东海陆架盆地南部中生代演化与动力学转换过程

东海陆架盆地处于欧亚板块东南缘，其构造演化、动力学机制转换同太平洋板块与欧亚板块碰撞及印度-澳大利亚板块远程推挤效应有关。中生代以来，该盆地形成和演化过程受到古太平洋板块多期俯冲及多构造体系的叠加改造，地质构造和地球物理场复杂，盆地演化及动力学过程等一直是争论的焦点。本文利用最新调查资料，通过构造物理模拟实验、构造解析和平衡地质复原剖面等方法，结合区域构造背景，系统分析了东海陆架盆地中生代演化过程，探讨了其构造动力学转换过程。研究认为东海陆架盆地自中生代以来经历了晚三叠世前的被动大陆边缘和晚三叠世-中侏罗世活动大陆边缘挤压坳陷型盆地阶段，挤压应力来源于伊泽奈崎板块向欧亚大陆板块的低角度俯冲；早白垩世晚期-晚白垩世活动陆缘伸展断陷型盆地阶段，应力来源于太平洋板块向欧亚大陆板块俯冲后撤导致的岩石圈减薄作用；古近纪为弧后伸展断陷型盆地阶段。同时认为东海陆架盆地古特提斯构造域向古太平洋构造域转换的时间应该发生在中三叠世末期，古太平洋板块低角度俯冲和俯冲后撤代表华南中生代深部地质过程。

Mesozoic Evolution and Dynamics Transition in Southern Shelf Basin of the East China Sea

The East China Sea Shelf basin is located on the southeastern edge of the Eurasian plate. Its tectonic evolution and dynamic mechanism transformation are related to the collision between the Pacific plate and the Eurasian plate and the remote push effect of the Indian-Australian plate. Since Mesozoic, the basin formation and evolution process has been superimposed by multi-period subduction and multi-tectonic systems of the Paleo-Pacific plate. The geological structure and geophysical field are complex, and the basin evolution and dynamic process has been the debate focus. Based on the latest survey data, the authors mainly studied the Mesozoic basin evolution in the southern shelf basin of the East China Sea by means of regional tectonic-sedimentary setting analysis, structural physical simulation experiments and recovery technology of balanced geological profiles, and discussed the dynamics transition process of the southern shelf basin of the East China Sea. Our data suggests that the southern shelf basin of the East China Sea has experienced 1) pre-Late Triassic passive continental margins and Late Triassic-Middle Jurassic active continental margin squeeze-depression, the extrusive stress originated from the low-angle subduction of the Izanagi plate to the Eurasian plate; 2) the Late Early Cretaceous-Late Cretaceous active continental marginal faulted basin, whose stress originated from the lithospheric thinning and paleo-environment resulting from the subduction of the Paleo-Pacific plate into the Eurasian plate; and 3) the Paleogene back-arc extension faulted-depression. It is also suggested that the transition time from the EW-trending Paleo-Tethys tectonic system to the NE-trending Paleo-Pacific tectonic system in the East China Sea Shelf occurred in the end of Middle Triassic. The low-angle subduction and withdrawal subduction of the Paleo-Pacific plate represents the Mesozoic deep geological process in the East China Sea Shelf.