Lopatin, B. G.

Orgo, V. V.

Pavlov, L. G.

Shkarubo, S. I.

English

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Polarforschung 69,131-135,1999 (erschienen 2001)Teetonic Structure of Novaya ZemlyaBy Boris G. Lopatin', Leonid G. Pavlov', Vladimir V. Orgo" and Sergei 1. Shkarubo"THEME 8: Polar Urals, Novaya Zemlya and Taimyr: TheNorthern Connection of the UralidesSummary: Recent interpretation of the geology of Novaya Zemlya Archipe-lago and adjacent shelf areas of the Barents and Kara Seas based on all data,including seismic profiling permit the authors to suggest that. Novaya Zemlyais an accretional assemblage of three tectonic blocks (terranes): The southernBlock with Baikalian basement, the Central Block with Karelian basementand the Northern Block, having an autonomous way of evolution. Analysis oflitho-tectonic assemblages has revealed the main stages of evolution, the mostprominent of which are: collision of the Southern and the Central blocks inLate Riphean - Cambrian, rifting with these blocks in Middle - Late Devonianand total orogeny (including the Northern Block) due to the collision of theBarents and the West Siberian plates in the Late Triassie - Early Jurassie.INTRODUCTIONThe geological surveying of the Novaya Zemlya Archipelagoat a 1 : 200 000 scale has been carried out by Polar MarineGeological Expedition (Novaya Zemlya division). Adjacentoff-share areas at a 1:1 000 000 scale have been mapped bythe Marine Arctic Geological Expedition (off-shore division).These surveys have provided a substantial data base for under-standing the structure and tectonic evolution of the NovayaZemlya fold system and its relationships to adjacent basins(GRAMBERG 1988, KORAGO et al 1984).MAIN STRUCTURAL FEATURESThe Novaya Zemlya Archipelago an uplifted part of the Paihoi- Novaya Zemlya fold system, having more than 200 km inwidth is partly covered by the Barents and Kara Seas. Tectoni-cally it is dominated by an early Mesozoic antiform betweenthe Barents and the West Siberian basins. The conjugation ofthis antifarm with the Barents Sea basins expressed by thethrust zone, which can be traced under flat lying MZ-KZ coverby seismic records. The boundary of the antiform and theWest-Siberian basin is less evident (Fig. 1).Novaya Zemlya (Fig. 2) is an accretional assemblage of threeblocks: the Southern block with Baikalian basement, theCentral Block, with Karelian basement, and the most peculiarNorthern Block with unknown basement, but older than LateRiphean. The blocks are bounded by deep-seated fault zones:Baidaratsky and Sporonavoloksky., All-Russia Research Institute for Geology and Mineral Resources ofthe World Ocean(VNIIOkeangeologia), 1 Angliisky pr., 190121 St. Petersburg, Russia<vniio@g-ocean.spb.su>, PMGRE. 24 Pobedy st., St. Petersburg - Lomonosov, Russia., Marine Arctic Geological Expedition (MAGE), 26 Perovskaya st., Murmansk, Russia.Manuscript receeived 02 February 1999, accepted 12 October 2000The fold belt of Novaya Zemlya is the result of Early Kimme-rian (late Triassie to early Jurassic) tectonic movements, dueto inferred collision of the Barents and the West Siberianplates, the stress being directed from ESE to WNW, as shownby the thrusting and reversed folding in the western flank ofNovaya Zemlya (Fig. 1).The Novaya Zemlya fold system is composed ofYuhznonovo-zemelsky (YNZA) and Severonovozemelsky (SNZA) anticli-noria (Fig. 2). The anticlinoria are separated by theKarmakulian saddle and related synclinoria - Barents to thewest and Kara to the east. The most prominent feature is theMain Novozemelsky fault zone. Kimmerian deformations arenot uniform in the Southern, Central and Northern blocks,being dependent on the basement structure and differentfeatures of the Paleozoic strata; they have different orientationto the Kimmerian compression. For the Southern blocksymmetrical folding is typical and thrusting is not typical. Thefold trend of the YNZA inherits the sublatitudinal trends of theBaikalian basement structures. In the core of the YNZA, theBaikalian basement is exposed. In the Central block linearfolding, accompanied by intensive thrusting, is wide spread. Inthe Northern Block the folding is of simple pattern.The SNZA occupies the Central and Northern blocks. Withinthe Central Block its structure is very complex and asymme-tric: zones with isoclinal folding and thrusting alternate withrather simple open folding. The most complex compressionalstructure is recorded along the Main Novozemelsky thrustzone. Structures of the SNZA have sublongitudinal trends,similar to those in the Riphean basement folding. The northernpart of SNZA, within the Northern Block, differs by havingrelatively simple structures, preserving the sublongitudinaltrend.Litho-tectonic assemblages ofsouthern and central blocksAs a result of detailed geological surveying the followinglitho-tectonic assemblages have been distinguished (Fig. 3):1) Early Riphean (1550-1490 Ma Tab. 1) terrigenous-carbo-nate assemblage: marbles, quartzites, and schists meta-morphosed in epidote-amphibolite facies.2) Late Riphean to Vendian, flysch-greywacke, deep waterassemblage: polymictic volcaniclastic sandstones, phyl-Iites, carbonaceous slates, metamorphosed in greenschistfacies.3) Late Riphean to Vendian (680-735 Ma, Tab, 1), alaskitegranite-granodiorite Mitjushev igneous suite.4) Cambrian to Middle Devonian, shallow shelf assemblage:feldspar-quartz sandstones, dolomites, limestones, shales,siltstones, gravelites and conglomerates, with phosphate131Barents sea Novaya Zemlya Kara seaFig. 1: Geological section after offshore seismic profiling.Scala: horizontal 1:1000 000PZ---KK,t-st20I10IoIei 10 30ei...- m"j,q"""d:==f=:==l!EIl1_~~~~..-=:=:r:=r====;r===ff~~~·2 1,.1-1,-3-4-5-6-7-8-9-10-11·12·13-14nodules, bioherms, numerous fossils, ripples marks andbioturbation.5) Late Devonian to Early Carboniferous carbonate - shelfassemblage: limestones, calcarenites, bioherms and calca-reous sandstones.6) Middle to Late Devonian carbonaceous - carbonate -volcaniclastic rocks of the initial stage of rifting: clay-stones, siltstones, shales, tholeiitic basalts, tuffs, tuffites,polymictic sandstones, gravelites, conglomerates,intruded by gabbro-dolerites sills and dykes.7) Late Devonian to Permian deep water, carbonaceous -siliceaus - carbonate rift related assemblage: claystones,siltstones, rodochrosite - bearing siliceous rocks, turbi-dites, olistolites, olistostromes, with graded bedding, andslumping.8) Late Permian flyschoidal and turbiditic assemblage: thetrough fill under conditions of avalanche sedimentation:polymictic, greywacke sandstones, claystones, siltstones,olistolites, olistostromes, and calcareous sandstones.9) Upper Permian to Lower Triassie molasse assemblagecoastal marine, subaeral: multicoloured sandstones, silt-stones, claystones, and conglomerates; with basaltic andandesitic tuffs.10) Late Triassie - Early Jurassie (196-210 Ma by V-Pb,(KORAGO. & CHUKHONIN 1988) granitoid, collisionalsuites: alaskites, granites, granodiorites, and monzo-diorites.Northern blocks11) Late Riphean to Early Ordovician carbonaceous, argilla-ceous and coarse terrigenaus assemblage of slope andrise: phyllites, metasandstones, metasiltstones, polymicticconglomerates, turbidites with gradational bedding andslumping.12) Early Ordovician to Early Devonian carbonate and terri-genaus - carbonate she1f assemblage: claystones, silt-stones, quartz and polymictic sandstones, conglomerates,and limestones, with graptolites, bioherms and crossbedding.13) Early Devonian to Early Carboniferous carbonate andterrigenous-carbonate shallow water shelf assemblage:limestones, usually algal, dolomites, minor siltstones,claystones, sandstones, and conglomerates, with crossbedding.14) Middle Carboniferous to Permian carbonate - terrigenousshallow water and subaerial assemblage: claystones, silt-stones, sandstones, and minor oolitic organic-detritallimestones.NN Location Rock 208 Pb206 Pb207 Pb206 PbAge, m.a. Reference110 k-b Sulmeneva Bay,56°07'E 74°31 'NSchist, Zircon'" '"0,130,110,0961 ±0,00450,0930±0,00501550±801490±100KORAGO &CHUKHONIN(1988)107 k-12 a _*_*_~_x_* Granite, Zircon 0,09 0,084±0,004 1300±90 KORAGO et al. 11(1984)NN Location Rock K% AR" AR" Age Referencemineral K" m. a.107 k-a Sulmeneva Schist, Amphibole 0,41 21,99 0,04495 645±53 KORAGO &56°07'E 74°31 'N CHUKHONIN103 k-7 -*-*-*-* Granite, Muscovite 6,53 312,1 0,04006 584±27 (1988)ITab.I: Pb-Pb thermo-emission method Results of isotopic dating of schists and granites from Novaya Zemlya. Used constants (year .1): A238=1,5513xlO' lO;Am=9,8485xI0 Io ; A,=0,58IxIO JO; Aß=4,962xI0'lo; U238/um=137,88, after GRAMBERG (1988), KORAGO et al. (1984), KORAGO & CHUKHONIN (1988)132KARA EAFig. 2: Main structuralelements of Novaya Zemlyafold system.LEGEND30 0 30 60 90 km.. .. I I INorth rnblockSubordinate structures: LA - Litkinskayaanticline, PA- Pahktusovskaya anticline,KS - Karmakulian saddleMain anticlinoria: YNZA- Yuhznonovo-zernelskv SNZA - SeveronovozemelskySynclinoria: BS -Barents, KS - KaroBF - Baidaratsky fault zone,SF - Sporonavoloksky fault zone.NF - Main Novozemelsky thrust-fault zone~ Boundaries ot the first order structuresk23 Boundaries of the second order structuresentrallockB RENTS S A74j--/---M~~~~~-\--t--\MAIN STAGES OF GEOLOGICAL EVOLUTIONAnalysis of the distribution of the litho-tectonic assemblageshas revealed the following main stages of geological evolu-tion:tures were formed. The Northern Block evolved indepen-dently.Ordovician - Early DevonianLate Riphean - Cambrian:During this time the Southern and Central blocks collidedalong the Baydaratskaya fault zone and the Baikalian struc-In this period a rather stable regime of a passive continentalshelf existed for the Southern and Central blocks. The terrainof the Northern Block was developed under changing shallowto deep water shelf - slope conditions and graptolitic shalefacies was widespread.133Note: The numbers in the legend correspondto the numbers of structural-lithologicalunits in the text60ISEA30IoIKARA30...1 82 9_3 10A 4 11.5 12.6 13.7 14BAR NTS SEA74° -r---+---Fig. 3: Map of litho-tectonic assemblages. I =Early Riphean terrigenous-carbonate assemblage; 2 =Late Riphean - Vendian flysch-greywacke assemblage; 3 =Late Riphean - Vendian igneous suite; 4 = Cambrian - Middle Devonian shallow shelf assemblage; 5 = Late Devonian - Early Carboniferous carbonate - shelfassemblage; 6 =Middle - Late Devonian carbonaceous - carbonate - volkaniclastic assemblage; 7 =Late Devonian - Permian deep-water assemblage; 8 =LatePermian flyshoidal and turbiditic assemblage; 9 =Upper Permian - Lower Triassie molasse assemblage; 10 =Late Triassie - Early Jurassie igneous suite; 11 =Late Riphean - Early Ordovician assemblage of slope and rise; 12 = Early Ordovician - Early Devonian carbonate shelf assemblage; 13 = Early Devonian - EarlyCarboniferous terrigenous-carbonate assemblage; 14 = Middle Carboniferous - Permian carbonate-terrigenous shallow-water assemblage.134Middle - Late DevonianThe time of initial rifting in the Southem and Central blocks,culminating in the Frasnian. Submergence and consequentdifferential vertical movements with intensive magmatism(suboceanic tholeiitic basalts) took place. The Northem Blockdid not undergo rifting and a carbonate shelf existed, withoutmagmatism.Late Devonian - PermianThe stage of rifting with a trough forming and filling, stronglydifferentiated into different zones, from a rather stable carbo-nate shelf in the Barents zone to continental slope conditionsin the Kara zone. In the latter under uncompensated deepwater environment, flysch and carbonaceous, siliceous, carbo-nate assemblage were deposited. The history of the NorthemBlock continued to be quite different, with shallow water,stable conditions prevailing.Late Permian - Early TriassieThe stage of intensive avalanche type sedimentation occuredin a post rift basin, the Uralian orogen being the source area.Accumulation of flysch, with turbidites started in rather deepwater and ended in shallow water conditions. Most part of theNorthem Block, by contrast was occupied by a coastal marineenvironment or by partly eroded, land areas.Late Triassie - Early JurassieThe stage of total Paihoi - Novaya Zemlya (including theNorthem Block) orogeny, with intensive folding, faulting andminor granitic magmatism, presumably, due to the collision ofthe Barents and the West Siberian plates.Younger historyOn the Novaya Zemlya archipelago, river valleys of Oligoceneage cut to the Late Mesozoie to early Cenozoic peneplain,allowing us to suggest that its latest uplift started in the Oligo-cene.ACKNOWLEDGMENTSThe authors are grateful to the authorities of the Polar MarineGeological Expedition and the Marine Arctic GeologicalExpedition for access to geologie al and geophysical data. Wewould also like to express appreciation to the Federal Institutefor Geoscience and Natural Resources (Hannover) and to theEuroprobe Research Program (Uppsala University) forsupport of our participation in ICAM III.ReferencesGramberg, I.S. (1988): Barents shelf plate.- VNIIOkeangeologia, Leningrad:"Nedra", 262 pp.Korago, E.A, Andreeva JA, Ershov Yu.P. & Chukhonin, AP. (1984): Precam-brian formations of the Northern Is1. of Novaya Zemlya.- In: NovayaZemlya in the earliest stages of development. Leningrad, PGO «Sevmor-geologia», p. 5-19.Korago, E.A. & Chukhonin, AP. (1988): Granite formations of NovayaZemlya. Izv. AN SSSR, seriya geolog., NIO, p. 28-35.135

Tectonic Structure of Novaya Zemlya

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