海南岛周邻新生代沉积盆地构造与差异性演化特征OA北大核心CSTPCD

The four Cenozoic sedimentary basins adjacent to Hainan Island have undergone significant development.These basins include Yingehai basin,Beibuwan basin,Qiongdongnan basin,and Zhu Ⅲ sag of the Zhujiangkou basin.Based on the latest geophysical data,we have redefined the structure and evolution of the Mesozoic-Cenozoic basins,as well as their relation to Hainan's onshore geological structures.The basins have well-developed NE and NW structures,but significant differences exist between them.The former NW-trending Yinggehai basin,influenced by the Red River fault,is characterized by tension and compressive torsion,resembling a pull-apart basin.On the other hand,the NE basins,located in the southern part of the continental margin of South China,are sandwiched between the Jiangshao-Bobai Faults and the southern Lishui-Nanao faults.The evolution of the Baisha basin is consistent with the Mesozoic basin in the continental margin of South China.The extensionalprocesses began in the Late Cretaceous,resulting in four instances of rifting.Subsequent magma activity led to the reconstruction of the sedimentary basin,exhibiting magma eruptions and high heat flow values.This tectonic distribution is extremely incompatible with the surrounding basins.Theoffshore fracture could extend to the southernmost region,showing obvious seismic activity.We infer that the tectonics of Hainan Island exhibit consistency with the northern South China Sea margin.