Abstract:

By means of the latest seismic data and surface geology, structure styles of Dabashan foreland thrust belt are comprehensively interpreted. According to  the difference in  their styles, three structure belts can be determined:NW buried thrust belt of Tongjiang-Huangjinkou,NW-NE intersection belt of Wubaochang-Tieshanpo,and EW structure belt of Wenquanjing-Fengjie. Correspondingly, front structure styles can be divided into 3 types: back-thrust fault type, folded detachment fault type, and vis-à-vis thrust faulted fold type. There are two main stages of structure deformations since Mesozoic. The first one is Late Indo-Sinian epoch, mainly forming NE folds; the other is Mid-Late Yanshan to Himalaya, mostly developing NW thrust faults. Multi-stages stacked structure deformations are very obvious, and controlled by combined pressure stress in different directions.

Key words: Dabashan foreland basin, structure style, stacked structure, thrust faulted-fold