晚中新世红河断裂走滑反转事件的海底滑坡证据

发布时间：2018-08-23 12:25

【摘要】：晚中新世(~5.5Ma),琼东南盆地深水区发育面积约18000km~2、最大沉积厚度达到930m的大型海底滑坡.大型海底滑坡具有明显的地震相特征,头部发育正断层,侧向边界形成陡崖,底部形成强剪切面,内部地震反射杂乱,被平行-亚平行的连续地震相所围限,呈现从南向北的主体搬运方向,主要物源来自于位于中南半岛以东、广乐隆起以北的琼东南盆地南部区域.在区域上,晚中新世红河断裂发生走滑反转,中南半岛的隆升和侵蚀加剧,南海西部的沉积速率突然加速,这些事件为大型海底滑坡的形成提供了基本条件与触发机制.大型海底滑坡的发现提供了晚中新世红河断裂走滑反转构造事件的沉积学证据,并通过海底滑坡顶界面地质时间的约束,推断红河断裂反转过程中最剧烈的构造活动发生在~5.5Ma.
[Abstract]:In the late Miocene (5. 5 Ma), a large submarine landslide with a maximum sedimentary thickness of 930 m was found in the deep water area of southeastern Hainan Basin. Large submarine landslides are characterized by seismic facies, with normal faults on the head, steep cliffs at the lateral boundary, strong shear planes at the bottom, disorderly internal seismic reflection, and bounded by parallel and sub-parallel continuous seismic facies. The main body transport direction from south to north comes from the southern area of Qiongdongnan basin located east of Indochina Peninsula and north of Guangle uplift. In the region, the strike-slip reversal occurred in the late Miocene Red River fault, the uplift and erosion of the Indochina Peninsula increased, and the deposition rate in the western part of the South China Sea suddenly accelerated. These events provided the basic conditions and trigger mechanism for the formation of large-scale submarine landslides. The discovery of large-scale submarine landslides provides sedimentological evidence for the strike-slip inversion tectonic events of the Honghe fault in the late Miocene, and through the constraints of geological time at the top interface of the submarine landslides, it is inferred that the most intense tectonic activity in the inversion process of the Honghe fault occurred at 5.5Ma.
【作者单位】：中国科学院深海科学与工程研究所;浙江大学海洋学院;中石油杭州地质研究院;
【基金】：国家自然科学基金项目(批准号:41576049)和国家自然科学基金重大研究计划项目(批准号:91228208,91028007,91428309)资助
【分类号】：P736

【相似文献】