南黄海陆架沉积物中褶皱的形态及成因  

Geometries and mechanism of folds in sediments on the southern Huanghai Sea shelf

作　　者：李西双[1] 李三忠[2] 刘保华[1] 赵月霞[1] 

机构地区：[1]国家海洋局第一海洋研究所 [2]中国海洋大学海洋地球科学学院,山东青岛266003

出　　处：《海洋学报》2006年第1期77-84,共8页

摘　　要：更新世以来南黄海陆架具有构造活动性强、沉积厚度大（100-300m）、褶皱变形保存完整等特点，是研究未固结沉积物中褶皱变形的理想“实验室”．高分辨率单道地震剖面揭示了南黄海陆架沉积物中具有不同几何形态的三种褶皱：（1）断层相关褶皱（包括断层扩展褶皱和断层牵引褶皱）；（2）横向弯曲褶皱；（3）复合作用褶皱．对褶皱的成因和几何形态的研究表明，控制未固结沉积物中褶皱形成的因素是基底断层及其形成的断块，而不是区域应力场．大量孔隙水可能对沉积物的几何形变具有重要的影响作用．沉积物中断层扩展褶皱和牵引褶皱在形变程度上具有连续性，说明两者在成因上存在联系．断层扩展褶皱可能引发的地震活动和变形带在海洋工程地质评估中应受到重视．Since Pleistocene tectonic activities are intensive, and about 100 to 300 m thick sediments are deposited on the southern Huanghai Sea （SHS） shelf. So fold deformations in the sediments are well presevered. Three types of folds with different geometries in the sediments have been revealed by single-channel seismic profiles on the SHS shelf and they are （1） fault-related fold （including fault-propagation fold and fault-drag fold）, （2） transversal bending fold, and （3） multi-action-folding fold. Studies on geometry and mechanism of folds show that it is base faults and fault blocks that control foldings in unconsolidated sediments on the SHS shelf. Large quantity of pore water in the sediments plays an important role in the deformation of sediment layers. The continuity of deformations of the fault-propagation fold and the faultdrag fold indicates that there is genesis relationship between them. Potential earthquakes induced by the fault-propagation folding and the deformation zone should be taken into account in the marine engineering geology evaluating of the SHS shelf.

关 键 词：南黄海陆架 沉积物 褶皱作用 基底断层 海洋工程 

分 类 号：P551[天文地球—构造地质学] P542.3[天文地球—地质学]