TY - JOUR

T1 - Tectonics of the Eastern Arctic and origin of the Amerasia Basin

AU - Sokolov, S.D.

AU - Lobkovsky, L.I.

AU - Vernikovsky, V.A.

AU - Poselov, V.A.

AU - Smirnov, O.E.

AU - Tuchkova, M.I.

AU - Shipilov, E.V.

AU - Sorokhtin, N.O.

AU - Baranov, A.A.

AU - Bobrov, A.M.

AU - Zholondz, S.M.

N1 - The development of tectonic models for the Arctic margins of Chukotka and Arctic Alaska, as well as geological history scenarios, was financially supported by the Russian Science Foundation, project No. 25-17-00036. The development of concepts about the tectonics of the western margin of the Amerasia Basin was supported by the Russian Science Foundation, project No. 24-17-00057. Geodynamic modeling was performed partly within the framework of the state assignment of the P.P. Shirshov Institute of Oceanology of the Russian Academy of Sciences No. FMWE-2021-0004, partly within the framework of the state assignment of the O.Yu. Schmidt Institute of Physics of the Earth of the Russian Academy of Sciences and partly within the framework of the state assignment of the Institute of Earthquake Prediction Theory and Mathematical Geophysics of the Russian Academy of Sciences.

PY - 2026/1/1

Y1 - 2026/1/1

N2 - We provide a brief description of the main structures in the Eastern Arctic, in the evolution of which two major stages have been distinguished and considered: the late Paleozoic–early Mesozoic and the Late Jurassic–Early Cretaceous. We have established the synchronicity of tectonic events on the Arctic margins of Northeast Asia and Arctic Alaska and within the structures of the Amerasia Basin, indicating the existence of a cause-and-effect relation between the compression (fold-and-thrust structures) and extension (rifting and spreading in the Canada Basin). We have proposed the tectonic models of the formation of fold-and-thrust structures in Chukotka and Arctic Alaska and have determined their similarities and differences. Paleotectonic reconstructions have been performed for 160 and 120 Ma. We present a critical review of the concepts about the formation of the structures in the Amerasia Basin and provide a subduction-convection geodynamic model according to the analysis of seismic tomography of the mantle and regional geology and tectonics data. This model was previously used to describe the Cretaceous and Cenozoic evolution of the Arctic lithosphere at a qualitative level. The model is based on the idea of the existence of a two-tier subduction system: a horizontally extended convection cell in the upper mantle, coupled with a conveyor mechanism of subduction of the Pacific lithosphere. As a result, there is a convergence of the “outer” Pacific subduction zone and the “inner” subduction zone located inside the South Anyui and Angayucham oceanic basins, which provides their closure and subsequent collision. Under the influence of the reverse upper mantle flow, scattered deformations of the Amerasia lithosphere occur, caused by viscous dragging with flows beneath the lithosphere, which is the reason for the diversity of the structures in the Amerasia Basin and the Canada Basin in particular. In addition, the developed geodynamic model is supplemented by a tectonic and magmatic mechanism of crustal subsidence and the formation of sedimentary basins.

AB - We provide a brief description of the main structures in the Eastern Arctic, in the evolution of which two major stages have been distinguished and considered: the late Paleozoic–early Mesozoic and the Late Jurassic–Early Cretaceous. We have established the synchronicity of tectonic events on the Arctic margins of Northeast Asia and Arctic Alaska and within the structures of the Amerasia Basin, indicating the existence of a cause-and-effect relation between the compression (fold-and-thrust structures) and extension (rifting and spreading in the Canada Basin). We have proposed the tectonic models of the formation of fold-and-thrust structures in Chukotka and Arctic Alaska and have determined their similarities and differences. Paleotectonic reconstructions have been performed for 160 and 120 Ma. We present a critical review of the concepts about the formation of the structures in the Amerasia Basin and provide a subduction-convection geodynamic model according to the analysis of seismic tomography of the mantle and regional geology and tectonics data. This model was previously used to describe the Cretaceous and Cenozoic evolution of the Arctic lithosphere at a qualitative level. The model is based on the idea of the existence of a two-tier subduction system: a horizontally extended convection cell in the upper mantle, coupled with a conveyor mechanism of subduction of the Pacific lithosphere. As a result, there is a convergence of the “outer” Pacific subduction zone and the “inner” subduction zone located inside the South Anyui and Angayucham oceanic basins, which provides their closure and subsequent collision. Under the influence of the reverse upper mantle flow, scattered deformations of the Amerasia lithosphere occur, caused by viscous dragging with flows beneath the lithosphere, which is the reason for the diversity of the structures in the Amerasia Basin and the Canada Basin in particular. In addition, the developed geodynamic model is supplemented by a tectonic and magmatic mechanism of crustal subsidence and the formation of sedimentary basins.

KW - Tectonics

KW - geodynamics

KW - Mesozoic

KW - Eastern Arctic

KW - Amerasia Basin

KW - Chukotka

KW - Arctic Alaska

KW - Central Arctic uplifts

UR - https://www.scopus.com/pages/publications/105029808828

UR - https://www.mendeley.com/catalogue/db2b5cff-74eb-3d2a-8369-03b9bdd843a9/

U2 - 10.2113/rgg20254961

DO - 10.2113/rgg20254961

M3 - Article

VL - 67

SP - 34

EP - 61

JO - Russian Geology and Geophysics

JF - Russian Geology and Geophysics

SN - 1068-7971

IS - 1

ER -