The Characteristics Of Tectonic Activity And Landscape Evolution In The Huola Mountain,Southern Tian Shan

As one of the most active intracontinental orogenic belts,the Tian Shan has experienced a complex tectonic evolution,including Paleozoic collisional events,denudation and beveling in Mesozoic,and Cenozoic reactivation.The Huola Mountain is an important part of the southern Tian Shan collision suture zone,connecting the middle Tian Shan plate and Tarim plate.Its tectonic activity and topography evolution are of great significance to understand the tectonic deformation of the Tian Shan.However,previous studies mainly focused on the fault belt in the northern margin of Tarim basin,and paid little attention to the overall geomorphic characteristics and tectonic activities of the Huola Mountain.On the other hand,the prominent planation surfaces provide an important window for exploring the tectonic deformation and landscape evolution.In this paper,tectonic activity in the Huola Mountain is studied through the analysis of drainage networks,and meanwhile,its topographic features and evolution are investigated by carrying out numerical modeling.The results show that: 1)spatial variation of tectonic activity is obvious in the Huola Mountain,with higher level in the south than that in the north;and along the southern range front,it decreases easterwards,which is consistent with results of previous studies of active faults;2)serial river captures occurred,namely capture of longitudinal drainages by transverse reaches,leaving elbows of capture and non-lithological knickpoints;3)numerical modeling reveals that the pre-existing(quickly-formed)tilted planation surface probably controls the subsequent landscape evolution and associated river reorganization.The drainage arrangement includes two distinct stages: the short-term and intense river capture period and the long-term slow divide migration period.The results would guide further investigations in active faults and paleoearthquakes in the Huola Mountain,and also provide insights into the the formation and evolution mechanism of the planation surfaces.