摘要
本文讨论南沙海域万安盆地和曾母盆地的地形地貌概况、沉积特征及区域断裂分布与剖面特性。万安盆地的新生代沉积分二个构造层,下构造层主要分布在基底半地堑中,为陆相沉积;上构造层为海相沉积。曾母盆地新生代沉积(未变质部分)按海退旋回划分出8个沉积旋回。万安盆地北东向断裂呈雁行排列,北西向断裂具走滑特征。作者指出上述沉积盆地的形成,与南海西南海盆的海底扩张紧密相关:万安盆地为拉张剪切盆地,曾母盆地为前陆盆地。
Here we discuss the topography and geomorpholohy, sedimentary characteristics, distribution of the rigional faults and seismic profiole's characteristics at Wan'an and Zengmu Basins in the Nansha area. Their Cenozoic sediments at Wan'an Basin were subdivided into two tectinical layers. The older, laid in half-grabens of the basement, is terrestrial; The upper is belong to marine facies. The Cenozoic sedi- ment in Zengmu Basin is subdivided into eight regressional sedimentary sequences accordimg to its re- gressional cycles. The NE faults in the Wan'an Basin are en echelon arrangement. The NW faults in the basin have stricke-slip characteristics. We believe that the formation of these basins relate with the sea floor spreading event of the SW Subbasin of South China Sea. The Wan'an Basin is an extensional- shearing basin, Zengmu Basin is a foreland basin.
出处
《南海地质研究》
1994年第6期1-15,共15页
Gresearch of Eological South China Sea
