How to order: Contents

Chapter 1 INTRODUCTION – Internet: EXPLORATION OF THE www.ngu.no/no/hm/Publikasjoner/Boker/ Chapter 2 IMAGING DEEP STRUCTURES BENEATH THE SURFACE ATLAS-Geological-history-of-the-Barents-Sea/ Chapter 3 FROM RIFT - TO MEGA-BASINS

Chapter 4 CONTINENTS IN MOTION - THE BARENTS SEA or IN A PLATE TE TONIC FRAMEWORK

Chapter 5 LOCHKOVIAN – Caledonian mountains in the west, and lowlands and shallow marine basins in the east e-mail: Chapter 6 FRASNIAN – Active rifting, and expansion of the marine [email protected] basin in the east

Chapter 7 VISEAN – Extensive alluvial plains in the west and 135 pages, hard cover marine carbonate shelves and deep basins in the east Chapter 8 MOSCOVIAN – Rising sea level and dryer climate

Chapter 9 ASSELIAN – Shallow carbonate shelves and deep basins NOK 250,- Chapter 10 WORDIAN – Temperate climate and extensive marine shelf

Chapter 11 INDUAN – Uralian uplift in the east and progradation into the shallow-water clastic shelf

Chapter 12 ANISIAN – Enclosed, restricted basins in the west, fl uctuating shorelines in the east

Chapter 13 CARNIAN – Orogen and uplift in the east, extensive westward coastal progradation

Chapter 14 HETTANGIAN – Wide continental lowlands

Chapter 15 TOARCIAN – Extensive coastal plains transgressed from east and west

Chapter 16 BAJOCIAN – Central uplift, maximum regression and prograding coastlines in the west and east

Chapter 17 TITHONIAN – Maximum transgression on an extensive shelf

Chapter 18 VALANGINIAN – Open marine shelf

Chapter 19 BARREMIAN – Tectonic uplift and prograding deltas in the north

Chapter 20 ALBIAN – Uplift in the northeast, deeply subsiding basins in the west

Chapter 21 EOCENE – Expanded hinterlands and shrinked basins

Chapter 22 LATE NEOGENE UPLIFT AND GLACIATIONS Geological History of the Barents Sea

The atlas presents a comprehensive compilation of the geology of the Barents Sea summarizing a vast amount of knowledge and data about this extensive Arctic region.

The geology of the region, which still today represents exploration frontiers, is illustrated by a series of geophysical and paleogeographic maps, which are based on the inte- grated knowledge from Russian and Norwegian institutions.

Western Barents Sea Eastern Barents Sea

A B C D 300- 300- Tilt derivative Tilt derivative MagTF The paleogeographic map span 200- 200- MagTF HP-75

100- 100- Mag (nT) Mag (nT) 0- 0- MagTF HP-75 -100- -100- MagTF from the Early Devonian to Eocene 80- 80- Bouguer 60- 60- Bouguer HP-75 40- 40- 20- 20- 0- 0- -20- Bouguer

Gravity (mGal) -20- Gravity (mGal) -40- Bouguer HP-75 -40- times, and are supplemented by -60- -60-

NW 7318/5-1 7321/7-1 7324/10-1 7228/2-1 SE NW Novaya SE Stappen High Bjørnøya Basin Svalis Dome Bjarmeland Platform Nordkapp Basin Nordkapp Basin Central Barents High South Barents Basin Zemlya 0- 0-

? ? ? ? ? geophysical maps and cross-sections ?

? ? ? -5- ? -5- Cenozoic ? intrusions (?) intrusions deep Paleozoic basin ?? ? ? Depth (km) showing the present day architecture. Depth (km) deep Paleozoic basin ? deep Paleozoic basin -10- Cenozoic undiff. Mid-Upper Triassic -10- ? Neogene Mid. Triassic deep Paleozoic basin Paleogene Lower Triassic II Upper Cretaceous Lower Triassic I - undiff. Lower Cretaceous Permian deep Paleozoic basin 100 km Jurassic Salt (Carboniferous) L. Gernigon-GEOBASE-NGU-2009 L. Gernigon-GEOBASE-NGU-2009 -15- -15- (km) 0 50 100 150 200 250 300 350 400 450 500 550 0 50 100 150 200 250 300 350 400 450 500 550 600 650 (km)

Regional geological profi les and potential fi eld signature across the Barents Sea. The locations of the profi les A-B and C-D are shown on page 43.

EDITORS: North Atlantic break-up The Barents Sea consists of complex structural features including platform areas, basement highs, graben features and large sag-basins. The most signifi - The Paleocene-Eocene transition marks the margin of the Barents Shelf. The crustal short- marine slope to basinal successions are pre- cant sedimentary basins, in terms of both thickness and areal extent, lie in the East Barents Sea located immediately west of Novaya Zemlya. This province Morten Smelror, continental break-up of the North Atlantic mar- ening was concomitant with major extension served along the western margin. In the Vest- was affected by a major phase of collision between the Laurasian continent and Western , which culminated in latest Permian-earliest Triassic time. gins and opening of the Norwegian-Greenland between Norway and Greenland and is esti- bakken Volcanic Province there is evidence of Novaya Zemlya marks the zone of this closure, which could be younger (Triassic-Jurassic) in that specifi c region. Huge basins, such as in the South Sea at around 55-54 Ma. This time interval is mated to have been around 30 km. breakup-related sill intrusions. Over the west- Barents Sea, formed in the foredeep zone to the Novaya Zemlya fold belt, and acted as major catchment areas for sediments shed from the front of the also characterised by a major magmatic event, Progressively, the continental strike-slip ern Barents Shelf, there is are major uncon- belt in Late Palaeozoic-Mesozoic times. Mesozoic sediments up to 10 km in thickness are present in these basins. Particularly signifi cant, is the presence Oleg Petrov, as witnessed by massive basaltic traps and the system, active from the Paleocene to the formities between the Paleogene to Miocene and thickness of Triassic deposits, locally 6–8 km, that accumulated in a series of deltas prograding westward from Novaya Zemlya.The Triassic forma- formation of volcanic rifted margins which Eocene, was followed by a passive shear-mar- strata and overlying glacial deposits marking tions are particularly affected by numerous sill intrusions, possibly linked to the Early Cretaceous volcanism recorded on and Svalbard. have been identifi ed from the Irish margin gin development, leading to break-up from the onset of the Northern Hemisphere glacia- This volcanism occurred during the rifting stage of the opening of the Canada Basin. To some extent, the deeper nature of the South Barents Sea basin is Geir Birger Larssen & up to the Lofoten and NE Greenland shelves. Early Oligocene time. Since Oligocene times, tions in the Late Pliocene. During the Pliocene- poorly constrained. Palaeozoic sediments are probably present locally in the South Barents Sea and could represent a prolongation of the rift system well Towards the north, the break-up development separation of the Barents Shelf and Greenland/ Pleistocene the entire Barents Shelf was eroded documented onshore in the Timan-Pechora Basin. along the sheared margin of western Barents North America has continued, leading to the and large amounts of sediment were shed into Sea was younger, locally magmatic (e.g., Vesta- opening of the Fram Straight and establishing towards the shelf margin accumulating as huge The West Barents Sea represents a different structural style, affected by several episodes of rifting. The West Barents Sea is a large Permo-Triassic platform Stephanie Werner bakken volcanic province) and comparatively a North Atlantic-Arctic marine connection in wedges of shelf-margin, slope and basinal ma- affected by major graben-type basins, as illustrated in this section. The main grabens were probably initiated by Late Palaeozoic extension, contained complex. the Miocene. rine origin (Bjørnøya and Storfjorden fans). signifi cant evaporite deposits of probable Late Carboniferous-Early Permian age and were major sites of Triassic deposition. The movements of Palaeo- Prior to the opening, a transpressive event Lower Tertiary deposits are virtually absent zoic salt most likely began in the Early Triassic and since then the diapirs observed in the Svalis Dome and Nordkapp Basin areas have undergone several occurred between Svalbard and the northern on the eastern and central Barents Shelf but phases of development during the Mesozoic and Cenozoic. Early Triassic extension initiated salt-tectonic activity in the Nordkapp Basin and diapirs grew passively until mid-Triassic times by maintaining their crest at or near the sea fl oor, while sediment accumulated in adjacent salt-withdrawal basins. The tectonic features of the basins observed today were fi nally shaped by subsequent Late Jurassic-Early Cretaceous reactivation and strong Cenozoic uplift. Between the Stappen High and the Savlis Dome, the Bjørnøya Basin underwent further extension leading to rapid subsidence in Cretaceous times, before the onset of the shear-margin development illustrated by the Vestbakken volcanic province. All these structural elements and salt-related features are refl ected both in the gravity and in the high-resolution magnetic signatures.

ISBN 978-82-7385-137-6 52 Continents in motion 53 Continents in motion