西太平洋俯冲带的演变:来自东北亚陆缘增生杂岩的制约

本文系统总结了东北亚陆缘晚古生代和中生代增生杂岩的构成与形成时代,并结合同时代火成岩组合及其时空变异以及沉积建造组合,重塑了西太平洋板块俯冲带的演变历史.结果表明:①位于佳木斯地块东缘的跃进山杂岩代表了二叠纪俯冲带,它是古亚洲洋构造体制的产物;②侏罗纪增生杂岩代表了侏罗纪俯冲带,与陆缘同期钙碱性火成岩组合以及含煤建造一...

Evolution of western Pacific subduction zones: Constraints from accretionary complexes in NE Asian continental margin

This paper systematically summarizes recent achievements in fossil accretionary complex studies in NE Asia,together with analysis of spatial—temporal variations of the coeval igneous rock association and sedimentary formations in NE Asia,with the aim of understanding the evolutionary history of the western Pacific subduction zones in NE Asia.The results indicate that:①the Yuejinshan accretionary complex represents the Permian subduction zone in the eastern Jiamusi Massif,and resulted from the evolution of the Paleo-Asian Oceanic regime;②Jurassic accretionary complex represents the Jurassic subduction zone in NE Asia,and together with the coeval calc—alkaline volcanic rocks,reveals the subduction onset of the Paleo-Pacific plate beneath the Eurasia;③provenance variations of terrigenous clastic rocks within the Jurassic complexes,together with paleomagnetic and biological data,indicate that a small angle of oblique subduction of the Paleo-Pacific plate and strike-slip tectonics took place in NE Asian continental margin,resulting in northward movement of the Jurassic complexes from lowaltitude to high-altitude;④Cretaceous—Paleogene accretionary complex represents Cretaceous—Paleogene subduction zone in NE Asia.Toward trench contracting of extents of the Cretaceous—Paleogene magmatisms reveals the westward subduction of the Paleo-Pacific plate and rollback of the subducted slab,and marks the formation of the eastern Asian big mantle wedge;and⑤the opening of the Japan Sea at the end of Paleogene and early stage of Neogene marks the formation of the present Pacific subduction zone and the northeastern Asian big mantle wedge.