论文部分内容阅读
南海位于濒太平洋构造域与特提斯—喜马拉雅构造域的衔接处,是解决东南亚大地构造问题的关键,历来倍受国际地学界所重视,调查研究成果颇丰。本次研究着重进行南海区域的天然地震面波(Vs)层析成像、不同阶次地幔流场计算和大地热流背景分析,所获丰富信息拓宽了该区的深部研究领域。Vs层析成像揭示该区的Vs结构存在明显纵向分层和横向分块性。横向上总体可以划分出两个低速异常区和一个高速异常区;低速异常区之一位于华南南部—印支半岛及其毗邻陆架区,其中心部位在印支中南部;低速异常区之二占据婆罗洲大部和北巽他陆架区;高速异常区以南沙海域为中心向深海平原过渡,往西缘像一楔子嵌入上述两低速区之间。纵向上Vs呈高—低—高三层相间格局,若以Vs=4.7km/s作为划分岩石圈底
The location of the South China Sea at the junction of the Pacific Rim tectonic domain and the Tethyan-Himalayan tectonic domain is the key to solving the problem of the tectonic formation in Southeast Asia. It has always been valued by the international geoscientists and the survey results have been quite satisfactory. This study focuses on the natural seismic surface wave (Vs) tomography in the South China Sea, the calculation of flow field in different order mantle, and the background of the geothermal heat flow. The obtained rich information broadens the deep research field in this area. Vs tomography reveals that the Vs structure of this area has obvious vertical stratification and lateral fragmentation. Generally speaking, two low-velocity anomalous regions and one high-velocity anomalous region can be divided horizontally. One of the low-velocity anomalous regions is located in southern South China-Indo-China Peninsula and its adjacent shelf region with its central part in the central-southern Indochina. Most Borneo and Beibei He shelf areas; high-speed anomalous area to the Nansha sea area as the center of transition to the deep-sea plains, to the west like a wedge embedded between the two low-speed zone. Vertical Vs was high-low-high three-phase pattern, if the Vs = 4.7km / s as the division of the rock bottom