古南海构造属性及其与特提斯和古太平洋构造域的关系

为了进一步理解南海地区前新生代的构造演化过程，明确古南海构造属性及其与特提斯和古太平洋构造域的关系，通过对古南海遗迹（蛇绿岩、蛇绿混杂岩以及俯冲增生带）的研究，结合周围陆区地质及古生物资料，将古南海的演化划分为4个阶段。①古特提斯残留海阶段（T₁-T₂）:古南海是在早-中三叠世的古特提斯残余海基础上发展而来，与古特提斯残余海是一个连续的演化过程。②古太平洋边缘海阶段（T₃）:晚三叠世，由于古特提斯洋的全面关闭，古南海主要受古太平洋的影响。③中特提斯与古太平洋叠加影响阶段（J-K₁）:早侏罗世，古南海开始扩张，并受中特提斯和古太平洋叠加影响；晚侏罗世，南沙地块向华南大陆开始漂移，古南海进一步强烈扩张。④俯冲消亡阶段（K₂末期-E）:晚白垩世，南沙地块开始裂离华南大陆，古南海开始向南俯冲；至始新世，伴随着新南海的扩张，古南海加速消亡于巽他地块之下，并在南海南部地区形成了卢帕尔线蛇绿岩带以及一系列的俯冲增生带。

Structural Properties of Paleo-South China Sea and Their Relationship with the Tethys and the Paleo-Pacific Tectonic Domain

In order to further understand the pre-Cenozoic tectonic evolution of the South China Sea, and figure out the tectonic attribute of Paleo-South China Sea（PSCS）and their relationship with the Tethys and the Paleo-Pacific tectonic domain，through the research on the PSCS relics (ophiolites, ophiolitic melange and subduction accretionary complex), in combination with geological and paleontological data of the surrounding land areas, the evolution of the PSCS is divided into four stages. ① Paleo-Tethys residual sea stage (T₁-T₂):The PSCS was in the Early-Middle Triassic Paleo-Tethys remnants sea，and the evolution with Paleo-Tethys remnants sea was a continuous progress. ②Paleo-Pacific marginal seas stages (T₃): In the Late Triassic, due to the complete closure of the Paleo-Tethys, the PSCS was mainly influenced by the Paleo-Pacific. ③ Tethys and Paleo-Pacific superposition impact stage (J-K₁): In the Early Jurassic, the PSCS began to expand, and was affected by the Tethys and ancient Pacific superimposition. In the Late Jurassic, the Nansha block began to drift towards to the South China continent, the PSCS further strongly expanded. ④Subduction stage (Later K₂-E):In the Late Cretaceous，the Nansha block began to crack from the southern mainland, and the PSCS subducted southward. To the Eocene, along with the new expansion of the South China Sea, the PSCS accelerated demise under Sundaland, and in the meanwhile，Lupar line ophiolite belts were formed in the southern region of the South China Sea as well as a series of subduction accretionary complex.