• 责任者：Lü Honghua (School of Resource and Environmental Sciences ; East China Normal University ; Shanghai 200241 ; China) ; Wang Wei
• 刊名：Quaternary Sciences
• 出版年：2013
• 卷期：33(4)
• 关键词：造山带 ; orogenic belts ; 剥蚀作用 ; denudation ; 天山 ; Tianshan Mountains
• 页码：p.812-822
• 图表：5 illus., 3 tables, 71 refs.
• 分类号：0300
• issnNo：ISSN1001-7410
• isbnNo：CN11-2708/P

     In response to the India-Asia collision during Cenozoic times,the Tian Shan range has been tectonically reactivated and intensely uplifted.Many previous studies have focused on the history of uplift and exhumation of the Tian Shan during the Cenozoic based on low-temperature thermochronology,magnetostratigraphy and syntectonic deposits,sedimentology,and rock magnetism.However,the divergent opinions still exist.Here we also employ apatite fission-track analysis on rock samples from a transect along the Vrümqi-Korla road crossing the eastern part of the Tian Shan in order to better understand the spatial difference in the exhumation history of the Tian Shan range.In the field,we selected sixteen rock samples（WK1~WK16）along the Road.The samples WK6~WK10 and WK12~WK15 were performed for all the analytical procedures of apatite fission track,which were mainly from the segment of the Road south of Shenglidaban.The other samples（WK1~WK5,WK11,and WK16）were not further analyzed due to the following reasons：（1）there are not enough apatite grains for sample preparation,or（2）there is any suitable apatite grains for fission track statistics.In the lab,we obtained the AFT data such as confined track length,Dpar（diameter of etched spontaneous fission tracks measured parallel to the crystallographic C-axis）,track angle to the crystallographic C-axis.Our fission-track data show that confined track length ranges from 12.8~14.1μm with standard deviation of 1.41~1.75μm,and that Dpar is 1.57μm to 2.03μm.AFT ages span 90~50Ma except for sample WK6 with the age of ca.158Ma.The positive correlation exists between these AFT age data and the corresponding elevations.The thermal modeling results show that the sampled part of the Tian Shan range has experienced two stages of exhumation during Cenozoic times,i.e. ,slow exhumation before ca.20±5Ma followed by subsequent rapid exhumation,with the exhumation rates of ca.10~30m/Ma and ca.70~160m/Ma,respectively.Together with the previous low-temperature thermochronological data,it appears that the exhumation process within the whole range during Cenozoic times is spatially different,and that the exhumation history within the Tian Shan range during the Cenozoic can be roughly divided into four stages,these occurring approximately in the Earliest Cenozoic（ca.65Ma）,the Middle Oligocene（ca.40±5Ma）,the Late Eocene to the Middle Miocene（ca.20±5Ma）,and the Middle to Late Miocene（ca.10±2Ma）,respectively.The rapid exhumation stage occurring in the Late Eocene to the Middle Miocene is regarded as one important exhumation process within the Tian Shan range during Cenozoic times.