Evolution and final closure of the Mongol-Okhotsk Ocean  

作　　者：Pan ZHAO Bei XU Yan CHEN 

机构地区：[1]State Key Laboratory of Lithospheric Evolution,Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029,China [2]Hebei Key Laboratory of Strategic Critical Mineral Resources,Hebei GEO University,Shijiazhuang 050031,China [3]Universitéd’Orléans,CNRS,BRGM,ISTO,UMR 7327,Orléans F-45071,France

出　　处：《Science China Earth Sciences》2023年第11期2497-2513,共17页中国科学（地球科学英文版）

基　　金：supported by the National Natural Science Foundation of China (Grant No. 92155203)。

摘　　要：Mongol-Okhotsk Orogenic Belt is the last main orogen that constructs modern tectonic framework of northeastern Asia. It has recorded the long-term evolution of the Mongol-Okhotsk Ocean(MOO) from its Early Paleozoic initial opening,through the Late Paleozoic-Early Mesozoic subduction, to its Mesozoic final closure, leading to the amalgamation of the Siberian Craton(SIB) and North China-Amuria Block(NCC-AMB). Opening of the MOO can be traced to the early stage of the Early Paleozoic. Northward subduction of the Mongol-Okhotsk oceanic slab beneath the southern margin of the SIB initiated in the Silurian, whereas the southward subduction beneath the northern margin of the NCC-AMB started in the Late Devonian. The bidirectional subduction of the Mongol-Okhotsk oceanic slab resulted in pulse arc magmatism, with three main peaks in the earliest Carboniferous, Late Permian, and Late Triassic-Early Jurassic. In the Late Triassic, the collision between the AMB and Western Mongolian Blocks led to the bending of the Western Mongolian Blocks, which caused the initial closure of the MOO in its western segment. Due to the clockwise rotation of the SIB and counterclockwise rotation of the NCC-AMB, the MOO showed a scissor-like closure from west to east. The final closure of the MOO occurred in the Middle-Late Jurassic, which also resulted in the formation of the Mongol Orocline. Since then, the amalgamation of blocks in northeastern Asia has finished, and the northeastern Asian continent went into the intraplate evolutional stage.

关 键 词：Northeastern Asia Mongol-Okhotsk Ocean Paleozoic-Mesozoic Subduction initiation Scissor-like closure 

分 类 号：P542[天文地球—构造地质学]