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Internet:www.ngu.no/no/hm/Publikasjoner/Boker/ATLAS-Geological-history-of-the-Barents-Sea/

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135 pages, hard cover

NOK 250,-

Contents

Chapter 1 INTRODUCTION – EXPLORATION OF THE BARENTS SEA Chapter 2 IMAGING DEEP STRUCTURES BENEATH THE SURFACE

Chapter 3 FROM RIFT - TO MEGA-BASINS Chapter 4 CONTINENTS IN MOTION - THE BARENTS SEA IN A PLATE TE TONIC FRAMEWORK

Chapter 5 LOCHKOVIAN – Caledonian mountains in the west, and lowlands and shallow marine basins in the east

Chapter 6 FRASNIAN – Active rifting, and expansion of the marine basin in the east

Chapter 7 VISEAN – Extensive alluvial plains in the west and 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 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.

The paleogeographic map span

from the Early Devonian to Eocene

times, and are supplemented by

geophysical maps and cross-sections

showing the present day architecture.

ISBN 978-82-7385-137-6

EDITORS:Morten Smelror,

Oleg Petrov,

Geir Birger Larssen &

Stephanie Werner

52 Continents in motion

The Paleocene-Eocene transition marks the

continental break-up of the North Atlantic mar-

gins and opening of the Norwegian-Greenland

Sea at around 55-54 Ma. This time interval is

also characterised by a major magmatic event,

as witnessed by massive basaltic traps and the

formation of volcanic rifted margins which

have been identifi ed from the Irish margin

up to the Lofoten and NE Greenland shelves.

Towards the north, the break-up development

along the sheared margin of western Barents

Sea was younger, locally magmatic (e.g., Vesta-

bakken volcanic province) and comparatively

complex.

Prior to the opening, a transpressive event

occurred between Svalbard and the northern

North Atlantic break-up

margin of the Barents Shelf. The crustal short-

ening was concomitant with major extension

between Norway and Greenland and is esti-

mated to have been around 30 km.

Progressively, the continental strike-slip

system, active from the Paleocene to the

Eocene, was followed by a passive shear-mar-

gin development, leading to break-up from

Early Oligocene time. Since Oligocene times,

separation of the Barents Shelf and Greenland/

North America has continued, leading to the

opening of the Fram Straight and establishing

a North Atlantic-Arctic marine connection in

the Miocene.

Lower Tertiary deposits are virtually absent

on the eastern and central Barents Shelf but

marine slope to basinal successions are pre-

served along the western margin. In the Vest-

bakken Volcanic Province there is evidence of

breakup-related sill intrusions. Over the west-

ern Barents Shelf, there is are major uncon-

formities between the Paleogene to Miocene

strata and overlying glacial deposits marking

the onset of the Northern Hemisphere glacia-

tions in the Late Pliocene. During the Pliocene-

Pleistocene the entire Barents Shelf was eroded

and large amounts of sediment were shed into

towards the shelf margin accumulating as huge

wedges of shelf-margin, slope and basinal ma-

rine origin (Bjørnøya and Storfjorden fans).

7318/5-1 7321/7-1 7324/10-1 7228/2-1

Permian

?

?

?

? ?

?

?

??

??

??

NW

A B

SE

L. Ge

rnigo

n-GE

OBAS

E-NG

U-20

09

JurassicLower Cretaceous Upper Cretaceous PaleogeneNeogeneCenozoic undiff.

Lower Triassic I - undiff.Lower Triassic IIMid. Triassic Mid-Upper Triassic

Salt (Carboniferous)

Bouguer HP-75

Bouguer

MagTF

MagTF HP-75

Tilt derivative

deep Paleozoic basin

Cenozoicintrusions

deep Paleozoic basin

Bjarmeland PlatformSvalis DomeBjørnøya BasinStappen High Nordkapp Basin

80-

60-

40-

0-

20-

-20-

-40-

-60-

300-

200-

100-

0-

-100-

Mag

(nT)

Gra

vity

(mG

al)

Dep

th (k

m)

0-

-5-

-10-

-15-0 50 100 150 200 250 300 350 400 450 500 550 (km)

Western Barents Sea

Continents in motion 53

?

? ?

?

C D

NW SE

L. Ge

rnigo

n-GE

OBAS

E-NG

U-20

09

Bouguer HP-75

Bouguer

MagTF

MagTF HP-75Tilt derivative

Cretaceous (?) intrusions

deep Paleozoic basin

deep Paleozoic basin

Nordkapp Basin Central Barents High South Barents BasinNovayaZemlya

100 km

80-

60-

40-

0-

20-

-20-

-40-

-60-

300-

200-

100-

0-

-100-

Mag

(nT)

Gra

vity

(mG

al)

Dep

th (k

m)

0-

-5-

-10-

-15-0 50 100 150 200 250 300 350 400 450 500 550 600 650 (km)

deep Paleozoic basin

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.

Eastern Barents Sea

The Barents Sea consists of complex structural features including platform areas, basement highs, graben features and large sag-basins. The most signifi -

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

was affected by a major phase of collision between the Laurasian continent and Western Siberia, which culminated in latest Permian-earliest Triassic time.

Novaya Zemlya marks the suture zone of this closure, which could be younger (Triassic-Jurassic) in that specifi c region. Huge basins, such as in the South

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

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

and thickness of Triassic deposits, locally 6–8 km, that accumulated in a series of deltas prograding westward from Novaya Zemlya.The Triassic forma-

tions are particularly affected by numerous sill intrusions, possibly linked to the Early Cretaceous volcanism recorded on Franz Josef Land and Svalbard.

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

poorly constrained. Palaeozoic sediments are probably present locally in the South Barents Sea and could represent a prolongation of the rift system well

documented onshore in the Timan-Pechora Basin.

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

affected by major graben-type basins, as illustrated in this section. The main grabens were probably initiated by Late Palaeozoic extension, contained

signifi cant evaporite deposits of probable Late Carboniferous-Early Permian age and were major sites of Triassic deposition. The movements of Palaeo-

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

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.