Kazakhstan Orocline bending in response to seamounts subduction

Abstract

Oroclines are map‐view deformation of Earth's crust resulting from bending of quasi‐linear elements. The Central Asian Orogenic Belt (CAOB) is one of the largest and long‐lived accretionary orogens in the world and mainly consists of the Kazakhstan and Tuva–Mongolian oroclines. However, the mechanism of the oroclines is still in debate. Therefore, in this paper, we combine some investigation of high bathymetric relief resistance to subduction, review oroclinal bending models of the Kazakhstan Orocline, and propose a tentative model that involves asymmetric rollback in response to seamounts subduction and accretion, followed by bending associated with the convergence of the Siberian and Tarim cratons. Moreover, the role of pinning due to seamount and ridge subduction is probably more important than the convergence of continents in the CAOB. This model is compatible with the occurrence of seamounts, the spatial migration of intra‐oceanic arcs, and the development of multiple rollback processes during amalgamation of Eurasia. However, only geochemical and geochronological data will enable definition of the seamounts in CAOB so far, without much matching structural data. So we need more work to understand seamounts subduction and accretion as well as orocline bending in CAOB.