?is sector are #cjj1 #fjj1 #hej1 #acjj1 #agjj1 & #bajj fa?oms4 ,insuffici5t pr(iles & dr$g+s are available 9 ?is area to p]mit ! correlation & dat+ ( ^! b5*es4 ,photographs 9 ! area %[ s&y & rocky bottom1 & ?us dr$g+ 9 ?is area might yield ri* rew>ds 9 anci5t s$im5ts4 ,! b5*es are s prom95t t a detail$ /udy ( ! topography %\ld be equally rew>d+4 ,( p>ticul> int]e/ is ! mann] 9 :i* ! broad b5*es 9 ! ,gibralt> area m]ge ) ! small] b5*es & breaks 9 slope ( ! /eep cont95tal slopes ( ,portugal & ,alg]ia4 ,! topography 9 ?is sector mo/ closely resembles t ( ! nor!rn ,blake ,plateau 7pr(iles ,w-#ba1 ,w-#bb7 & ! nor!rn "p ( ! ,anglo-,fr5* sector4 ,9 all ^! areas _m b5*es are develop$1 & /eep slopes are only locally develop$4 ,nor?we/ ,african ,sector4--,! cont95tal m>g9 f nor?we/ ,morocco to ,dak> is rem>kably uni=m & r closely resembles ! nor!a/]n ,unit$ ,/ates sector4 ,! cont95tal %elf & slope are well develop$ 7,fig4 #ai74 ,! %elf is #ae to #gj miles 9 wid? & ?us is some:at n>r[] ?an ei!r ! ,nor? ,am]ican %elf or ! ,anglo-,fr5* %elf4 ,! %elf break ranges f #ej to #hj fa?oms4 ,! cont95tal-slope gradi5ts range f #a3ae to #a3dj & are ?us some:at less /eep ?an 9 ! ,am]ican sectors4 ,prom95t b5*es are common at #cjj1 #fjj1 #hej1 #abjj1 & #afjj fa?oms4 ,! cont95tal rise is well develop$ & is comp\nd4 ,! ma9 contra/ betwe5 ! ,nor? ,african & ,am]ican sectors is ! great] wid? ( ! ,african cont95tal rise4 ,(f nor!a/]n ,unit$ ,/ates a l9e ( isolat$ volcanic peaks cuts across ! cont95tal rise & abyssal pla94 ,9 ! ,nor? ,african cont95tal m>g9 volcanic peaks are l>g]1 m num]\s1 & lie 9 coalesc+ l9es or along ridges4 ,! ,cape ,v]de & ,can>y gr\ps lie 9 ! cont95tal rise ne> ! out] edge ( ! upp] cont95tal rise4 ,all prov9ces except ! cont95tal %elf wid5 f ,gibralt> s\?w>d t[>d ,cape ,v]de4 ,on pr(ile ,e-#aa (f ,casablanca ! di/ance f ! %elf break to ! l[] cont95tal rise is only #ej miles z comp>$ ) a simil> measurem5t ( #ejj miles at ,cape ,v]de4 ,(f ,casablanca ! cont95tal slope ext5ds to #adjj fa?oms :]e ! gradi5t drops to less ?an #a3dj f #a3aj-a3bj on ! cont95tal slope4 ,! upp] cont95tal rise :i* wid5s to m ?an #ajj miles f>!r s\? is only poorly develop$ (f ,morocco4 ,no o!r deep-sea e*o-s\nd+ pr(iles are available = ! ,moroccan cont95tal m>g94 ,surveys ( ! cont95tal slope made by ! ,fr5* ,hydrographic ,s]vice dur+ ! pa/ few ye>s w1 :5 publi%$ 9 full1 und\bt$ly provide mu* valuable in=mation on ! topographic b5*es 9 ?is important area 7,gr\sson1 #aieg74 ,illu/ration3 ,,heez5 et al41 ,,pl4 #h ,,figure #a4 ,,cont95tal ,,rise ,,we/ ,,( ,,/4 ,,nazaire1 ,,france ,,figure #b4 ,,biscay ,,abyssal ,,pla94 ,,note ,,small ,,mid-,,ocean ,,canyon ,,figure #c4 ,,biscay ,,abyssal ,,pla9 ,,pdr ,,records ,,european ,,cont95tal ,,rise ,,& ,,biscay ,,abyssal ,,pla9 ,dep? 9 fa?oms4 ,illu/ration3 ,heez5 et al41 ,,pl4 #i ,,figure #a4 ,,small-,,scale ,,r\ghness1 ,,upp] ,,cont95tal ,,rise ,,figure #b4 ,,roll+ ,,topography1 ,,upp] ,,cont95tal ,,rise ,,figure #c4 ,,cape ,,v]de ,,abyssal ,,pla9 ,,figure #d4 ,,abyssal ,,hills ,illu/ration3 ,heez5 et al41 ,,pl4 #aj ,,pdr ,,record ,,( ,,abyssal ,,hills1 ,,s\!a/ ,,( ,,b]muda ,,rise ,note sub-bottom e*os f b5ea? int]montane bas9 floor4 ,dep? 9 fa?oms4 ,illu/ration3 ,heez5 et al41 ,,pl4 #aa ,area ( ea* photograph is ab\t #f by #h feet4 ,,plate #aa4--,,ocean-,,bottom ,,photographs ,,on ,,! ,,cont95tal ,,m>g9 ,,& ,,ocean-,,bas9 ,,floor ,,figure #a4 7,/ation ,t#a-c1 photo #bg7 ,dep? #bfj fa?oms1 location #dg #db,n41 #jg #cd,w41 j bel[ %elf break we/ ( ,/4 ,nazaire1 ,france4 ,note small ripples :i* appe> to be sup]impos$ on l>g] ripples4 ,,figure #b4 7,/ation ,t#a-c1 photo #g7 ,dep? #bhe fa?oms1 location sev]al hundr$ feet f photograph 9 ,figure #a4 ,note holo?urians & solit>y coral atta*$ to rocks4 ,ripple m>ks are less prom95t ?an 9 ,figure #a4 ,,figure #c4 7,/ations ,t#a-af1 photo #bh7 ,dep? #bfjj fa?oms1 location #df #ej,n41 #aa #be,w41 nor!rn "p ( ,biscay ,abyssal ,pla94 ,note tracks ( bottom crawl]s1 & ! prom95t conical m\nds1 ea* ) a c5tral hole4 ,,figure #d4 7,/ation ,t#a-ah1 photo #bi7 ,dep? #bfej fa?oms1 location #dc #ef,n41 #aa #ab,w41 s\!rn "p ( ,biscay ,abyssal ,pla94 ,note me&]+ ridge made by subsurface burr[]4 ,note also />fi%1 upp] left1 & quantity ( fecal pellets & holes 9 ! bottom4 ,,figure #e4 7,/ation ,t#a-bj1 photo #ec7 ,dep? #bhej fa?oms1 location #db #ah,n41 #ad #dg,w41 nor!a/]n "p ( ,ib]ia ,abyssal ,pla94 ,note holes ) conv]g+ tracks & l>ge m\nd 9 upp] "r4 ,,figure #f4 7,/ation ,t#a-eh1 photo #ad7 ,dep? #cjgb fa?oms1 location #bi #ag,n41 #eg #bc,w41 ,abyssal ,hills s\!a/ ( ,b]muda ,rise4 ,! r\nd objects are manganese nodules4 ,note %>k's too? 9 l[] "r4 ,note also small holes indicat+ bottom dwell]s1 & me&]+ rais$ ridge ( sub-bottom burr[]4 ,( p>ticul> int]e/ are ! small moats surr\nd+ _m ( ! nodules2 !y are probably sc\r m>ks caus$ by bottom curr5ts4 ,^! curr5ts mu/ be v g5tle s9ce none ( ! nodules seems to %[ evid5ce ( rec5t roll+4 ,positions ( /ations %[n on ,plate #cj4 ,pr(ile ,e-#ab passes f ! ,african coa/ betwe5 ,fu]tev5tura & ,gran ,can>y t[>d ! nor!a/4 ,"h ! cont95tal slope ext5ds only to #ajjj fa?oms4 ,! ,can>y ,isl&s rise abruptly f ! cont95tal rise4 ,except = gradi5ts ( ! ord] ( #a3ae on ! /eep slopes ( ^! volcanic isl&s ! gradi5ts ( ! cont95tal rise are #a3cjj-a3ajjj4 ,pr(iles ,e-#ac & ,e-#ad end on ! ea/ ne> ,gran ,can>y & ?us d n %[ mo/ ( ! upp] cont95tal rise4 ,!y d %[ ! rem>kably wide & ne>ly level l[] cont95tal rise :i* rea*es a wid? ( m ?an #ejj miles4 ,pr(iles ,e-#ae & ,e-#af lie (f ,spani% ,sah>a4 ,9 bo? pr(iles ! gradi5t is #a3aj to #a3bj betwe5 ! #ej-;fa?om %elf break & a b5* at #cjj-ejj fa?oms4 ,9 bo? pr(iles ! gradi5t drops bel[ #a3dj at ab\t #abjj fa?oms4 ,bo? pr(iles %[ num]\s prom95t b5*es on ! cont95tal slope4 ,! upp] cont95tal rise ) gradi5ts ( #a3cej-a3abjj ext5ds to ! we/]n limit ( ! pr(iles4 ,9 pr(iles ,e-#ag & ,e-#ah ! cont95tal slope becomes g5tl]1 & only 9 ! upp] #ejj fa?oms ( ,e-#ah does ! gradi5t exce$ #a3be4 ,! upp] cont95tal rise is ab\t #fj miles wide ) dep?s pr$om9antly ab\t #afjj fa?oms1 & ! l[] cont95tal rise lies at ab\t #bajj fa?oms & is v smoo?4 ,illu/ration3 ,,figure #ai4--;,cont95tal-m>g9 prov9ces3 ,type pr(iles (f ,nor?we/ ,africa ,pr(iles ,e-#ai1 ,e-#bj1 & ,e-#ba cross ! cont95tal m>g9 (f ,dak> & ! ,cape ,v]de ,plateau :i* rises f ! l[] cont95tal rise4 ,! ,cape ,v]de ,plateau consi/s l>gely ( ! coalesc+ bases ( ! volcanic ,cape ,v]de ,isl&s4 ,! l[] cont95tal rise & ! abyssal pla9 rea* _! maximum wid? at ?is latitude4 ,! wid? ( ! ocean1 ! wid? ( ! ,mid-,atlantic ,ridge1 ! wid? ( ! abyssal hills1 & ! dep? at ! axis ( maximum dep? all rea* _! maximum values = ! ,nor? ,atlantic at ?is po9t4 ,! *>act]i/ics ( ! cont95tal rise 9 ?is sector are li/$ 9 ,table #b4 ,! reliability ( ^! figures is mu* poor] ?an ^? giv5 = nor!a/]n ,unit$ ,/ates1 ow+ to ! small] numb] ( pr(iles 9 ?is sector4 ,,table #b4--;,g5]al *>act]i/ics ( ! cont95tal rise nor?we/ ,africa ,sector ,values measur$ f ,pr(iles ,e-#aa to ,e-#ba ,dep? ,segm5t ,upp] edge ,l[] edge ,gradi5t ,wid? ,upp] cont95tal rise #a #abjj #bjj #aejj #bjj #a3ij #cj #cj #aj8 #b #aejj #bjj #afjj #bjj #a3bjj #ajj #cj #ae8 #c #afjj #bjj #ahjj #ajj #a3ajj #ej #be #ae8 ,l[] cont95tal rise #a #ahjj #ajj #bjjj #ajj #a3djj #bjj #ge #ej #b #bjjj #ajj #bjjj #ajj #a3aejj #ejj #aej #ej #c #bjjj #ajj #bgjj #ajj #a3ejj #bjj #bjj #ej ,abyssal pla9 #bgjj #ajj #cjjj #ge #a3abej #bej #bjj #ej ---------------------------------------- ---------------------------- ,a fam\s subm>9e canyon1 ! ,fosse de ,cay>1 lies j nor? ( ,cape ,v]de4 ,o!r subm>9e canyons are c]ta9ly pres5t 9 ! sector s9ce any pr(ile p>allel to ! /rike ( ! topography reveals l>ge irregul>ities probably relat$ to canyons4 ,e*ograms 7,pls4 #i1 #ac7 tak5 9 ! cont95tal rise 9 ?is sector %[ di/9ct contra/s 9 ! topographic detail ( ! sea floor4 ,! rugg$ topography ( ! abyssal hills 7,pl4 #i1 fig4 #d7 contra/s %>ply ) ! ne>ly flat1 extremely smoo? abyssal pla94 7,pl4 #i1 fig4 #c74 ,! cont95tal rise is n[h]e s smoo? nor s flat z ! abyssal pla94 ,! cont95tal rise ranges f #aj- to #bj-;fa?om roll+ hills #e-aj miles 9 wid? to #b- to #e-;fa?om hills a few hundr$ feet across 7,fig4 #ai74 ,at ! seaw>d edge ( ! abyssal pla9 ! e*o s\nd] p5etrates ! bottom to reveal int]faces #e-bj fa?oms bel[ 7,pl4 #ac1 ,fig4 #d74 ,sub-bottom p5etration ( #e-ae fa?oms is occasionally enc\nt]$ on ! cont95tal rise on local topographic highs4 ,l[] cont95tal-rise hills ( ! type obs]v$ (f ea/]n ,unit$ ,/ates h n be5 obs]v$ (f ,africa4 ,,b5*es ,,& ,,t]races ,,( ,,! ,,cont95tal ,,m>g9 ,! topography ( ! cont95tal m>g9 prov9ces is divid$ into a s]ies ( b5*es or t]races4 ,! l>ge/ are ! cont95tal %elf & slope 7cont95tal t]race7 & ! upp] & l[] cont95tal rise4 ,sup]impos$ on ea* ( ^! major features is a s]ies ( small] b5*es & t]races :i* range f features a few miles wide to simple breaks 9 ! gradi5t ( ! cont95tal slope4 ,_m ( ^! features c be trac$ = hundr$s ( miles 7,heez5 et al41 9 press72 "s are int]mitt5t1 o!rs *ange 9 dep? ) di/ance along ! %elf2 /ill o!rs are only locally develop$4 ,we c propose at lea/ f\r possible orig9s = t]races or b5*es3 7#a7 anci5t %ore features2 7#b7 /ructural 7or rock7 b5*+2 7#c7 block fault+2 & 7#d7 l&slide or slump sc>s4 ,! subm]g$ t]races )9 a few hundr$ feet bel[ pres5t sea level c probably be/ be expla9$ z anci5t bea*es =m$ dur+ ! l[] sea levels ( ! ,plei/oc5e4 ,! fact t ! same levels are f\nd along coa/s ( div]se geology & tectonic developm5t supports ! eu/atic orig9 ( t]races betwe5 sea level & #gj-ajj fa?oms4 ,! gradi5ts ( ! cont95tal %elf are s l[ & ! b5*es are s p]si/5t t block fault+ & slump sc>s are exclud$ z g5]al explanations4 ,! b5*es ( ! cont95tal slope ext5d to dep?s ( #aejj fa?oms & v>y 9 dep? f po9t to po9t along ! cont95tal slope4 ,^! _c be ,plei/oc5e eu/atic levels unless we consid] t !y 7 =m$ prior to rec5t l>ge cru/al de=mations4 ,aga9 ! p]si/5ce ( ! b5*es = _m miles argues aga9/ a fault-sc>p or slump-sc> hypo!sis4 ,?us1 :ile ! b5*es ( ! cont95tal %elf are probably anci5t bea*es1 p>ticul>ly ^? trac$ at ! same dep? = ?\s&s ( miles1 ! b5*es ( ! cont95tal slope are probably rock b5*es1 :ile "s may repres5t /ep fault+4 ,,subm]g$ ,,bea*es ,,on ,,! ,,cont95tal ,,%elf3 ,9 ,table #c ! dep?s ( t]races or p]si/5t levels ( ! cont95tal %elf are li/$ = select$ po9ts 9 ! ,nor? ,atlantic4 ,!re is a rem>kable uni=mity 9 ^! data2 ! same levels are f\nd ne> ,newf\ndl&1 9 ,florida1 & on oceanic isl&s f> f ! glaciat$ areas4 ,on ! basis ( data obta9$ 9 ! ,nor? ,atlantic x is n possible to date ! diff]5t t]races1 b probably mo/ 7 =m$ 9 ! p]iod betwe5 #ab1jjj & #e1jjj ye>s ,b4,p4 :5 ! sea rose 9 consequ5ce ( ! melt+ ( ! ,wiscons9 glaci]s4 ,cor+ & dr$g+ on ^! subm]g$ anci5t bea*es c\ld probably produce mat]ial datable by ! radioc>bon me?od4 ,,table #c4--;,dep? 79 fa?oms7 ( prom95t cont95tal-%elf t]races ,ea* column bas$ on only "o nonprecision e*ogram ,/4 ,*>les- ,b> ,/4 ,plac5tia,john's1,norfolk1ton1 ,bim9i1,miami1bados1,v9c5t1,dak>,dak> ,bay1 ,nfd4,nfd4 ,va4 ,s4 ,c4 ,b4,w4,i4 ,fla4 ,b4,w4,i4,c4,v4,i4 ,nor?,s\? #aj #ab #aj #h #aj #h #aj #ae #ae #ae #bj #ah #bj #bj #ah #bj #bj #be #bd #cj #cj #bh #cj #bh #bh #ce #ch #ce #ce #cb #dj #ch #ch #ch #db #de #db #de #db #de #ej #ej #ee #ee #eh #ef #ed #ee #ee #fh #fe #fh #fe #fj #gb #gf #gb #hj #hj #hj #hj #he #ha #hj #gh ---------------------------------------- ------------------------------------- ,,cont95tal ,,m>g9 ,,b5*es3 ,on ea* pr(ile across ! cont95tal m>g9 is a s]ies ( b5*es & *anges 9 gradi5t :i* range f ! %elf break to slight *anges 9 gradi5t on ! cont95tal slope4 ,if a field geologi/ ent]s a new area ( s$im5t>y rocks :]e road cuts d n exi/ he inv>iably goes to ! /ream valleys1 & "h he gets 8 fir/ & be/ view ( ! geologic section4 ,! /ream's gradi5t is adju/$ to ! resi/ance ( ! rocks ov] :i* x cuts1 & ! =m ( ! valley-side slopes reveals ! nature ( ! und]ly+ rocks ev5 if !y are grass$ ov]4 ,?is obvi\s field me?od _h nev] be5 fully appli$ to ! cont95tal m>g94 ,/etson 7#aicf7 dr$g$ 9 ! canyons ( ,georges ,bank1 & 8 hauls includ$ ,cretace\s s&/ones & ,t]ti>y m>ls & gre5 s&s4 ,he conclud$ t ! canyons _h be5 cut deep into ! cont95tal m>g9 to expose ! und]ly+ ,cretace\s rocks1 b he consid]$ ! cont95tal slope ! product ( depositional processes4 ,h[ev] ,upham 7#ahid7 _h sugge/$ t ! cont95tal slope =m$ a cont9u\s outcrop ( ,t]ti>y & ,cretace\s s$im5ts f ,newf\ndl& to ,florida1 a sugge/ion ! writ]s consid] q probable4 ,t is to say1 an analogy c be made betwe5 ! cont95tal slope & "o face ( ! ,gr& ,canyon or to an erosional esc>pm5t b\nd+ a high mesa or plateau l ! ,book ,cliffs ( ,utah & ,colorado4 ,only a few areas ( ! _w are suffici5tly well s\nd$ to provide data = a /udy ( /ructural b5*es4 ,"o _c expect to see id5tical /ructural b5*es 9 ea* pr(ile ev5 across a slope compos$ ( a lat]ally uni=m s]ies ( horizontal b$s ( contra/+ li?ologies4 ,! exact mode ( erosion1 ! local sy/em ( jo9t+1 & *ance v>iations 9 a numb] ( o!r v>iables make x necess>y to h a l>ge numb] ( closely spac$1 accurately locat$ pr(iles4 ,we are =tunate t ! ,coa/ & ,geodetic ,survey has survey$ virtually ! entire cont95tal slope f ,georges ,bank to ,norfolk1 ,virg9ia4 ,almo/ all ^! s\nd+ l9es are run at "r angles to ! /rike ( ! topography & are ?us suitable = analysis ( /ructural b5*es4 ,9 ?is same area ! dr$g+s ( ,/etson 7#aicf7 on ,georges ,bank & ! ,esso ,hatt]as ,light te/ provide u ) in=mation on ! /ratigraphy ( ! s$im5ts :i* =m ! cont95tal %elf & slope4 ,! seismic "w ( ,ew+ & collaborators 7#aicg et seq47 provides u ) fur!r in=mation on ! dips & on ! dep?s ( a numb] ( s$im5t>y rock s]ies ( contra/+ li?ology4 ,fi%]m5 began f9d+ fossilif]\s rocks on ,georges ,bank well ov] a c5tury ago4 ,!y 7 n p>ticul>ly pleas$ to obta9 rocks in/ead ( fi% & g5]ally ?rew ! accurs$ rocks back into ! sea4 ,"s curi\s fi%]m5 br\ght a few ( ! rocks to %ore1 h[ev]1 & 9 "t "s ( ^! 7 receiv$ by ! museums 7,upham1 #ahid2 ,dahl1 #aibe74 ,^! rocks conta9 ,t]ti>y & ,cretace\s fossils4 ,! dep?s & positions ( recov]y ( ! rocks 7 g5]ally unkn[n to ! museums1 & no cle> idea c\ld be ga9$ ( ! exact occurr5ce ( ?is mat]ial4 ,/etson 7#aicf2 #aidi7 conduct$ a s]ies ( sci5tific dr$g+ op]ations 9 ! ,georges ,bank area4 ,8 aim 0 to recov] m ( ^! old] rocks f kn[n dep? ranges & positions4 ,he conclud$ t ! old] rocks outcrop only 9 ! subm>9e canyons4 ,he f\nd no consi/5t dep? ranges = ! s]ies ( ,mioc5e & ,upp] ,cretace\s rocks obta9$4 ,illu/ration3 ,,figure #bj4--;,georges ,bank canyons ,*>t %[s position ( s\nd+ l9es & dr$ge hauls us$ to con/ruct project$ pr(ile & inf]r$ geologic section %[n 9 ,figure #ba 7a74 ,s\nd+ l9es f ,coa/ & ,geodetic ,survey ,*>t #acac4 ,9 ! ,georges ,bank area a s]ies ( prom95t b5*es cont9ues along ! cont95tal slope4 ,if ^! are /ructural b5*es we %\ld be able to trace !m up ! canyons & ?us det]m9e ! dip ( ! =mations4 ,if ! b5*es are ! result ( /ep fault+ or l&slide sc>s !y w\ld n ext5d up ! canyons4 ,9 ord] to te/ ^! alt]natives1 a s]ies ( pr(iles has be5 plott$ f ! surveys ( ! ,coa/ & ,geodetic ,survey4 ,a l9e 0 drawn :i* p>allel$ mo/ ( ! cont\rs ( ! cont95tal slope = #bj miles or m 7,fig4 #bj74 ,a second l9e 0 drawn at "r angles to ?is fir/ /rike l9e4 ,all s\nd+ l9es 9 ! area 7 project$ to ?is second dip l9e along l9es p>allel to ! /rike l9e1 & plott$ z a composite project$ pr(ile 7,fig4 #ba74 ,if ! fir/ l9e 0 ess5tially ! /rike ( rock lay]s !n we %\ld be able to det]m9e ! dip ( ! b$s by pick+ ! successive b5*es z !y occur on successive pr(iles across ! canyon4 ,9 ,figure #ba ! results ( ! analysis ( ,oceanograph] & ,hydrograph] canyons are pres5t$4 ,! dr$ge hauls by ,/etson 7#aidi7 h also be5 project$ on ?is pr(ile4 ,we see t a major b5* occurs at ,a :i* passes bel[ ! hauls 9 :i* fossilif]\s ,nav>ro 7,upp] ,cretace\s7 0 obta9$ & ?r\gh ! upp] limit ( ! hauls :]e ,matawan 7,upp] ,cretace\s7 0 obta9$4 ,?us if ?is horizon or "o closely p>allel to x is ! ,nav>ro-,matawan contract1 ! app>5t discrepancies ( ! dep? ranges ( ,/etson's dr$ge hauls are expla9$4 ,mu* m important to ! pres5t /udy is ! dat+ ( a prom95t /ructural b5*4 ,illu/ration3 ,,figure #ba4--,two project$ pr(iles ( ,georges ,bank canyons ,location ( s\nd+s = pr(ile 7a7 %[n 9 ,figure #bj4 ,s\nd+s project$ along /rike to con/ruct pr(ile4 ,s\nd+s = bo? pr(iles tak5 f ,coa/ & ,geodetic ,survey ,*>t #acac4 ,illu/ration3 ,,figure #bb4--;,geologic section at ,cape ,hatt]as1 ,virg9ia ,well logs f ,swa9 7#aidg7 & ,spangl] 7#aiej74 ,f\r s\nd+ pr(iles made by ,r4 ,v4 ,,atlantis are project$ to pr(ile4 ,note t resi/ant =mations =m prom95t /ructural b5*es on cont95tal slope4 ,! ,esso ,hatt]as ,light ,no4 #a te/ enc\nt]$ cry/all9e rock at #afdj fa?oms dep?1 b5ea? ,l[] ,cretace\s /rata 7,spangl]1 #aiej74 ,! sev]al holes drill$ 9 ! vic9ity reveal$ rem>kably con/ant dips ov] a wide area4 ,?is is 9 fact true ( ! :ole coa/al pla94 ,s9ce ! ,hatt]as well is only #ag miles f ! cont95tal slope1 x seems reasonable to project ! dips to ! cont95tal slope4 ,we c !n obs]ve :e!r prom95t b5*es on ! cont95tal slope correlate ) resi/ant /rata 9 ! well4 ,we f9d 7,fig4 #bb7 t !y d4 ,9 ! area betwe5 ,cape ,hatt]as & ,nova ,scotia sev]al cores h reveal$ rework$ ,eoc5e1 ,mioc5e1 & ,cretace\s ,=am9if]a4 ,9 #aidg ,nor?rop & ,heez5 7#aiea7 obta9$ a photograph & a core at #ejj fa?oms on ! cont95tal slope4 ,! core conta9$ ,eoc5e 7,jackson7 s$im5ts1 & ! photograph %[$ a rock l$ge bel[ ! m>l sampl$4 ,al?\gh s$im5t cores1 p>ticul>ly ^? ( rework$ mat]ial1 d n provide z reliable in=mation z dr$ge hauls1 ?is outcrop ( un-rework$ ,eoc5e may also be us$ 9 dat+ ! /ructural b5*es ( ! cont95tal slope4 ,! /ructural b5*es betwe5 ,cape ,hatt]as & ,cape ,may are rem>kably uni=m & p]si/5t 7,fig4 #bc74 ,on ! basis ( ! extrapolation %[n 9 ,figure #bb1 ! /ructural b5*es 9 ?is area h be5 correlat$ ) ! =mations enc\nt]$ 9 ! ,hatt]as well4 ,nor? ( ,cape ,may a major angul> uncon=mity sep>ates ! late ,t]ti>y & ,cretace\s =mations4 ,eoc5e has n be5 f\nd nor? ( ,nantucket4 ,upp] ,cretace\s has be5 f\nd at ab\t #djj fa?oms (f ,georges ,bank 7,fig4 #ba71 & ,l[] ,cretace\s has be5 dr$g$ at #bjj fa?oms (f ,banqu]eau ,bank1 ,nova ,scotia4 ,betwe5 #aide & #aiej work]s on ! ,,atlantis made sev]al s\nd+ pr(iles ea/ ( ,georgia1 ,nor? ,c>ol9a1 & ,s\? ,c>ol9a4 ,ea* cross$ ! precipit\s ,blake ,esc>pm5t4 ,x 0 q cle> t no s$im5t c\ld be accumulat+ on su* a /eep esc>pm5t & t b$s ( anci5t s$im5ts & p]haps cry/all9e rocks mu/ outcrop on ! esc>pm5t4 ,9 #aidi & #aiej a few cores 7 tak5 on ! esc>pm5t :i* enc\nt]$ ,mioc5e & ,eoc5e s$im5ts 9 dep?s ( #ejj-hjj fa?oms 7,ericson1 ,ew+1 & ,heez51 #aieb74 ,! m>k$ simil>ity ( all topographic pr(iles fur!r support$ ! view t ! esc>pm5t 0 =m$ by ! outcrop ( an ord]ly sequ5ce ( horizontal s$im5t>y rock lay]s4 ,) ?is specific problem 9 m9d a cruise 0 made to ! ,blake-,bahama area on ! rese>* vessel ,,atlantis1 9 #aiea4 ,m ?an #ej cores 7 obta9$4 ,s$im5ts ( ,rec5t to ,upp] ,cretace\s age 7 obta9$ on ! ,blake ,esc>pm5t & f ! /eep walls ( ! ,bahama ,*annels 7,ericson1 ,ew+1 & ,heez51 #aieb74 ,seismic-refraction "w by ,katz & ,ew+ 7#aiee7 & ,nafe et al4 7unpubli%$7 & reflection "w by ,ew+ & ,l&isman 7unpubli%$7 h reveal$ t di/9ct seismic int]faces c be trac$ into ! /ructural b5*es on ! ,blake ,esc>pm5t4 ,! anci5t s$im5ts f ! ,blake ,esc>pm5t & ! log ( ! ,&ros well all[ ! dat+ ( "s ( ^! =mation contacts4 ,at pres5t ! mo/ prom95t b5* at #abjj-aejj fa?oms appe>s to m>k ! base ( ! ,upp] ,cretace\s4 ,dr$g+ & fur!r cor+ on ! ,blake ,esc>pm5t bel[ #adjj fa?oms is "o ( ! mo/ promis+ projects ( its type despite ! great difficulties involv$4 ,illu/ration3 ,,figure #bc4--;,correlation ( /ructural b5*es (f nor!a/ ,unit$ ,/ates ,s\nd+s by ,coa/ & ,geodetic ,survey2 #ce #cj,n4-#ch #cj,n4 ,lee 7#aiea71 :o made a topographic /udy ( ,exuma ,s\nd1 ,bahamas1 trac$ sev]al prom95t b5*es ?r\gh #ea cross sections ( ! s\nd4 ,illu/ration3 ,,figure #bd4--;,geologic section3 ,we/]n ,europe bas$ on refraction measurem5ts ,data f ,day et al4 7#aief7 & ,hill 7#aieg74 ,geologic ages are ^? assign$ by ,day on ! basis ( velocity2 !y are n bas$ on dr$g+ or drill+4 ,seismic-refraction pr(iles h be5 made across ! cont95tal slope s\?we/ f ! ,engli% ,*annel4 ,^! /udies 7 initiat$ by ,bull>d & ,gaskell 7#aida7 & h be5 mo/ rec5tly report$ on by ,day et al4 7#aief74 ,! seismic section ( ,day et al4 7#aief7 7,fig4 #bd7 sugge/s t ! prom95t b5* at #afjj fa?oms & ! %ort b /eep sc>p j bel[ repres5t ! outcrop ( ! metamorphic basem5t on ! cont95tal slope4 ,x is po/ulat$ t ! prom95t b5* at #ijj fa?oms may repres5t ! base ( ! ,mesozoic1 & ! small] b5* at #cjj fa?oms ! base ( ! ,mioc5e4 ,t]ti>y s$im5ts h be5 obta9$ f ! walls ( canyons 9 ! ,bay ( ,biscay 9 dep?s d[n to ab\t #aejj fa?oms 7,b\rc>t & ,m>ie1 #aiea74 ,! age assignm5ts 9 ,figure #bd are tak5 directly f ,day et al4 7#aief7 & h n be5 confirm$ by dr$g+ on ! cont95tal slope4 ,! writ]s conclude t ! majority ( ! topographic b5*es ( ! cont95tal slope & o!r category ,,ii prov9ces are /ructural b5*es :i* reflect ! outcrop ( resi/ant rock lay]s4 ,?is ( c\rse implies t ! cont95tal slope is n a simple depositional feature b a /ructural or erosional "o4 ,s9ce ! /ructural b5*es are pres5t bo? 9 ! canyons & on ! un-dissect$ slope1 ! occurr5ce ( ,t]ti>y & ,cretace\s rocks on ! cont95tal slope _c be expla9$ by erosion ( subm>9e canyons into an o!rwise depositional t]race 9 ! mann] impli$ by ,/etson 7#aidi74 ,! exi/5ce ( su* p]si/5t b5*es implies t ! entire wid? ( ! category ,,ii prov9ces mu/ be at mo/ only ?9ly cov]$ by rec5t s$im5ts4 ,s9ce ! discov]y ( ! great importance ( turbidity curr5ts & ! relatively l[ slopes necess>y = _! occurr5ce1 x has be5 a great puzzle to ! writ]s h[ s$im5ts c\ld be p]man5tly deposit$ on ! pres5t cont95tal slope4 ,! answ] is simply t !y are n4 ,9 addition to ! turbidity curr5ts :i* provide a me*anism = ! seaw>d transport ( s$im5t d[n ! cont95tal m>g91 deep-ocean curr5ts probably sort & transport mu* s$im5t along a c\rse p>allel to ! cont95tal slope4 ,x has rec5tly be5 demon/rat$ 7,swall[ & ,wor?+ton1 #aieg7 t velocities ( #aj-bj cm_/sec are atta9$ by ocean curr5ts :i* fl[ p>allel to ! cont95tal slope4 ,! p>ticul> measurem5t ref]r$ to 0 made at #afjj fa?oms on ! cont95tal slope s\? ( ,cape ,hatt]as :]e a #ag cm_/sec s\?w>d-mov+ curr5t 0 obs]v$4 ,! /rong curr5t is n a local ph5om5on s9ce x 0 f\nd 9 ! ,s\? ,atlantic by ,w/ 7#aice7 & is pr$ict$ by !ories ( ocean circulation 7,/ommel1 #aieg74 ,photographs ( ripple m>ks on ! cont95tal slope 7,see = in/ance ,fig4 #ac 9 ,elm5dorf & ,heez51 #aieg7 _h indicat$ high velocities1 b x 0 n possible to di/+ui% betwe5 a curr5t & an oscillatory orig94 ,! total effect ( slides1 slumps1 turbidity curr5ts1 & /rong ocean-bottom curr5ts is ! removal ( mo/ ( ! unconsolidat$ ,rec5t s$im5ts f ! cont95tal slope4 ,! deposition ( a s]ies ( ,mesozoic & ,t]ti>y s$im5ts on ! subsid+ m>g9 ( ! cont95tal block has produc$ a w$ge ( s$im5t>y rock l>gely ( %all[ m>9e facies4 ,ea* successive /rata laid d[n on ! %elf 0 abruptly t]m9at$ at ! %elf break by ! processes ( erosion :i* cont9u\sly or p]iodically cle> ! unconsolidat$ s$im5t f ! cont95tal slope4 ,deposition on ! %elf 0 int]rupt$ by sev]al m>9e regressions :i* produc$ uncon=mities 9 ! /ratigraphic sequ5ce4 ,nafe & ,drake 7#aieg7 obs]v$ t ! increase ( seismic velocity ) dep? & !re=e ! increase 9 compaction ) dep? is m rapid on ! cont95tal %elf ?an 9 ! deep sea4 ,?is is probably 9 "p ! result ( erosion ( previ\sly deposit$ s$im5ts & s$im5t>y rocks along ! uncon=mities & 9 "p ! result ( gr\nd-wat] cem5tation dur+ p]iods ( em]g5ce4 ,ea* uncon=mity %\ld m>k a li?ologic *ange & consequ5tly a *ange 9 ! resi/ance to erosion ( ! rock s]ies4 ,_m /ructural b5*es may indicate surfaces ( uncon=mity4 ,! mo/ rec5t uncon=mity 9 ! sequ5ce lies betwe5 ! surface ( ! em]g$ ,wiscons9 cont95tal %elf & ! ov]ly+ po/-glacial %elf s$im5ts4 ,! %elf break is def9$ z ! mo/ prom95t break 9 slope betwe5 ! cont95tal %elf & cont95tal slope4 ,! mo/ prom95t break may locally be a ,plioc5e or ,mioc5e /ructural b5*1 b else:]e late ,plei/oc5e or ,rec5t /rata may =m ! %elf break4 ,rates ( subsid5ce1 erosion1 & s$im5t supply v>y f place to place along ! cont95tal %elf1 & ! lack ( con=mity ei!r 9 dep? or 9 age ( ! %elf break is ?us easily expla9$4 ,! deep] /ructure ( ! cont95tal m>g9 indicates a fundam5tal /ructural discont9uity at ! base ( ! cont95tal slope 7category ,,ii prov9ces74 ,x w\ld seem a small extrapolation to attribute a fault orig9 to ! cont95tal slope4 ,al?\gh fault+ may h play$ a l>ge "p 9 ! e>lie/ hi/ory ( ! category ,,ii prov9ces1 alt]nate p]iods ( s$im5tation & m>9e planation on ! cont95tal %elf & long-cont9u$ erosion by slumps1 turbidity curr5ts1 & deep-sea curr5ts on ! cont95tal slope1 toge!r ) a g5]al subsid5ce ( ! area1 c\ld h alone produc$ ! *>act]i/ic =m ( ! cont95tal t]race4 ,fur!r "w on /ructural b5*es co-ord9at$ ) a /udy ( anci5t s$im5ts f dr$ges & cores %\ld enable u to draw a geologic map ( ! cont95tal slope ( ea/]n ,unit$ ,/ates & ,europe 7,heez5 et al41 9 prep>ation74 ,,geology ,,& ,,geophysics ,,( ,,cont95tal ,,m>g9 ,,physiographic ,,prov9ces ,seismicity ( ! cont95tal-m>g9 prov9ces4--,plate #bi %[s ! di/ribution ( epic5t]s 9 ! ,nor? ,atlantic4 ,except 9 ! ,pu]to ,rico ,tr5* & ! adjac5t ,antilles ,arc1 e>?quakes are exce$+ly r>e 9 ! cont95tal-m>g9 prov9ces ( ! ,nor? ,atlantic4 ,f ! ,bahamas ?r\gh ! ,gr& ,banks ! only e>?quakes report$ s9ce #aiaj are two ne> ! ,laur5tian ,*annel4 ,9 ! ea/]n ,atlantic an e>?quake belt crosses ! cont95tal m>g9 ne> ,gibralt> b does n seem to be directly associat$ ) ! ,atlantic cont95tal m>g9s4 ,if ! cont95tal slope 9 ! area cov]$ by ,plate #bi is a fault sc>p1 we mu/ inf] t ! motion has n[ be5 arre/$4 99 99 99 99 99 ,magnetic anomalies & cont95tal-m>g9 prov9ces4--,! fir/ cont9u\sly record$ total-int5sity magnetic data = ! ,atlantic 7 obta9$ 9 #aidf on a flight f ,long ,isl&1 ,new ,york1 to ,b]muda1 & return 7,kell] et al41 #aied74 ,! fir/ data f a %ip-t[$ magnetomet] 7 obta9$ 9 #aidh 7,heez51 ,ew+1 & ,mill]1 #aiec74 ,! initial measurem5ts %[$ 7#a7 sev]al l>ge 7 #cjj7 anomalies on ! cont95tal %elf1 7#b7 a l>ge 7 #ejj7 anomaly ov] ! cont95tal slope1 7#c7 an exceptionally smoo? field ov] ! category ,,iii prov9ces1 7#d7 r\gh fields ) #e- to #ae-mile wide #ajj to #bjj anomalies ov] oceanic ridges & rises1 7#e7 enorm\s anomalies 7 #ajjj7 ov] seam\nts & isl&s1 & 7#f7 l>ge anomalies 7 #ejj7 ov] ! cre/ ( ! ,mid-,atlantic ,ridge4 ,! l>ge anomalies on ! cont95tal %elf 7 consid]$ to indicate l>ge volcanic cones buri$ by ! s$im5ts ( ! cont95tal %elf 7,mill] & ,ew+1 #aief74 ,! anomaly ov] ! cont95tal slope 0 consid]$ to be ! magnetic-edge effect associat$ ) ! abrupt edge ( ! cont95tal block4 ,! r\gh fields ov] ! oceanic rises & ridges 7 attribut$ to v>iations 9 ! susceptibility ( ! cru/al rocks1 probably relat$ to volcanic extrusions & intrusions4 ,! anomaly ov] ! cre/ ( ! ,mid-,atlantic ,ridge 0 n recogniz$ z a g5]al patt]n until lat] :5 _m measurem5ts 7 made4 ,! major puzzle = :i* no explanation 0 readily obta9$ 0 ! orig9 ( ! smoo? field ov] ! cont95tal rise4 ,! smoo? or quiet field has be5 obs]v$ on ea* cross+ ( ! category ,,iii prov9ces1 & ev5 su* a %>p-sid$ feature z ! ,pu]to ,rico ,tr5* fail$ to %[ a magnetic anomaly 7,davidson & ,mill]1 #aief74 ,we c ?us /ate t all category ,,iii prov9ces are *>act]iz$ by a smoo? magnetic field4 ,! significance ( ?is po9t is n yet cle>1 b x mu/ be ( major importance to ! full und]/&+ ( ! cont95tal m>g94 ,cru/al /ructure & cont95tal-m>g9 prov9ces4--,maurice ,ew+ & 8 associates h made m ?an #ajjj seismic-refraction measurem5ts to det]m9e ! cru/al /ructure ( cont95tal m>g9s4 ,mo/ ( ! publi%$ results p]ta9 to ! ea/]n cont95tal m>g9 ( ! ,unit$ ,/ates 7,drake et al41 9 press71 b mu* mat]ial w soon be publi%$ on ! cont95tal m>g9 ( ,sah>a1 ,si]ra ,leone1 ,brazil1 ,arg5t9a1 ,guiana1 ,spa91 ,morocco1 ! ,gulf ( ,mexico1 & ! ,c>ibbean ,sea4 ,9 addition ext5sive "w has be5 accompli%$ by ,bull>d1 ,gaskell1 & ,hill 9 ! we/]n approa*es to ! ,engli% ,*annel4 ,9 "s areas seismic1 gravity1 & magnetic measurem5ts 7 made along ! same l9es & h be5 subject$ to an integrat$ analysis 7,worzel & ,%urbet1 #aiee;c74 ,9 ,plate #bf f\r pr(iles replott$ f publi%$ sections are %[n4 ,ea* pr(ile is plott$ at #dj3a exagg]ation1 & dep?s are indicat$ 9 fa?oms & kilomet]s to facilitate comp>ison ) ! pr(iles & topographic descriptions giv5 else:]e 9 ?is pap]4 ,"s /ations :i* lie up to #ajj miles f a pr(ile h be5 project$ along ! /rike ( ! topography4 ,9 g5]al ea* pr(ile indicates 7#a7 a ?ick l5s ( s$im5t & s$im5t>y rock b5ea? ! cont95tal rise2 7#b7 a major discont9uity 9 cru/al /ructure at ! base ( ! cont95tal slope2 & 7#c7 a w$ge ( l[-velocity s$im5t>y rocks 7unconsolidat$7 ov]ly+ a l5s ( high]-velocity 7semi-consolidat$ & consolidat$7 s$im5t>y rocks b5ea? ! cont95tal %elf4 ,! bas91 fill$ ) high]-velocity s$im5t>y rocks1 is =m$ by an upturn$ lip ( cry/all9e basem5t rocks ne> ! cont95tal slope4 ,local v>iations 9 ?ickness & velocity give rise to int]e/+ m9or configurations1 b ! basic /ructure is ne>ly id5tical 9 all ! sections4 ,! ma9 contra/ is t ! category ,,iii prov9ces are und]la9 by ?ick s$im5t>y rocks 9 ! case ( ! cont95tal rise1 & successively ?9n] accumulations ( s$im5t>y rock are associat$ ) ! m>g9al bas9s & m>g9al tr5*es4 ,s9ce ! ma9 diff]5ce 9 ! cont95tal-m>g9 sections seems to be a greatly enhanc$ cont95tal-rise s$im5t>y section to ! nor? z comp>$ ) ! ,blake ,plateau--,bahama--,pu]to ,rico region1 x seems reasonable to conclude t ! ma9 diff]5ce 9 ! topography is ! result ( diff]5t s$im5tation rates or a diff]5t "t ( orig91 r ?an ( a va/ly diff]5t /ructural orig94 ,! s$im5t>y rock column b5ea? ! cont95tal rise is truly geosyncl9al 9 ?ickness4 ,:e!r ?is great l5s ( s$im5t & s$im5t>y rock w ev5tually be de=m$ into a m\nta9 range to =m a new addition to ! cont95t z advocat$ by ! accretion s*ool or :e!r x w lie =ev] on ! sea floor is "o ( ! great speculations ( geology4 99 99 99 99 99 ,s$im5t di/ribution & physiographic prov9ces ( ! cont95tal m>g94 ,! rec5t s$im5ts ( ! category ,i prov9ces are l>gely s&s1 silts1 silty lutites1 & c>bonates 7,/etson1 #aich2 ,%ep>d & ,cohee1 #aicf2 ,newell1 #aiee74 ,all ^! s$im5ts c be assign$ to ! or?oqu>tzite suite ( ,pettijohn 7#aieg74 ,judg+ f ! anci5t s$im5ts dr$g$ f ! cont95tal slope & obta9$ by drill+1 ! category ,i prov9ces h be5 receiv+ or?oqu>tzite s$im5ts at lea/ s9ce ! ,cretace\s4 ,9 category ,,ii prov9ces ,rec5t s$im5ts are ei!r lack+ or are v ?94 ,^? ,rec5t s$im5ts :i* tempor>ily rema9 9 ! prov9ce range f =am9if]al lutites1 f\nd 9 su* areas z ! ,bahamas1 to silty lutites relatively poor 9 pelagic fossils1 f\nd 9 ! high] latitudes4 ,9 g5]al category ,,ii prov9ces are *>act]iz$ by nondeposition or erosion4 ,! s$im5ts ( ! category ,,iii prov9ces include bo? pelagic & cla/ic t]rig5\s s$im5ts4 ,! out] ridge is cov]$ by ,globig]9a ooze 9 dep?s %all[] ?an ab\t #bbjj fa?oms & by r$ clay 9 deep] areas4 ,! cont95tal rise is g5]ally cov]$ by silty =am9if]al lutites1 b1 :]e subm>9e canyon deltas spread out f ! m\?s ( subm>9e canyons 7,ericson et al41 #aiea1 #aieb71 b$s ( grad$ s& & silts f a few c5timet]s to a few met]s 9 ?ickness are int]b$d$ ) lutites4 ,9 ! m>g9al tr5*es & m>g9al bas9s grad$ calc>e\s s&s alt]nate ) l[-c>bonate lutites4 ,! category ,,iii prov9ces ( nor?we/ ,africa are dom9at$ by two gr\ps ( volcanic isl&s & seam\nts :i* contribute fl[s & volcanic detritus to ! cont95tal-rise s$im5ts4 ,9 g5]al ! category ,,iii prov9ces are dom9at$ by s$im5ts ascribable to ! graywacke suite ( ,pettijohn 7#aieg74 99 99 99 99 99 ,pa/1 pres5t1 & future ( cont95tal-m>g9 physiographic prov9ces4--,x takes only a little imag9ation to see a hi/orical or g5etic sequ5ce 9 ! f\r pr(iles ( ,plate #bf4 ,! ,pu]to ,rico ,tr5*--out]-ridge pr(iles ?us may repres5t a cont95tal m>g9 9 y\?1 ! ,blake--,bahama--out]-ridge pr(ile a m>g9 9 late y\? or e>ly maturity1 & ,newf\ndl& & nor!a/ ,unit$ ,/ates pr(iles a m>g9 9 late maturity or old age4 ,! l5s ( s$im5ts t has fill$ ! m>g9al tr5* (f nor!a/]n ,unit$ ,/ates is truly geosyncl9al 9 ?ickness 7,drake et al41 9 press74 ,! s$im5ts ( ! %elf l5s are simil> 9 li?ology to ! or?oqu>tzite suite ( a mio-geosyncl9e 7cf4 ,kay1 #aiea71 & ! ?ick] cont95tal-rise l5s is probably simil> 9 li?ology to ! graywacke-volcanic suite ( a eugeosyncl9e4 7,kay1 #aiea74 ,x seems virtually c]ta9 t anci5t or?ogeosyncl9es 71 be=e de=mation1 closely analog\s to ! cont95tal m>g9s4 ,! major problem is complet+ ! sequ5ce f fill$ geosyncl9e to fold$ m\nta9s is ! me*anism by :i* ! e>?'s cru/ b5ea? ! geosyncl9e ?ick5s by #bj-cj km4 ,al?\gh we _c pr$ict ! future ( ! pres5t cont95tal m>g9 ) any assurance until ! me*anism ( ?ick5+ is und]/ood1 x seems probable t be=e de=mation ! old] or?ogeosyncl9es 7 simil> 9 mo/ details to ! mod]n cont95tal m>g9s4 ,x seems possible t ! pres5t cont95tal m>g9s w 9 "s future geological p]iod be uplift$ into fold$ m\nta9s4 ,,ocean-,,bas9 ,,floor ,,g5]al ,,description ,! second ( ! ?ree basic topographic divisions ( ! oceanic depression is ! ocean-bas9 floor4 ,includ$ 9 ?is division are ^? prov9ces ( ! oceanic depression t are n includ$ 9 ! cont95tal m>g9 or ! mid-oceanic ridge4 ,! ocean-bas9 floor is divid$ into ?ree categories3 7#a7 abyssal floor1 7#b7 oceanic rises1 & 7#c7 seam\nts & seam\nt gr\ps4 ,! fir/ category includes two types ( prov9ces1 abyssal pla9s & abyssal hills1 :i* occupy ! deepe/ portion ( ! ocean-bas9 floor4 ,includ$ 9 ^! prov9ces are su* features z abyssal gaps & mid-ocean canyons4 ,! second category includes ! l>g] positive features ( ! ocean-bas9 floor1 & ! l>ge seam\nts & seam\nt gr\ps fall 9 ! ?ird category4 ,! l&w>d limit ( ! ocean-bas9 floor is ! #a3ajjj gradi5t isople? along ! cont95tal m>g94 ,along ! mid-oceanic ridge ! b\nd>y is tak5 z t sc>p or sc>p zone :]e ! av]age level rises appreciably above ! axis ( maximum dep? ( ! bas9 floor4 ,broad elevations :i* rise above ! bas9 floor z isolat$ rises are t]m$ oceanic rises & are includ$ 9 ?is discussion ev5 ?\gh !y may be /ructurally m closely relat$ to ! mid-oceanic ridge or ! cont95tal m>g94 ,,abyssal ,,pla9s ,g5]al discussion4--,an abyssal pla9 has be5 def9$ 7,heez51 ,ew+1 & ,ericson1 #aied7 z an area ( ! deep-ocean floor 9 :i* ! ocean bottom is flat & ! slope ( ! bottom is less ?an #a3ajjj4 ,abyssal pla9s h be5 f\nd 9 all oceans1 *>act]i/ically at ! foot ( ! cont95tal rise4 ,koczy 7#aied2 #aief7 & ,gaskell & ,a%ton 7#aied7 h describ$ ! abyssal pla9 s\? ( ! ,bay ( ,b5gal4 ,koczy 7#aief7 has describ$ pla9s 9 ! equatorial ,atlantic on ei!r side ( ! ,mid-,atlantic ,ridge4 ,on ,exp$ition ,deep ,freeze work]s on ! ,,uss ,,glaci]1 us+ a ,,pdr1 discov]$ an abyssal pla9 9 ! ,w$dell ,sea4 ,work]s on ! ,r4 ,v4 ,,vema 9 #aieg confirm$ ! exi/5ce ( abyssal pla9s 9 ! ,arg5t9e & 9 ! ,cape & ,angola bas9s ( ! ,s\? ,atlantic4 ,m5>d 7#aiee7 has describ$ abyssal pla9s (f ! ,cali=nia & ,alaska coa/s4 ,abyssal pla9s are really important & are pres5t (f all coa/s except ^? hav+ a long1 cont9u\s1 unfill$ m>g9al tr5*4 ,! abyssal pla9s %[n on ! physiographic diagram h be5 nam$ 9 ord] to facilitate ref]5c+4 ,! abyssal pla9s ( ! we/]n ,atlantic betwe5 ,newf\ndl& & ! ,we/ ,indies are be/ kn[n4 ,! abyssal pla9 s\? ( ,newf\ndl& 7,heez5 et al41 #aied7 has be5 nam$ ! ,sohm ,abyssal ,pla9 foll[+ ! usage ( ,murray 7#aiab7 :o ref]r$ to ?is area z ,sohm ,deep 9 sev]al publications4 ,! abyssal pla9 s\? ( ! ,b]muda ,rise ref]r$ to z ! abyssal pla9 9 ! ,n>es ,bas9 7,heez51 ,ew+1 & ,m5zies1 #aiee2 ,lusk9 et al41 #aied7 is nam$ on ! prov9ce *>t 7,pl4 #bj7 ! ,n>es ,abyssal ,pla91 also foll[+ ! usage ( ,murray 7#aiab71 :o nam$ ?is area ! ,n>es ,deep4 ,! abyssal pla9 s\?we/ ( ! ,b]muda ,rise 0 includ$ 9 ! ,n>es ,abyssal ,pla9 until ! discov]y 9 #aiee t ! two p>ts 7 sep>at$ by a /eep abyssal gap at #bd ,n4 #fh ,w4 necessitat$ ! splitt+ (f ( ?is pla9 f ! ,n>es ,abyssal ,pla94 ,! "n ,hatt]as ,abyssal ,pla9 us$ on ! map 0 sugge/$ by ! close proximity ( ! v prom95t ,cape ,hatt]as4 ,an abyssal pla9 is probably pres5t 9 ! ,newf\ndl& bas91 b no ,,pdr s\nd+s h be5 obta9$ 9 t area4 ,! "n ,newf\ndl& ,abyssal ,pla9 is sugge/$ subject to confirmation by a precision survey4 ,! out] ridge :i* runs s\? f ,cape ,hatt]as p>allel+ ! coa/ l9es ( ! ,bahamas encloses ! ,blake-,bahama ,bas9 7,ericson1 ,ew+1 & ,heez51 #aieb72 a n>r[ abyssal pla9 is f\nd along its we/]n m>g94 ,?is pla9 is nam$ ! ,blake-,bahama ,abyssal ,pla94 ,betwe5 ! ,great] ,antilles & ! ,bahama ,banks is a depression call$ ! ,old ,bahama ,*annel 9 ! nor?2 f>!r s\? x is kn[n z ! ,hispaniola-,caicos ,*annel4 ,! ,hispaniola-,caicos ,*annel 9 p>ticul> conta9s an abyssal pla9 :i*1 al?\gh mu* small] ?an ! l>ge1 deep-sea abyssal pla9s1 has all ! *>act]i/ics ( slope flatness & s$im5t composition4 ,?is is call$ ! ,hispaniola-,caicos ,abyssal ,pla94 ,! smalle/1 yet p]haps ! mo/ /rik+1 ,atlantic abyssal pla9s are ^? at ! bottom ( ! ,pu]to ,rico ,tr5* at dep?s ( ab\t #dceh fa?oms 7#dehe correct$74 ,!y exhibit ! prop] degree ( flatness1 l[ gradi5t 7,ew+ & ,heez51 #aiee71 & ! %all[-wat] cla/ic s$im5ts typical ( abyssal pla9s4 ,s\? ( ,cuba 9 ! s\?we/ corn] ( ! diagram lies a major deep-sea tr5*4 ,only ! ea/]n end ( ?is ,cayman ,tr5* is %[n 9 ! diagram4 ,on ! floor ( ?is /eep-wall$ tr5* lies a n>r[ tr5* pla9 or sy/em ( semi-connect$ tr5* pla9s :i* lie at dep?s ( ab\t #cjjj fa?oms s\? ( ,guantanamo1 ,cuba1 b deep5 to #cfib fa?oms s\? ( ! ,cayman ,isl&s4 ,^! are kn[n z ! ,cayman ,tr5* ,pla9s4 ,?is area w be describ$ 9 m detail 9 a lat] publication devot$ to ! topography ( ! ,c>ibbean4 ,9 ! ea/]n ,atlantic ea* abyssal pla9 has be5 cross$ at lea/ ?ree times by %ips employ+ a ,,pdr1 a cov]age :i*1 al?\gh suffici5t to e/abli% _! exi/5ce1 is va/ly inf]ior to ! cov]age ( ! we/]n ,atlantic abyssal pla9s4 ,! ,biscay ,abyssal ,pla9 occupies a l>ge portion ( ! ,bay ( ,biscay4 ,x is connect$ by an abyssal gap at #dc #cj,n41 #ab #jj,w41 to ! ,ib]ia ,abyssal ,pla9 :i* lies we/ ( ! nor!rn two-?irds ( ! ,ib]ian ,p59sula4 ,a small abyssal pla9 we/ ( ! ,tagus ,riv] takes its "n f ?is riv]4 ,! great abyssal pla9 :i* skirts ,madeira on ! ea/ & s\? & ext5ds ov] a va/ area to ! we/ is ref]r$ to z ! ,madeira ,abyssal ,pla94 ,! ,can>y ,isl&s & associat$ banks =m ! b\nd>ies ( a small oval depression kn[n z ! ,can>y ,abyssal ,pla94 ,! va/ abyssal pla9 :i* skirts ! ,african cont95t we/ ( ,cape ,v]de is nam$ ! ,cape ,v]de ,abyssal ,pla94 ,! ea/]n m>g9 ( ! map j rea*es ! abyssal pla9 9 ! we/]n ,m$it]ranean :i* ,heez5 & ,ew+ 7#aiee7 h nam$ ! ,bale>ic ,abyssal ,pla94 ,abyssal pla9s 7 n discov]$ until ! use ( cont9u\sly record+ e*o s\nd]s 0 ext5d$ to abyssal dep?s foll[+ ,_w ,w> ,,ii 7,tol/oy & ,ew+1 #aidi74 ,:ile ! e>ly nonprecision e*o s\nd]s 7 sometimes adequate to di/+ui% ! limits ( p>ticul> pla9s1 real advances 9 _! /udy requir$ ! developm5t ( precision s\nd]s & ! ext5sive use !re( 7,heez51 ,ew+1 & ,ericson1 #aied74 ,s9ce ! v exi/5ce ( abyssal pla9s has be5 kn[n = less ?an #aj ye>s & only rec5tly h any ( !m be5 adequately del9eat$1 ! problem ( _! nom5clature has nev] be=e aris54 ,9 ! cases ( ! ,n>es & ,sohm abyssal pla9s we h tak5 ! "n ,murray has giv5 to ! deeps 9 :i* ! pla9s occur4 ,= ,cape ,v]de1 ,ib]ia1 & ,newf\ndl& abyssal pla9s we h foll[$ ! "n ,w/ 7#aidj;b7 propos$ = ! bas9 )9 :i* ! pla9s lie4 ,! ,biscay1 ,tagus1 ,hatt]as1 ,blake-,bahama1 ,hispaniola-,caicos1 & ,bale>ic h be5 giv5 ! "n ( a prom95t ne>-by l& area1 9 accordance ) recogniz$ practice4 ,! ,horse%oe ,abyssal ,pla9 takes its "n f ! horse%oe-%ap$ l9e ( seam\nts :i* surr\nds x except on ! ea/]n side4 99 99 99 99 99 ,regional description4--,! relief ( ! abyssal pla9s is s l[ t ord9>y small-scale exagg]at$ pr(iles 7,pls4 #bb1 #bg7 reveal no?+ ( its detail$ "*4 ,9 a few areas exceptionally good ,,pdr records h be5 obta9$ :i* %[ relief ( a few feet 7,pl4 #ab74 ,,sohm ,,abyssal ,,pla93 ,! be/-/udi$ abyssal pla9 is ! ,sohm ,abyssal ,pla9 s\? ( ,newf\ndl&4 ,9 addition to ! #aiec ,,vema ,,pdr survey 7,heez5 et al41 #aied7 ! area 0 /udi$ ext5sively 9 #aiee & cross$ by ! trans-,atlantic cruises ( #aied & #aief4 ,! pla9 is ,t-%ap$ & g5]ally ab\t #bjj miles wide2 dep?s range f #bgjj to #cjjj fa?oms 7uncorrect$74 ,! dep? increases 9 ea* arm ( ! ,t t[>d ! /em :]e ! slope *anges to s\?4 ,! greate/ dep? is f\nd at ! s\? b\nd>y ( ! pla9 ne> #bi ,n4 ,9 ! nor!rn "p ( ! pla9 small topographic irregul>ities are unkn[n1 b t[>d ! s\? peaks #ej to #ejj fa?oms high increase 9 numb] until !y f9ally replace ! pla94 ,nor? ( ! ,b]muda ,rise ! pla9 surr\nds a l9e ( huge seam\nts4 ,h[ev]1 ev5 "h no small hills are f\nd4 ,9 ! /rip ext5d+ betwe5 #cj & #cg ,n41 ! ea/ & we/ b\nd>ies ( ! pla9 are =m$ by sc>ps #bjj to #hjj fa?oms high4 ,! b\nd>y on ! nor? side ( ! ,b]muda ,rise is =m$ by a di/9ct %all[+1 b no sc>p is se54 ,!re is "s ju/ification = sep>at+ ! nor?we/ arm ( ! ,sohm ,abyssal ,pla9 nor? ( ! ,b]muda ,rise f ! re/ ( ! ,sohm ,abyssal ,pla9 s9ce a mid-ocean canyon runs f ! nor?we/ to ! c5tral sections ( ! pla94 ,a sill might lie nor!a/ ( ! nor!a/ tip ( ! ,b]muda ,rise4 ,"h ! bottom gradi5t *anges slightly1 & an extremely l>ge magnetic anomaly is associat$ ) ! region4 ,h[ev]1 ! pla9 n>r[s only slightly at ?is po9t1 &1 s9ce we _c tell h[ _m individual bas9s 7 fill$ to =m an abyssal pla91 we w consid] t ! ,sohm ,pla9 n[ includes ! :ole area1 keep+ 9 m9d t ! nor?we/ arm may h only rec5tly m]g$ ) ! re/4 ,s\? ( ,newf\ndl& ! cont95tal rise m]ges ) ! abyssal pla9 ) no sc>p or l9e ( hills4 ,"h ! b\nd>y is tak5 at ! po9t :]e ! gradi5t is g5tl] ?an #a3ajjj4 ,?is is n an entirely arbitr>y def9ition s9ce an appreciable *ange 9 gradi5t g5]ally occurs ne> ?is po9t4 ,s\? ( ! b\nd>y ! gradi5t gradually decreases to #a3cjjj at #cg ,n41 beyond :i* x decreases ev5 m gradually & rea*es #a3ejjj at ! s\!rn edge ( ! pla94 ,,hatt]as ,,abyssal ,,pla93 ,nor!a/ ( ! ,b]muda ,rise on a l9e betwe5 ,long ,isl& 7,n4 ,y47 & ,b]muda a small area ( abyssal hills lies betwe5 ! cont95tal rise on ! nor?we/1 ! ,b]muda ,rise on ! s\!a/1 ! ,sohm ,abyssal ,pla9 on ! nor!a/1 & ! ,hatt]as ,abyssal ,pla9 on ! s\?we/4 ,al?\gh ?is area has be5 trav]s$ by m tracks ?an any area ( simil> size 9 ! ,atlantic1 ! relation%ips "h are /ill some:at obscure4 ,?is area ( "s #fjjj squ>e miles is "o ( irregul> relief1 b x is n kn[n if x is ( ! "* ( an irregul> sill or a complex abyssal gap1 al?\gh ! latt] seems m probable4 ,! nor?we/ m>g9 ( ! ,hatt]as ,abyssal ,pla9 is abruptly =m$ by ! l[] cont95tal rise hills4 ,! ea/]n b\nd>y is g5]ally di/9ct & 9 places is =m$ by a #ej- or #ajj-;fa?om sc>p1 b g5]ally x is n s impressive z ! ea/ & we/ b\nd>ies ( ! ,sohm ,abyssal ,pla94 ,s\? ( ab\t #cd ,n41 ! we/]n b\nd>y ( ! ,hatt]as ,abyssal ,pla9 is =m$ by ! out] ridge4 ,9 "s sectors ! ea/]n flank ( ! out] ridge is r g5tle1 & ! abyssal pla9 g5tly laps ! ridge )\t a %>p break4 ,?is b\nd>y is g5]ally %>p nor? ( #bg ,n4 b to ! s\? is less def9ite4 ,! ,hatt]as ,pla9 slopes s\!a/ to ab\t #ca ,n4 :]e ! direction ( slope *anges to s\?4 ,a gradi5t ( ab\t #a3cjjj & dep?s ( ab\t #bijj fa?oms are rea*$ at #be ,n4 ,)9 ab\t #fj miles ( ,vema ,gap ! pla9 is brok5 by num]\s mid-ocean canyons :i* conv]ge on ! gap 7,pl4 #ad1 fig4 #c74 ,! ,hatt]as ,abyssal ,pla9 has no kn[n seam\nts or sea knolls1 9 contra/ to ! ,sohm ,abyssal ,pla9 & ,n>es ,abyssal ,pla94 ,! s$im5ts ( ! ,hatt]as ,abyssal ,pla9 resemble ! nor!rn abyssal pla9s 9 hav+ _m b$s ( qu>tz silts 7,pl4 #bh7 & contra/ %>ply ) ! ,blake-,bahama ,abyssal ,pla9 :]e calc>e\s s&s are abundant4 ,on ! we/ ! out] ridge =ms a cont9u\s b>ri] to turbidity-curr5t s$im5ts com+ f ! ne>-by ,bahamas s t ! only s\rce ( turbidity-curr5t s$im5ts is f ! ,cape ,hatt]as region to ! nor? or possibly f ! ,hudson ,canyon via ! suspect$ abyssal gap m5tion$ above4 ,! type ( s$im5t is entirely consi/5t ) ! gradi5t ( ! pla9 :i* slopes s\?w>d f ! ,hatt]as region4 ,illu/ration3 ,heez5 et al41 ,,pl4 #ad ,,figure #a4 ,,sub-,,bottom ,,e*oes ,,on ,,record ,,f ,,s\!rn ,,b]muda ,,rise ,,figure #b4 ,,mid-,,ocean ,,canyon ,,no4 #b ,,figure #c4 ,,mid-,,ocean ,,canyon ,,9 ,,hatt]as ,,abyssal ,,pla91 ,,we/ ,,( ,,vema ,,gap ,,pdr ,,records ,,( ,,mid-,,ocean ,,canyon ,,no4 #b ,,& ,,canyons ,,at ,,vema ,,gap ,dep? 9 fa?oms4 ,illu/ration3 ,heez5 et al41 ,,pl4 #ae ,area ( ea* photograph is ab\t #f by #h feet4 ,,plate #ae4--,,ocean-,,bottom ,,photographs ,,( ,,seam\nts ,,figure #a4 7,/ation ,v#d-ab1 photo #af7 ,dep? #gjj fa?oms1 location #ce #ab,n41 #ae #ah,w41 on seam\nt ( ! ,horse%oe ,gr\p4 ,note biocla/ic debris lodg$ 9 depressions on ! rocky bottom4 ,photographs %[n 9 ,figures #a1 #b1 & #c are no m ?an a few hundr$ feet ap>t4 ,,figure #b4 7,/ation ,v#d-ab1 photo #aj7 ,dep? #gjj fa?oms1 location #ce #ab,n41 #ae #ah,w4 ,rippl$ s&y bottom4 ,,figure #c4 7,/ation ,v#d-ab1 photo #g7 ,dep? #gaj fa?oms1 location same z ,figures #a & #b4 ,note curr5t ripple m>ks4 ,! photograph indicates an appreciable curr5t f left to "r4 ,,figure #d4 7,/ation ,v#d-af1 photo #ai7 ,dep? #aajj fa?oms1 location #ce #jg,n41 #ac #jd,w41 on ! side ( ,amp]e ,seam\nt4 ,note w9n[ r[ ( d>k & light gravel-siz$ detritus :i* resembles simil> mat]ial on ! ,rift ,m\nta9s %[n 9 ,figure #a ( ,plate #ai4 ,,figure #e4 7,/ation ,v#d-ah1 photo #bf7 ,dep? #ge fa?oms1 location #ce #aj,n41 #ab #ee,w41 ne> ! top ( ,amp]e ,seam\nt4 ,,figure #f4 7,/ation ,v#d-ad1 photo #dg7 ,dep? #aajj fa?oms1 location #ce #ab,n41 #ae #bb,w4 on same seam\nt z ,figures #a-c4 ,bottom appe>s to consi/ ( light-color$ s$im5t ?9ly veil$ by d>k co>s] s$im5t4 ,! :ite polka dots appe> to repres5t piles ( ! und]ly+ light s$im5t br\ght to ! surface by burr[]s4 ,positions ( /ations %[n on ,,plate #cj ,,blake-,,bahama ,,abyssal ,,pla93 ,! ,blake-,bahama ,bas9 is a long n>r[ bas9 betwe5 ! great ,blake ,esc>pm5t & calc>e\s ,bahama ,isl& banks on ! we/ & ! out] ridge on ! ea/4 ,a n>r[ abyssal pla9 #bj to #gj miles wide spreads out f ! base ( ! esc>pm5t 7,pl4 #e1 fig4 #c74 ,! pla9 is %all[e/ & wide/ j ea/ ( ! ,nor!a/ ,provid5ce ,*annel & deep5s & n>r[s t[>d its nor!rn & s\!rn ends4 ,s$im5t cores tak5 #fj miles (f ! m\? ( ,nor!a/ ,provid5ce ,*annel conta9$ grad$ b$s ( calc>e\s s& a few met]s ?ick 7,ericson et al41 #aieb74 ,! mat]ial 0 obvi\sly d]iv$ f ! ,bahamas1 presumably ?r\gh ! action ( turbidity curr5ts runn+ out ?r\gh ! ,provid5ce ,*annels1 ! s\!rn entrance ( ,exuma ,s\nd1 & ! num]\s subm>9e canyons :i* dissect ! slopes (f ! isl&s4 ,! dep? ( ! pla9 ranges f #bfjj to #bgej fa?oms1 & its area is ab\t #gjjj squ>e miles4 ,,n>es ,,abyssal ,,pla93 ,s\? & s\!a/ ( ! ,b]muda ,rise lies ! ,n>es ,pla91 a #cg1jjj-squ>e-mile abyssal pla9 t slopes ea/w>d f ,vema ,gap t[>d ! ,mid-,atlantic ,ridge4 ,f #fb to #fd ,w4 its nor!rn & s\!rn b\nd>ies are abrupt1 & only ?ree or f\r small abyssal hills h be5 obs]v$ 9 ! pla94 ,ea/ ( #fd ,w4 ! gradi5t ( ! pla9 exce$s #a3bejj1 & ! frequ5cy ( hills increases until at #fa ,w4 ! pla9 consi/s ( a s]ies ( f+]s :i* ext5d into ! abyssal hills4 ,! s$im5t cores obta9$ 9 ! ,n>es ,abyssal ,pla9 consi/ ( alt]nat+ r$ clays & qu>tz silts 7,ericson et al41 #aieb2 9 press74 ,! ,n>es ,abyssal ,pla9 is ! deepe/ ( ! broad abyssal pla9s ( ! ocean-bas9 floor4 ,x is also ! f>!/ f ! l&4 ,if ! turbidity curr5ts smoo!d ! ,n>es ,pla9 !y w\ld all h _h to fl[ ?r\gh ,vema ,gap s9ce ! out] ridge-tr5* complex to ! s\? prev5ts curr5ts f ?is area f rea*+ ! ,n>es ,abyssal ,pla94 ,! idea ( a r\te ?r\gh ,vema ,gap is support$ by ! fact t ! pla9 slopes ea/w>d f ! gap4 ,,hispaniola-,,caicos ,,abyssal ,,pla93 ,! depression betwe5 ! ,bahamas & ! coa/s ( ,cuba & ,hispaniola deep5s ea/ ( ,cay ,lobos & rea*es its maximum dep? ( #bbbj fa?oms nor?we/ ( ,cape ,francis ,viejo ( ,hispaniola4 ,at ,cay ,lobos ! *annel is a /eep ,v-%ap$ depression ) a maximum dep? ( #djj fa?oms1 b to ! ea/ ?is ,v-%ap$ *annel op5s out to an abyssal pla9 ab\t #aejj fa?oms deep4 ,betwe5 ?is po9t & ,great ,inagua ,isl& ! flat floor slopes ea/ rea*+ a dep? ( #aege fa?oms j s\?we/ ( ,inagua4 ,?is portion is call$ ! ,old ,bahama ,abyssal ,pla94 ,s\? ( ,great ,inagua is ano!r ,v-%ap$ *annel 9 :i* ! dep? drops f #agjj fa?oms on ! we/ to #bbjj fa?oms on ! ea/4 ,f ?is po9t to ,cape ,francis ,viejo ! ,hispaniola-,caicos ,abyssal ,pla9 is ne>ly flat4 ,s$im5ts collect$ f ?is pla9 confirm$ ! turbidity-curr5t orig9 ( ! smoo? topography4 ,! cores conta9$ plant debris1 %all[-wat] fossils1 & a v>iety ( rework$ old] mat]ial 7,ericson1 ,ew+1 & ,heez51 #aieb2 ,ew+ & ,heez51 #aiee2 ,ericson et al41 #aiee74 ,,pu]to ,,rico ,,tr5* 7,,abyssal7 ,,pla9s3 ,a tr5* pla9 is an abyssal pla9 9 ! bottom ( a deep-sea tr5*4 ,s9ce ! discov]y ( ! ,pu]to ,rico ,tr5* 7,abyssal7 ,pla9s simil> features h be5 report$ = ! ,middle ,am]ica ,tr5* 7,fi%]1 #aied71 ! ,kurile-,kam*atka ,tr5* 7,ud9tsev1 #aiee71 & ! ,p]u-,*ile ,tr5* 7,zeigl]1 #aieh74 ,two tr5* pla9s are kn[n f ! ,pu]to ,rico ,tr5*4 ,! small] "o occupies a bas9 s\? ( a m$ian ridge1 & ! l>g] "o lies along ! deep axis ( ! tr5*4 ,!y range 9 wid? f #a-b miles to ab\t #ab miles4 ,s$im5t cores tak5 9 ! tr5* pla9 conta9$ b$s ( grad$ calc>e\s s& conta9+ fragm5ts ( ,halim$a & %all[ b5?ic ,=am9if]a 7,ericson1 ,ew+1 & ,heez51 #aieb74 ,! dep? ( ! l>g] tr5* pla9 ranges only slightly f #dceh fa?oms 7#dehe fa?oms correct$74 ,! tr5* %all[s ea/w>d1 & ! pla9s disappe>4 ,,cayman ,,tr5* 7,,abyssal7 ,,pla9s3 ,! ,cayman ,tr5* conta9s tr5* pla9s v simil> to ^? 9 ! ,pu]to ,rico ,tr5*4 ,! limits ( ! ,cayman ,tr5* ,pla9s %[n on ! physiographic diagram may n be too reliable2 x has n be5 r$raft$ s9ce ! mo/ rec5t tracks %[n on ! track *>t 7 obta9$4 ,,biscay ,,abyssal ,,pla93 ,! ,bay ( ,biscay is occupi$ by a l>ge abyssal pla9 :i* beg9s a few miles nor? ( ! nor!rn limit ( ! map & ends at ! ,!ta ,gap at #dc #cj,n4 ,! pla9 ranges f #beej to #bfej fa?oms 9 dep? & is ab\t #bjj miles wide4 ,cores ( grad$ s& & silt h be5 obta9$ f ! floor ( ! pla94 ,sev]al mid-ocean canyons #c to #e fa?oms deep & a qu>t] ( a mile to #b miles wide h be5 obs]v$ 9 ! pla9 7,pl4 #h71 b data are n suffici5t to det]m9e _! exact c\rses4 ,x is sugge/$ t !y conv]ge on ,!ta ,gap & t "s may be ext5sions ( subm>9e canyons ( ! cont95tal slope4 ,,ib]ia ,,abyssal ,,pla93 ,s\? ( ,!ta ,gap & we/ ( ! nor!rn ?ird ( ! ,ib]ian ,p59sula lies an oval abyssal pla9 ( ab\t #be1jjj squ>e miles4 ,! dep? ( ?is pla9 ranges f #bggj fa?oms ne> ,!ta ,gap & at ! base ( ! cont95tal rise to #bhbj fa?oms ne> ! ea/]n m>g9 ( ! abyssal hills prov9ce4 ,! pla9 fans out f ,!ta ,gap & gradually m]ges ) ! normal we/w>d slope f ! cont95tal rise ( nor? ,ib]ia4 ,,tagus ,,abyssal ,,pla93 ,we/ ( ! canyons (f ! m\? ( ! ,tagus lies a small circul> pla9 ( #gajj squ>e miles4 ,its dep? ranges f #bfej to #bgjj fa?oms1 & x slopes we/w>d ) slightly fan-%ap$ cont\rs ext5d+ f ! m\?s ( ! two l>ge canyons4 ,a rec5t s$im5t sampl+ campaign reveal$ num]\s grad$ silt & s& lay]s 9 ! pla9 7,pl4 #bh74 ,,horse%oe ,,abyssal ,,pla93 ,a small abyssal pla9 ( #ebjj squ>e miles lies 9 ! c5t] ( a horse%oe-%ap$ r+ ( seam\nts1 j we/ ( ,gibralt>4 ,,madeira ,,& ,,cape ,,v]de ,,abyssal ,,pla9s3 ,f ,gibralt> to ,cape ,v]de & ext5d+ s\?w>d to ! ,si]ra ,leone ,rise at #aj ,n4 a va/ abyssal pla9 p>allels ! coa/ ( ,africa4 ,= mo/ ( its l5g? ! we/]n b\nd>y ( ?is pla9 is #gej miles f ! coa/4 ,! av]age wid? ( ! pla9 is #bjj miles1 & x occasionally rea*es #cjj miles4 ,an ea/w>d ext5sion ( ! abyssal hills approa*es )9 #bjj miles ( ! ,can>y ,isl&s1 =m+ a natural con/riction :i* divides ! pla9 into a nor!rn "p1 ! ,madeira ,abyssal ,pla91 & a s\!rn "p1 ! ,cape ,v]de ,abyssal ,pla94 ,! ,madeira ,abyssal ,pla9 occupies #aej1jjj squ>e miles4 ,! ,azores-,gibralt> ,ridge =ms its nor!rn b\nd>y1 & ! abyssal hills its we/]n b\nd>y4 ,dep?s ne> ! seaw>d limit ( ! pla9 rea* #bigj fa?oms4 ,! nor!rn "p ( ! ,madeira ,pla9 is brok5 by a s]ies ( l[ sc>ps 7,pl4 #ac1 fig4 #c74 ,! gradi5t ( ! pla9 betwe5 successive sc>ps is ab\t #a3aejj4 ,! ,cape ,v]de ,abyssal ,pla9 occupies #bjj1jjj squ>e miles ( sea floor 7,pl4 #i1 fig4 #c74 ,! transition f abyssal pla9 to abyssal hills is gradual4 ,_m hills are scatt]$ 9 ! pla9 ne> ! b\nd>y4 ,small sc>ps ( ! k9d obs]v$ 9 ! ,madeira ,abyssal ,pla9 h n be5 f\nd4 ,rec5t s\nd+s s\?we/ ( ,madeira indicate t a l[ topographic feature :i* might be call$ ! ,madeira ,rise cont9ues into ! nor!a/ "p ( ! area %[n z ,madeira ,abyssal ,pla94 ,?is abyssal pla9 is ?us some:at small] ?an indicat$ 9 ! draw+s4 ,two ,,pdr records f ?is rise area are illu/rat$ 7,pl4 #ac1 figs4 #a1 #b74 ,s9ce ! limits ( ! ,madeira ,abyssal ,pla9 are bas$ on only f\r s\nd+ pr(iles1 future surveys w cause relatively great *anges 9 ?is portion ( ! diagram4 ,,abyssal ,,hills ,def9ition & di/ribution4--,an abyssal hill is a small hill t rises f ! ocean-bas9 floor & is f a few fa?oms to a few hundr$ fa?oms 9 height & f a few hundr$ feet to a few miles 9 wid?4 ,! t]m abyssal hills prov9ce is appli$ to ^? areas ( ! ocean-bas9 floor 9 :i* ne>ly ! entire area is occupi$ by hills--t is1 ! prov9ce lies at approximately ! dep? ( ! adjac5t abyssal pla9 b lacks a smoo? floor4 ,isolat$ abyssal hills & gr\ps ( abyssal hills also occur 9 ! abyssal pla9s4 ,illu/ration3 ,,figure #be4--;,index *>t1 location ( abyssal hills pr(iles illu/rat$ 9 ,figures #bf & #bg ,limits ( abyssal hills prov9ces %[n by dott$ l9es4 ,illu/ration3 ,,figure #bf4--;,elev5 pr(iles1 ,we/]n ,atlantic ,abyssal ,hills ,prov9ce #dj3a v]tical exagg]ation2 positions %[n on ,figure #be4 ,abyssal hills are f\nd along ! seaw>d m>g9 ( mo/ abyssal pla9s & probably occur 9 pr(usion 9 bas9s isolat$ f adjac5t l& areas by ridges1 rises1 or tr5*es4 ,9 ! ,nor? ,atlantic ! abyssal hills =m two /rips p>allel to ! ,mid-,atlantic ,ridge = virtually its entire l5g?4 ,! ,b]muda ,rise is bord]$ on ! s\!a/ by abyssal hills :i* jo9 ) ! /rips adjo9+ ! ,mid-,atlantic ,ridge 7,fig4 #be74 ,s\!a/ ( ! ,b]muda ,rise ! abyssal pla9 is abs5t1 & consequ5tly ! ,we/]n ,atlantic ,abyssal-,hills ,prov9ce exce$s #ejj miles 9 wid?4 ,illu/ration3 ,,figure #bg4--;,eight pr(iles1 ,ea/]n ,atlantic ,abyssal ,hills ,prov9ce ,v]tical exagg]ation #dj3a2 positions %[n on ,figure #be4 ,9 ! ,nor? ,atlantic ! axes ( maximum dep? on ! ea/]n & on ! we/]n sides ( ! ,mid-,atlantic ,ridge lie 9 ! abyssal-hills prov9ce4 ,?is patt]n probably cont9ues ?r\gh ! ,s\? ,atlantic1 ,indian ,ocean1 & ,s\? ,pacific oceans4 ,individual abyssal hills are id5tical to ! small] hills :i* rise f ! /eps ( ! ,mid-,atlantic ,ridge & are probably ( ! same orig94 ,! abyssal hills & ! ,l[] ,/ep ( ! ,mid-,atlantic ,ridge c be di/+ui%$ topographically only by ! contra/ 9 level4 ,regional description4--,! abyssal hills )9 ! area ( ! physiographic diagram are illu/rat$ by pr(iles ,,:-#a-aa & ,,eh-#a-h reproduc$ 9 ,figures #bf & #bg respectively4 ,,we/]n ,,atlantic3 ,! abyssal-hills prov9ce ranges f a few miles to m ?an #abe miles 9 wid? f ! nor? edge ( ! map to ! ,s\!a/ ,newf\ndl& ,ridge4 ,along pr(ile ,,:-#a ! prov9ce consi/s ( ab\t a doz5 hills #c-d miles wide & #ej-ajj fa?oms high1 :ile 9 ,,:-#b ! hills are #d-aj miles 9 wid?1 & "s exce$ #bjj fa?oms 9 height4 ,! abyssal-hills prov9ce appe>s to p9* out at ! ,s\!a/ ,newf\ndl& ,ridge4 ,s\?we/ ( ! ,s\!a/ ,newf\ndl& ,ridge ! abyssal hills =m a belt #fj-abj miles wide :i* skirts along ! nor? edge ( ,corn] ,rise4 ,9 ?is area1 z illu/rat$ by ,,:-#c1 -#d1 & -#e1 ! l>ge/ abyssal hills n[h]e exce$ #bej fa?oms 9 height4 ,! individual hills range f #c to #ab miles wide2 maximum dep?s betwe5 individual hills frequ5tly exce$ ! dep? ( ! adjac5t abyssal pla9 by #ej-ajj fa?oms4 ,along ! nor?we/ corn] ( ,corn] ,rise ! abyssal-hills prov9ce p9*es out4 ,s\? ( ,corn] ,rise ! prov9ce appe>s on bo? ! ea/ & ! we/ sides ( ! ,sohm ,abyssal ,pla91 & isolat$ abyssal hills become m num]\s )9 ! abyssal pla94 ,9 pr(ile ,,:-#f ! abyssal hills )9 ! prov9ce rea* #cjj fa?oms 9 height & are #c-e miles wide4 ,a few high] peaks occur su* z ! two 9 pr(ile ,,:-#f1 "o #ejj fa?oms high & #bj miles wide & ! o!r #gjj fa?oms high & #ae miles wide4 ,9 addition eight isolat$ hills #ajj to #age fa?oms high rise f ! pla9 9 ! same pr(ile4 ,to ! s\?1 ! frequ5cy ( hills )9 ! pla9 increases1 & ! hills prov9ce wid5s4 ,9 pr(ile ,,:-#g ! prov9ce increases to #ce miles 9 wid? on ! ea/ side ( ! ,sohm ,pla9 & to #ajj miles 9 wid? on ! we/ side4 ,! small] individual hills 9 ! pla9 are #bjj fa?oms high1 9 contra/ to ! av]age ( #ajj fa?oms 9 ,,:-#f4 ,tw5ty-"o individual hills rise f ! pla9 9 ,,:-#g1 9 contra/ to #ae 9 ,,:-#f4 ,9 ,,:-#h ! abyssal pla9 is repres5t$ by a flat-floor$ valley only #ab miles wide2 ! rema9+ #ejj-mile wid? ( ! abyssal floor is occupi$ by abyssal hills4 ,individual hills are #cjj to #fjj fa?oms high & #e to #aj miles wide 7,fig4 #bh2 ,pl4 #aj74 ,if we fill$ all ! depressions on ,,:-#h ) #ajj fa?oms ( s$im5ts ! pr(ile w\ld closely resemble ,,:-#g4 ,illu/ration3 ,,figure #bh4--,trac+ ( ,,pdr record1 abyssal hills1 s\!a/ ( ,b]muda ,rise ,,:-#i & ,,:-#aj are v simil> to ,,:-#h except t individual hills seem to become broad] & l[] t[>d ! s\?4 ,! height ( individual hills 9 ,,:-#aj ranges f #ajj to #bej fa?oms4 ,s\? ( ,,:-#h ! abyssal-hill prov9ce splits into two /rips :i* bord] ! ,n>es ,abyssal ,pla94 ,! we/]n /rip lies bel[ ! ea/]n sc>p ( ! ,b]muda ,rise ,sc>p ,zone1 & ! ea/]n /rip foll[s ! ,mid-,atlantic ,ridge1 s5d+ a n>r[ /rip we/w>d along ! nor!rn edge ( ! out] ridge nor? ( ,pu]to ,rico4 ,a numb] ( hills #ej fa?oms high & #b-e miles wide are scatt]$ ov] ! ea/]n "p ( ! ,n>es ,abyssal ,pla94 ,abyssal hills are r>e 9 ! abyssal pla9 we/ ( #fe ,w4 ,! abyssal-hill prov9ce along ! s\?we/]n ,b]muda ,rise is extremely n>r[ & int]mitt5t4 ,no abyssal hills h be5 record$ = ! ,hatt]as ,abyssal ,pla91 & only locally is ! prov9ce develop$ along ! we/]n side ( ! ,b]muda ,rise4 ,locally abyssal hills are mod]ately well develop$ along ! nor!rn m>g9 ( ! ,b]muda ,rise4 ,,ea/]n ,,atlantic3 ,! abyssal floor we/ ( ! ,anglo-,fr5* %elf is extremely n>r[2 ! abyssal pla9 & abyssal hills comb9$ are only #hj miles wide4 ,! abyssal-hills prov9ce is abs5t1 b1 z %[n on ,,eh-#a & ,,eh-#b 7,fig4 #bg71 l>ge hills rise f ! seaw>d edge ( ! ,biscay ,abyssal ,pla94 ,^! hills are #e-aj miles wide & #ajj-djj fa?oms high4 ,we/ ( ! ,ib]ia ,abyssal ,pla9 7,,eh-#c7 ! abyssal-hills prov9ce is wid] & bett] develop$ ?an ne> ! ,biscay ,abyssal ,pla94 ,s\? ( ,gibralt> ! abyssal floor wid5s s\?w>d2 nor?we/ ( ,cape ,v]de x is m ?an #bjj miles wide4 ,pr(ile ,,eh-#f runs obliquely ?r\gh ! prov9ce & indicates an exagg]at$ wid? = ! prov9ce4 ,individual hills are #e-aj miles wide & #ajj-fjj fa?oms high 7,pl4 #i1 fig4 #d74 ,! abyssal-hills prov9ce is wide/1 & ! hills are ! highe/ :]e ! dep? is greate/1 a relation simil> to t obs]v$ on ! opposite side ( ! ,mid-,atlantic ,ridge 9 ! sector s\!a/ ( ! ,b]muda ,rise4 99 99 99 99 99 ,orig9 ( abyssal-hills topography4--,! topography ( ! abyssal hills is consid]$ to repres5t ! orig9al surface buri$ b5ea? ! abyssal pla9s & p]haps b5ea? ! cont95tal rise4 ,?is explanation agrees well ) ! smoo? topography & ! di/ribution ( deep-sea s&s 9 ! abyssal pla94 ,! orig9 ( ! hills topography is a m difficult problem4 ,we h no rock samples f ^! prov9ces4 ,individual hills _c be /udi$ ) pres5t seismic-refraction te*niques2 !y d n seem to h a *>act]i/ic magnetic anomaly2 & ,worzel has only rec5tly develop$ a me?od ( gravity measurem5t :i* c be appli$ to a feature z small z an abyssal hill4 ,at pres5t we h only topography z a basis ( speculation ( _! orig94 ,z f> z we "k1 individual abyssal hills are n disc]nibly diff]5t f ! small] hills ( ! /eps ( ! ,mid-,atlantic ,ridge or mu* ( ! topography ( ! oceanic rises1 & ?us !re is no reason to assume t ! abyssal hills h a diff]5t orig94 ,we h not$ t abyssal hills range f #ej to #fjj fa?oms 9 height & ) "s exceptions f #d to #aj miles 9 wid?4 ,h[ev]1 _m ( ! hills are ab\t #bjj fa?oms high & #e miles wide4 ,! hills are v /eep-sid$1 & frequ5tly ! s\nd] simply records a s]ies ( highlights f a succession ( peaks 7,pl4 #aj2 ,pl4 #i1 fig4 #d74 ,s\nd+s are difficult to obta9 9 ! abyssal-hills prov9ces because ( ! great dep? & prim>ily ! prepond]ance ( /eep slopes 7,pl4 #aj74 ,we d n "k :e!r individual hills are conical or elongate or1 9 fact1 if !y run 9 n>r[1 s9u\s ridges z sugge/$ by ,tol/oy 7#aiea74 ,accurate1 detail$ mapp+ ( portions ( ! abyssal-hills prov9ces on scales ( approximately #a3bj1jjj or l>g] %\ld provide additional limits on !ories ( orig94 ,at pres5t we _c decide among vulcanism1 fault+1 or fold+1 al?\gh fold+ seems ! lea/ probable4 ,,o!r ,,major ,,features ,,( ,,! ,,abyssal ,,floor ,abyssal gaps4--,if two adjac5t b di/9ct abyssal pla9s h no ?r\gh passage at or bel[ ! level ( ! high] pla91 !y are said to be sep>at$ by a sill1 a ridge1 or a rise1 dep5d+ on ! dim5sions ( ! feature involv$4 ,h[ev]1 sev]al pla9s are connect$ by con/rict$ passages4 ,an abyssal gap is a con/rict$ passage connect+ two abyssal pla9s :i*1 9 ! vic9ity ( ! gap1 lie at diff]5t levels4 ,! sea floor slopes d[n cont9u\sly ?r\gh ! gap f ! high] to ! l[] abyssal pla91 at a gradi5t consid]ably great] ?an t ( ei!r adjac5t abyssal pla94 ,prom95t abyssal gaps are kn[n 9 ! we/]n ,nor? ,atlantic 7,vema ,gap7 & 9 ! ea/]n ,nor? ,atlantic 7,!ta ,gap74 ,an abyssal gap connects ! ,colombia & ,v5ezuela abyssal pla9s ( ! ,c>ibbean4 99 99 99 99 99 ,mid-ocean canyons4--,:]eas mo/ subm>9e canyons are furr[s cut into ! cont95tal-m>g9 prov9ces1 a class ( canyon is f\nd 9 ! abyssal pla9s1 g5]ally associat$ ) abyssal gaps4 ,a mid-ocean canyon is a /eep-wall$1 flat-floor$ p]si/5t l9e> depression1 #a-e miles wide & a few to m ?an #ajj fa?oms deep1 :i* occurs 9 an abyssal pla94 ,ea* mid-ocean canyon discov]$ 9 ! ,nor? ,atlantic leads to an abyssal gap 9 a mann] :i* sugge/s a g5etic relation%ip4 ,all recogniz$ mid-ocean canyons p>allel ! adjac5t cont95tal m>g94 ,al?\gh all slope d[nw>d cont9u\sly !y cut across ! regional slope ( ! abyssal pla94 ,mid-ocean canyons or features resembl+ !m h be5 f\nd 9 ! ,indian ,ocean ,bay ( ,b5gal 7,dietz1 #aiec71 9 ! nor?we/ ,atlantic 7,ew+ et al41 #aiec71 ! we/]n ,atlantic1 & ! equatorial ,atlantic 7,beckmann1 9 prep>ation74 ,gibson 7#aieh7 has report$ "o 9 ! ,gulf ( ,alaska4 ,?ree 9 ! ,atlantic & "o 9 ! ,gulf ( ,alaska h be5 mapp$4 ,al?\gh mid-ocean canyons probably jo9 ) cont95tal-m>g9 subm>9e canyons1 no su* connection has be5 mapp$4 ,m5>d 7#aiee7 has record$ f ! ,nor? ,pacific sev]al cross+s ( features resembl+ ! mid-ocean canyons ( ! ,atlantic1 :i* he ref]s to z deep-sea *annels4 99 99 99 99 99 ,regional description4--,abyssal gaps & mid-ocean canyons are f\nd 9 bo? ! we/]n ,atlantic & ea/]n ,atlantic4 ,illu/ration3 ,,figure #bi4--,nor?we/ ,atlantic ,mid-,ocean ,canyon ,survey$ positions & ext5sions2 g5]aliz$ ba?ymetry simplifi$ f ,smi?1 ,s\le1 & ,mosby 7#aicg7 ,illu/ration3 ,,figure #cj4--;,eight ea/-we/ pr(iles %[+ ,nor?we/ ,atlantic ,mid-,ocean ,canyon ,s\nd+s obta9$ ) ,,nmc s\nd] run ) precision controll$ ac p[] 9 #aidi ,illu/ration3 ,,figure #ca4--;,=ty-eight cross sections ( ,nor?we/ ,atlantic ,mid-,ocean ,canyon ,s\nd+s orig9ally record$ on ,,uqn-#a;,b s\nd] ) precision controll$ ac p[] 9 #aieb ,illu/ration ,,we/]n ,,atlantic3 ,! major abyssal pla9s ( ! we/]n ,atlantic are connect$ f nor? to s\? by a s]ies ( abyssal gaps & mid-ocean canyons4 ,! ,nor?we/ ,atlantic ,mid-,ocean ,canyon 7,fig4 #bi7 beg9s 9 an unkn[n area nor? ( ! limit ( ! physiographic diagram 7,ew+ et al41 #aiec74 ,x runs s\? p>allel to ! cont95tal m>g9 ( ! ,gr& ,banks on ! we/ & to ! ,mid-,atlantic ,ridge on ! ea/ until x rea*es ! ,s\!a/ ,newf\ndl& ,ridge1 :]e x cuts ?r\gh a n>r[ abyssal gap4 ,aft] pass+ ?r\gh ! gap1 ! canyon turns we/1 broad5s1 & is f9ally lo/ 9 ! ,sohm ,abyssal ,pla94 ,! mid-ocean canyon is ab\t #c miles wide & #ej fa?oms deep nor? ( ! ,s\!a/ ,newf\ndl& ,ridge 7,fig4 #cj74 ,! we/ wall is ab\t #aj-ae fa?oms high] ?an ! ea/ wall 7,fig4 #cb74 ,! canyon has be5 mapp$ by m ?an #hj e*o-s\nd+ pr(iles 7,fig4 #ca74 ,! av]age slope ( ! sea floor at "r angles to ! axis ( ! canyon 9 mo/ places exce$s ! gradi5t ( ! canyon4 ,! gradi5t we/ to ea/ is ab\t #a3aejj1 :ile ! gradi5t ( ! canyon f nor? to s\? is #a3bbej4 ,illu/ration3 ,,figure #cb4--,long pr(ile ( ,nor?we/ ,atlantic ,mid-,ocean ,canyon ,num]als ,i-,,viii indicate location ( pr(iles ( ,figure #cj4 ,! mid-ocean canyon =ms g5tle me&]s 7,fig4 #bi74 ,z ! gradi5t ( ! canyon decreases1 ! canyon *anges its cross-section =m f a n>r[1 deep canyon to a broad1 %all[ "o 7,figs4 #ca & #cb74 ,! mid-ocean canyon foll[s an exceptionally n>r[ & deep abyssal gap ?r\gh ! ,s\!a/ ,newf\ndl& ,ridge4 ,at its n>r[e/ po9t ! gap is no wid] ?an ! mid-ocean canyon4 ,mid-,ocean ,canyon ,no4 #b is ne>ly id5tical to ! ,nor?we/ ,atlantic ,mid-,ocean ,canyon 9 %ape & =m 7,pl4 #ad1 fig4 #b74 ,x has be5 trac$ = only #cej miles ?r\gh ! nor?we/ arm ( ! ,sohm ,abyssal ,pla94 ,!re is a /rong sugge/ion ( a l[ sill runn+ nor!a/ ( ! ,b]muda ,rise t[>d ! tail ( ! ,gr& ,banks4 ,su* a sill w\ld cut (f ! nor?we/ arm ( ! ,sohm ,abyssal ,pla94 ,mid-,ocean ,canyon ,no4 #b w\ld 9 ?is case be associat$ ) ?is abyssal gap connect+ ! high] nor?we/ arm ) ! deep] c5tral & s\!rn p>ts ( ! ,sohm ,pla94 ,a l>ge magnetic anomaly :i* crosses ! pla9 at ?is po9t is possibly evid5ce ( a buri$ ridge b5ea? ! abyssal pla94 ,mid-,ocean ,canyon ,no4 #b has be5 trac$ f ! vic9ity ( ,kelv9 ,seam\nt ea/w>d to ! suppos$ sill4 ,z 9 ! case ( ! ,nor?we/ ,atlantic ,mid-,ocean ,canyon ! gradi5t at "r angles to ! canyon axis g5]ally exce$s ! gradi5t ( ! canyon floor4 ,a sy/ematic diff]5ce 9 dep? betwe5 ! two walls 0 n f\nd 9 ,mid-,ocean ,canyon ,no4 #b4 ,a small area 7#hjjj squ>e miles7 ( abyssal hills lies betwe5 ! nor?we/ arm ( ! ,sohm ,abyssal ,pla9 & ! nor!rn edge ( ! ,hatt]as ,abyssal ,pla94 ,al?\gh _m s\nd+ l9es h be5 run ?r\gh ?is area x is n yet cle> :e!r ?is area is be/ ref]r$ to z an abyssal gap or a sill1 al?\gh ! evid5ce seems to favor a gap4 ,! we/]n end ( ! ,sohm ,pla9 seems to rea* a smoo? sill a few doz5 miles ea/ ( ,c>yn ,peak1 & ! abyssal pla9 surr\nd+ ,c>yn ,peak1 at ! m\? ( ! ,hudson ,canyon1 seems ei!r to be isolat$ or to be connect$ ) ! ,hatt]as ,abyssal ,pla9 to ! s\? ?r\gh an abyssal gap4 ,an abyssal gap may possibly connect ,sohm ,pla9 to ! ea/]n end ( ! ,n>es ,abyssal ,pla91 b 9 consid]ation ( ! ea/w>d gradi5ts ( ! ,n>es ,abyssal ,pla9 x seems probable t no gaps cut all ! way ?r\gh ! wide abyssal-hills prov9ce :i* sep>ates ! two pla9s4 ,! gap connect+ ! ,hatt]as ,abyssal ,pla9 & ! ,n>es ,abyssal ,pla9 s\?we/ ( ! ,b]muda ,rise has be5 nam$ ,vema ,gap aft] ! ,rese>* ,vessel ,,vema :i* has be5 us$ mo/ ext5sively 9 ?is area4 ,vema ,gap is ab\t #bj miles wide & #gj miles long2 its long axis is ori5t$ approximately we/-ea/4 ,! ,hatt]as ,pla9 rea*es a dep? ( #bijj fa?oms a few miles we/ ( ! gap4 ,! gradi5t ( ! pla9 is ab\t #a3cjjj at t po9t4 ,! ,n>es abyssal pla9 to ! s\!a/ lies at ab\t #cjgj fa?oms & slopes ea/w>d ) a gradi5t ( ab\t #a3cejj4 ,! floor ( ! gap1 9 %>p contra/ to ! adjac5t pla9s1 slopes ea/w>d at an av]age gradi5t ( #a3cjj4 ,! edge ( ! ,hatt]as ,abyssal ,pla9 is cut by sev]al mid-ocean canyons #bj fa?oms deep & a mile wide :i* develop a few miles to ! we/ & conv]ge on ! abyssal gap4 ,associat$ ) ,vema ,gap is a l>ge magnetic anomaly simil> to ! "o obs]v$ ne> ! suppos$ gap nor? ( ! ,b]muda ,rise1 :i* aga9 c\ld possibly be evid5ce ( a prom95t buri$ ridge =m+ ! sill ( ! gap4 ,! ,old ,bahama ,*annel ,abyssal ,pla9 & ! ,hispaniola-,caicos ,abyssal ,pla9 are probably connect$ by a /eep-wall$ abyssal gap :i* runs we/ to ea/ s\? ( ,great ,inagua ,isl&4 ,illu/ration3 ,,figure #cc4--,trac+ ( ,,pdr record across ,!ta ,gap ,,ea/]n ,,atlantic3 ,! only abyssal gap kn[n 9 ! ea/]n ,atlantic 0 s\nd$ by ,m_/,v ,,!ta & is "h nam$ ,!ta ,gap4 ,?is gap lies (f ! nor?we/ cape ( ,spa9 betwe5 ! ,biscay & ,ib]ia abyssal pla9s4 ,its exi/5ce is bas$ on only a few pr(iles1 "o ( :i* is illu/rat$ 9 ,figure #cc4 ,small depressions a few fa?oms deep & #a-b miles wide 7 obs]v$ 9 ! ,biscay ,abyssal ,pla9 & may repres5t mid-ocean canyons1 :i* may possibly connect ) ,!ta ,gap 7,pl4 #h1 fig4 #b74 ,insuffici5t precision-s\nd+ tracks are available 9 ?is area to det]m9e ! exact nature ( ^! features4 99 99 99 99 99 ,orig9 ( abyssal-floor topography4--,! explanation t abyssal pla9s repres5t portions ( ! abyssal floor buri$ b5ea? s$im5ts transport$ by turbidity curr5ts1 & t ! abyssal hills repres5t ?is unburi$ surface1 has be5 (f]$ by ,heez5 et al4 7#aiea2 #aied7 & by ,m5>d 7#aiee74 ,abyssal gaps are pictur$ z passages ?r\gh :i* turbidity curr5ts fl[ f a high] pla9 to a l[] "o4 ,s$im5t mu/ h fill$ 9 ! ,hatt]as ,pla9 to ! pres5t dep? ( ! we/]n end ( ,vema ,gap be=e ! ,n>es ,abyssal ,pla9 c\ld beg9 to =m4 ,ew+ et al4 7#aiec7 sugge/ t ! ,nor?we/ ,atlantic ,mid-,ocean ,canyon 0 probably =m$ by turbidity curr5ts :i* fl[ f ! vic9ity ( ,gre5l& to ! ,sohm ,abyssal ,pla94 ,:e!r ! canyon-=m+ process 0 l>gely erosional or depositional rema9s to be se51 b ! n>r[1 deep abyssal gap 9 ! ,s\!a/ ,newf\ndl& ,ridge sugge/s erosion4 ,! p>allelism ( ! ,mid-,ocean ,canyon ) ! ,mid-,atlantic ,ridge ev5 sugge/s a tectonic orig94 ,! deep-sea s&s ( ! canyon floor & its cont9u\s gradi5t argue z /rongly = a turbidity-curr5t orig94 ,! features ( ! smoo? p>ts ( ! abyssal floor seem cle>ly ! result ( deposition by turbidity curr5ts 7,ericson et al41 #aiee2 9 press74 ,,oceanic ,,rises ,def9ition & di/ribution4--,an oceanic rise is a l>ge area 7measur$ 9 hundr$s ( miles71 n connect$ to or includ$ 9 a mid-oceanic ridge or connect$ to a cont95tal rise1 :i* rises a few hundr$ fa?oms above ! surr\nd+ abyssal floor4 ,! topography ( an oceanic rise ranges f g5tle to extremely rugg$4 ,includ$ 9 ?is classification is ! ,b]muda ,rise & ,corn] ,rise ( ! ,nor? ,atlantic1 ! ,rio ,gr&e ,rise ( ! ,s\? ,atlantic1 & a numb] ( simil> b unnam$ features 9 ! ,indian & ,pacific oceans4 99 99 99 99 99 ,regional description4--,only ?ree oceanic rises are situat$ 9 ! ,nor? ,atlantic4 ,!y are3 ,b]muda ,rise1 ,corn] ,rise1 & ,rockall ,rise4 ,( ^! only ! ,b]muda ,rise has be5 cross$ by _m e*o-s\nd+ trav]ses4 ,,b]muda ,,rise3 ,9 ! c5t] ( ! ,nor? ,am]ica ,bas9 & surr\nd+ ! isl& ( ,b]muda is an oval asymmetrical ar* ab\t #cjj by #fjj miles ) ! long axis ori5t$ nor!a/4 ,! topography ( ! ,b]muda ,rise is relatively g5tle z comp>$ to ! ,mid-,atlantic ,ridge b consid]ably m rugg$ ?an ! cont95tal rise 7,pl4 #bg74 ,! rise is usually di/9ctly m>k$ on ! we/ by a #aj- to #ajj-;fa?om decrease 9 dep? & a *ange f ! monoton\sly smoo? abyssal pla9 on ! we/ to g5tly roll+ hills1 #bj-ej fa?oms high & #b-aj miles wide 7,pl4 #af74 ,9 contra/ ! ea/]n edge ( ! rise is m>k$ by a s]ies ( sc>ps #cjj-ijj fa?oms high 7,pl4 #ag71 & ! adjac5t rise topography is relatively rugg$4 ,we/ ( ! sc>p zone ! topography is q smoo? to ! we/]n m>g9 ( ! rise 7,pl4 #af74 ,an apron #cj miles wide surr\nds ! #bcjj-;fa?om high p$e/al :i* supports ! isl& ( ,b]muda 7,pl4 #bj74 ,f ?is apron ,ericson1 ,ew+1 & ,heez5 7#aieb71 report$ quantities ( %all[-wat]-d]iv$ c>bonate cla/ics4 ,nor? ( ,b]muda ! rise is m>k$ by a numb] ( high seam\nts :i* cont9ue across ! adjac5t abyssal pla9 & =m ! ,kelv9 ,gr\p ( seam\nts4 ,_m ( ^! appe> to be flat-topp$4 ,! ,b]muda ,rise is b\nd$ on ! ea/ & nor? by ! ,sohm ,abyssal ,pla91 on ! we/ by ! ,hatt]as ,pla91 & on ! s\? by ! ,n>es ,pla94 ,= a %ort di/ance on ! nor?we/ & a few hundr$ miles on ! s\!a/ ! rise is bord]$ by abyssal hills4 ,! we/]n edge ( ! ,b]muda ,rise is =m$ 9 places by a sc>p1 b p>ticul>ly 9 ! nor?we/ ! ,b]muda ,plateau seems to dip g5tly b5ea? ! ,hatt]as ,abyssal ,pla94 ,! details ( ! topography ( ! ,b]muda ,rise are demon/rat$ by ! s]ies ( radiat+ pr(iles 9 ,plate #bg4 ,b]muda ,p$e/al4--,! isl&s ( ,b]muda lie along ! s\!a/ rim ( a flat-topp$ p$e/al ^: surface lies less ?an #bj fa?oms bel[ sea level4 ,! sides ( ! ,b]muda ,p$e/al slope at gradi5ts ( #a3e to #a3cj & fall rapidly to ! #bcjj-;fa?om cont\r :]e ! base ( ! p$e/al is rea*$4 ,! p$e/al is #ej miles by #hj miles at its base4 ,cores conta9+ ,t]ti>y s$im5ts & rec5t reef detritus1 & 9 "o case basaltic rock1 h be5 obta9$ f ! sides ( ! ,b]muda ,p$e/al 7,pl4 #bh74 ,b]muda ,apron4--,encircl+ ! base ( ! ,b]muda ,p$e/al is a smoo?1 g5tly slop+ apron or depositional t]race4 ,! wid? ( ! apron is irregul> & ranges f #dj miles on ! ea/ to #bj miles on ! we/4 ,gradi5ts decrease to #a3gjj away f ! p$e/al1 b ! out] edge ( ! apron 9 places has gradi5ts ( #a3ij4 ,on "s pr(iles hills up to #abe fa?oms 9 height occur ne> ! out] edge ( ! apron & become increas+ly num]\s until at a di/ance ( #de miles f ! p$e/al ! apron is n recognizable z a topographic feature4 ,! limits ( ! apron w ultimately be def9$ by a /udy ( ! s$im5ts4 ,b]muda ,plateau4--,! ,b]muda ,plateau is an oval area ( #ij1jjj squ>e miles1 :i* lies r\ghly 9 ! c5t] ( ! ,b]muda ,rise4 ,! topography is *>act]iz$ by l[ hills & r ext5sive int]montane valleys 7,pl4 #af74 ,few individual hills exce$ #ej fa?oms 9 height4 ,! topography ( ! sub-prov9ce is well illu/rat$ 9 ,plate #af4 ,! dep? is #bdjj to #bgjj fa?oms4 ,! plateau is b\nd$ on ! s\!a/ by ! ,b]muda ,sc>p ,zone4 ,on ! we/ x ext5ds almo/ to ! edge ( ! rise4 ,on ! nor? ! ,cresc5t ,peaks & ,muir ,seam\nt ,gr\p h made x difficult to def9e ! edge ( ! plateau4 ,cresc5t ,peaks4--,nor?we/ ( ,b]muda a cresc5t-%ap$ l9e ( conical peaks bord]s ! ,b]muda ,apron4 ,individual peaks are #fjj fa?oms high & #d to #f miles wide at _! base4 ,?is range ( peaks =ms a di/9ct sub-prov9ce :i* rises f ! ,b]muda ,plateau4 ,b]muda ,sc>p ,zone4--,! ,b]muda ,plateau is brok5 along its ea/]n m>g9 by a s]ies ( sc>ps 7,pl4 #ag74 ,!re appe> to be two sy/ems ( sc>ps1 "o tr5d+ ab\t ,n4 #ee ,w4 & ! o!r ab\t ,n4 #ce ,e4 ,individual sc>ps range f #ajj to #gjj fa?oms 9 height4 ,! int]sect+ set ( l9es %[n on ! prov9ce *>t 7,pl4 #bj7 indicates prom95t sc>ps 9 ?is area4 ,da%$ l9es repres5t m speculative sc>ps4 ,a fur!r /udy ( ?is int]e/+ area is und]way1 & x is hop$ t a m-detail$ mapp+ ( ^! sc>ps w be possible4 ,ne$less to say1 dr$g+ on ^! sc>ps %\ld br+ ri* rew>ds 9 fossil s$im5ts & igne\s rocks :i* are und\bt$ly expos$ on ^! precipit\s cliffs4 ,! g5]al "* ( ! sc>p zone is illu/rat$ 9 ,plate #ag by an e*ogram4 ,!re seem to be ?ree or f\r major ne-sw sc>ps4 ,9 ! ea/-c5tral ,b]muda ,rise ! areas betwe5 ! sc>p zones rema9 at virtually ! same dep? z ! unfractur$ ,b]muda ,rise f>!r we/4 ,h[ev]1 t[>d ! s\!a/ ! int]-sc>p areas drop z a s]ies ( /eps4 ,! dep? along ! base ( ea* sc>p is nev]!less deep] ?an ! next l[] /ep4 ,! small] topographic features ( ! s\!a/ "p ( ! sc>p zone are v simil> to ! abyssal hills to ! s\!a/ & are ?us probably ( ! same orig94 ,! /rips betwe5 successive sc>ps t5d to %all[ to ! s\!a/ & rea* m9imum dep?s j be=e ! next sc>p is rea*$4 ,muir ,seam\nt ,gr\p4--,9 #aide work]s on ! ,u4,s4,s4 ,,muir discov]$ a l>ge seam\nt #adj miles nor!a/ ( ! ,b]muda ,isl&s4 ,subsequ5t reconnaissance surveys by ! ,lamont ,geological ,obs]vatory 7,tol/oy1 #aiea2 ,tol/oy & ,ew+1 #aidi7 reveal$ t ! peak 0 asymmetrical 9 ea/-we/ pr(ile 7consid]ably /eep] on ! ea/7 & t ! seam\nt 0 elongate nor!a/-s\?we/ p>allel to ! axis ( ! ,b]muda ,rise4 ,cores tak5 ne> its summit conta9$ ,eoc5e to ,plei/oc5e s$im5t4 ,additional seam\nts h be5 discov]$ 9 ! area by ,worzel & ,%urbet 7#aiee7 & ,nor?rop & ,fros* 7#aied74 ,! asymmetrical pr(ile & ! elongate %ape p>allel to ! axis ( ! ,b]muda ,rise sugge/ t ,muir ,seam\nt is a tectonic uplift r ?an a volcanic pile1 b admitt$ly und]sea vulcanism ne$ n always produce symmetrical cones4 ,z kn[n1 ,muir ,seam\nt is #ce miles wide 7nor?we/-s\!a/71 #fj miles long 7nor!a/-s\?we/71 & rises #agjj fa?oms above ! ,b]muda ,rise4 ,! m9imum s\nd+ record$ is #hdf fa?oms4 ,! ,muir ,seam\nt & ne>-by associat$ peaks app>5tly are n directly relat$ to ! ,kelv9 ,seam\nt ,gr\p f>!r nor?4 ,! nor? & nor?we/ m>g9 ( ! ,b]muda ,rise1 l t on ! we/1 is 9 "s places a sc>p & 9 o!r places a g5tle transition4 ,ne> ! nor?we/ corn] ( ! ,b]muda ,rise a range ( hills ea* ab\t #bj fa?oms high & #c miles wide foll[s ! m>g9 ( ! rise = _m miles4 ,! nor!a/]n m>g9 ( ! ,b]muda ,rise is abrupt 9 mo/ places1 & 9 "s places a s+le sc>p #ejj fa?oms high is all t sep>ates ! ,b]muda ,rise f ! adjac5t abyssal pla94 ,s$im5ts ( ! ,b]muda ,rise4--,mo/ ( ! ,b]muda ,rise lies bel[ ! dep? ( #bejj fa?oms1 & ?us ! s$im5t ranges f =am9if]al clay ?r\gh r$ clay ) a pr$om9ance ( r$ clay4 ,9 ! vic9ity ( ! ,b]muda ,p$e/al calc>e\s detrital s$im5ts h built a depositional apron ar\nd ! base ( ! p$e/al 9 dep?s ( #bcjj to #bdej fa?oms 7,pl4 #bh74 ,! seam\nts ( ! ,b]muda ,rise are rocky1 z %[n by photographs & bottom samples4 ,sev]al cores f ! ,muir ,seam\nt reveal$ a v>iety ( ,t]ti>y =am9if]al lutites4 ,) ! exception ( ! detrital s$im5ts ( ! ,b]muda ,apron1 ! sc\r$ cre/s & flanks ( ! l>g] seam\nts1 & ! /eep] sc>ps1 ! ,b]muda ,rise is cov]$ prepond]antly by pelagic s$im5ts4 ,?is is 9 %>p contra/ to ! surr\nd+ abyssal pla9 & ne>-by cont95tal rise1 :]e cores reveal frequ5t alt]ations ( detrital & pelagic s$im5ts 7,pl4 #bh74 ,,corn] ,,rise3 ,mu* less ext5sive & less well kn[n is ,corn] ,rise :i* lies directly s\? ( ! ,gr& ,banks on ! ea/ side ( ! ,sohm ,abyssal ,pla94 ,corn] ,rise is s nam$ because its nor?we/ b\nd>y ) ! abyssal floor =ms a %>p1 ne>ly "r-angl$ corn] 7,pl4 #bj74 ,! ma9 "p ( ,corn] ,rise is =m$ by a gr\p ( l>ge1 poorly survey$ seam\nts4 ,sev]al ( ! peaks rise to #aejj fa?oms4 ,! area is repres5t$ 9 pr(ile ,i ( ,plate #bb 7betwe5 mile m>ks #ajjj & #abjj74 ,photographs tak5 on ,corn] ,seam\nt at ! nor?we/]n extremity ( ,corn] ,rise %[$ rippl$ & h>d-clay bottom to #abjj fa?oms4 ,! fact t ^! seam\nts app>5tly =m a prolongation ( ! ,kelv9 ,seam\nt ,gr\p sugge/s ! ne$ = detail$ inve/igation ( ! latt] seam\nts & ! probability t additional volcanic seam\nts may be f\nd along ! same tr5d4 ,illu/ration3 ,,figure #cd4--,natural scale pr(ile1 ,kelv9 ,seam\nt ,gr\p ,,rockall ,,rise3 ,s\?we/ ( ,rockall ,bank betwe5 #ai,w4 & #bc,w4 on ! #ej? p>allel1 ris+ f ! abyssal floor ( ! nor!a/]n ,atlantic1 is an ill-def9$ area ( irregul> topography :i* seems n to belong to ! ,l[] ,/ep ( ! ,mid-,atlantic ,ridge4 ,little is kn[n ( ?is area1 & its classification z a rise may n survive m detail$ /udy4 ,! area is illu/rat$ 9 ,plate #be by pr(ile ,e-#a4 ,,seam\nts ,,( ,,! ,,ocean-,,bas9 ,,floor ,a seam\nt is def9$ z any isolat$ elevation :i* rises m ?an #ejj fa?oms above ! sea floor4 ,^? seam\nts :i* lie entirely on oceanic rises h be5 describ$ z "p ( ! rise topography4 ,n[ we w describe ! seam\nts ( ! abyssal floor4 ,,kelv9 ,,seam\nt ,,gr\p3 ,an impressive r[ ( l>ge conical peaks runs f ! vic9ity ( ,georges ,bank = #fjj miles t[>d ! nor!a/ tip ( ! ,b]muda ,rise4 ,a pr(ile plott$ at natural scale :i* crosses five ( ! l>ge/ seam\nts is reproduc$ 9 ,figure #cd4 ,! l9e ( seam\nts runs across ! cont95tal rise1 abyssal pla91 & ! ,b]muda ,rise1 seem+ly little affect$ on cross+ ! prov9ce b\nd>ies4 ,! l>g] seam\nts su* z ,kelv9 ,seam\nt are ab\t #bjjj fa?oms high] ?an ! adjac5t pla9 & are z mu* z #ce miles 9 diamet] at ! base4 ,^? :i* rise f ! cont95tal rise or ! abyssal pla9 d s abruptly1 sugge/+ t _! bases are p>tially buri$4 ,! tops ( mo/ ( ^! seam\nts lie betwe5 #eej & #hej fa?oms1 & at lea/ a few are flat-topp$4 ,!y are ?us v simil> to ! flat-topp$ guyots ( ! ,pacific 9 size1 %ape1 & ! range ( dep?s ( _! flat summits 7,hamilton1 #aief74 ,photographs tak5 on ^! seam\nts %[$ rock1 ripples & live solit>y corals4 ,,c>yn ,,seam\nt3 ,a small conical peak1 #ajjj fa?oms high1 ^: base is #h miles 9 diamet]1 lies 9 ! abyssal pla9 we/ ( ! ,b]muda ,rise 7#cf #de,n474 ,a magnetic survey ( ! peak has be5 publi%$ by ,mill] & ,ew+ 7#aief74 ,!y f\nd an exceptionally l>ge anomaly associat$ ) ! peak1 :i* cle>ly %[$ its volcanic orig94 ,cores f ! peak conta9$ manganese nodules1 alt]$ volcanic rocks1 & ,upp] ,cretace\s to ,rec5t fossils1 :i* %[s t x is at lea/ z old z ,upp] ,cretace\s4 ,! base ( ! peak rises f ! abyssal pla9 :i* ext5ds out f ! ,hudson ,subm>9e ,delta4 ,,horse%oe ,,seam\nt ,,gr\p3 ,ab\t #cjj miles due we/ f ! ,/raits ( ,gibralt> an impressive gr\p ( seam\nts lies 9 a horse%oe-%ap$ arc4 ,sev]al ( ^!1 mo/ notably ,amp]e & ,joseph9e seam\nts1 rise to less ?an #ajj fa?oms4 ,joseph9e ,seam\nt is ! l>ge/ ( ! gr\p & lies along an ea/-we/ topographic tr5d 7! ,azores-,gibralt> ,ridge74 ,9 ! s\!rn half ( ! ,horse%oe ,gr\p ! individual seam\nts appe> to be coalesc+ cones simil> to ! seam\nts ( ! ,kelv9 ,gr\p4 ,seam\nts ( ! nor!rn half1 al?\gh imp]fectly kn[n1 seem to be elongat$ ea/-we/4 ,! s\!rn half ( ! gr\p appe>s to resemble volcanic cones1 :ile 9 ! nor!rn half tectonic de=mation seems to h play$ a l>g] "p4 ,! seam\nts h be5 cor$1 dr$g$1 & photograph$ by a ,lamont ,obs]vatory exp$ition4 ,! s$im5ts obta9$ f ! seam\nts are middle ,t]ti>y to ,rec5t 7,sutton et al41 #aieg74 ,illu/ration3 ,heez5 et al41 ,,pl4 #af ,,figure #a4 ,,we/]n ,,b]muda ,,rise ,,figure #b4 ,,c5tral ,,b]muda ,,rise ,,figure #c4 ,,ea/-,,c5tral ,,b]muda ,,rise ,,figure #d4 ,,ea/]n ,,b]muda ,,rise ,,repres5tative ,,pdr ,,records ,,f ,,b]muda ,,rise ,dep? 9 fa?oms4 ,illu/ration3 ,heez5 et al41 ,,pl4 #ag ,,pdr ,,record1 ,,b]muda ,,sc>p ,,zone ,dep? 9 fa?oms4 ,illu/ration3 ,heez5 et al41 ,,pl4 #ah ,,figure #a4 ,,high ,,fractur$ ,,plateau ,,figure #b4 ,,upp] ,,/ep ,,pdr ,,records ,,mid-,,atlantic ,,ridge ,dep? 9 fa?oms4 ,illu/ration3 ,heez5 et al41 ,,pl4 #ai ,area ( ea* photograph is ab\t #f by #h feet4 ,,plate #ai4--,,ocean-,,bottom ,,photographs2 ,,mid-,,atlantic ,,ridge ,,figure #a4 7,/ation ,t#a-i1 photo #db7 ,dep? #adaj fa?oms1 location #dh #ch,n41 #bh #dh,w41 on ,we/]n ,rift ,m\nta9s1 ,mid-,atlantic ,ridge4 ,9 ?is plate ,figures #a1 #b1 & #c are closely spac$ photographs less ?an #ajj feet ap>t4 ,note ! co>se-gra9$ light & d>k gravel 9 w9n[ r[ 9 ! =egr\nd & ! light-color$ clay or ooze bottom 9 backgr\nd4 ,( ! sixty photographs tak5 at ?is location ?ree resembl$ ,figures #b & #c1 sev]al resembl$ ,figure #a1 & 9 ! rema9d] ! ocean floor 0 compos$ entirely ( ! light & d>k gravel4 ,,figure #b4 7,/ation ,t#a-i1 photo #dc7 ,location ab\t #ej feet f photo %[n 9 ,figure #a1 same dep? & position4 ,! d>k color ( ! rocks may be due to a coat+ ( manganese dioxide4 ,h[ev]1 ! rocks may actually be compos$ ( d>k mat]ial2 no dr$g+s 7 tak5 "h4 ,all dr$g+s f ,mid-,atlantic ,ridge h br\ght up basalt & 9 "s cases also gabbroic & s]p5t9iz$ rock4 ,x seems likely t ! rock 9 ,figure #b & #c ( ?is plate is basalt4 ,note ! abundance ( sessile life on ! rocky areas 9 contra/ to its abs5ce 9 ! gravel-cov]$ areas4 ,,figure #c4 7,/ation ,t#a-i1 photo #de7 ,location ab\t #ajj feet f photo %[n 9 ,figure #b1 same dep? & position4 ,rock bottom on ! ,we/]n ,rift ,m\nta9s1 ,mid-,atlantic ,ridge4 ,,figure #d4 7,/ation ,v#d-g1 photo #bg7 ,dep? #ejj fa?oms1 location #cg #be,n41 #ca #aj,w41 ,we/]n ,rift ,m\nta9s1 ,mid-,atlantic ,ridge1 s\? ( ! ,azores ,plateau4 ,,figure #e4 7,/ation ,t#a-ed1 photo #ae7 ,dep? #bajj fa?oms1 location #bc #jg,n41 #dc #de,w41 ,upp] ,/ep 7ea/]n side71 ,mid-,atlantic ,ridge4 ,app>atus 9 l[] "r atta*$ to cam]a4 ,note tracks ( crawl+ animal 9 left side ( photo & small holes 9 bottom s$im5t4 ,photograph contra/s %>ply ) ^? f ,rift ,m\nta9s 9 lack ( curr5t or oscillation ripples & rock outcrops4 ,,figure #f4 7,/ation ,t#a-ad1 photo #f7 ,dep? #bacj fa?oms1 location #df #jd,n41 #ag #dc,w41 ,l[] ,/ep 7ea/]n side71 ,mid-,atlantic ,ridge4 ,note fecal pellets1 m\nds1 & small holes4 ,aga9 lack ( evid5ce ( /rong curr5ts or outcrops is notable4 ,positions ( /ations %[n on ,plate #cj ,photographs ( ! seam\nts g5]ally %[ w9n[$ & rippl$ s$im5t & rock 7,pl4 #ae74 ,virtually all loose s$im5t is be+ remov$ f ! seam\nts4 ,! horse%oe1 op5 to ! ea/1 encloses an abyssal pla9 :i* is1 judg+ f ! sea-floor gradi5ts1 f$ l>gely f ! ea/ by turbidity curr5ts orig9at+ 9 ! ,/raits ( ,gibralt> & ! ,gulf ( ,cadiz areas4 ,,milne ,,seam\nt3 ,e>ly *>ts ( ! we/]n ,atlantic %[$ an ext5sive bank ( #bj1jjj squ>e miles ris+ f ! c5t] ( ,newf\ndl& ,abyssal ,pla94 ,at ab\t ! c5t] ( ?is area an exceptionally high peak has be5 discov]$ by cable %ips1 & ! old "n ,milne ,seam\nt has be5 assign$ to ?is peak4 ,x rises m ?an #bejj fa?oms above ! abyssal floor4 ,two seam\nts ( simil> size h be5 f\nd nor? & s\? ( ! ,milne ,seam\nt by work]s on ! ,r4 ,v4 ,,atlantis 7,fig4 #cj74 ,z ! abyssal floor is bett] survey$ _m m isolat$ seam\nts w und\bt$ly be discov]$1 & !y may reveal tectonically significant patt]ns4 ,,seismicity ,,( ,,! ,,ocean-,,bas9 ,,floor ,! ocean-bas9 floor prov9ces are virtually devoid ( e>?quakes ( a size detectable at di/ant seismic obs]vatories4 ,( c\rse small e>?quakes 7 #e1 ,ri*t] scale7 w\ld probably n be locatable 9 su* remote regions4 ,! virtual abs5ce ( l>g] %ocks makes x improbable t _m small ones occur !re ei!r4 ,two e>?quakes h occurr$ 9 ! ,b]muda ,rise1 "o ne> ! we/ b\nd>y & "o 9 ! sc>p zone ( ! s\!a/ ,b]muda ,rise 7,pl4 #bi74 ,sev]al quakes 7 felt 9 ,b]muda be=e in/rum5tal record+ 0 available to p]mit location ( _! epic5t]s4 ,two quakes occurr$ 9 ! abyssal pla9 nor?we/ ( ! ,cape ,v]de ,isl&s1 & two 7 locat$ ne> ,!ta ,gap nor?we/ ( ,cape ,f9i/]e4 ,all o!r e>?quakes ( ! c5tral "p ( ! ocean bas9 are associat$ ) ! ,mid-,atlantic ,ridge or its ea/]n ext5sion4 ,,ocean-,,bas9 ,,floor ,,prov9ces ,,& ,,cru/al ,,/ructure ,! results ( seismic-refraction measurem5ts 9 ! ocean-bas9 floor c be divid$ into two categories dep5d+ on :e!r ! measurem5ts 7 made 7#a7 9 ! abyssal floor1 or 7#b7 on an oceanic rise4 ,measurem5ts 9 ! abyssal floor ( ! we/]n ,atlantic 7,ew+1 ,sutton1 & ,(fic]1 #aied7 reveal$ ! simple patt]n %[n 9 ,figure #ce;b & e--namely1 t b5ea? #d-e km ( wat] lies 4#e-a km ( s$im5ts & s$im5t>y rock ) a compressional-wave velocity ( ab\t #b km_/sec1 ov]ly+ #c-d km ( oceanic cru/al rocks 7#f4e km_/sec72 b5ea? ?is ! sub-,m mantle rocks %[ a velocity ( ab\t #h4a km_/sec4 ,?is patt]n has be5 obs]v$ by mo/ work]s 9 ! abyssal floors ( o!r oceans 7,raitt1 #aieg2 ,hill1 #aief74 ,(fic]1 ,ew+1 & ,wu5s*el 7#aieb7 & ,katz & ,ew+ 7#aiee7 h report$ on ! /ructure ( ! ,b]muda ,rise4 ,! topographic *ange f abyssal floor to ! ,b]muda ,rise is accompani$ by a correspond+ *ange 9 cru/al /ructure 7,fig4 #ce;b & d74 ,a typical column measur$ on ! ,b]muda ,plateau is %[n 9 ,figure #ce;d4 ,"h ! sub-,m velocity appe>s to be l[]1 or possibly a new int]m$iate-velocity lay] is ins]t$ betwe5 ! oceanic cru/ & ! true mantle4 ,9 ! ,b]muda ,rise seismic velocities 9 ! oceanic cru/ diff] some:at f ! typical abyssal-floor values4 ,9 ! ,b]muda ,apron & adjac5t p>ts ( ! ,b]muda ,plateau 7,fig4 #ce;c7 above ! oceanic cru/ a ?ick 7up to #d km7 section ( #d4e km_/sec velocity is f\nd :i* has be5 q reasonably id5tifi$ z s$im5t>y & volcanic rocks4 ,seismic-reflection measurem5ts 9 ! smoo!r p>ts ( ! ocean-bas9 floor fall into two g5]al gr\ps4 ,reflection records f ! oceanic rises g5]ally %[ a succession ( reflections :i* c be correlat$ = consid]able di/ances4 ,reflection records f ! abyssal pla9s 9 g5]al %[ _m reflections :i* are usually impossible to correlate ev5 betwe5 adjac5t %ots4 ,?is diff]5ce has be5 expla9$ by ,ericson1 ,ew+1 & ,heez5 7#aieb7 9 t]ms ( ! di/ribution ( turbidity-curr5t deposits4 ,9 ! abyssal pla9s relatively frequ5t turbidity fl[s h deposit$ an alt]nat+ sequ5ce ( clays & silts :i* return a great numb] ( reflections to ! reflection seismograph4 ,9 contra/ ! rises receive only pelagic s$im5tation1 & ?us ! lay]+ ( _! s$im5t>y cov] is simple & widespread s9ce x relates to major *anges 9 pelagic s$im5tation ( pa/ geologic ages4 ,illu/ration3 ,,figure #ce4--;,cru/al sections 9 v>i\s physiographic prov9ces1 det]m9$ by seismic-refraction measurem5ts 7a74 ,ea/]n ,new ,york2 ,katz & ,ew+ 7#aiee7 7b74 ,we/]n ,sohm ,abyssal ,pla92 ,/ation ,a #agb-bh1 f ,katz & ,ew+ 7#aiee7 7c74 ,b]muda ,apron2 ,/ation ,a #agb-bj f ,katz & ,ew+ 7#aiee7 & ,(fic] et al4 7#aieb7 7d74 ,b]muda ,plateau2 ,/ation ,a #agb-ai1 f ,katz & ,ew+ 7#aiee7 7e74 ,n>es ,abyssal ,pla92 p]sonal communication f ,j4 ,i4 ,ew+ 7f74 ,mid-,atlantic ,ridge2 p]sonal communication f ,j4 ,i4 ,ew+ ,,mid-,,oceanic ,,ridge ,,def9ition ,! ?ird basic subdivision ( ! oceanic depression is ! ,mid-,oceanic ,ridge1 a cont9u\s m$ian ridge :i* runs ! l5g? ( ! ,nor? ,atlantic1 ,s\? ,atlantic1 ,indian & ,s\? ,pacific oceans1 = m ?an #dj1jjj miles 7,heez5 & ,ew+1 9 press74 ,9 ! c5t] ?ird ( ! physiographic diagram a %ort segm5t ( ?is _w-encircl+ ridge is repres5t$4 ,,mid-,,atlantic ,,ridge ,"o c f9d ref]5ces to ! ,mid-,atlantic ,ridge 9 ! sci5tific lit]ature dat+ back m ?an #hj ye>s4 ,be=e ! adv5t ( ! e*o s\nd] ! lat]al limits ( ! ,mid-,atlantic ,ridge 7 v difficult to def9e1 & ev5 n[ widely diff]5t def9itions are us$4 ,murray 7#aiab7 m5tion$ t ! ridge lay 9 dep?s less ?an #bjjj fa?oms b po9t$ out t locally on ! ridge dep?s exce$$ #bjjj fa?oms4 ,! ,,meteor exp$ition *>ts & pr(iles g5]ally imply by _! label+ t ! ridge is ! area enclos$ by ! #djjj-met] cont\r 7#bbej fa?oms74 ,%ep>d 7#aidh7 /ates t its av]age dep? is ab\t #aejj fa?oms1 b x rises ab\t #ajjj fa?oms above deep] zones on ei!r side4 ,tol/oy & ,ew+ 7#aidi7 & ,tol/oy 7#aiea7 9 g5]al limit ! ridge to dep?s ( less ?an #bejj fa?oms1 al?\gh 9 "o "p ( ! text ,tol/oy & ,ew+ limit x to less ?an #bbdj fa?oms1 & ,tol/oy 7#aiea7 implies t ! ridge ext5ds to #bijj fa?oms4 ,9 ! pres5t pap] ! ,mid-,atlantic ,ridge is consid]$ z a morpho-tectonic unit def9$ 9 t]ms ( morphology1 & !re=e its def9ition is n bas$ on a clos$ isoba?4 ,! ,mid-,atlantic ,ridge is t portion ( ! ,mid-,oceanic ,ridge sy/em :i* lies )9 ! limits ( ! ,atlantic ,ocean4 ,x consi/s ( a broad1 fractur$ m$ian ar* or swell :i* occupies approximately ! c5t] ?ird ( ! ocean4 ,its cre/ lies ne> ! m$ian l9e ( ! ocean1 & its lat]al b\nd>ies are =m$ by sc>ps#b :i* lie ne> ! axes ( maximum dep? ( ! ea/]n & we/]n bas9s4 ,adjac5t to ! ,mid-,atlantic ,ridge bo? to ! ea/ & to ! we/ is ! abyssal floor 7usually abyssal hills7 ( ! ocean-bas9 floor4 #b ,sc>ps h be5 se5 on e record$ cross+4 ,if !y %\ld be abs5t on a future cross+1 x is expect$ t a major *ange 9 gradi5t w be f\nd :i* w s]ve z a consi/5t def9ition = ! ridge b\nd>y4 ,exagg]at$ pr(iles are useful 9 br++ out ! major morphological *>act]i/ics ( deep-sea topography4 ,= "s purposes1 h[ev]1 x is desirable to /udy ! topography 9 pr(iles ) no v]tical exagg]ation4 ,two su* pr(iles are %[n 9 ,figures #cg-da4 ,! position ( ! two pr(iles is indicat$ 9 ,figure #cf4 ,a v good idea ( ! individual slopes c be ga9$ f a /udy ( ^! natural-scale pr(iles1 b ! prov9ce b\nd>ies are v difficult to id5tify4 ,a typical cross pr(ile at #dj3a exagg]ation is %[n 9 ,figure #db1 a typical oceanic cross section1 9 :i* ea* physiographic prov9ce ( ! ,mid-,atlantic ,ridge is labell$4 ,illu/ration3 ,,figure #cf4--;,index to natural-scale ,mid-,atlantic ,ridge pr(iles reproduc$ 9 ,figures #cg-da ,,prov9ces ,,( ,,! ,,mid-,,atlantic ,,ridge ,! ,mid-,atlantic ,ridge 0 subdivid$ by ,tol/oy & ,ew+ 7#aidi7 & ,tol/oy 7#aiea7 into 7a7 ! c5tral backbone or ma9 range :i* is %all[] ?an #afjj fa?oms1 & 7b7 ! flanks or ! t]rac$ zone betwe5 ! #afjj- & #bejj-;fa?om isoba?s4 ,9 ?is pap] we use a simil> b some:at diff]5tly def9$ sy/em by divid+ ! prov9ces ( ! ,mid-,atlantic ,ridge into two categories3 7#a7 ! cre/ prov9ces1 & 7#b7 ! flank prov9ces4 99 99 99 99 99 ,cre/ prov9ces4--,! prov9ces ( ! cre/ ( ! ,mid-,atlantic ,ridge consi/ ( 7#a7 ! ,rift ,valley 7or ,valleys72 7#b7 ,rift ,m\nta9s2 & 7#c7 ,high ,fractur$ ,plateau 7,fig4 #dc74 ,! ,azores ,plateau1 :i* =ms "p ( ! cre/1 pres5ts additional problems & is discuss$ sep>ately4 ,,rift ,,valley3 ,! mo/ /rik+ feature on an av]age pr(ile across ! ,mid-,atlantic ,ridge is a deep not* or cleft 9 ! cre/ ( ! ridge4 ,9 a small p]c5tage ( ! s\nd+ pr(iles two or ?ree su* valleys are pres5t1 & on a few pr(iles no notable depressions are obs]v$4 ,on an av]age pr(ile ! floor ( ! valley lies at ab\t #bjjj fa?oms1 :ile ! adjac5t peaks av]age ab\t #ajjj fa?oms bel[ ! sea surface4 ,! wid? ( ! valley betwe5 ! cre/s ( ! adjac5t peaks ranges betwe5 #ae & #cj miles1 & ! dep? ( ! valley floor b5ea? ! highe/ adjac5t peak ranges f #gjj to #bajj fa?oms4 ,! wid? ( ! valley #ejj fa?oms above its floor ranges f #e to #bb miles4 ,! range 9 obs]v$ dep?s ( ! valley is #aaej to #bhej fa?oms 9 ! area ( ! physiographic diagram4 ,! adjac5t peaks range f #ejj to #acjj fa?oms )9 ! same area 7exclud+ ! area ne> ! ,azores7 7,fig4 #dg74 ,illu/ration3 ,,figure #cg4--,natural-scale ,mid-,atlantic ,ridge pr(ile #a;,a ,slope corrections h be5 appli$ to pr(iles #a & #b4 ,! me?od is describ$ by ,elm5dorf & ,heez5 7#aieg74 ,illu/ration3 ,,figure #ch4--,natural-scale ,mid-,atlantic ,ridge pr(ile #a;,b ,illu/ration3 ,,figure #ci4--,natural-scale ,mid-,atlantic ,ridge pr(ile #a;,c ,illu/ration3 ,,figure #dj4--,natural-scale ,mid-,atlantic ,ridge pr(ile #b;,a ,illu/ration3 ,,figure #da4--,natural-scale ,mid-,atlantic ,ridge pr(ile #b;,b ,illu/ration3 ,,figure #db4--,type pr(ile1 prov9ces ( ! ,mid-,atlantic ,ridge ,illu/ration3 ,,figure #dc4--,trac+ ( ,,pdr record1 ,rift ,valley1 ,rift ,m\nta9s1 ,high ,fractur$ ,plateau1 & ,upp] ,/ep ,illu/ration3 ,,figure #dd4--,trac+ ( ,,pdr record1 ,we/]n ,rift ,m\nta9s ,tw5ty-six cross+s ( ! ,rift ,valley are %[n 9 ,figure #de4 ,! pr(iles c be divid$ into ?ree gr\ps3 7#a7 s+le well-develop$ rift valley2 7#b7 sev]al well-develop$ deep valleys2 7#c7 no p>ticul>ly deep c5tral valley4 ,mo/ ( ! pr(iles 7#bj7 fall into ! fir/ class2 ! second class is repres5t$ by #e1 & only #a falls 9 ! ?ird class4 ,! topography ( ! floor ( ! rift is r\gh4 ,9 no in/ance has a flat floor be5 obs]v$4 ,:]e ! valley is wide/ m\nta9s a few hundr$ fa?oms high protrude f its floor4 ,,rift ,,m\nta9s3 ,! /eep walls flank+ ! rift ea* =m "o side ( a l>ge r\gh-sid$ block4 ,!y might be consid]$ z tilt$ blocks ^: fac+ slopes =m ! ,rift ,valley4 ,! back or out] slope ( ! ,rift-,m\nta9s ,prov9ce is g5]ally brok5 into m\nta9s z mu* z #ejj fa?oms high & #aj miles wide 7,fig4 #dd74 ,! lat]al limit ( ! ,rift-,m\nta9s ,prov9ce is rea*$ :5 ! av]age slope ( ! sea floor flatt5s m>k$ly4 ,because ( ! high local relief x is sometimes difficult to pick ! b\nd>y ( ! ,rift ,m\nta9s1 b 9 almo/ all record$ pr(iles ! approximate position ( ! b\nd>y is unmi/akable4 ,illu/ration3 ,,figure #de4--,tw5ty-six rift valley pr(iles1 ,mid-,atlantic ,ridge ,position ( pr(iles %[n on ,plate #bc ,illu/ration3 ,,figure #df4--;,five repres5tative pr(iles1 cre/ & we/]n flank ( ,mid-,atlantic ,ridge ,,high ,,fractur$ ,,plateau3 ,! ,high ,fractur$ ,plateau is adjac5t to ! ,rift ,m\nta9s on ei!r side ( ! ridge 7,fig4 #db74 ,! local relief is ab\t #djj fa?oms f peak to adjac5t valley1 & ! di/ance f peak to peak ranges f #h to #bj miles4 ,9 contra/ to ! adjac5t flank prov9ces !re are no fill$ int]montane valleys1 & ! valleys are deep] & n>r[] ?an 9 ! adjac5t ,upp] ,/ep ,prov9ce4 ,)9 ! limits ( ! physiographic diagram1 ! av]age dep? ( ! ,high ,fractur$ ,plateau ranges f #aejj to #aijj fa?oms4 99 99 99 99 99 ,flank prov9ces4--,betwe5 ! out] m>g9 ( ! ,high ,fractur$ ,plateau prov9ces & ! level ( ! ocean-bas9 floor lies a succession ( p>allel prov9ces1 kn[n z ! ,upp] ,/ep1 ! ,middle ,/ep1 & ! ,l[] ,/ep4 ,! limits ( ^! prov9ces are ! lea/ well def9$ ( all ! prov9ces describ$ 9 ?is pap]4 ,! flanks ( ! ridge are *>act]iz$ by r\gh topography 7,pl4 #ah74 ,peaks ( m ?an #bjj fa?oms high occur at a frequ5cy ( ab\t #ae p] #ajj miles4 ,"s ( ! valleys betwe5 peaks are smoo?1 p>ticul>ly 9 ! prov9ces s\? ( ! ,azores ,plateau4 ,! flanks ( ! ,mid-,atlantic ,ridge are brok5 by sc>ps :i* seem to p]si/ = relatively long di/ances p>allel to ! tr5d ( ! cre/ 7,pl4 #bj74 ,^! sc>ps or sc>p zones break ! ridge into a succession ( units "h call$ /eps 7,fig4 #df74 ,an alt]native solution also s]i\sly consid]$ by ! writ]s is t ! /eps might m correctly be consid]$ z a s]ies ( tilt$ blocks :i* c\ld be ref]r$ to z ramps4 ,! diff]5ce betwe5 ! two solutions c be appreciat$ by inspect+ ,figures #db & #df4 ,! writ]s mu/ emphasize t ! t]m t]races ( ,tol/oy is 9 no s5se ! same z ! t]m /ep us$ 9 ?is pap]4 ,tol/oy def9$ 8 t]races z a succession ( smoo? %elves1 ea* f #a to #ej miles 9 wid?1 :i* occupy a zone #bjj-cjj miles wide4 ,features fitt+ ?is def9ition are call$ int]montane bas9s 9 ?is pap]1 foll[+ a sugge/ion made by ,heez5 et al4 7#aiea74 ,! location ( smoo?-floor$ int]montane bas9s is %[n on ,plate #bj4 ,!y are f\nd only 9 ! area ext5d+ ab\t #h s\?we/ ( ! ,azores4 ,small arr[s indicate ! slope ( ! smoo? floors4 ,9 g5]al all ! valleys slope away f ! cre/ ( ! ridge4 ,/eps1 on ! contr>y1 are a succession ( av]age levels sep>at$ by sc>ps or sc>p zones & 9 g5]al are n smoo? except t a few bas9s may be fill$4 ,h[ev]1 ?is fill+ is limit$ to a small area s\? ( ! ,azores4 ,! flanks are divid$ into ?ree /eps3 upp]1 middle1 & l[]4 ,! division ( any?+ into ?ree p>ts is suspici\s1 :e!r x be a geologic p]iod or a physiographic region4 ,su* divisions usually are lat] replac$ z m in=mation is obta9$4 ,?is is probably true ( ! ?ree /eps4 ,we are m confid5t ( ! significance ( ! b\nd>ies %[n on ! prov9ce *>t ?an ( ! uniqu5ess ( ! enclos$ areas1 because ea* b\nd>y m>ks a major sc>p or sc>p zone4 ,! /eps are def9$ 9 "p 9 any limit$ area on ! basis ( _! mean dep?4 ,9 g5]al ! ,upp] ,/ep ranges f #afej to #bcjj1 ! ,middle ,/ep f #bbej to #bejj1 & ! ,l[] ,/ep f #bcej to #bhjj fa?oms4 ,j z ! maximum dep? ( ! ridge & ! axis ( maximum dep? ( ! bas9 v>y ) di/ance along ! ridge 7or ) latitude71 s ! /eps v>y 9 dep? & wid? 7,fig4 #dg74 ,illu/ration3 ,,figure #dg4--;,axial pr(ile ( ! ,mid-,atlantic ,ridge 7a74 ,di/ance betwe5 prov9ce b\nd>ies ( ! ea/]n & we/]n flanks ( ! ,mid-,atlantic ,ridge measur$ along p>allels ( latitude4 7b74 ,wid? ( ! ,rift ,valley measur$ at #bej fa?oms & at #ejj fa?oms above ! valley bottom & betwe5 ! highe/ peaks ( ! ,ea/]n & ! ,we/]n ,rift ,m\nta9s4 ,wid? 9 miles measur$ at "r angles to ! tr5d ( ! ridge4 7c74 ,! dep? bel[ sea level ( ! ,rift ,valley1 ! ,rift ,m\nta9s & ! we/]n & ea/]n axes ( maximum dep?4 ,! dep?s %[n on ?is graph are 9 uncorrect$ e*o-s\nd+ fa?oms4 99 99 99 99 99 ,azores ,plateau4--,! ,azores ,plateau is an area ( #eb1jjj squ>e miles ( sea floor1 surr\nd+ ! ,azores ,isl&s1 :]e ! dep? is less ?an #ajjj fa?oms4 ,! ,azores ,isl&s are ori5t$ s\?-s\!a/-nor?-nor?we/ along a topographic tr5d :i* /rikes (f t[>d ! ,/raits ( ,gibralt>4 ,?is topographic connection betwe5 ! ,azores ,plateau & ! s\!rn ,ib]ian ,p59sula has be5 call$ ! ,azores-,gibralt> ,ridge1 :i* ! pres5t writ]s consid] z a poorly develop$ mid-oceanic ridge ( ! same g5]al class z ! ,mid-,atlantic ,ridge4 ,! ,azores ,plateau itself m]ges ) ! ,rift ,m\nta9s ( ! ,mid-,atlantic ,ridge4 ,! sea-floor topographic tr5ds ( ! ea/]n "p ( ! plateau are p>allel to ! kn[n tectonic & volcanic tr5ds ( ! ,azores ,isl&s 7,ago/9ho1 #aicg74 ,9 ! we/]n "p ( ! ,azores ,plateau tr5ds are nor?-s\? p>allel to ! ma9 tr5ds ( ! ,mid-,atlantic ,ridge4 ,al?\gh bo? ,w/ 7#aidj;a7 & ,tol/oy 7#aiea7 h publi%$ cont\r *>ts ( ! ,azores ,plateau1 x rema9s l>gely a my/]y :e!r ! tr5ds ( ! ea/]n ,azores ,plateau cross or jo9 ! axial tr5ds ( ! ,mid-,atlantic ,ridge4 ,! ,azores ,plateau or bulge is g5]ally consid]$ z a highly fractur$ tectonic uplift 9 :i* vulcanism has play$ a comp>atively small "p 7,cloos1 #aici74 99 99 99 99 99 ,azores-,gibralt> ,ridge4--,an ill-def9$ irregul> ridge runs f ! ea/]n end ( ! ,azores ,plateau to ! ,/raits ( ,gibralt>4 ,l>gely on ! basis ( its seismicity we inf] t ?is ridge is /ructurally & topographically simil> to ! ,mid-,atlantic ,ridge4 ,! few exi/+ topographic pr(iles across ?is feature sugge/ t ! e>?quake belt is associat$ ) a rift valley ( ! same g5]al type z ! c5tral ,rift ,valley ( ! ,mid-,atlantic ,ridge4 ,dep?s 9 ?is rift appe> to rea* #bcjj-bhjj fa?oms1 & ! dep? ( ! tops ( ! adjo9+ m\nta9s range f #afjj to #bjjj fa?oms4 ,! flank prov9ces are ev5 less well develop$4 99 99 99 99 99 ,atlantis-,plato-,cruis]-,great ,meteor ,seam\nt ,*a94--,s\? ( ! ,azores a *a9 ( great seam\nts bran*es (f f ! ,high ,fractur$ ,plateau & crosses ! ,upp] & ,middle /eps 9 a ne>ly nor?-s\? direction4 ,^! seam\nts--,atlantis1 ,plato1 ,cruis]1 & ,great ,meteor--9 g5]al h broad1 ne>ly flat summits at dep?s ( #ajj-bej fa?oms4 ,! l>ge/ "o1 ,great ,meteor1 0 discov]$ by work]s on ! ,,meteor 9 #aicg4 ,?is seam\nt1 #fj miles across at its base1 rises maje/ically m ?an #bfjj fa?oms above ! floor ( ! ocean4 ,s&s & calc>e\s rocks h be5 dr$g$ f ! summits1 & ,t]ti>y s$im5ts h be5 obta9$ f ! flanks ( ! seam\nts4 ,photographs ( ! tops & ( ! flanks to a dep? ( #afjj fa?oms %[ ripple m>ks4 ,?is gr\p is describ$ 9 a pap] by ,heez51 ,ew+1 ,ericson1 & ,b5tley 79 press74 ,,geology ,,& ,,geophysics ,,( ,,mid-,,atlantic ,,ridge ,,physiographic ,,prov9ces ,seismicity ( ! ,mid-,atlantic ,ridge4--,! e>?quake epic5t]s in/rum5tally det]m9$ = ! ,nor? ,atlantic up to #aief are %[n 9 ,plate #bi4 ,ne>ly all e>?quakes fall 9 ! cre/ zone4 ,consid]+ t det]m9ation ( %ocks is accurate only to )9 - to #a 1 x is q surpris+ t ! plott$ epic5t]s =m su* a n>r[ belt4 ,inve/igation ( ! problem ( ! physiographic prov9ce mo/ seismically active reveals t _m epic5t]s actually plot 9 ! ,rift ,valley & t virtually all t d n are )9 ab\t #a ( ! ,rift ,valley4 ,all seismic activity !re=e is limit$ to ! cre/ prov9ces1 & probably virtually all ! activity is conc5trat$ )9 ! ,rift-,valley ,prov9ce4 ,a l9e ( epic5t]s runs f ! ,rift ,valley ne> ,flores ,isl& ( ! ,azores t[>d ! ,/raits ( ,gibralt>4 99 99 99 99 99 ,s$im5ts & physiographic prov9ces ( ! ,mid-,atlantic ,ridge4--,! ,mid-,atlantic ,ridge is ! major site ( undi/urb$ pelagic s$im5tation ( ! ,atlantic because ( its isolation f d[n-slope movem5ts />t+ on ! cont95tal m>g94 ,h[ev]1 turbidity curr5ts mu/ =m ne> ! %ores ( oceanic isl&s & ! edges ( %all[ banks & probably contribute s$im5ts to ! int]montane valleys4 ,photographs tak5 on ! ,rift ,m\nta9s & on ! sides ( major seam\nts %[ sc\r m>ks & ripple m>ks1 indicat+ consid]able w9n[+ & sc\r by deep-ocean curr5ts 7,pl4 #ai74 ,?is s$im5t c>ri$ f ! tops ( peaks & deposit$ on ! /eep m\nta9 sides probably slumps occasionally & =ms turbidity curr5ts :i* fl[ to ! adjac5t valley floors 7,pl4 #bh74 ,= ?is reason cores tak5 9 int]montane valleys & ne> ! high] peaks w h consid]able int]lay]+ ( turbidity-curr5t deposits1 & mu* ( ! sides & cre/s ( individual high m\nta9s is b>e rock4 ,9 ! ,rift ,m\nta9s true pelagic s$im5ts are only occasionally f\nd4 ,x is /rik+ to note t 9 cor+ & bottom photography b>e-rock slopes are f\nd mo/ commonly 9 ! ,rift ,m\nta9s & ,high ,fractur$ ,plateau1 b flat-floor$ int]montane bas9s are abs5t 9 ^! prov9ces4 ,?is mu/ indicate ei!r t ! topography ( ! ,rift ,m\nta9s is v new or t ! s$im5t erod$ f ! cre/ prov9ces is c>ri$ all ! way to ! ,upp] ,/ep ,prov9ce :]e x is deposit$ 9 ! int]montane bas9s4 99 99 99 99 99 ,rocks ( ! ,mid-,atlantic ,ridge4--,our k ( ! li?ology ( ! ,mid-,atlantic ,ridge comes f ?ree s\rces3 7#a7 rocks dr$g$ f ! sea floor1 7#b7 detrital rock fragm5ts f\nd 9 s$im5t cores1 & 7#c7 rocks expos$ on ! isl&s ( ! ,ridge4 ,"s ( ! e>lie/ rock dr$g+ on ! ,mid-,atlantic ,ridge 0 done 9 #ahhe by ! ,,talisman exp$ition4 ,9 #aidi ,furon 7#aidi7 report$ ! occurr5ce ( fossil trilobites 9 dr$ge samples :i* _h be5 /or$ = m ?an half a c5tury 9 a ,fr5* ,museum4 ,"o dr$g+ 0 made 9 ! ,high ,fractur$ ,plateau ( ! ea/]n ,atlantic at #db #ba,n41 #ag #ab,w41 9 #dbee met]s dep? 7#bccj fa?oms74 ,furon believes t ! mat]ial 0 9 situ & !re=e pro( ( e>ly ,paleozoic outcrops on ! ,mid-,atlantic ,ridge4 ,! abundant evid5ce ( glacially raft$ rocks ev5 z f> s\? z #cj ,n4 ca/s s]i\s d\bt on ?is conclusion1 b nev]!less ! possibility t ! mat]ial might h be5 9 situ mu/ be consid]$4 ,! ,mid-,atlantic ,ridge ,exp$ition ( #aidg l$ by ,ew+ made a numb] ( successful rock-dr$ge hauls on ! ,mid-,atlantic ,ridge4 ,! mo/ successful hauls 7 made 9 ! ,rift ,valley & on ! adjac5t ,rift ,m\nta9s at ab\t #cj ,n4 ,lat4 ,! specim5s h be5 describ$ by ,%& 7#aidi71 :o report$ oliv9e gabbro1 s]p5t9e1 basalt1 & diabase4 ,"o lime/one ( probably ,t]ti>y age 0 collect$ ! same ye> b has n be5 describ$4 ,! suite ( cry/all9e rocks obta9$ is simil> to ^? f\nd on oceanic isl&s else:]e on ! ,mid-,oceanic ,ridge4 99 99 99 99 99 ,cru/al /ructure & ! ,mid-,atlantic ,ridge prov9ces4--,! cru/al /ructure ( ! ,mid-,atlantic ,ridge prov9ces has be5 det]m9$ at ab\t #bj places by ! seismic-refraction te*nique 7,fig4 #ce;f74 ,^! /udies1 conduct$ by ,john ,i4 ,ew+ & ,w4 ,m4 ,ew+ 79 press71 h %[n t ! av]age cru/al /ructure ( ! cre/ prov9ces & ,upp] ,/ep consi/s ( #j4d km ( l[-velocity s$im5t & #b4h km ( rock ) a velocity ( #e4a km_/sec ov]ly+ a sub/ratum 9 :i* ! velocity is #g4c km_/sec4 ,! ?ickness ( ! lay] ( l[-velocity s$im5t v>ies consid]ably f place to place4 ,9 ! cre/ prov9ces ! #e4a km_/sec lay] is commonly expos$4 ,9 ! flank prov9ces appreciable ?icknesses 7to #a km7 ( s$im5t h be5 measur$4 ,! s$im5t seems to ?ick5 betwe5 major sc>p zones & ridges z if ! s$im5t 7 collect+ 9 longitud9al bas9s p>allel to ! axis ( ! ridge4 ,an insuffici5t numb] ( measurem5ts h be5 made to det]m9e :e!r ^! accumulations correlate ) ! b\nd>ies ( individual int]montane bas9s or ) ! limits ( individual /ep prov9ces4 ,! /ructure ( ! abyssal floor1 cre/ prov9ces1 & flank prov9ces is comp>$ 9 ,figure #ce4 ,! two high]-velocity lay]s %[n 9 ! abyssal-floor sections 7,n>es & ,sohm ,abyssal ,pla91 ,fig4 #ce71 h be5 obs]v$ 9 all measurem5ts made 9 ^! prov9ces4 ,! #f4g km_/sec lay] is g5]ally consid]$ to be gabbroic1 & ! #h4a km_/sec lay] is by def9ition ! e>?'s mantle4 ,9 ! ,mid-,atlantic ,ridge section ! upp] high-velocity mat]ial has an av]age velocity ( #e4a km_/sec & is g5]ally id5tifi$ z basaltic rock4 ,! velocity ( ! und]ly+ mat]ial 7#g4c km_/sec7 is int]m$iate betwe5 ! velocity ( oceanic cru/al rocks 7#f4g km_/sec7 & t ( mantle rocks 7#h4a km_/sec71 z obs]v$ bo? b5ea? ! cont95ts & b5ea? ! abyssal floor4 ,ew+ & ,ew+ 79 press7 sugge/ t ?is int]m$iate velocity is ! result ( a physical mixture ( oceanic cru/al rocks & mantle rocks4 ,to expla9 su* l>ge-scale mix+ !y propose t ext5sive vulcanism & intrusion along ! ,mid-,atlantic ,ridge h produc$ an int]m+l+ ( ! cru/al & mantle rocks1 & t ?is 0 associat$ ) convection cells 9 ! deep mantle :i* supply l>ge quantities ( basaltic magma & produce ext5sional =ces on ! cru/ & upp] mantle4 ,ne>ly #bj cross+s ( ! cre/ ( ! ridge h be5 made ) ! total-int5sity magnetomet] t[$ beh9d rese>* vessels employ+ cont9u\sly record+ e*o s\nd]s4 ,a *>act]i/ic anomaly patt]n has be5 not$ by ,ew+1 ,heez51 & ,hir%man 7#aieg74 ,! ,rift ,valley is *>act]iz$ by a l>ge positive anomaly1 :ile ! adjo9+ ,rift ,m\nta9s %[ negative anomalies ( #cjj to #ejj gammas 7,fig4 #dh74 ,free-air gravity anomalies ov] ! cre/ prov9ces & ,upp] ,/ep are usually #cj-ej mg positive1 :ile ! ,rift ,valley z measur$ 9 two places gave free-air anomalies ( -#c & -#bj mg4 ,illu/ration3 ,,figure #dh4--,pr(ile ( total magnetic int5sity & topography1 ,mid-,atlantic ,ridge ,s\nd+s made ) ,,pdr4 ,magnetic measurem5ts made ) fluxgate total-int5sity magnetomet]4 ,magnetic values 9 gammas relative to an arbitr>y z]o4 ,illu/ration3 ,,figure #di4--,physiographic prov9ces & trans-,atlantic /ructure ,bas$ on scatt]$ seismic-refraction measurem5ts 9 ! ,nor? ,atlantic :i* h be5 project$ along prov9ce b\nd>ies4 ,! topographic pr(ile 0 piec$ toge!r f cont9u\sly record$ e*o-s\nd+ pr(iles f ,new ,york to ,spani% ,sah>a4 ,9 ! cont95tal m>g9 ! upp] lay] repres5ts ! s$im5t>y rock4 ,! da%$ symbol indicates ! cont95tal cru/al rocks4 ,! l[] lay] repres5ts oceanic cru/al rocks4 ,! mantle lies bel[ ! l[e/ lay]4 ,a heat-fl[ measurem5t by ,e4 ,c4 ,bull>d 9 ! ,rift ,valley prov9ce 9 ! ,nor? ,atlantic indicat$ a value ( ab\t #g #aj cal4_/cm_/sec4 :i* is ab\t #f times ! av]age value ( #a4b #aj cal4_/cm_/sec obs]v$ 9 ! ,l[] ,/ep & abyssal floor ( ! ea/]n ,atlantic 7,bull>d1 #aied2 ,bull>d et al41 #aief74 ,high heat-fl[ values h also be5 obs]v$ on ! ,ea/] ,isl& ,ridge ( ! ,s\!a/ ,pacific1 sugge/+ t ! entire ,mid-,oceanic ,ridge rift sy/em may be s *>act]iz$4 ,an adequate syn!sis & explanation ( all ^! conv]g+ l9es ( evid5ce has n yet be5 =mulat$4 ,h[ev]1 ! correlation ( s _m types ( geophysical & geological data speaks favorably = ! validity & tectonic significance ( ! physiographic prov9ces describ$ "h4 ,on ! basis ( ! obs]v$ correspond5ce ( cru/al /ructure & physiographic prov9ces a hypo!tical trans-,atlantic /ructure section 0 prep>$ 7,fig4 #di74 ,seismic-refraction measurem5ts 7 project$ along prov9ce b\nd>ies & plott$ b5ea? an e*o-s\nd+ pr(ile f ,new ,york to ,spani% ,sah>a4 ,! black splot*$ areas repres5t ! #g4c km_/sec lay]4 ,?is velocity int]m$iate betwe5 #h4a km_/sec ( normal mantle & #f4g km_/sec ( normal oceanic cru/ is consid]$ 7#a7 a mixture ( ! two normal lay]s2 7#b7 a l[-velocity "p ( ! mantle1 or 7#c7 a di/9ct cru/al lay] *>act]i/ic ( mid-oceanic ridges4 ,! /ructure %[n = ! cont95tal m>g9 ( ,africa is bas$ on analogy ) ! /ructure ( ! cont95tal m>g9 ( nor!a/]n ,unit$ ,/ates4 ,?is proc$ure seems ju/ifi$ by ! close simil>ity ( ! cont95tal-m>g9 physiographic prov9ces ( ! two areas4 99 99 99 99 99 ,orig9 ( ! ,mid-,atlantic ,ridge4--,( ! _m !ories :i* h be5 propos$ = ! orig9 ( ! ,mid-,atlantic ,ridge almo/ all h be5 extremely speculative1 & none has be5 bas$ on any v detail$ k ( ! feature4 ,we are /ill a long way f hav+ a compreh5sive k ( ! ,ridge4 ,! v>i\s !ories ( orig9 & _! factual basis h be5 briefly review$ by ,tol/oy & ,ew+1 :o conclude t x is impossible to say if ! feature is prim>ily ( fold$ or fault$ orig94 ,9 a pap] 9 press ,heez5 & ,ew+ comp>e 9 detail ! topography & seismicity ( ! ,african rift valleys & ! ,rift ,valley ( ! ,mid-,atlantic ,ridge4 ,_! conclusion is t ! two areas are ( basically ! same /ructure1 & 9 fact bo? =m p>ts ( ! same cont9u\s /ructural feature4 ,s9ce ! ,african rift valleys seem cle>ly to be ! result ( normal fault+ result+ f ext5sion ( ! cru/1 ,heez5 & ,ew+ conclude t ! topography ( ! ,mid-,atlantic ,ridge is l>gely ! result ( normal fault+4 ,:e!r ! =ces are ! result ( horizontal ext5sion or v]tical uplift rema9s ! mo/ important unsolv$ problem 9 connection ) ! orig9 ( ! cont95tal z well z ! suboceanic rift-valley sy/ems4 ,hess 7#aied7 has propos$ a me*anism relat+ suboceanic uplift to expansion due to s]p5tization ( ! upp] mantle4 ,,sub-,,bottom ,,reflections ,,record$ ,,on ,,precision ,,dep? ,,record] ,,records ,,& ,,physiographic ,,prov9ces ,9 "s areas ( ! ocean ,,pdr records %[ a reflect+ surface a few fa?oms bel[ ! bottom4 ,su* horizons are obs]v$ only :5 ! s\nd] is op]at$ ) a %ort 7#e-millisecond7 p+ l5g? 79 e*o s\nd+ ! transmitt$ s\nd is call$ ! p+1 & its duration is call$ ! p+ l5g?74 ,:5 a long p+ is us$ ! fir/ return+ e*o masks any subsequ5t e*oes occurr+ less ?an ab\t #aj fa?oms aft] ! fir/ e*o4 ,to e/abli% cont9uity ( ! l[] horizon x is necess>y to run ! record] )\t int]ruption1 s5d+ p+s once a second4 ,s9ce a faulty p++ circuit or "s accid5t ( geometry c\ld conceivably s5d out two closely spac$ p+s1 ! suppos$ sub-bottom e*oes mu/ be c>efully *eck$ to make sure t !y are n bo? bottom e*oes f two closely spac$ p+s4 ,if two p+s 7 be+ s5t out ! second e*o w\ld always symmetrically und]lie ! bottom surface4 ,if1 h[ev]1 ! two surfaces %[ local v>iations1 x c be safely conclud$ t ! deep] "o is a true sub-bottom e*o4 ,9 ord] to obs]ve sub-bottom e*oes ! sea floor %\ld be reasonably smoo? s9ce 9 rugg$ relief side e*oes & cross+ highlight hyp]bolas obscure any sub-bottom e*oes :i* might occur4 ,sub-bottom e*oes 9 ! ,gulf ( ,ma9e h be5 well describ$ by ,murray 7#aidg74 ,9 local in%ore areas prom95t sub-bottom e*oes record$ by unmodifi$ or slightly modifi$ /&>d e*o s\nd]s h be5 us$ to map basem5t rocks 7,smi? et al41 #aieb74 ,9 ! deep sea1 sub-bottom e*oes or p5etration are obs]v$ mo/ frequ5tly 9 ! cont95tal rise1 oceanic rises1 & ! f> edges ( ! abyssal pla9s4 ,p5etration is r>e on ! op5 cont95tal %elf & on ! cont95tal slope4 ,z ! dep? increases1 e*oes are m difficult to obta91 s t records f diff]5t dep?s _c be directly comp>$ 9 ref]5ce to ease ( p5etration4 ,x nev]!less seems to be true t sub-bottom e*oes are r>e or abs5t on ,,pdr records f ! p>ts ( ! abyssal pla9s close/ to ! cont95tal m>g94 ,p5etration 9 ! cont95tal rise is common b frequ5tly irregul> & int]mitt5t4 ,"o ( ! mo/ p]si/5t & uni=m sub-bottom reflect+ horizons obs]v$ occurs on ! out] ridge ea/ ( ! ,bahamas 7s\? ( #cj ,n47 7,pl4 #f74 ,records f ! abyssal pla9 imm$iately adjac5t to ! abyssal hills 7,pl4 #ac ,fig4 #d7 & f ! flat-floor$ tongues 9 ! abyssal hills 7,pl4 #aj7 reveal "s ( ! deepe/ & /ronge/ sub-bottom e*oes4 ,good sub-bottom e*oes are common 9 ! ,b]muda ,plateau4 ,! sub-bottom reflect+ lay]s frequ5tly crop out1 & ! ov]ly+ s$im5ts ?ick5 & ?91 reveal+ app>5tly noticeable v>iations 9 ! rate ( accumulation ( s$im5ts4 ,outcropp+ ( sub-bottom lay]s on ! /eep] slopes indicate slump+1 :ile ! deep5+ ( ! sub-bottom reflect+ horizon 9 valleys indicates a great] rate ( deposition4 ,high-frequ5cy s\nd is normally /rongly att5uat$ by transmission ?r\gh s$im5ts4 ,! obs]vation ( sub-bottom reflections ) high-frequ5cy s\nd pulses 7#ab kc7 indicates 7#a7 t ! surface s$im5t is uni=m & is ( l[ d5sity1 & 7#b7 t a fairly %>p d5sity *ange occurs b5ea? ?is surface lay] ( l[-d5sity mat]ial4 ,9 areas su* z ! out] ridge f #bb to #bi ,n4 ,lat4 & ! s\!rn ,b]muda ,rise1 x c be safely assum$ t ! upp] lay] consi/s ( deep-sea r$ clay4 ,d5sity measurem5ts on r$ clay h indicat$ values ( #a4be to #a4de4 ,! lack ( sub-bottom reflections ov] ! p>ts ( ! abyssal pla9s close to ! cont95ts is attribut$ to ! num]\s s& & silt lay]s f\nd 9 ! cores :i* reflect mo/ ( ! s\nd4 ,! occurr5ce ( good reflections b5ea? ! out] edges ( ! abyssal pla9s c\ld be expla9$ by ei!r assum+ t = a long geologic "t no s&-or silt-c>ry+ turbidity curr5t has rea*$ ?is area1 or t r$ clay is deposit$ "h mu* fa/] ?an else:]e4 ,an extremely prom95t sub-bottom reflector obs]v$ ov] a va/ area ( ! ea/ tropical ,pacific has be5 id5tifi$ by cor+ ) a #aj-;cm ?ick b$ ( :ite1 vitre\s a%4 ,?is sugge/s t sub-bottom reflections f\nd else:]e may1 9 g5]al1 repres5t a% horizons4 ,?is1 ( c\rse1 w\ld presuppose a% falls s va/ t "s record %\ld h be5 pres]v$ on l&4 ,!re is no reason to assume t !re is b a s+le cause ( deep-sea sub-bottom e*oes4 ,! widespread occurr5ce ( ! sub-bottom int]face on ! deep] isolat$ rises may be ( great importance if x be int]pret$ z evid5ce ( a sudd5 *ange 9 s$im5tation result+ 9 a *ange f high]- to l[]-d5sity s$im5t4 ,x is j conceivable1 h[ev]1 t "s un/able diag5etic process may cause a sudd5 increase 9 compaction at a dep? correspond+ to ! sub-bottom reflection4 ,! sub-bottom reflections 9 dep?s ( #bfjj fa?oms on ! s\!rn ,b]muda ,rise & ! out] ridge is ab\t 4#jb second aft] ! bottom e*o1 & ?is indicates a lay] ab\t #aj fa?oms ?ick4 ,at a rate ( deposition ( #a cm_/#ajjj ye>s ?is *ange 9 s$im5t type w\ld h occurr$ #bj million ye>s ago4 ,9 a remotely situat$ oceanic area ! factors controll+ :e!r r$ clay or ,globig]9a ooze is laid d[n are l>gely relat$ to dep? & temp]ature ( ! bottom wat]4 ,^! two factors are relat$ to ^? :i* control ! solubility ( ! c>bonate & ?us ! type ( bottom deposit4 ,emiliani & ,edw>ds 7#aiec71 f a /udy ( oxyg5 isotopes 9 b5?ic ,=am9if]a 9 ,t]ti>y deep-sea s$im5ts f ! ea/]n ,pacific1 conclud$ t ! temp]ature ( ,pacific bottom wat] decreas$ #h ,c4 f ! ,eoc5e to ! pres5t4 ,?is %\ld h caus$ a great increase 9 ! solution ( c>bonate assum+ o!r factors un*ang$4 ,sub-bottom reflections !n may also be int]pret$ z ! result ( a *ange 9 ! temp]ature or ! circulation ( bottom wat] 9 ! deep bas94 ,ext5sive1 bas9-wide sub-bottom reflectors1 :e!r ! result ( va/ b$s ( a% or widespread *anges 9 pelagic s$im5tation1 imply ev5ts ( global importance4 ,! fur!r inve/igation & id5tification ( ^! reflectors %\ld produce data ( f>-rea*+ application 9 geology1 climatology1 & paleo-oceanography4 ,,summ>y ,,( ,,prov9ce ,,*>act]i/ics ,! ,atlantic ,ocean floor consi/s ( ?ree major morphological divisions3 7#a7 cont95tal m>g91 7#b7 ocean-bas9 floor1 & 7#c7 ,mid-,oceanic ,ridge4 ,! cont95tal m>g9 is =m$ by ?ree categories ( prov9ces :i* repres5t 7#a7 ! subm]g$ cont95tal plat=m1 7#b7 ! /eep edge ( ! cont95tal block1 & 7#c7 ! rais$ or depress$ edge ( ! ocean floor4 ,! topographic detail ( ! cont95tal m>g9 is pr$om9antly smoo? except = ! subm>9e canyons & m9or irregul>ities ( ! upp] cont95tal rise4 ,a close correspond5ce ( topography & di/ribution ( rec5t s$im5ts is app>5t4 ,= example1 deep-sea s&s are f\nd 9 ! subm>9e canyons & on ! canyon deltas ( ! l[] cont95tal rise4 ,! cont95tal slope appe>s to be a ?9ly v5e]$ or b>e outcrop ( ,t]ti>y & ,mesozoic s$im5ts4 ,individual topographic b5*es c be trac$ = _m miles along ! /rike4 ,on ! basis ( publi%$ descriptions & dat+ ( dr$g$ rock1 c]ta9 prom95t b5*es are id5tifi$ z ! outcrop patt]n ( v>i\s ,cretace\s & ,t]ti>y =mations4 ,! l[] cont95tal rise c be directly trac$ into ! out] ridge at ,cape ,hatt]as4 ,! upp] cont95tal-rise & ! m>g9al-tr5* prov9ces lie betwe5 ! abrupt cont95tal slope & ! out] ridge4 ,seismic-refraction measurem5ts 9 ! cont95tal m>g9 indicate ! greate/ ?ickness ( s$im5t>y rocks "u ! upp] cont95tal rise4 ,?us if we consid] ! initial =m z an unfill$ depression x w\ld h be5 rem>kably simil> to ! =m ( ! pres5t m>g9al tr5*es4 ,! ocean-bas9 floor lies betwe5 ! cont95tal m>g9 & ! ,mid-,oceanic ,ridge & consi/s ( ! deep] abyssal floor & ! elevat$ oceanic rises4 ,on ! abyssal floor adjac5t to ! cont95tal m>g9s are f\nd ! flatte/ surfaces ( ! e>?4 ,^! abyssal pla9s app>5tly 7 built by turbidity-curr5t deposits4 ,! unburi$ abyssal floor is repres5t$ by ! abyssal hills4 ,! oceanic rises are broad uplifts :i* rise f ! abyssal floor ?r\gh a s]ies ( sc>ps4 ,oceanic rises are cov]$ ) pelagic s$im5ts except locally ne> isl&s & seam\nts4 ,! cru/al /ructure ( oceanic rises diff]s significantly f ! typical abyssal floor 9 hav+ l[] velocities & g5]ally ?ick] cru/al lay]s4 ,! ,mid-,oceanic ,ridge is a broad fractur$ ar* ^: axis foll[s ! m$ian l9e ( ! ocean4 ,x g5]ally cov]s ! c5t] ?ird ( ! ocean4 ,! ridge prov9ces are divid$ into cre/ prov9ces & flank prov9ces4 ,! cre/ prov9ces include 7#a7 ! ,rift ,valley1 a long axial cleft #ae-cj miles wide & #ejj-aejj fa?oms deep2 7#b7 ! ,rift ,m\nta9s :i* =m ! sides ( ! ,rift ,valley2 & 7#c7 ! ,high ,fractur$ ,plateau1 a rugg$ plateau :i* bord]s ! ,rift ,m\nta9s4 ,! flank prov9ces consi/1 on ea* side1 ( r\ghly ?ree /eps sep>at$ by l>ge sc>ps4 ,a seismic belt accurately foll[s ! ,rift ,valley4 ,! topography ( ! ,mid-,oceanic ,ridge seems be/ expla9$ by ext5sive normal fault+4 ,! mid-oceanic ,rift ,valley connects ) & is probably ( ! same orig9 z ! ,african rift valleys4 ,,bibliography ,,ago/9ho1 ,j41 #aicg1 ,volcanic activity 9 ! ,azores3 ,bullet9 ,volcanologique1 v4 ,,ii 7,s]ies ,,ii71 p4 #chj-djj ,,&rade1 ,c4 ,f4 ,,de1 #aicg1 ,os vales ,subm>9os ,portugueses3 ,s]vicos ,geologicos de ,portugal1 ,lisboa1 #bce p4 ,,anonym\s1 #aice1 ,g5]al ba?ymetric *>t ( ! oceans1 ,%eet ,a#a3 ,in=mation conc]n+ ! prep>ation ( ! ?ird edition ( ,%eet ,a#a2 ,nor? ,atlantic ,ocean3 ,int4 ,hydro4 ,bur41 ,spec4 ,pub4 #cj1 #cj p4 ---- #aici1 ,a summ>y ( e*o s\nd+ app>atus3 ,int4 ,hydro4 ,bur41 ,monaco1 ,spec4 ,pub4 #cc1 #acg p4 ---- #aiec1 ,limits ( oceans & seas3 ,intl4 ,hydro4 ,bur41 ,monaco1 ,spec4 ,pub4 #bc1 #bc p4 ,,arm/rong1 ,j4 ,c41 #aiec1 ,oceanography 9 ! ,tongue ( ! ,ocean1 ,bahamas1 ,b4,w4,i43 ,special ,report ( ! ,am]ican ,museum ( ,natural ,hi/ory1 ,n4 ,y41 #fc p4 ,,atwood1 ,w4 ,w41 #aidj1 ,! physiographic prov9ces ( ,nor? ,am]ica3 ,g9n & ,co41 ,bo/on1 #ecf p4 ,,b>?olomew1 ,j4 ,c4 ,,son ,,ltd41 #aieb1 ,map ( ,we/]n ,europe1 scale #a3c1jjj1jjj3 ,ed9burgh ,geographical ,in/41 ,ed9burgh1 ,scotl& ---- #aiee1 ,map ( ,africa1 scale #a3aj1jjj1jjj3 ,ed9burgh ,geographical ,in/41 ,ed9burgh1 ,scotl& ,,b5tley1 ,c41 ,,& ,,worzel1 ,j4 ,l41 #aief1 ,geophysical inve/igations 9 ! em]g$ & subm]g$ ,atlantic coa/al pla91 ,"p ,x3 ,cont95tal %elf1 slope & rise s\? ( ! ,gr& ,banks3 ,geol4 ,soc4 ,am4 ,bull41 v4 #fg1 p4 #a-ah ,,b\rc>t1 ,j41 #aidi1 ,geographie du fond des m]s3 ,payot1 ,p>is1 #cjg p4 ,,b\rc>t1 ,j41 & ,m>ie1 ,p41 #aiea1 ,sur la nature du ,rebord ,cont95tal a l'oue/ de la ,man*e3 ,c4 ,r4 ,acad4 de ,sci5ce1 ,p>is1 t4 #bcb1 p4 #bcdf-bcdh ,,bull>d1 ,e4 ,c41 #aied1 ,! fl[ ( heat ?r\gh ! floor ( ! ,atlantic ,ocean3 ,proc4 ,roy4 ,soc4 ,a1 v4 #bbb1 p4 #djh-dbi ,,bull>d1 ,e4 ,c41 ,,& ,,gaskell1 ,t4 ,f41 #aida1 ,subm>9e seismic inve/igations3 ,proc4 ,roy4 ,soc4 ,a1 v4 #agg1 p4 #dgf-dii ,,bull>d1 ,e4 ,c41 ,,maxwell1 ,a4 ,e41 ,,& ,,revelle1 ,r41 #aief1 ,heat fl[ ?r\gh ! ocean floor1 p4 #aec-agi 9 ,advances 9 geophysics3 v4 #c1 ,academic ,press1 ,n4 ,y41 #cbj p4 ,,cloos1 ,h41 #aici1 ,zur ,tektonik d] ,azor53 ,geol4 ,runds*au1 v4 #cj1 p4 #ejf-eaj ,,dahl1 ,w4 ,h41 #aibe1 ,t]ti>y fossils dr$g$ (f ! nor!a/]n coa/ ( ,nor? ,am]ica3 ,am4 ,j\r4 ,sci41 #e? s]41 v4 #aj1 p4 #bae ,,davidson1 ,m4 ,j41 ,,& ,,mill]1 ,e4 ,t41 #aief1 ,an airborne magnetic survey ( ! ,we/ ,indies1 ,gulf ( ,mexico1 & ! ea/]n ,unit$ ,/ates cont95tal m>g9 7,ab/ract73 ,am4 ,geophys4 ,union ,trans41 v4 #cg1 p4 #cda ,,day1 ,a4 ,a41 ,,hill1 ,m4 ,n41 ,,laughton1 ,a4 ,s41 ,,& ,,swall[1 ,j4 ,s41 #aief1 ,seismic prospect+ 9 ! we/]n approa*es ( ! ,engli% ,*annel3 ,qu>t4 ,j\r4 ,geol4 ,soc4 ,london1 v4 ,,cxii1 p4 #ae-dd ,,de ,,smitt1 ,v4 ,p41 #aicb1 ,e>?quakes 9 ! ,nor? ,atlantic z relat$ to subm>9e cables 7,ab/ract73 ,am4 ,geophys4 ,union ,trans41 p4 #ajc-aji ,,dietri*1 ,g41 #aici1 ,e9ige ,morphologis*e ,ergebnisse d] ,,meteor-,,fahrt1 ,janu> bis ,mai #aich3 ,ann4 d4 ,hydrogr4 u4 ,m>it4 ,met]ol41 v4 #fg1 p4 #bj-bc ,,dietz1 ,r4 ,s41 #aieb1 ,geomorphic evolution ( cont95tal t]race 7cont95tal %elf & slope73 ,am]4 ,assoc4 ,petrol4 ,geol4 ,bull41 v4 #cf1 p4 #ahjb-ahbj ---- #aiec1 ,possible deep-sea turbidity-curr5t *annels 9 ! ,indian ,ocean3 ,geol4 ,soc4 ,am4 ,bull41 v4 #fd1 p4 #cge-cgh ---- #aied1 ,me?ods ( explor+ ! ocean floor1 p4 #aid-bjj 9 ,isaacs1 ,j4 ,d41 ,isel91 ,c4 ,o',d41 ,editors1 ,oceanographic in/rum5tation3 ,natl4 ,acad4 ( ,sci41 ,publ4 #cji1 ,wa%+ton1 ,d4 ,c4 ,,dietz1 ,r4 ,s41 ,,& ,,m5>d1 ,h4 ,w41 #aiea1 ,orig9 ( abrupt *ange 9 slope at cont95tal %elf m>g93 ,am]4 ,assoc4 ,petrol4 ,geol4 ,bull41 v4 #ce1 p4 #aiid-bjaf ,,drake1 ,c4 ,l41 ,,sutton1 ,g41 ,,& ,,ew+1 ,m41 9 press1 ,cont95tal m>g9s & geosyncl9es1 ea/ coa/ ( ,nor? ,am]ica1 nor? ( ,cape ,hatt]as ,,drake1 ,c4 ,l41 ,,worzel1 ,j4 ,l41 & ,beckmann1 ,w4 ,c41 #aied1 ,geophysical inve/igations 9 ! em]g$ & subm]g$ ,atlantic coa/al pla94 ,"p ,,ix1 ,gulf ( ,ma9e3 ,geol4 ,soc4 ,am4 ,bull41 v4 #ff1 p4 #ieg-igj ,,elm5dorf1 ,c4 ,h41 ,,& ,,heez51 ,b4 ,c41 #aieg1 ,oceanographic in=mation = eng9e]+ subm>9e cable sy/ems3 ,bell ,sy/em ,te*4 ,j\r41 v4 ,,xxxvi1 p4 #ajdg-ajic ,,em]y1 ,k4 ,o41 #aiej1 ,a deep fa?ogram across ! ,nor? ,atlantic3 ,am4 ,j\r4 ,sci41 v4 #bdh1 p4 #ajj-ajf ,,emiliani1 ,c41 ,,& ,,edw>ds1 ,g41 #aiec1 ,t]ti>y ocean bottom temp]atures3 ,nature1 v4 #aga1 no4 #dcei1 p4 #hhg-hhh ,,ericson1 ,d4 ,b41 #aieb1 ,nor? ,atlantic deep-sea s$im5ts & subm>9e canyons3 ,n4 ,y4 ,acad4 ,sci4 ,trans41 s]4 ,,ii1 v4 #ae1 p4 #ej-ec ,,ericson1 ,d4 ,b41 ,,ew+1 ,m41 ,,& ,,heez51 ,b4 ,c41 #aiea1 ,deep-sea s&s & subm>9e canyons3 ,geol4 ,soc4 ,am4 ,bull41 v4 #fb1 p4 #ifa-ife ---- #aieb1 ,turbidity curr5ts & s$im5ts 9 ! ,nor? ,atlantic3 ,am]4 ,assoc4 ( ,petrol4 ,geol4 ,bull41 v4 #cf1 p4 #dhi-eab ,,ericson1 ,d4 ,b41 ,,ew+1 ,m41 ,,heez51 ,b4 ,c41 ,,& ,,woll91 ,g41 #aiee1 ,s$im5t deposition 9 ! deep ,atlantic1 p4 #bje-bbj 9 ,pold]va>t1 ,arie1 ,editor1 ,cru/ ( ! e>?3 ,geol4 ,soc4 ,am4 ,spec4 ,pap] #fb1 #gfb p4 ,,ericson1 ,d4 ,b41 ,,ew+1 ,m41 ,,woll91 ,g41 ,,& ,,heez51 ,b4 ,c41 9 press1 ,two-hundr$ & tw5ty-"o ,atlantic deep-sea cores3 ,geol4 ,soc4 ,am4 ,,ew+1 ,j4 ,i41 ,,& ,,ew+1 ,w4 ,m41 9 press1 ,seismic refraction measurem5ts 9 ! ,atlantic ,ocean bas9s1 ,m$it]ranean ,sea1 on ! ,mid-,atlantic ,ridge & 9 ! ,norwegian ,sea3 ,geol4 ,soc4 ,am4 ,bull4 ,,ew+1 ,j4 ,i41 ,,(fic]1 ,c4 ,b41 ,,johnson1 ,h4 ,r41 ,,& ,,edw>ds1 ,r4 ,s41 #aieg1 ,geophysical inve/igations ( ! ea/]n ,c>ibbean4 ,tr9idad ,%elf1 ,tobago ,tr\gh1 ,b>bados ,ridge1 ,atlantic ,ocean3 ,geol4 ,soc4 ,am4 ,bull41 v4 #fh1 p4 #hig-iab ,,ew+1 ,m41 ,,& ,,heez51 ,b4 ,c41 #aiee1 ,pu]to ,rico ,tr5* topographic & geophysical data1 p4 #bee-bfh 9 ,pold]va>t1 ,arie1 ,editor1 ,cru/ ( ! e>?3 ,geol4 ,soc4 ,am4 ,spec4 ,pap] #fb1 #gfb p4 ---- #aief;a1 ,oceanographic rese>* programs ( ! ,lamont ,geological ,obs]vatory3 ,geog4 ,rev41 v4 ,,xlvi1 p4 #ejh-ece ---- #aief;b1 ,"s problems ( ,ant>ctic subm>9e geology3 ,ant>ctica 9 ! ,i4 ,g4 ,y41 ,geophys4 ,mon41 no4 #a1 p4 #ge-ha ,,ew+1 ,m41 ,,& ,,worzel1 ,j4 ,l41 #aied1 ,gravity anomalies & /ructure ( ! ,we/ ,indies1 ,"p ,i3 ,geol4 ,soc4 ,am4 ,bull41 v4 #fe1 p4 #afe-agd ,,ew+1 ,m41 ,,cr>y1 ,a4 ,p41 ,,& ,,ru!r=d1 ,h4 ,m41 #aicg1 ,geophysical inve/igations 9 ! em]g$ & subm]g$ ,atlantic ,coa/al ,pla91 ,"p ,i3 ,geol4 ,soc4 ,am4 ,bull41 v4 #dh1 p4 #gec-hjb ,,ew+1 ,m41 ,,ericson1 ,d4 ,b41 ,,& ,,heez51 ,b4 ,c41 #aieh1 ,s$im5ts & topography ( ! ,gulf ( ,mexico1 p4 #iie-ajec 9 ,weeks1 ,l41 ,editor1 ,habitat ( ,oil2 ,am]4 ,assoc4 ,petrol4 ,geol41 ,tulsa1 #achdp4 ,,ew+1 ,m41 ,,heez51 ,b4 ,c41 ,,& ,,hir%man1 ,j41 #aieg1 ,mid-,atlantic ,ridge seismic belt & magnetic anomalies 7,ab/ract73 ,comm4 ,no4 #aaj bis4 ,assoc4 ,seismol4 ,ass4 ,g54 ,u4 ,g4 ,g4 ,i41 ,toronto ,,ew+1 ,m41 ,,sutton1 ,g4 ,h41 ,,& ,,(fic]1 ,c4 ,b4 ,,jr41 #aied1 ,seismic refraction measurem5ts 9 ! ,atlantic ,ocean1 ,"p ,,vi3 ,typical deep /ations1 ,nor? ,am]ica ,bas93 ,seismol4 ,soc4 ,am4 ,bull41 v4 #dd1 p4 #ba-ch ,,ew+1 ,m41 ,,wooll>d1 ,g4 ,p41 ,,v9e1 ,a4 ,c41 ,,& ,,worzel1 ,j4 ,l41 #aidf1 ,rec5t results 9 subm>9e geophysics3 ,geol4 ,soc4 ,am4 ,bull41 v4 #eg1 p4 #iji-icd ,,ew+1 ,m41 ,,heez51 ,b4 ,c41 ,,ericson1 ,d4 ,b41 ,,nor?rop1 ,j41 ,,& ,,dorman1 ,j41 #aiec1 ,exploration ( ! ,nor?we/ ,atlantic ,mid-,ocean ,canyon3 ,geol4 ,soc4 ,am4 ,bull41 v4 #fd1 p4 #hfe-hfh ,,f5neman1 ,n4 ,m41 #aich1 ,physiography ( ,ea/]n ,unit$ ,/ates3 ,mc,graw-,hill1 ,n4 ,y41 #gad p4 ,,fi%]1 ,r4 ,l41 #aied1 ,on s\nd+ 9 tr5*es3 ,deep ,sea ,rese>*1 v4 #b1 no4 #a1 p4 #dh-eh ,,frassetto1 ,r41 ,,& ,,nor?rop1 ,j41 #aieg1 ,virg9 ,isl&s ba?ymetric survey3 ,deep ,sea ,rese>*1 v4 #d1 p4 #ach-adf ,,furon1 ,r41 #aidi1 ,sur les trilobites dragues #dbee m4 de pr(ondeur p> le ,talisman 7#ahhc73 ,c4 ,r4 ,acad1 de ,sci41 ,p>is1 t4 #bbh1 p4 #aeji-aeaj ,,gaskell1 ,t4 ,f41 ,,& ,,a%ton1 ,w41 #aied1 ,h4 ,m4 ,s4 ,,*all5g]',s _w voyage #aiej-eb4 "p #b3 ,intl4 ,hydro4 ,rev41 v4 #ca1 p4 #aja-aaa ,,gibson1 ,w4 ,m41 #aieh1 ,gulf ( ,alaska tr\gh p>allels ,aleutian ,tr5*3 ,geol4 ,soc4 ,am4 ,bull41 v4 #fi1 p4 #faa-fad ,,gr\sson1 ,r41 #aieg1 ,ba?ymetrie de la cote ,atlantique de ,m>oc3 ,m9i/re de la ,df5se ,nationale1 ,p>is1 ,bull4 d',in=mation ,c4,o4,e4,c41 ann4 ,,ix1 no4 #h1 p4 #daa-dab ,,gut5b]g1 ,b41 ,,& ,,ri*t]1 ,c4 ,f41 #aied1 ,seismicity ( ! e>?3 ,pr9ceton ,univ4 ,press1 ,pr9ceton1 ,n4 ,j41 #caj p4 ,,hamilton1 ,e4 ,l41 #aief1 ,sunk5 isl&s ( ! ,mid-,pacific ,m\nta9s3 ,geol4 ,soc4 ,am4 ,memoir #fd1 #ig p4 ,,heez51 ,b4 ,c41 #aied1 ,me?ods ( explor+ ! ocean floor1 p4 #bjj-bje 9 ,isaacs1 ,j4 ,d41 & ,isel91 ,c4 ,o',d41 ,editors1 ,oceanographic ,in/rum5tation3 ,natl4 ,acad4 ( ,sci41 ,publ4 #cji ---- #aief1 ,! orig9 ( ! subm>9e canyons3 ,sci5t4 ,am]ican1 v4 #aie1 p4 #cf-da ---- ,9 prep>ation1 ,"s precision s\nd+ pr(iles by ,u4,s4,s4 ,,glaci] & ,u4,s4,s4 ,,wy&ot 9 ,ant>ctic wat]s ,,heez51 ,b4 ,c41 ,,& ,,ew+1 ,m41 #aieb1 ,turbidity curr5ts & subm>9e slumps1 & ! ,gr& ,banks e>?quake3 ,am4 ,j\r4 ,sci41 v4 #bej1 p4 #hdi-hgc ---- #aiee1 ,orleansville e>?quake & turbidity curr5ts3 ,am]4 ,assoc4 ,petrol4 ,geol4 ,bull41 v4 #ci1 p4 #beje-bead ---- ,9 press1 ,seismicity ( ! ,mid-,atlantic ,ridge3 ,am]4 ,geophys4 ,union ,trans4 ,,heez51 ,b4 ,c41 ,,ericson1 ,d4 ,b41 ,,& ,,ew+1 ,m41 #aied1 ,fur!r evid5ce = a turbidity curr5t foll[+ ! #aibi ,gr& ,banks e>?quake3 ,deep ,sea ,rese>*1 v4 #a1 p4 #aic-bjb ,,heez51 ,b4 ,c41 ,,ew+1 ,m41 ,,ericson1 ,d4 ,b41 #aiea1 ,subm>9e topography 9 ! ,nor? ,atlantic3 ,geol4 ,soc4 ,am4 ,bull41 v4 #fb1 p4 #adjg-adji ---- #aied1 ,reconnaissance survey ( ! abyssal pla9 s\? ( ,newf\ndl&3 ,deep ,sea ,rese>*1 v4 #b1 p4 #abb-acc ,,heez51 ,b4 ,c41 ,,ew+1 ,m41 ,,& ,,m5zies1 ,r4 ,j41 #aiee1 ,! influ5ce ( subm>9e turbidity curr5ts on abyssal productivity3 ,oikos1 v4 #f1 p4 #agj-ahb ---- #aieh1 ,subm>9e turbidity fl[s3 ,priroda1 ,feb4 #aieh1 p4 #ajj-ajd 79 ,russian7 ,,heez51 ,b4 ,c41 ,,ew+1 ,m41 ,,& ,,mill]1 ,e4 ,t41 #aiec1 ,trans-,atlantic pr(ile ( total magnetic int5sity & topography1 ,dak> to ,b>bados3 ,deep ,sea ,rese>*1 v4 #a1 p4 #be-cc ,,heez51 ,b4 ,c41 ,,ew+1 ,m41 ,,ericson1 ,d4 ,b41 ,,& ,,b5tley1 ,c4 ,r41 9 press1 ,! flat-topp$ ,atlantis1 ,cruis] & ,great ,meteor seam\nts3 ,geol4 ,soc4 ,am4 ,bull4 ,,heez51 ,b4 ,c41 & o!rs1 9 prep>ation1 ,subm>9e /ructural b5*es & dr[n$ bea*es ( ! ,atlantic ,,hess1 ,h4 ,h41 #aied1 ,geological hypo!ses & ! e>?'s cru/ "u ! ocean3 ,roy4 ,soc4 ,proc41 ,a4 v4 #bbb1 p4 #cda-cdh ---- #aicc1 ,int]pretation ( geological & geophysical obs]vations1 ,navy ,pr9ceton gravity exp$ition to ,we/ ,indies 9 #aicb3 ,naval ,obs]vatory ,publ4 no4 #ai1 p4 #bg-ed ,,hill1 ,m4 ,n41 #aied1 ,topography ( ! ,mid-,atlantic ,ridge 7,ab/ract73 ,ab/racts ( ,rome meet+ ( ,u4,g4,g4,i4 ---- #aief1 ,notes on ! ba?ymetric *>t ( ! nor!a/ ,atlantic3 ,deep ,sea ,rese>*1 v4 #c1 p4 #bbi-bca ---- #aieg1 ,rec5t geophysical exploration ( ! ocean floor1 p4 #abi-afc 9 ,ahr5s1 ,l4 ,h41 et al41 ,editors1 ,physics & *emi/ry ( ! e>?3 ,p]gamon ,press1 ,london1 #bei p4 ,,johnson1 ,,d\glas1 #aici1 ,orig9 ( subm>9e canyons3 ,columbia ,univ4 ,press1 ,new ,york1 #baf p4 ,,katz1 ,s41 ,,& ,,ew+1 ,m41 #aiee1 ,seismic-refraction measurem5ts 9 ! ,atlantic ,ocean1 ,"p ,,vii1 ,atlantic ,ocean bas9 we/ ( ,b]muda3 ,geol4 ,soc4 ,am4 ,bull41 v4 #fg1 p4 #dge-eaj ,,kay1 ,m41 #aiea1 ,nor? ,am]ican geosyncl9es3 ,geol4 ,soc4 ,am4 ,memoir #dh1 #adc p4 ,,kell]1 ,f4 ,j41 ,,meus*ke1 ,j4 ,l41 ,,& ,,alldr$ge1 ,l4 ,r41 #aied1 ,a]omagnetic surveys 9 ! ,aleutian1 ,m>%all1 & ,b]muda isl&s3 ,am]4 ,geophys4 ,union ,trans41 v4 #ce1 p4 #eeh-egb ,,knott1 ,s4 ,t41 ,,& ,,h]sey1 ,j4 ,b41 #aief1 ,int]pretation ( high resolution e*o-s\nd+ te*niques & _! use 9 ba?ymetry1 m>9e geophysics1 & geology3 ,deep ,sea ,rese>*1 v4 #d1 p4 #cf-dd ,,koczy1 ,f4 ,f41 #aied1 ,a survey on deep sea features tak5 dur+ ! ,sw$i% ,deep ,sea ,exp$ition3 ,deep ,sea ,rese>*1 v4 #a1 p4 #agj-ahd ---- #aief1 ,e*o s\nd+s1 ,reports ( ,sw$i% ,deep ,sea ,exp$itions1 v4 ,,iv1 ,bottom inve/igations3 ,fasc4 ,,ii1 p4 #ii-aeh1 ,gteborgs ,kungl4 ,vet5skaps-o* vitt]hetssamhlle ,,ku551 ,,ph4 ,h41 #aiej1 ,m>9e geology3 ,wiley1 ,new ,york1 #efh p4 ,,lee1 ,c4 ,s41 #aiea1 ,geophysical surveys on ! ,bahama ,banks3 ,in/4 ,petrol4 ,j\r4 ,london1 v4 #cg1 no4 #ccd1 p4 #fcc-feg ,,lobeck1 ,a4 ,k41 #aibd1 ,block diagrams3 ,wiley1 ,new ,york1 #bjf p4 ---- #aici1 ,geomorphology3 ,mc,graw-,hill1 ,new ,york1 #gca p4 ---- #aidh1 ,physiographic diagram ( ! ,unit$ ,/ates3 ,geog4 ,press1 ,n4 ,y4 ,,lusk91 ,b41 ,,& ,,israel1 ,h4 ,g41 #aief1 ,precision dep? record] ,,mk-,v3 ,lamont ,geological ,obs]vatory & ,"t ,facsimile ,corp41 ,te*4 ,rept4 no4 #ab1 #ca p4 ,,lusk91 ,b41 ,,heez51 ,b4 ,c41 ,,ew+1 ,m41 ,,& ,,l&isman1 ,m41 #aied1 ,precision measurem5ts ( ocean dep?3 ,deep ,sea ,rese>*1 v4 #a1 p4 #aca-adj ,,mat!ws1 ,d4 ,j41 #aici1 ,tables ( ! velocity ( s\nd 9 pure wat] & sea wat] = use 9 e*o s\nd+ & e*o rang+3 ,admiralty ,hydrographic ,dept41 ,london1 #eb p4 ,,maury1 ,m4 ,f41 #ahee1 ,physical geography ( ! sea3 ,h>p]s1 ,new ,york1 #chi p4 ,,m5>d1 ,h4 ,w41 #aiee1 ,deep sea *annels1 topography & s$im5tation1 ,am]4 ,assoc4 ,petrol4 ,geol4 ,bull41 v4 #ci1 p4 #bcf-bee ,,mill]1 ,e4 ,t41 ,,& ,,ew+1 ,m41 #aief1 ,geomagnetic measurem5ts 9 ! ,gulf ( ,mexico & 9 ! vic9ity ( ,c>yn ,peak3 ,geophysics1 v4 ,,xxi1 p4 #djf-dcb ,,murray1 ,h4 ,w41 #aidg1 ,topography ( ! ,gulf ( ,ma9e3 ,geol4 ,soc4 ,am4 ,bull41 v4 #eh1 p4 #aec-aif ,,murray1 ,j41 ,,& ,,hjort1 ,j41 #aiab1 ,dep?s ( ! ocean3 ,john ,murray1 ,london1 #hba p4 ,,nafe1 ,j41 ,,& ,,drake1 ,c4 ,l41 #aieg1 ,v>iation ) dep? 9 %all[ & deep wat] m>9e s$im5ts ( porosity1 d5sity & ! velocities ( compressional & %e> waves3 ,geophysics1 v4 ,,xxii1 p4 #ebc-eeb ,,newell1 ,n4 ,d41 #aiee1 ,bahamian plat=ms1 p4 #cjc-caf 9 ,pold]va>t4 ,arie1 ,editor1 ,cru/ ( ! e>?3 ,geol4 ,soc4 ,am4 ,special ,pap] #fb1 #gfb p4 ,,nor?rop1 ,j41 ,,& ,,fros*1 ,r41 #aied1 ,seam\nts 9 ! ,nor? ,am]ica bas93 ,deep ,sea ,rese>*1 v4 #a1 p4 #beb-beg ,,nor?rop1 ,j41 ,,& ,,heez51 ,b4 ,c41 #aiea1 ,an outcrop ( ,eoc5e s$im5t on ! cont95tal slope3 ,j\r4 ,geol41 v4 #ei1 p4 #cfi-cii ,,(fic]1 ,c4 ,b41 ,,& ,,ew+1 ,m41 #aied1 ,geophysical inve/igations 9 ! em]g$ & subm]g$ ,atlantic coa/al pla91 ,"p ,,vii1 ,cont95tal %elf1 cont95tal slope1 & cont95tal rise s\? ( ,nova ,scotia3 ,geol4 ,soc4 ,am4 ,bull41 v4 #fe1 p4 #fec-fgj ,,(fic]1 ,c4 ,b41 ,,ew+1 ,m41 ,,& ,,wu5s*el1 ,p4 ,c41 #aieb1 ,seismic refraction measurem5ts 9 ! ,atlantic ,ocean bas91 ,"p ,,iv1 ,b]muda1 ,b]muda ,rise1 & ,n>es ,bas93 ,geol4 ,soc4 ,am4 ,bull41 v4 #fc1 p4 #ggg-hji ,,(fic]1 ,c4 ,b41 ,,ew+1 ,j4 ,i41 ,,edw>ds1 ,r4 ,s41 ,,& ,,johnson1 ,h4 ,r41 #aieg1 ,geophysical inve/igations 9 ! ea/]n ,c>ibbean4 ,v5ezuelan ,bas91 ,antilles ,isl& ,arc1 & ,pu]to ,rico ,tr5*3 ,geol4 ,soc4 ,am4 ,bull41 v4 #fh1 p4 #cei-cgh ,,pettijohn1 ,f4 ,j41 #aieg1 ,s$im5t>y rocks3 ,h>p]s1 ,new ,york1 #gah p4 ,,press1 ,f41 ,,& ,,beckmann1 ,w4 ,c41 #aied1 ,geophysical inve/igations 9 ! em]g$ & subm]g$ ,atlantic coa/al pla91 ,"p ,,viii1 ,gr& ,banks & adjac5t %elves3 ,geol4 ,soc4 ,am]ica ,bull41 v4 #fe1 p4 #bii-cad ,,raisz1 ,e41 #aieb1 ,l&=ms ( ! ,unit$ ,/ates3 ,h>v>d ,univ41 ,cambridge1 ,mass4 ,,raitt1 ,r4 ,w41 #aief1 ,seismic-refraction /udies ( ! ,pacific ,ocean bas91 ,"p ,i1 ,cru/al ?ickness ( ! equatorial ,pacific3 ,geol4 ,soc4 ,am4 ,bull41 v4 #fg1 p4 #afbc-afdj ,,ri*>ds1 ,h4 ,j41 ,,& ,,ruhle1 ,j4 ,l41 #aiee1 ,mollusks f a s$im5t core f ! ,hudson subm>9e canyon3 ,pa4 ,acad4 ,sci4 ,proc41 v4 ,,xxix1 p4 #ahf-aij ,,s*ott1 ,g41 #aidb1 ,geographie des ,atlantis*5 ,ozeans3 ,c4 ,boys51 ,hamburg1 #dch p4 ,,s*,,l]1 ,f41 #aieb1 ,on ! accuracy ( configuration ( sea bottom pr(iles ) high frequ5cy e*o s\nd]s3 ,intl4 ,hydro4 ,review1 v4 ,,vii1 p4 #abf-ace ,,%&1 ,s4 ,j41 #aidi1 ,rocks ( ! ,mid-,atlantic ,ridge3 ,j\r4 ,geol41 v4 #eg1 p4 #hi-ib ,,%ep>d1 ,f4 ,p41 #aica1 ,sa9t ,lawr5ce 7,cabot ,/rait7 subm>9e tr\gh3 ,geol4 ,soc4 ,am4 ,bull41 v4 #db1 p4 #hec-hfd ---- #aidh1 ,subm>9e geology3 ,h>p]s1 ,new ,york1 #cdh p4 ,,%ep>d1 ,f4 ,p41 ,,& ,,cohee1 ,g4 ,v41 #aicf1 ,cont95tal %elf s$im5ts (f ! ,mid-,atlantic /ates1 ,geol4 ,soc4 ,am4 ,bull41 v4 #dg1 p4 #dda-deg ,,%ep>d1 ,f4 ,p41 ,,treff5d51 ,j4 ,m41 ,,& ,,cohee1 ,g4 ,v41 #aicd1 ,orig9 ( ,georges ,bank3 ,geol4 ,soc4 ,am4 ,bull41 v4 #de1 p4 #bha-cjb ,,%urbet1 ,g4 ,l41 ,,& ,,worzel1 ,j4 ,l41 #aieg1 ,gravity anomalies & /ructure ( ! ,we/ ,indies1 ,"p ,,iii3 ,geol4 ,soc4 ,am4 ,bull41 v4 #fh1 p4 #bfc-bff ,,smi?1 ,e4 ,h41 ,,s\le1 ,f4 ,m41 ,,& ,,mosby1 ,o41 #aicg1 ,,m>ion & ,,g5]al ,,gre5e exp$itions to ,davis ,/rait & ,labrador ,sea "u ! direction ( ! ,u4 ,s4 ,coa/ ,gu>d1 #aibh-aica-aicc-aicd-aice3 ,u4 ,s4 ,coa/ ,gu>d ,bull41 v4 #ai1 p4 #a-bei ,,smi?1 ,w4 ,o41 ,,upson1 ,j4 ,e41 & o!rs1 #aieb1 ,prelim9>y report on ! ,passamaquoddy b$rock survey1 ,july-,augu/ #aiea3 ,u4 ,s4 ,geol4 ,survey ,wat] ,res\rces ,division1 #di p4 ,,spangl]1 ,w4 ,b41 #aiej1 ,subsurface geology ( ,atlantic coa/al pla9 ( ,nor? ,c>ol9a3 ,am]4 ,assoc4 ,petrol4 ,geol4 ,bull41 v4 #cd1 p4 #ajj-acb ,,spangl]1 ,w4 ,b41 ,,& ,,pet]son1 ,j4 ,j41 #aiej1 ,geology ( ,atlantic coa/al pla9 9 ,new ,j]sey1 ,delaw>e1 ,m>yl&1 & ,virg9ia3 ,am]4 ,assoc4 ,petrol4 ,geol4 ,bull41 v4 #cd1 p4 #a-ii ,,/etson1 ,h4 ,c41 #aicf1 ,geology & paleontology ( ,georges ,bank canyons3 ,geol4 ,soc4 ,am4 ,bull41 v4 #dg1 p4 #cci-cff ---- #aich1 ,s$im5ts ( ! cont95tal %elves (f ! ea/]n coa/ ( ! ,unit$ ,/ates4 ,woods ,hole ,oceanogr4 ,in/4 ,pap]s 9 ,physical ,oceanography & ,meteorology1 v4 ,v1 no4 #d1 p4 #e-dh ---- #aidi1 ,! s$im5ts & /ratigraphy ( ! ea/ coa/ cont95tal m>g92 ,georges ,bank to ,norfolk ,canyon3 ,woods ,hole ,oceanogr4 ,in/4 ,pap]s 9 ,physical ,oceanography & ,meteorology1 v4 ,,xi1 no4 #b1 p4 #a-fj ,,/ocks1 ,t41 ,,& ,w,,/1 ,g41 #aice1 ,die ,tief5v]hltnisse des (f55 ,atlantis*5 ,ozeans3 ,deuts*e ,atlantis*5 ,exp$4 ,,meteor1 #aibe-bi1 ,wiss4 ,erg4 ,bd41 ,,iii1 ,teil #a1 ,lief #a1 #ca p4 ,,/ommel1 ,h41 #aieg1 ,a survey ( ocean curr5t !ory3 ,deep ,sea ,rese>*1 v4 #d1 p4 #adi-ahd ,,sutton1 ,g4 ,h41 ,,b]ckhem]1 ,h41 ,,& ,,nafe1 ,j4 ,e41 #aieg1 ,physical analysis ( deep sea s$im5ts3 ,geophysics1 v4 ,,xxii1 p4 #ggi-hab ,,swa91 ,f4 ,m41 #aidg1 ,two rec5t wells 9 coa/al pla9 ( ,nor? ,c>ol9a3 ,am]4 ,assoc4 ,petrol4 ,geol4 ,bull41 v4 #ca1 p4 #bjed-bjfj ,,swall[1 ,j4 ,c41 ,,& ,,wor?+ton1 ,l4 ,v41 #aieg1 ,measurem5ts ( deep curr5ts 9 ! we/]n ,nor? ,atlantic3 ,nature1 v4 #agi1 p4 #aahc ,,tol/oy1 ,i41 #aiea1 ,subm>9e topography 9 ! ,nor? ,atlantic3 ,geol4 ,soc4 ,am4 ,bull41 v4 #fb1 p4 #dda-dej ,,tol/oy1 ,i41 ,,& ,,ew+1 ,m41 #aidi1 ,nor? ,atlantic hydrography & ! ,mid-,atlantic ,ridge3 ,geol4 ,soc4 ,am4 ,bull41 v4 #fj1 p4 #aebg-aedj ,,torphy1 ,s4 ,r41 ,,& ,,zeigl]1 ,j4 ,m41 #aieg1 ,subm>9e topography ( ,ea/]n ,*annel ,gulf ( ,ma9e1 ,j\r4 ,geol41 v4 #fe1 p4 #dcc-dda ,,ud9tsev1 ,g4 ,b41 #aiee1 ,topography ( ! ,kurile-,kam*atka ,tr5*3 ,trans4 ,in/4 ( ,oceanology1 v4 ,,xii1 p4 #af-fa 79 ,russian7 ,,upham1 ,w41 #ahid1 ,! fi%+ banks betwe5 ,cape ,cod & ,newf\ndl&3 ,am4 ,j\r4 ,sci41 #c;d s]41 v4 #dg1 p4 #abc-abi ,,veat*1 ,a4 ,c41 ,,& ,,smi?1 ,p4 ,a41 #aici1 ,atlantic subm>9e valleys ( ! ,unit$ ,/ates & ! ,congo ,subm>9e ,valley3 ,geol4 ,soc4 ,am4 ,special ,pap] #g1 #aja p4 ,,wa%+ton1 ,h4 ,s41 #aicj1 ,orig9 ( ! ,mid-,atlantic ,ridge3 ,md4 ,acad4 ,sci4 ,j\r41 v4 #a1 p4 #bj-bi ,,wiseman1 ,j4 ,h4 ,d41 ,,& ,,ovey1 ,c4 ,d41 #aiej1 ,rec5t inve/igations on ! deep sea floor3 ,geol4 ,assoc4 ,proc41 v4 #fa1 p4 #bh-hd ---- #aiec1 ,def9itions ( features on ! deep sea floor3 ,deep ,sea ,rese>*1 v4 #a1 p4 #aa-af ---- #aiee1 ,propos$ names ( features on ! deep sea floor #b2 ,g5]al pr9ciples gov]n+ ! allocation ( names3 ,deep ,sea ,rese>*1 v4 #b41 p4 #bfa-bfc ,,worzel1 ,j4 ,l41 ,,& ,,%urbet1 ,g4 ,l41 #aiee;a1 ,gravity int]pretations f cru/al sections1 p4 #hg-ajj 9 ,pold]va>t1 ,arie1 ,editor1 ,cru/ ( ! e>?1 ,geol4 ,soc4 ,am4 ,special ,pap] #fb1 #gfb p4 ---- #aiee;b1 ,! ,toro ,seam\nt3 ,geol4 ,soc4 ,am4 ,bull41 v4 #ff1 p4 #dfe-dff ,,worzel1 ,j4 ,l41 ,,& ,,%urbet1 ,g4 ,l41 #aiee;c1 ,gravity anomalies at cont95tal m>g9s3 ,nat4 ,acad4 ,sci41 ,proc41 v4 #da1 p4 #deh-dfi ,w,,/1 ,g41 #aice1 ,die ,/ratosphre3 ,deuts*e ,atlantis*5 ,exp$4 ,,meteor1 #aibe-bi1 ,wiss4 ,erg41 ,bd4 ,,vi1 ,teil #a1 ,lief4 #a-b41 p4 #aji-bhh ,w,,/1 ,g41 #aidj;a1 ,das relief des ,azor5 ,sockels und des ,me]esbod5s ,nrdli* und ,nordwe/li* d] ,azor53 ,ann4 d4 ,hydrogr4 u4 ,m>it4 ,met]ol41 ,augu/-,beiheft1 ,lief #b1 p4 #a-ai ---- #aidj;b1 ,zur ,nom5klatur d] ,gross=m5 d] ,ozeanbod53 ,assoc4 ,oceanog4 ,union ,geod4 ,geophys4 ,int]nat41 ,publ4 ,sci4 no4 #h1 p4 #ab-abd ---- #aidc1 ,d] sub>ktis*e ,bod5/rom 9 d] we/atlantis*5 ,mulde3 ,ann4 d4 ,hydrogr4 u4 ,m>it4 ,met]ol41 ,h4 ,,iv_/,,vi1 p4 #bdd-bee ---- #aieg1 ,quantitative ,unt]su*ung5 zur ,/atik und ,dynamik des ,atlantis*5 ,ozeans2 ,/romges*w9digneit5 und ,/romm5g5 9 d5 ,tief5 des ,atlantis*5 ,ozeans3 ,deuts*e ,atlantis*5 ,exp$4 ,,meteor1 #aibe-bi1 ,wiss4 ,erg41 ,bd4 ,,vi1 ,teil #b1 #dbj p4 ,,zeigl]1 ,j41 ,,a!>n1 ,w4 ,d41 ,,& ,,small1 ,h41 #aieg1 ,pr(iles across ! ,p]u-,*ile tr5*3 ,deep ,sea ,rese>*1 v4 #d1 p4 #bch-bdi ,,au?or ,,index ,ago/9ho1 ,j41 #ih1 #aji ,alldr$ge1 ,l4 ,r41 #ea1 #aaa ,&rade1 ,c4 ,f4 de1 #e1 #ba1 #cg1 #aji ,arm/rong1 ,j4 ,c41 #cf1 #aji ,a%ton1 ,w41 #ee1 #aaj ,a!>n1 ,w4 ,d41 #fj1 #aac ,atwood1 ,w4 ,w41 #aa1 #aji 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#eh ,heat fl[1 measurem5t (1 #ajc ,high ,fractur$ ,plateau1 #a1 #ae1 #ij1 #ia1 #id1 #ie1 #ii ,hispaniola-,caicos ,abyssal ,pla91 #ef1 #fj ,hispaniola-,caicos ,*annel1 #cf ,holo?urians1 photographs (1 #ci ,horse%oe ,abyssal ,pla91 #eg1 #fa ,horse%oe ,seam\nt ,gr\p1 #ei1 #gh ,hudson ,subm>9e ,canyon1 #h1 #bg-bh1 #ca1 #eh1 #gb ,hudson ,subm>9e ,*annel1 #h ,hudson ,subm>9e ,delta1 #bh1 #gh ,hydrographic ,dep>tm5t1 ,briti% ,admiralty1 vii1 #c1 #f ,hydrograph] ,canyon1 #dc ,ib]ia ,abyssal ,pla91 #ef1 #fj ,ib]ia ,bas91 #ab ,int]montane bas9s1 #ie1 #ii ,int]national ,hydrographic ,bureau 7,monaco71 vii1 #c1 #e1 #aa1 #ab ,joseph9e ,seam\nt1 #gh ,,kev9 ,,moran1 ,tug1 #gj ,kelv9 ,seam\nt ,gr\p1 #gb1 #gg1 #gh ,labrador ,bas91 #ab ,lahave ,bank1 #bd ,lamont ,geological ,obs]vatory1 #c1 #f1 #h1 #ba ,l&w>d slopes ( tr5*es1 #a1 #ai1 #cf ,laur5tian ,*annel1 #bc ,lisbon ,subm>9e ,canyon1 #cg ,l[] ,cont95tal ,rise ,hills1 #ef ,l[] ,/ep1 ,mid-,atlantic ,ridge1 #a1 #ae1 #ij1 #ia1 #id1 #ie1 #if ,madeira ,abyssal ,pla91 #ef1 #eh1 #fa ,madeira ,isl&1 pr(ile ne>1 #bh1 #bi ,madeira ,rise1 #eh1 #fa ,magnetic anomalies cont95tal m>g91 #ea1 #eb ,mid-,atlantic ,ridge1 #ea1 #ajj1 #aja ocean-bas9 floor1 #ea1 #fe1 #gb seam\nts1 #ea ,magnetic surveys airborne1 #ea %ip-t[$1 #ea ,manganese nodules1 #ci1 #gh ,mantle1 #hj1 #ajb ,m>g9al bas9-out] ridge complex1 #bj1 #cf ,m>g9al esc>pm5ts ,bay ( ,biscay1 #ai1 #cg ,blake1 #ai1 #cb1 #ce ,gulf ( ,mexico1 #ai1 #cc ,new ,zeal&1 #ai ,m>g9al plateaus1 #ah1 #cb1 #cg ,blake ,plateau1 #ag1 #cb1 #dg1 #dh1 #ei ,we/]n ,europe1 #cg ,m>g9al tr5*es1 #bj1 #cf1 #ec1 #ajg fill$1 #eb-ed ,pacific1 #ai1 #fj ,pu]to ,rico ,tr5*1 #ag1 #cf1 #eb1 #ef1 #fj ,m>g9al tr5*-out] ridge complex1 #a1 #bj1 #cf1 #ec ,matawan 7,cretace\s7 =mation1 #dd1 #de1 #df ,m]cator projection1 #c ,,meteor1 ,rese>* ,vessel1 #hc1 #ih ,mid-,atlantic ,ridge axial pr(ile1 #if cre/ prov9ces1 #a1 #hd flank prov9ces1 #a1 #ie heat fl[1 #ajc ,high ,fractur$ ,plateau1 #a1 #ij1 #id1 #ie limits (1 #hc ,l[] ,/ep1 #a1 #ij1 #id1 #ie ,middle ,/ep1 #a1 #ij1 #id1 #ie ocean-bottom photographs1 #gh1 #ii orig9 (1 #ajc rocks (1 #ii ,rift ,m\nta9s1 #a1 #ij1 #ib1 #id ,rift ,valley1 #a1 #hd1 #ij1 #ia1 #ib1 #ic1 #id s$im5ts on1 #ii seismicity (1 #ih1 #ii /ructure (1 #ha1 #ajj1 #ajb1 #ajg trilobites f1 #ii type pr(ile1 #ij ,upp] ,/ep1 #a1 #ij1 #id1 #ie ,mid-,atlantic ,ridge ,exp$itions 7#aidg-dh71 #ii ,middle ,/ep1 #a1 #ae1 #id1 #ie1 #if ,mid-ocean canyons ,bay ( ,b5gal1 #ff ,bay ( ,biscay1 #fj deep-sea *annels1 #ff def9ition1 #ff di/ribution (1 #ff-gb equatorial ,atlantic1 #ff ,gulf ( ,alaska1 #ff ,mid-,ocean ,canyon ,no4 #b41 #ga-gb ,nor?we/ ,atlantic ,mid-,ocean ,canyon1 #bb1 #ff-gb ,mid-,oceanic ,ridge1 #a1 #ae1 #hc-ajd1 #ajg cre/ prov9ces1 #a1 #ae1 #hc def9ition1 #hc flank prov9ces1 #a1 #ae1 #ie ,milne ,seam\nt1 #gi ,morpho-tectonic prov9ces1 #b ,,muir1 ,u4,s4,s41 #gf ,n>es ,abyssal ,pla91 #ef1 #eg1 #ei1 #gd1 #ha ,national ,geographic ,society1 vii1 #ii ,nav>ro 7,cretace\s7 =mation1 #dd1 #de1 #df ,navidad ,bank1 #cd1 #cf ,navigational control1 accuracy (1 #e ,naz> ,subm>9e ,canyon1 #cg ,newf\ndl& ,abyssal ,pla91 #ef1 #eh ,newf\ndl& ,bas91 #ab1 #ef1 #fg1 #fh1 #fi1 #gj1 #ga ,nom5clature ( deep-sea relief #aa1 #ab1 #ae ,nor? ,am]ica ,bas91 #ab ,nor? ,atlantic ,ocean major bas9s (1 #ab map ( e>?quakes 91 fac+ page1 #abb map ( s$im5t di/ribution1 fac+ page1 #abb s\nd+s1 #e /ructure section1 #ajb ,nor? ,can>y ,bas91 #ab ,nor!a/ ,provid5ce ,*annel1 #ce1 #cf ,nor?we/ ,atlantic ,mid-,ocean ,canyon1 #bb1 #fg1 #fh1 #fi1 #gj1 #ga ,ocean-bas9 floor1 #a1 #ae1 #be1 #ee-hb1 #ajb1 #ajg abyssal floor1 #a1 #ae1 #ee-gd cru/al /ructure1 #hj-ha1 #ajb oceanic rises1 #a1 #ae1 #ee1 #gd-gh seam\nts (1 #gh-gi seismicity (1 #hj ,oceanic cru/1 #hj-ha1 #ajj1 #ajb ,oceanic rises ,b]muda ,rise1 #gd-gg ,corn] ,rise1 #fd1 #gg def9ition1 #gd di/ribution1 #gd ,rio ,gr&e ,rise1 #gd ,rockall ,rise1 #gh ,oceanograph] ,canyon1 #dc ,old ,bahama ,*annel1 #cf ,oliv9e gabbro1 #ii ,or?ogeosyncl9e1 #ed ,or?oqu>tzite1 #ec ,out] ridges ,antilles ,out] ,ridge1 #cb1 #cc1 #cf1 #eb1 #ec1 #ei1 #fj def9ition1 #bj s$im5ts on1 #ec ,s\!a/ ,newf\ndl& ,ridge1 #bb1 #fc1 #fg1 #gj1 #ga1 #gb ,paleozoic outcrops1 #ii ,pelagic deposits1 #ec1 #ha1 #ii1 #ajg ,photographs1 sea floor1 #ci1 #ej1 #ei1 #gi ,physiographic diagram1 prep>ation (1 #c1 #d1 #e ,physiographic prov9ce *>t1 ,atlantic ,ocean1 #c1 #af ,plant debris1 #fj ,plato ,seam\nt1 #ih ,plei/oc5e bea*es1 subm]g$1 #db ,portuguese subm>9e canyons ,lisbon1 #cg ,naz>1 #cg ,setbal1 #cg ,precision ,dep? ,record] 7,,pdr7 accuracy (1 #h developm5t (1 #h op]ation (1 #i positions ( ,,pdr s\nd+ tracks1 #f ,precision ,dep? ,record] 7,,pdr7 records1 #bh1 #cb1 #cd1 #cf1 #ch1 #eh1 #fd1 #gc1 #gh1 #ia1 #ib ,pu]to ,rico ,tr5*1 #cf ,pu]to ,rico 7,tr5*7 ,abyssal ,pla91 #ag1 #cf1 #eb1 #ef1 #fj ,rec5t s$im5ts1 erosion (1 #ej ,r$ clay1 #cc1 #gf1 #ajf ,reflections1 sub-bottom1 #be1 #cb1 #da1 #aje-ajf ,rese>* vessels ,,albatross ,,iii1 vii ,,atlantis1 vii1 #g1 #h1 #gi ,,c>yn1 vii1 #gh ,,discov]y ,,ii1 vii ,,kev9 ,,moran1 #gj ,,meteor1 #hc1 #ih ,,talisman1 #ii ,,!ta1 vii1 #b1 #g ,,vema1 vii1 #f1 #gb ,rift ,m\nta9s1 #a1 #ae1 #hd1 #ij1 #ia1 #ib1 #ic1 #id1 #ie1 #if1 #ig1 #ih1 #ii1 #ajj1 #ajg ,rift ,valley1 #a1 #ae1 #hd1 #ij1 #ia1 #ic1 #id1 #ie1 #if1 #ih1 #ii1 #ajj1 #aja1 #ajb1 #ajc1 #ajg ,rio ,gr&e ,rise1 #gd ,ripple ,m>ks1 #ci1 #ej1 #ea1 #ei1 #gi ,rock dr$g+1 #ci1 #db1 #dc1 #de1 #df1 #dg1 #gf ,rockall ,rise1 #gh ,sable ,isl&1 #bd ,sable ,isl& ,bank1 #bd ,s&1 deep-sea1 #bh1 #fj1 #fa1 #gd ,sc>ps1 #fa ,abyssal ,pla91 #fa ,b]muda ,rise1 #gf ,mid-,atlantic ,ridge1 #hc ,scotian ,%elf1 #bc1 #bd ,sc\r m>ks1 photographs (1 #ci1 #ei ,seam\nts ,amp]e1 #gh ,atlantis1 #ih ,c>yn1 #gh ,cruis]1 #ih ,great ,meteor1 #ih ,joseph9e1 #gh ,kelv91 #gg1 #gh ,milne1 #gi ,muir1 #gf ,plato1 #ih ,seam\nt ,gr\ps ,atlantis-,plato-,cruis]-,great ,meteor ,seam\nt ,gr\p1 #ih ,horse%oe ,seam\nt ,gr\p1 #ei1 #gh ,kelv9 ,seam\nt ,gr\p1 #gf1 #gg1 #gh ,muir ,seam\nt ,gr\p1 #gf ,seam\nts1 s$im5t>y processes on1 #ei1 #gg ,s$im5t di/ribution abyssal pla91 #gd ,b]muda ,rise1 #gf cont95tal m>g91 #ec correlation ) topography1 #ajg map ( ,nor? ,atlantic1 fac+ page1 #abb ,mid-,atlantic ,ridge1 #ii ,seismicity cont95tal m>g91 #ea epic5t] map1 ,nor? ,atlantic1 fac+ page1 #abb ,mid-,atlantic ,ridge1 #ih ocean-bas9 floor1 #hj ,seismic-reflection measurem5ts1 #hj ,seismic-refraction measurem5ts cont95tal m>g91 #eb1 #ha1 #ajb ,mid-,atlantic ,ridge1 #ha1 #ajj1 #ajb ocean-bas9 floor1 #fe1 #hj1 #ha1 #ajb ,s]p5t9e1 #ii ,s]p5tization1 #ajc ,setbal ,subm>9e ,canyon1 #cg ,%>ks too?1 photograph (1 fac+ page1 #ci ,%elf break1 #ag1 #ej1 #ea ,si]ra ,leone ,rise1 #fa ,slump+1 #ej1 #ea1 #ii1 #aje ,sohm ,abyssal ,pla91 #ee1 #ef1 #eg1 #ga1 #gb1 #gd ,s\nd velocity corrections1 #ab1 #ac ,s\nd+ corrections slope1 #ae velocity1 #ab1 #ac ,s\nd+ tracks nonprecision1 #g ,,pdr1 #f ,s\nd+ velocity1 #ab ,s\nd+s e*o1 #h1 #i hemp l9e1 #h wire1 #h ,s\? ,atlantic1 ,physiographic ,diagram1 v ,s\? ,can>y ,bas91 #ab ,s\!a/ ,newf\ndl& ,ridge1 #bb1 #fc1 #fg1 #gj1 #ga1 #gb ,sub-bottom e*oes1 #be1 #cb1 #da1 #aje-ajf ,subm>9e canyons1 #bj ,cape ,breton1 #cg ,fosse de ,cay>1 #da ,gilb]t1 #dd ,gr& ,banks1 ne>1 #bc ,hudson1 #h1 #bg1 #bh1 #cj1 #ca1 #eh1 #gb ,hydrograph]1 #de1 #df ,lisbon1 #cg ,lydonia1 #dd ,naz>1 #cg ,nor!a/ ,provid5ce1 #ce ,oceanograph]1 #dd1 #de1 #df ,setbal1 #cg ,/>fi%1 photograph (1 fac+ page1 #ci ,/ructural b5*es1 #dc1 #dh1 #di ,subm>9e topography1 outl9e (1 #ae ,sunk5 isl&s1 #gh ,tagus ,abyssal ,pla91 #ef1 #eg1 #fa ,,talisman1 ,rese>* ,vessel1 #ii ,tectonic map1 ,atlantic ,ocean1 #b ,tectonic uplift1 #gg1 #gh1 #ih ,t]rac$ zone1 #ie ,t]races1 cont95tal %elf1 #db ,t]ti>y ocean-bottom temp]atures1 #ajf ,t]ti>y outcrops1 #df1 #dg1 #dh1 #gf1 #gi1 #ajg ,,!ta1 ,m_/,v1 7seal]71 vii1 #gb ,!ta ,gap1 #ff1 #gb1 #gc1 #gd ,times ,facsimile ,company ,precision ,dep? ,record]1 #h1 #i ,tracks & trails1 photographs (1 fac+ pages1 #ci1 #gi ,tr5* 7,abyssal7 ,pla9s ,cayman1 #ef1 #fj ,kurile-,kam*atka1 #fj ,middle ,am]ica1 #fj ,p]u-,*ile1 #fj ,pu]to ,rico1 #ag1 #cf1 #eb1 #ef1 #fj ,trilobites1 ,mid-,atlantic ,ridge1 #ii ,turbidity curr5ts1 #bc1 #ej1 #ea1 #gd1 #gi1 #hj1 #ii1 #ajf1 #ajg ,uncon=mities1 #ej ,u4 ,s4 ,coa/ ,survey1 #h ,u4 ,s4 ,navy ,bureau ( ,%ips1 vii ,hydrographic ,(fice1 #e ,(fice ( ,naval ,rese>*1 vii ,units3 dep?1 slope1 di/ance1 #ab ,upp] ,/ep1 #ae1 #gh1 #ij1 #ia1 #id1 #ie1 #if ,vema ,gap1 #eh1 #fj1 #ff1 #gb1 #gd ,,vema1 ,rese>* ,vessel1 vii1 #f1 #gb ,virg9 ,isl&s ,bank1 #cf ,volcanic cones1 buri$1 #ea ,volcanic detritus1 #ec ,volcanoes1 #ci1 #gg1 #gh ,we/ ,europe ,bas91 #ab ,we/ ,florida ,esc>pm5t1 #cc ,woods ,hole ,oceanographic ,in/itution1 vii1 viii1 #c1 #g ,yorkt[n 7,mioc5e7 =mation1 #dd1 #de1 #df ,illu/ration3 ,heez5 et al41 ,,pl4 #bj ,,physiographic ,,prov9ces1 ,,atlantic ,,ocean_/a ,illu/ration3 ,heez5 et al41 ,,pl4 #ba ,,control ,,*>t ,all cont9u\sly record$ e*o-s\nd+ pr(iles us$ 9 prep>ation ( ,plates #a & #bj are %[n4 ,solid l9es indicate ,lamont ,geological ,obs]vatory & ,woods ,hole ,oceanographic ,in/itution cruises4 ,da%$ l9es indicate s\nd+s suppli$ by ,briti% ,admiralty4 ,l9es %[n by alt]nate long da% & two %ort da%es indicate closely spac$ discrete s\nd+s ( ,,meteor4 ,illu/ration3 ,heez5 et al41 ,,pl4 #bb ,,six ,,trans-,,atlantic ,,topographic ,,pr(iles ,s\nd+s 9 fa?oms cont9u\sly record$ by an ,,nmc e*o s\nd] on ! ,r4 ,v4 ,,atlantis4 ,! lett]s amda%2q indicate :]e s\nd+s f diff]5t cruises 7 jo9$4 ,illu/ration3 ,heez5 et al41 ,,pl4 #bc ,,index ,,*>t ,,%[+ ,,locations ,,( ,,pr(iles ,,( ,,plates #bd1 #be1 #bf ,,& ,,figure #de ,illu/ration3 ,heez5 et al41 ,,pl4 #bd ,,?irty-,,f\r ,,pr(iles ,,( ,,! ,,cont95tal ,,m>g93 ,,we/]n ,,nor? ,,atlantic ,pr(ile locations %[n on ,plate #bc4 ,note small topographic details4 ,s\nd+s spac$ approximately #a mile ap>t4 ,illu/ration3 ,heez5 et al41 ,,pl4 #be ,,tw5ty-,,?ree ,,pr(iles ,,( ,,! ,,cont95tal ,,m>g9 ,,( ,,europe ,,& ,,africa ,illu/ration3 ,heez5 et al41 ,,pl4 #bf ,,cru/al ,,/ructure ,,& ,,cont95tal-,,m>g9 ,,prov9ces ,,f\r ,,repres5tative ,,pr(iles1 ,,positions ,,( ,,pr(iles ,,%[n ,,on ,,plate #bc4 ,data = ,w-#f f ,b5tley & ,worzel 7#aief71 ,w-#aj & ,w-#aa f ,katz & ,ew+ 7#aiee71 & ,w-#cc f ,ew+ & ,worzel 7#aied7 & ,(fic] et al4 7#aieg74 ,seismic data project$ to cont9u\sly record$ s\nd+ pr(iles4 ,v]tical exagg]ation #dj3a4 ,illu/ration3 ,heez5 et al41 ,,pl4 #bg ,,five ,,topographic ,,pr(iles1 ,,we/]n ,,nor? ,,atlantic ,s\nd+s cont9u\sly record$ on ,,nmc s\nd]4 ,illu/ration3 ,heez5 et al41 ,,pl4 #bh ,,di/ribution ,,( ,,deep-,,sea ,,s&s ,,9 ,,relation ,,to ,,physiographic ,,prov9ces ,data f ,ericson et al4 7#aieb2 #aiee7 bas$ on pi/on cores tak5 by ,lamont ,geological ,obs]vatory exp$itions4 ,illu/ration3 ,heez5 et al41 ,,pl4 #bi ,,e>?quake ,,epic5t]s1 ,,nor? ,,atlantic ,date f ,gut5b]g & ,ri*t] 7#aied7 & ! epic5t] c>ds ( ! ,u4,s4 ,coa/ & ,geodetic ,survey ?r\gh #aief4 ,illu/ration3 ,heez5 et al41 ,,pl4 #cj ,,location ,,( ,,pdr ,,records ,,& ,,bottom ,,photographs ,,reproduc$ ,,z ,,illu/rations4 ,transcrib]'s ,notes3 ,! l>ge diagram = plate #a m5tion$ 9 ! note on p4 v is miss+4 ,x 0 n physically atta*$ to ! book p] note4 ,sil5tly correct$ simple spell+1 gramm>1 & typographical errors4 ,reta9$ ana*roni/ic & non-/&>d spell+s z pr9t$4 ,enclos$ italics m>kup 9 und]scores4