福建九龙江下游NW向断裂带第四纪以来活动特征

Quaternary Active Features of the NW-striking Fault Zone in Jiulong River Downstream Area,Fujian Province

通过对福建九龙江下游NW向断裂带断层上覆地层的切割关系、断裂两侧第四纪等时地貌面的差异性变化、浅层地震勘探、断层两侧钻孔探测等资料分析,研究了断裂第四纪以来的活动特征及断裂构造的组合特征。结果表明:(1)郭坑—江东桥断裂(F1)、珠坑断裂(F3)、金峰—大帽山断裂(F7)为早第四纪(Q1-2)断裂;岱山岩—珩坑断裂(F6)的观音山—古湖段为早第四纪(Q1-2)断裂、古湖—洪塘段为晚更新世活动断裂;覆船山—康山断裂(F4)、九龙江(西溪)断裂(F5)为晚更新世早期活动断裂,海沧—钱屿断裂(F2)为晚更新世活动断裂。(2)郭坑—江东桥断裂和金峰—大帽山断裂将本区切割成3个地块,形成了小田坑山地垒、漳州地堑、锅尖山地垒的构造组合形式。漳州地堑再被覆船山—康山断裂和岱山岩-珩坑断裂切割成3个地块,又形成了较小的圆山地垒、九龙江西溪河谷地堑、马鞍山地垒的构造组合形式。

The Quaternary active features and combination relation of NW-striking fault zone in the downstream area of Jiulongjiang in Fujian province are researched through analysis of Quaternary geology,geomorphology,high-resolution seismic profiling,dating and drilling.The results show that：（1） The Guokeng-Jiangdong fault（F1）,Zhukeng fault（F3） and Jinfeng-Damaoshan fault（F7） actived in early Quaternary（Q1-2）.Daishanyan-Hengkeng fault（F6） actived in early Quaternary and late Pleistocene on different segments.The Fuchuangshan-Kangshan fault（F4） and Jiulongjiang（west stream） fault（F5） actived in early late Pleistocene.The Haicang-Qiangyu fault（F2） actived in late Pleistocene.（2） The Guokeng-Jiangdongqiao fault and the Jinfeng-Damaoshan fault divided the research area into 3 blocks and formed the Structural Assemblage of Xiaotiankeng horst,Zhangzhou graben and Guojianshan horst.Than the Zhangzhou graben was divided into 3 blocks by the Fuchuanshan-Kangshan fault and the Daishanyan-Hengkeng fault,and formed the smaller Structural Assemblage of Yuanshan horst,Jiulongjiang Xixi valley graben and Maanshan horst.