南黄海盆地中部隆起海相上构造层分布及断裂系统特征

DISTRIBUTION PATTERN OF MARINE UPPER STRUCTURAL LAYER AND FAULT SYSTEM ON THE CENTRAL UPLIFT OF THE SOUTH YELLOW SEA BASIN

南黄海盆地中部隆起区发育2套海相构造层,以下志留统高家边组泥岩滑脱带为界可划分为海相上构造层和海相下构造层。海相上构造层构造相对较复杂,以冲断结构为主,褶皱及叠瓦状逆冲断裂发育。对南黄海盆地中部隆起区多道地震资料进行处理解释表明,中部隆起区广泛发育海相上构造层,平面上总体表现为自西向东厚度呈厚—薄—厚的沉积格局。断裂系统发育,以近EW向断裂最为发育,其次为NE向断裂,NW向断裂则较为零星。构造应力以挤压和走滑为主,主要发育挤压、压扭和张扭3种构造样式。

There are two marine structural layers on the Central Uplift of the South Yellow Sea Basin.They are separated by a mudstone detachment zone of Lower Silurian,the Gaojiabian Formation.The upper structural layer is relatively complex,where develop thrust folds and imbricate thrust faults.Multi-channel seismic data on the Central Uplift shows that the marine structural layer is widely developed,and its thickness varies in a pattern of thick-thin-thick from west to east.Faults are developed along the strike of E-W direction,dominated by the tectonic stress of compression and strikeslip.Three structural styles of compression,extension-twisting and compression-twisting have been discovered.