关键词: 南海, 古南海, 特提斯, 古太平洋, 构造属性

Abstract:

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.

Key words: South China Sea, Paleo-South China Sea, Tethys, Paleo-Pacific, tectonic attribute