Olenek–Anabar Composite Tectono-Sedimentary Element, northern East Siberia

Abstract

The Olenek-Anabar Composite Tectono-Sedimentary Element (OLA CTSE) is located in the northern part of the Siberian Craton. Its structure and depositional history is controlled by two main tectonic events: (i) Mesoproterozoic rifting; (ii) Ediacaran-Cambrian (to Middle Devonian?) post-rift thermal subsidence. The sedimentary succession is mainly represented by Mesoproterozoic to Cambrian strata including the black shales of lower-middle Kuonamka Formation (Fm). The hydrocarbon potential of the OLA CTSE is defined by the presence of large superficial bitumen fields, anticlinal structures, large reefal build-ups, and direct proximity to the potential source rock (Kuonamka Fm). A very scarce grid of seismic profiles and lack of exploration wells limits the knowledge of the petroleum potential. The lack of seals and broad occurrences of faults causing significant vertical permeability of sediment cover, abundant occurrences of mafic and kimberlite magmatism are limiting factors regarding the petroleum potential. Wells drilled during the Soviet-era did not recover any commercial discoveries.