The Paleozoic Rocks of the Severnaya Zemlya Archipelago and Their Hydrocarbon Potential

Olga K. Bogolepova and Alexander P. Gubanov
CASP, Cambridge University, Canbridge, United Kingdom.

The Severnaya Zemlya Archipelago is located on the edge of the Kara Shelf, between the Kara and Laptev Seas; it includes four large islands (October Revolution, Bol’shevik, Komsomolets and Pioneer) and a small group of islands in the southwest, the Sedov Archipelago.

Paleozoic sedimentary rocks dominate the geology of Severnaya Zemlya. Cambrian shallow marine siliciclastics, dark shales and sandstones are unconformably overlain by Early-Mid Ordovician coastal to shallow marine sandstones, siltstones, limestones, marls and volcanics. Late Ordovician to Silurian sandstone and limestone were then deposited, with Telychian (Upper Llandovery) black shales and bituminous limestone associated with a major transgression. Devonian clastics dominate in western Severnaya Zemlya and are unconformably overlain by rare Carboniferous and Permian sandstone. On October Revolution Island, Late Carboniferous clastics rest with angular unconformity on folded Early Ordovician rocks. On Bol’shevik Island, post tectonic granite intrusions yield ages of ~345 Ma (Tournaisian-Visean boundary).

The hydrocarbon potential of Severnaya Zemlya is poorly studied. Middle Devonian oil-prone source rocks from Pioneer Island have been reported, but there are no published data on the potential of Cambrian and Silurian black shales and bituminous limestone.

To the southwest of Severnaya Zemlya in the adjacent North Kara Basin, the Early Carboniferous unconformity and the overlying complex of Late Carboniferous-Permian clastics are visible on a seismic reflection profile. The North Kara Basin is assumed to contain a similar Paleozoic succession to that exposed on Severnaya Zemlya, and stratigraphic similarities with Timan-Pechora would suggest a potentially favourable hydrocarbon potential.

AAPG Search and Discover Article #90096©2009 AAPG 3-P Arctic Conference and Exhibition, Moscow, Russia