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西太平洋区的边缘海是全球构造壮观区域之一.在板块构造图案中,它既是板块聚敛带又是岩石圈板块张裂区.在这些边缘海中尤以南海更为突出,它是东南亚油气资源富集区之一.本文根据新近获得的一些地球物理调查资料和海上钻探研究成果,试图以板块构造观点,对南海新生代岩石圈板块的构造变动与沉积分布的关系作一简要概述,不当之处请予指正.一、南海新生代岩石圈板块的演化南海位于印度洋-澳大利亚、太平洋和欧亚三大板块的聚合处,直接或间接地受这三大板块的相对运动和相互作用的控制,且在整个地史演变过程中,其地质构造的发生、发展也较为复杂.本-阿勃拉姆和上田(Ben-Avraham＆Uyeda,1973)在南海中央海盆发现有东西向地磁条带的存在;而后泰勒和赫茨(Taylar＆Hayes,1979)又进一步测定南海海盆的地磁异常条带具有良好的线性,走向为北东东,并根据其对称性,确定了海盆新生代扩张轴位于北纬16°附近,其主要扩张期为中渐新世至早中新世(17—32m·y)这与Watanabe等(1977)按照热流值确定的年龄(14—36m·y)基本吻合.据地震折射资料认为:海盆为洋壳性质,厚度变化在5—6公里之间.路德维格(Ludwing,1970)曾在其些折射剖面上见到声波速度为6.5—7.4公里/秒的层3(L3)厚度约为正常洋
The marginal sea in the western Pacific Ocean is one of the most spectacular structures in the world, and in plate-tectonic pattern it is both a plate convergence zone and a lithospheric plate rift zone, and the South China Sea is more prominent in these marginal seas. It is a source of oil and gas resources in Southeast Asia Based on some recent geophysical survey data and offshore drilling research results, this paper attempts to give a brief overview of the tectonic and sedimentary distribution of the Cenozoic lithospheric plate in the South China Sea from the perspective of plate tectonics. 1. Please refer to the evolution of the Cenozoic lithospheric plate in the South China Sea. The South China Sea is located at the converging point of the three major plates of the Indian Ocean, Australia, Pacific Ocean and Eurasia. The South China Sea is directly or indirectly controlled by the relative movement and interaction of these three plates. In addition, Ben-Avram and Uyeda (1973) found the existence of east-west geomagnetic stripe in the Central South China Sea Basin. Taylor and Hertz (1979) further determined that the geomagnetic anomaly bands in the South China Sea Basin have a good linearity and are going to the north east and east Symmetry, it was confirmed that the Cenozoic extension axis of the basin was located at latitude 16 ° north, with the main expansion period being from Miocene to Early Miocene (17-32 m · y). This is consistent with the age determined by Watanabe et al. (1977) (14-36 m · y). According to the seismic refraction data, the sea basin is characterized by oceanic crust with a variation of 5-6 km in thickness. Ludwing (1970) has seen some of its refraction profiles Layer 3 (L3) with an acoustic velocity of 6.5-7.4 km / s is approximately normal in thickness