南海及其围区中生代岩相古地理和构造演化  

Mesozoic lithofacies, paleo-geography, and tectonic evolution of the South China Sea and surrounding areas

作　　者：周蒂[1] 孙珍[1] 陈汉宗[1] 丘元禧[2] 

机构地区：[1]中国科学院南海海洋研究所,广东广州510301 [2]中山大学,广东广州510275

出　　处：《地学前缘》2005年第3期204-218,共15页Earth Science Frontiers

基　　金：国家重大基础研究发展规划课题(G2000046702);国家自然科学基金重点项目(40238060);中国科学院知识创新重要方向项目(KZCX2-SW-117-05);国家专项(2001DIA50041)

摘　　要：以岩相古地理分析和编图为基础,结合构造变动和岩浆活动资料,阐述了南海及其围区中生代构造演化。中生代时研究区位于欧亚大陆的东南缘,受特提斯域和太平洋域交替复合影响。早三叠世时古特提斯洋经过黑水河盆地东延至南海。从中三叠世开始构造岩相古地理演化出现明显的东西分异。晚三叠世时,受印支运动影响华南地块与印支地块拼合,研究区西部抬升,黑水河水道关闭;而研究区东部和东南部却受古太平洋的影响发生海侵,形成“粤东-西北加里曼丹海盆”,该海盆在早侏罗世遭受更大海侵,导致与中特提斯的良好贯通。中侏罗世在中特提斯发生过短暂海侵而形成“滇缅海”。晚侏罗世至早白垩世是中特提斯洋和古太平洋的俯冲鼎盛期,形成绵延数千km的欧亚大陆东南缘俯冲增生带。文中还讨论了中特提斯向南海延伸的通道、中特提斯与古太平洋对南海中生代演化的交替和复合影响以及南海东北部新近发现的晚中生代俯冲带等问题。The Mesozoic tectonic evolution of the South China Sea and surrounding areas is explained using the compilation of lithofacies maps, paleo-geography and the analysis of deformation and magmatism. During the Mesozoic era, the study area was situated at the SE margin of the Eurasian continent and subjected to the far-field influences of Tethyan and Pacific tectonics. In the Early Triassic, the Paleo-Tethys ocean extended eastward to the study area through the Song IDa River passage. A significant E-W directed tectonic evolution had begun since the Middle Triassic. In the Late Triassic, the western area uplifted as a result of the suture of the Indosinian and South China blocks during the Indosinian orogeny. This resulted in the closure of the Song IDa river passage. Meanwhile, a transgression of Paleo-Pacific ocean occurred in the eastern and southeastern portion of the study area, forming the “East Guangdong-NW Kalimantan Sea”. In the Early Jurassic, the transgression was stronger, causing the deepening of the sea basin and providing a good connection and exchange with the Meso-Tethys ocean. In the Middle Jurassic, a shortlived transgression occurred in eastern Meso-Tethys and resulted in the formation of “Yunnan-Burma Sea”. The Late Jurassic to the Early Cretaceous was the climax of the subduction of both Meso-Tethys and Paleo-Pacific towards the Eurasian continent, forming the great “Circum SE Eurasia Subduction-accretion Belt” which extended over several thousand kilometers along the eastern and southeastern Asian margins. The paper also discusses issues of the water exchange between Meso-Tethys and the South China Sea, of the influences of Tethyan and Pacific tectonics in the evolution of the area, and of the newly recognized buried segment of the Mesozoic subduction-accretion belt in northem South China Sea.

关 键 词：南海 欧亚大陆东南缘 中生代 岩相古地理 构造演化 

分 类 号：TE121.3[石油与天然气工程—油气勘探]