划分华南不同块体的地球物理根据及与地球化学分区特征的对比研究

The Division of South China Continent into Different Blocks Based on Geophysical Evidence and Comparison of Geochemical Features in Different Regions

根据华南的航磁、地震和大地电磁等地球物理方法的探测结果 ,将华南大陆划分为 3个不同块体 :扬子地块、华夏地块和东南沿海地块 ;并计算了华南视磁化强度的分布。根据视磁化强度的分布研究华南磁性分区特征 ,并利用深地震测深剖面资料和大地电磁资料对磁性分区的边界加以控制和印证 ,最后以多种地球物理方法确定的边界作为块体的边界。因此 ,这样对地块的划分比较客观。依据地球物理划分的结果与花岗岩同位素地球化学的研究结果进行了简单的比较 。

In this paper, the South China continent is divided into three blocks, namely Yangtze block, Huaxia block, and Southeast Coastal block, on the basis of the data from deep seismic sounding, aeromagnetic surveying, and electromagnetic sounding. The apparent magnetization was calculated. The magnetic features of different regions in South China were studied according to the distribution of apparent magnetization. In addition, the boundaries of the regions were delimited and verified by using the data from deep seismic sounding and electromagnetic sounding. The boundaries of the regions are regarded as the boundaries of the blocks in South China. Therefore the results from the above study are quite objective. The authors made a brief comparison between these results and the data obtained from isotopic geochemistry of granitoids in South China so as to show that the division of the continent into different blocks is constrained by geophysical and geochemical data.