First Results of Stratigraphic Drilling in the East Siberian Sea Focused on Geological Studies of the Suture Zone of the Continental Shelf’s Marginal Structures and Deep-Water Areas of the Arctic Ocean

Abstract

A shallow well was drilled in the East Siberian Sea for the first time with the purpose of geological study of the suture zone of deep waters of the Arctic Ocean and marginal structures of the continental shelf. The works have been carried out at the initiative of the Federal Agency on Mineral Resources (Rosnedra) in August 2022. The well was drilled by the Russian Geological Research Institute (VSEGEI) and Rosgeologia with the assistance of Rosneft and was linked to the Rosneft’s long-term stratigraphic drilling program. Drilling was accompanied by continuous seismic-acoustic profiling and well thermometry. The maximum depth of the well was 472 m from the bottom of the sea floor; 147.5 m of core was taken to a depth of 268 m. Two sedimentary sequences were identified in the section: the Lower Jurassic–Lower Cretaceous gently deformed sequence and the Upper Neogene–Quaternary horizontally lying sequence. The sequences are separated by a thick unsampled interval with horizons of confined waters. The Jurassic–Lower Cretaceous sequence composes a northwestern-dipping monocline broken by faults and probably belongs to the complex filling the Zhokhov marginal trough of the Verkhoyansk–Chukotka orogen on the Eastern Arctic shelf.