FISHERIES RESEARCH BOARD OF CANADA Translation Series No. 2493 Patterns of the dissection of the continental slope and foot of the northern commercial basin (Labrador Sea, Norwegian- Greenland Basin) by B. N. Kotenev, and G. G. Matishov Original title:Zakonomernosti raschleneniya materikovogo sklona i podnozhiya severnogo promyslovogo baseina (Labradorskoe more, Norvezhsko-Grenlandskii bassein) From: Trudy Polyarnyi Nauchno-Issledovatel'skii Proektnii Institut Morskogo Rybnogo KhOzyaistva Okeanografii (PINRO) (Proceedings of the Polar Research Institute of Marine Fisheries and Oceanography), 28 : 13-22, 1972 Translated by the Translation Bureau(AMA) Foreign Languages Division Department of the Secretary of State of Canada Department of the Environment Fisheries Research Board of Canada Biological Station St. John's, Nfld. 1973 20 pages typescript ., j' - SECRETARY OF STATE 1_iCt+^ SECRETARIAT D'ÉTAT iîii^iSl_Ai1aN BUREAU SUREAU DES TRADUCTIONS MULTlL,IN GUAI- 5^RVIC ES DIVISION DES SERVICES çANAOA PiYiStON MULTILINGUES ^--------- . :•,?„?.^ FhJm - TitADUCTiON DE IN-TO -EN "' 1 U.S, :^i ^i Îl •- A;,T'EIIR 13,N. Tiotenev,• G.G. Miatishov. TITLE IN ENGLISH rTITRÈ ANGLAIS Patterns of the dissecti.on of the continental s7_one and foot of the No'2 thern commercial basin (Labrador Sea, Nort^regian-Green]:and :'a.si.n ) TITLE IN FOREIGN LANGUAGE (^iRP.tÏSLITERATE FOREIGN CHARACTERS) TITRE EN LANGUE ETRANGÉRE (TRANSCRIRE EN CARACTÉRES ROMAINS) Zakono?uernostl rasçh:teneniya matorjkpvogo sklona i podnozhiya severno^o ,oa7ornyslovo^;o' basseina ( Labradcirr,?Coe more, ^,,'^orvezhsko- Grer.:l-e.ndskii be.,.ssein) REFERENCE IN FOREIGN LANGUAGE ( NAME OF BOOK OR PUBLICATION) IN FULL. TRANSL1TERATE FOREIGN CHARACTERS, REFÉRENCE EN LANGUE ETR?.NGERE ( NOM DU LIVRE OU PUBLICATION). AU COMPLET, TRANSÇRIRF EN CARACTi:RES ROMAINS. mrudf :'o1Jr,-irno-z•o nauehno-issledovate^ ^si;o^:o i proektno-,o instituta mor5kogo -rybno^o l.hoz5ra,istva. i o?.so^^„^o;raf i^. lin. N. Tv^ . Knipovicha (i'il^.kg) REFERENCE IN ENGLISH _ FEFEREt:CE EN ANGLAIS -x'Yoceediyï :;s of the N. i^l. hnipovich Z'olar Scientific Research and °ro ject 1-7_ ;nnino- Institute of 1^-7ar:jne Fisheries and Oceanography (k'INaO) PUBLISHER - EDITEUR PAGE NUMBERS IN ORIGINAL QAfiE QF RU@LICATION NUMEROS DES PAGES DANS @ATE P.E PUBLICATION L'ORIGINAL .ï'1 N _E0 Pp. 13-22 YEAR ISSUE NO. kQ44ME PLACE 0F PU©LÎCÀTIÔN ANNEE NUMERO NUMBER OF TYPED PAGES LIEU DE PUBLICATION NOMBRE DE PAGES DACTYLOGRAPHIEES Iriuxmansk, USSR 19 7q 28 20 REQUESTING DEPARTMENT TRANSLATION BUREAU NO. MINISTÈRE-CLIENT Environment NQTRE DOSSIER NO 143702 BRANCH OR DIVISION TRANSLATOR (INITIALS) Fisheries Service DIRECTION OU DIVISION TRADUCTEUR (INITIALES) --'--$zôlogical Sta;tiôri PERSON REQUESTING DEMANDÉ PAR ._ UNEDIT'LID TRANSLATION For ill:oifliZiiOn only YOUR NUMBER V(}TRE DOSSIER NO TRADUCTION NON l:EVJSEE tnformatIon sculement; DATE OF REQUEST UATE DE LA DEMANDE 7at^uari 15 , 1973 5^OS-Î 00-1 0•,4 (R.E V. 2 /68.1 7Q30•21•029•8333 DEPARTMENT OF THE SEÇRETARY OF STATE SECRÉTARIAT D'ÉTAT • , «TRANLA. TION BUREAU BUREAU DES TRADUCTIONS MULTILINGUAL SERVICES DIVISION DES SERVICES DIVISION MULTILINGUES DEPARTMENT DI VISION/BRANCH CI TV CLIENT MINISTÈRE DIVISION/DIRECTION VILLE Fisheries Service St. John's, Nfld. Environiueut Biological Station bj.2EAU NO. LANGUAGE TRANSLATOR (INITIALS) N° DU BUREAU LANGUE TRADUCTEUR ( INI TI ALES) 143702 Rus sian A. Ma. MAR 3 0 1973 Trudy PolyarnoRo nauchno-issledovatel'skogo i proektnogro instituta morskogo rvbnoPm khozyaistva i okeanografii im. N. M. KniDovicha (EnR0) (Proceedings of the N. M. Knipovich Polar Scientific Research and Project Planning Institute of Marine Fisheries and Oceanography) Issue XXVIII, 1972, pp. 13-22 (USSR) UDC 551.35(261.1) PATTERNS OF THE DISSECTION OF THE CONTINENTAL SLOPE AND FOOT OF TEE NORTHERN COMMERCIAL BASIN (LABRADOR SEA, NORWEGIAN- GREENLAND BASIN) UNEDITED TRANSLATION Fo r By B.N. Kotenev, G.G. Matishov. ,. information only tADLICTI-41 NON REVISEE tnformation soulemont Submarine •anyons, channels and other types of valley- 13* shaped deDressions are widespread on the continental slope and foot in the Northwest Atlantic (Labrador Sea) and in the Norwegdan-Greenland basin (1, 3, 5, 61 79 8, 11, 12, 13, 14). Analysis of the echo-sounding data collected by the 16* PINRO marine geology laboratory in recent years allows us to define more precisely the peculiarities of the structure and q:Istribution of the main canyons, channels and valleys on the slope and foot (fig. 1) and to give their senètic classification (table 1). It became clear that the patterns Numbers in the right-hand margin indicate the corresponding pages 5OS..200-.10-31 in the oripsinal• 7530-21.029.5332 . 2 . f -;tructur distrnution of valley-shped de'pressions 1 6* are closely connected ulth the ,7eo1o.-4cal and morpho1o3ical structure of the su'=2rine continental marins (of the shelf and slope) and Tith physical 7eoraphical conditions favourable for the preservation of negative relief forms on the slope. In the relief of the bottom of the region under study, the following morphological zones are well distinguished: shelf, continental slope, foot and mid-oceanic ridge (1, 5, 7, 11, 13, 14). STRUCTURE OF THE SHELF. The shelf of the Northwest Atlantic and the Norwegian- Greenland Basin is a submarine Plain, bordering the continen- tal dry land which was covered by glaciers everywhere in the Pleistocene. The cover still exists in Greenland. Many researchers (5, 7, 9) connect with the activity of the glaciErs such specific features of the, relief of this glacial shelf as: the longitudinal and transverse channels, internal and external parts of the shelf and the deep water in the outer Part and others. According to the peculiarities of the geological structure end morpholoy within this region one can distin three main types of shelf. A narrow- shelf (up to 20-30 miles), bordering on re -eneratedEmountains on] land (N.w. Norway, - SoUthern Greenland, Southern Iceland), on which longitudinal channels are absent. Its surface is complicated by narrow, sometimes .iJ`^ .._i:^.. \^.''^.._.l'.. •^ ( . r• !' ..^:..^iL^._ ) .:^i^3^1:.'_i c^..t^.^ ti..t=d on L11- ^ ^. 7 t^ _ ^ ^ l" •^ .l , - 7 ... ^._..._ . .. .... .".^^ i. ..L !. i, 'D r ^.i.. a ^-_...! r! .^_^.! ,1 .1.' •L :_. ^.'J_^^ia^the l.e o^:^te_^ edge with relief contours which are inherent in rocky outcrops indicate that the strong rocks of the cr-yst2.lline foundation are not covered by sedimentary rocks^ (9 , 10, 13 ). This type of shelf is like a 7,aidened internal part of a tyi ical glacial shelf , without the external part. The narroti* shelf (up to 60 miles) of Western and Eastern Greenland-Spitzbergen has typical glacial features. An almost continuous chain of longitudinal deep (up to 700 ni-) channels with echeloned sections separates the 17* confined (u-,-) to 10-15 miles) internal roclicy "part of the shelf with depths up to 100-200 metres from the outer part. NarroT, deep v^^lleys comin- out of the fjords, seps,ra.te sub- marine rocks and various nositive and negative relief forms of exaration origin allow us to see this part of the shelf as a flooded part of I'strendflet" (3). The external part is dissected by frequent transverse chLanne7_s T•r;.th depths of up to 600 metres into a row of longitudinal rises (banks). Their surface, with denths of 50-200 r.etres, is relatively levelled and as shoinl by geoph,ysico,l research in Western Greonland, rocks of crystalline foundation within its limits are covered by sedimentary rocks up to 1 k;n. in thickness (13 .. ,.,.... ,_ . ^ . ... _ . _. :_.. • 17* Te uide 1,,l-rador shelf, comprising the Southeastern end of affin Lard and Central Noruay5 is characterised by an unusually stron develoent of the external Dart and its slight dissection, by . infrequent but quite large transverse channels and by a great thickness of sedimentary bedrocks (9, 10, 13). shelf The Barents Sea/has the same structure, which is vast in size (600 x 800 miles), a deeply sunken submarine Plain (up. to 3 .00-400. metres) dissected by large channels into a row of rises (4). In the marginal parts this plain is surrounded by regenerated mountains of Spizbergen, _ Franz Josef Land, Novaya Zemlya and the Scandinavian Peninsula; these mountains are separatedfrom the plain by an almost continunus chain of longitudinal channels. A heavy thickness of sedimentary rocks from the Paleozoic up to the Paleogene (2) indi- cates the prolonged 'sinking of the earth's crust within the limits of the Barents Sea. Thus, the szeological history of the development of -the submarine continental margins of the Northern Hemisphere was reflected in the morphology of the shelf. In the marginal regions of the continents where the earth's crust sinks during a prolonged Period, a rather wide part of the outer shelf is develoPed. Where the marginal regions of the continents are drawn into an arch rise, and the submarine continental margin does not stand out geologically, the shelf is narrow and the sedimentary cover 5• is ribocnt. The transitional type of the submarine margin 17* is chalracterizd by a narrow width and an insiznificant thic:me:::z of sedànentry rock. THE TRANSVERSE DISSECTION OF THE CONTINENTAL SLOPE. The continental sloue is the inclined surface which separates the shallow plains of the shelf from the -bottom of the deepwater troughs. The morphology of the slope and, in particular, its transverse dissection are closely connected with the geological structure of the blocks of the earth's crust which it frames. In those parts of the region where the sloPe borders on a narrow or not wide shelf it is steep (from 5 to 10-30 0 ) and is strongly dissected by transverse canyons (fig. 2, profiles l-4 1 table 2). btudies off North Western Norway on the 34th voyage of the PINRO R/V "Ak.