Basement and depositional systems (source-to-sink) in the northern Barents Sea and adjacent parts of the proto-Arctic (BarN-S2S)

The geological development of the Barents Sea is closely linked to both the Arctic and the North Atlantic areas. Through a wide range of research projects, as well as extensive petroleum exploration, we have improved our knowledge of the sedimentary basins in the SW Barents Sea, and how their development is closely linked to what we know from the continental margins further south in the North Atlantic. Through close cooperation with Russian colleagues we have also gained a better understanding of the geological development in the central and eastern Barents Sea. We have much less knowledge about the northern Barents Sea, other than that this area is closely related to the geological development of the Arctic Ocean and surrounding continental margins. Archipelagos in the northern Barents Sea (Svalbard, Franz Josef Land and northern Novaya Zemlya) represent important windows into the geology. In this project, together with Russian scientists, we have studied the geology both in the subsurface offshore and based on material from onshore areas. Rock samples from field surveys have been analyzed and the results integrated with information from geophysical data. We have carried out a comprehensive mapping of the Barents Sea based on seismic and borehole data from both the Norwegian and Russian side. Regional maps and profiles from this mapping have formed the basis for modelling with focus on geological processes that have contributed to basin subsidence. It has been an interplay between several processes each having a characteristic wavelength and amplitude. Increased knowledge of these processes contributes to improved understanding of the basins burial and temperature histories, which again have impact on the petroleum systems in the Barents Sea. We have also worked on research topics that link uplift and erosion of Novaya Zemlya to structures and deposition in the eastern Barents Sea. Field studies carried out by our Russian partners have provided better control on the age (Late Triassic-Early Jurassic) and amount of erosion related to the uplift of Novaya Zemlya. Based on seismic data tied to boreholes we have studied how the erosional products were deposited in the eastern Barents Sea. This has improved our understanding of the basin evolution in central and western parts of the Barents Sea, in particular with respect to formation of contractional structures (domes) which may form traps for oil and gas. Large parts of the Norwegian Barents Sea appear to have been affected by geological processes linked to the uplift of Novaya Zemlya. New knowledge about the northern Barents Sea is put into a larger context and integrated into updated models of the formation and evolution of the Arctic Ocean. We are particularly interested in possible northern source areas for the sediments that were deposited in the basins of the northern and central Barents Sea, both to understand their primary composition and the properties that they now have after subsidence and burial. The early development of the Arctic Ocean was associated with extensive volcanism, which we can study based on both samples from land and geophysical data. Large areas in the Arctic were uplifted and eroded in Early Cretaceous time and large rivers transported enormous sediment volumes to deltas that prograded soutwards across Svalbard and the northern Barents Sea. The Barents Sea, including the archipelagos (Svalbard and Franz Josef Land), has also undergone a significant uplift during the last 10-30 million years, which led to erosion and removal of thick rock units. We want to better understand how much is missing and when/how this happened.

The project results have enhanced our understanding of fundamental processes and key questions related to the geological evolution of the wider Barents Sea area. Differences in crustal and basin architectures between western and eastern parts of the Barents Sea have been documented, and these reflect different mechanisms involved in basin formation and evolution. Large-scale depositional systems have been related to their uplifted source-areas in a plate tectonic and paleogeographic context. The integrated project results can also be used by the petroleum industry to reduce exploration risk. The project has contributed to increased interdisciplinary collaboration between researchers mainly working with onshore field based investigations and associated analytical work in laboratories, and researchers working offshore and subsurface mainly based on geophysical data. It has also contributed to increased international research collaboration between Norwegian and Russian colleagues.

In this Norwegian-Russian project we seek to establish collaboration between two teams having complementary competence, the University of Oslo (UiO) Centre for Earth Evolution and Dynamics (CEED), and St. Petersburg State University (SpbSU) Institute of Earth Science for studying in concert the basement and depositional systems in the northern Barents Sea and adjacent regions. The proposed project will have a multi-/interdisciplinary approach and will combine offshore and onshore geological and geophysical data and prior knowledge for producing a detailed Paleozoic-Early Cenozoic model of the northern Barents Sea tectonic and depositional evolution. The primary objective is to model the tectonic and depositional evolution of the northern Barents Sea. The Paleozoic-Mesozoic sedimentary basin fill history will be linked to basement provinces in a source-to-sink context with special emphasis on northern source area(s). To achieve our goal, we need to undertake several geophysical and geological studies, which will lead to a number of secondary products like: (1) Basement age, composition and structure; (2) Distribution of provenance and clastic material paths; (3) Estimates of erosion and uplift rates and timing; (4) Depositional environments of Paleozoic and Mesozoic rocks onshore; (5) Onshore paleo-stresses; (6) Onshore/offshore correlation of stratigraphy and tectonic events; (7) Interpretation of fault kinematics and estimation of extension offshore; (8) Distribution and quality of source and reservoir rocks; (9) Plate tectonic and paleogeographic reconstructions. The new results will enhance our understanding of fundamental processes and key questions related to the geological evolution of the wider Barents Sea area. At the same time they can be used by the petroleum industry to reduce exploration risk by producing new information on the distribution and quality of potential source and reservoir rocks and their burial/uplift and temperature histories.