Sedimentology and Hydrocarbon Significance of the Devonian-Carboniferous Succession in Novaya Zemlya, Arctic Russia

Guo, Li¹, Roman Schekoldin², Robert A. Scott¹, James P. Howard¹, Jenny E. Omma¹ (1) University of Cambridge, Cambridge, United Kingdom (2) St Petersburg State Mining Institute, St Petersburg, Russia

Widespread hydrocarbon occurrences are present in Devonian-Carboniferous carbonate units of the Novaya Zemlya fold-and-thrust belt, Arctic Russia. These discoveries provide an important insight into the hydrocarbon potential of less deformed rocks in the adjacent Barents and Kara seas.

The sedimentary facies of Devonian-Carboniferous strata reflect deposition on the margin of Baltica: on the Barents Sea side of the archipelago, shallow marine shelf carbonates were deposited, with abundant coral-stromatoporoid reefs; on the Kara Sea side of the archipelago, deep-water slope and basin floor settings predominate, with trubidities, shales, cherts and carbonate mudstones. A number of potential source rocks were identified in the succession. Extensional tectonism affected deposition, particularly during the late Givetian to early Frasnian interval when fault-block rotation, subaerial erosion and basic volcanism occurred.

The Novaya Zemlya fold-and-thrust belt was formed during the Late Palaeozoic to Early Mesozoic collision of Baltica and Siberia. Hydrocarbon occurrences are mainly hosted by syn-tectonic fractures and associated secondary pore systems in carbonates on the Barents Sea side of the archipelago. However, in adjacent basins, good primary porosity may be preserved in undeformed rocks of equivalent age. For example, intense dissolution and karstification of mid-Devonian carbonates may have accompanied subaerial exposure. Dolomites that generated abundant secondary porosity in the Late Devonian and Early Carboniferous may also make good targets.