FIRST RESULTS OF STRATIGRAPHIC DRILLING IN THE EAST SIBERIAN SEA FOCUSED ON THE GEOLOGICAL STUDIES OF THE SUTURE ZONE OF THE CONTINENTAL SHELF’S MARGINAL STRUCTURES A ND DEEP-WATER AREAS OF THE ARCTIC OCEAN

Abstract

At the initiative of the Federal Agency on Mineral Resources (Rosnedra), in August 2022, a shallow well was drilled in the East Siberian Sea for the first time with a purpose of geological studying the suture zone of deep waters of the Arctic Ocean and marginal structures of the continental shelf. The well was drilled by VSEGEI and Rosgeologia with the assistance of NK Rosneft and linked to the Rosneft’s long-term stratigraphic drilling program. Drilling was accompanied by continuous seismoacoustic profiling and well thermometry. The maximum well depth was 472 m from the bottom surface; in it, 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 ascending thermal water. The Jurassic-Lower Cretaceous sequence occurs as 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.