Characteristics and latest activity of Hongshanzui fault in northwestern Yili basin, Xinjiang Province

Located in Huocheng, Xinjiang, the Hongshanzui fault is a frontal fault of the fold-and-thrust belt developed in the fore-land area on the northern margin of Yili basin. The fault strikes NWW and dips NNW. Field observations show that this fault is a steep reverse fault with dip angle over 50°. The hanging wall of the fault consists of Neogene red beds, whereas upper Pleistocene loess and Holocene sediments are exposed on the footwall. According to the contact relationship and regional structure in the study area, the fault might have been formed at the end of Early Pleistocene. Disrupted strata along Hongshanzui fault indicate intensive activities since Late Quaternary, and hence the latest activity of this fault in Holocene and disrupted gravel and sand beds at the surface also deserve much attention.