南海中—西沙地块前新生代构造变形特征

发布时间：2018-05-26 06:28

本文选题：构造变形 + 前新生界　；参考：《海洋地质与第四纪地质》2017年02期

【摘要】：为确定南海西部的中—西沙地块是否存在前新生代地层与构造,对研究区内多道反射地震剖面资料进行了地层-构造解释,并结合围区钻井、拖网等岩石地层资料,在研究区北部发现了前新生代地层-构造变形形迹。运用回剥法、去断层恢复法和地质反序法对前新生代地层的构造变形进行了古恢复。结果表明,研究区的地层可划分为上、中、下三套构造层,其中属于前新生界的下构造层可见褶皱、逆冲等挤压构造样式,前新生代末期,其构造形态表现为一系列连续的宽缓褶皱,结合断层逆冲推覆方向可判断其主要挤压应力来自于东南方向,并推测该挤压作用与古南海的扩张有关。
[Abstract]:In order to determine whether there are pre-Cenozoic strata and structures in the Meso-Xisha block in the western part of the South China Sea, stratigraphic and structural interpretation of multi-channel reflection seismic profile data in the study area is carried out, combined with lithostratigraphic data such as drilling and trawling in the enclosed area. In the northern part of the study area, pre-Cenozoic stratigraphic-tectonic deformation patterns were found. The tectonic deformation of the pre-Cenozoic strata has been restored by the methods of back-stripping, fault-removal and geological inversion. The results show that the strata in the study area can be divided into three sets of tectonic layers, including the upper, middle and lower tectonic layers, which belong to the pre-Cenozoic, in which the compressional structural styles such as fold and thrust are visible in the lower tectonic layers, which belong to the pre-Cenozoic, and the late Cenozoic is the end of the study area. Its structural form is a series of continuous wide and slow folds, which can be judged by the direction of fault thrust and nappe, and the main compressive stress comes from the southeast direction, and it is presumed that the compression is related to the expansion of the Paleo-South China Sea.
【作者单位】：中国科学院南海海洋研究所边缘海与大洋地质重点实验室;中国科学院大学;广州海洋地质调查局;
【基金】：国家自然科学基金项目(41476039、91328205和41276048) “中国海及邻域地质地球物理及地球化学系列图”项目(GZH200900504-WX02)
【分类号】：P736.1

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