关键词: 阿尔金主断裂, 河流相砾岩, 疏勒河, 左行走滑

Abstract: Previous results about the magnitude and rate of strike-slip movement along the eastern segment of the Altun Fault are quite inconsistent with each other. This is mostly because that the Quaternary strike-slip rate was inferred mainly from the offset of drainage system or from interglacial sediments,while these data focused mainly on late Quaternary. Tracing the early Pleistocene alluvial gravel bed outcropped along the easternmost segment of the Altun Fault,we discovered that the western boundary of the ancient alluvial fan deposits of the Shulehe River is now about 10km away from the outlet of the river. We believe that this is an important evidence indicating that the Quaternary left-lateral strike-slip displacement along the easternmost segment of the Altun Fault is about 10km. Basing on the analysis of terraces at the outlet of the Shulehe River,we conclude that the 2.8km elbow-like winding of the Shulehe River channel along the Altun Fault indicates not only the left-lateral strike-slip of the Altun Fault,but also the effect of lateral erosion at the meander reach of the river. The magnitude of the Quaternary dislocation and slip rate along the easternmost segment of the Altun Fault are discussed in this paper as well.

Key words: Altun Fault, alluvial gravel bed, Shulehe River, left-lateral strike-slip