东亚大陆边缘的板块重建与构造转换

东亚大陆边缘中新生代期间的动力学演化始终是地质研究的难点和热点,特别是对其大陆边缘性质、类型和演化过程始终不明朗,并存在巨大争论。系统综述了40多年来已有东亚大陆边缘二叠纪以来板块重建的主要方案,特别是近10年来东亚陆缘新的研究成果,侧重探讨了晚三叠世以来东亚大陆边缘类型转换、不同构造域的交接-转换过程。认为东亚陆缘总体经历了三叠纪前的被动陆缘阶段、晚三叠世-早白垩世的大陆岩浆弧发育的安第斯型活动陆缘阶段、早白垩世晚期-始新世的走滑拉分盆地发育的安第斯型活动陆缘阶段和渐新世以来的日本型活动大陆边缘阶段。这对于认识中国东部海域渤海湾、黄海、东海和南海盆地成因具有指导意义。同时,分析了各阶段海-陆分布特征及其变迁规律、板块格局变动过程及其动力学背景。

TECTONIC TRANSITION AND PLATE RECONSTRUCTIONS OF THE EAST ASIAN CONTINENTAL MAGIN

It is a hot debate on the Meso-Cenozoic dynamics of the East Asian continental margins, since the nature, type and evolution of its continental margins are not well-known.. This paper systematically summarizes the results of plate reconstructions on the East Asian continental margin since Permian over the past 40 years with emphasis on the new research results in the past 10 years. The paper mainly focuses on the variation in types of the East Asian continental margin since Late Triassic, the transitions among different tectonic domains. Our data suggests that the East Asian continental margins as a whole experienced a pre-Triassic passive continental margin, a Late Triassic-Early Cretaceous continental magmatic arc of the Andean-type active continental margin, a Late Cretaceous-Eocene strike-slipping Andean-type active continental margin with of pull-apart basins, and a post-Oligocene Japanese-type active continental margin successively. Tectonic trasition is important for understanding of the formation of the Bohaisx Bay, the Yellow Sea, the East China Sea and the South China Sea basins in East China. The changes of the continent-ocean distribution, plate configuration and dynamics at the various stages are also discussed.