商丹断裂南阳盆地第四纪活动研究

Study on quaternary activity in Nanyang Basin of Shangdan Fault

为了研究商丹断裂的空间展布及断裂活动性特征,跨断裂布设了4条浅层地震勘探测线和1条钻孔联合地质剖面.综合分析表明,商丹断裂为一条走向NWW的正断层,钻孔联合地质剖面揭示断裂上断点埋深为13—19 m,最新活动时代为中更新世晚期.

The Shangdan fault is the structural suture between the North China Plate and the Yangtze Plate.It is also a large,complex structure and long-term active fault.The fault is buried in Quaternary of the Nanyang Basin.Recently,it is prevalent to combine shallow seismic profile and drill exploration to study the activitives of buried faults.This work studied the spatial extension and the active age of the Shangdan fault by combination on shallow seismic exploration of three profiles and a composite drilling cross-section across the fault.The results show that the Shangdan fault is a NWW-trending normal fault.The composite drilling cross-section reveals that the buried depth of the fault’s up-breakpoint is about 13 to 19 m and the latest age of activity is the late Middle Pleistocene.