Geological Evolution of the Kara Sea Region in the Russian Arctic Illustrated by Seismic Examples

Brit Thyberg

Seismic data from the Kara Sea, both regional and detailed surveys, have been compiled, reprocessed and interpreted - also integrating information from onshore geology in surrounding areas. The main goal has been to establish a regional tectonostratigraphic framework that can be used in further exploration of this frontier area. The southern and northern Kara Sea comprise distinctly different geological provinces separated by a structural high linking northern Novaya Zemlya and Taimyr. The southern Kara Sea forms the northern extent of the West Siberian Basin petroleum province. Rift structures of a likely Late Permian-Early Triassic age, probably associated with igneous activity, are underlain by Paleozoic basement rocks of unknown age and composition. The Triassic succession is thin, particularly in comparison to the Barents Sea on the other side of Novaya Zemlya. The Jurassic-Cretaceous succession is thicker and contains both source and reservoir rocks proven by several major gas/gas-condensate fields (e.g. Rusanov and Leningrad). The northern Kara Sea has a much thinner Mesozoic sedimentary cover, overlying a rather thick succession of mainly Lower Paleozoic sedimentary rocks (terrigeneous clastics, carbonates and evaporites). The Lower Paleozoic strata were deformed by contraction related to a Late Paleozoic orogenic event affecting the Taimyr-Severnaya Zemlya region. The northern Kara Sea is largely unexplored but older (Paleozoic) petroleum system(s) may be present. The main structural elements and the differences between the southern and northern Kara Sea will be highlighted by seismic data examples, and the contrasts to the wide and deep East Barents Sea Basin will also be discussed.

AAPG Search and Discovery Article #90177©3P Arctic, Polar Petroleum Potential Conference & Exhibition, Stavanger, Norway, October 15-18, 2013