关键词: 野马河北侧断裂, 左旋走滑, 逆冲, 速率, 晚第四纪

Abstract: The slip rate decreased at Subei,Shibaocheng and Shulehe regions on the eastern segment of Altyn Fault,the regions called as "singularity points". Subei is one of "singularity points" on the eastern segment of Altyn Fault,and the north of Yemahe Fault in the northeast of Subei is the fault we study in this paper. The fault is located in the northeast of Yemahe Basin. It starts at Erdaogou gully in the east and ends at Niujuan gully,extending along the Yema mountain front and parallel to the Altyn Fault in the direction of NEE on the whole. It separates Sinian from Quaternary gravel layer. There are plenty of left-lateral slip-strike and thrusting geomorphologic phenomena and exposed stratigraphic sections on the sides of gullies. Ridges and gullies are dislocated synchronously.Through more than one month investigation,we obtained the distribution and the geological and geomorphologic characteristics of the fault,measured a series of left-lateral slip gullies,ridges and thrust scarps and got the relevant data. Some samples are also collected. The left-lateral slip of gullies is distributed from 1.3m to 175m,and the height of thrust scarps is from 0.95m to 8.53m. The horizontal averaged slip rate of the fault is calculated to be 1.27?0.18mm/a,and the averaged thrusting rate is 0.4?0.07mm/a. This fault,together with the Danghenanshan thrust fault at its south,resolved part of the movement components of the eastern segment of Altyn Fault.

Key words: the north of Yemahe Fault, left-lateral strike-slip, thrust rate, late Quaternary