摘要
天山造山带中新生代快速剥露对于了解天山构造演化过程意义重大.然而,人们对于中新生代精确的冷却时间还一直存在争议.本文报道了塔里木盆地北缘库车河剖面中生界砂岩中碎屑磷灰石裂变径迹数据和早二叠世流纹岩热史演化模拟结果.热年代学年龄趋势显示碎屑磷灰石裂变径迹的主要年龄组分为143.0~148.9 Ma和35.7~38.1 Ma,其中较年轻的组分已经完全重置,揭示了库车坳陷的剥露信息.热史模拟结果显示了160~140 Ma的快速冷却事件.结合库车河剖面前人的碎屑锆石U-Pb和重矿物数据,笔者认为欧亚南缘拉萨地体的拼贴是通过刚性的塔里木将挤压应力传递至天山,导致其在晚侏罗世‒早白垩世强烈隆升剥蚀,大量碎屑被搬运沉积在塔里木盆地北缘,造成库车坳陷中广泛发育的早白垩世亚格列木组砾岩及其与晚侏罗世地层之间的角度不整合.在欧亚板块南缘多块体持续拼贴的远程效应下,天山经历始新世快速隆升变形,变形持续向南扩展,导致库车坳陷在晚始新世遭受变形和抬升.
The rapid Mesozoic-Cenozoic exhumation of the Tianshan mountain range is of great significance for understanding its tectonic evolution process.However,the main exhumation time of the Mesozoic-Cenozoic remains controversial.In this study,we report new detrital apatite fission track data from the Mesozoic sedimentary succession on the northern margin of the Tarim basin(Kuqa river section)and the Early Permian rhyolite inverse thermal history modelling results.Thermochronologic age trends along the analyzed succession reveal two major age populations in 143.0-148.9 Ma and 35.7-38.1 Ma,of which the younger population has been completely reset,indicative of the exhumation information of the Kuqa depression.Inverse thermal history modelling results show a rapid cooling event occurred at 160-140 Ma.We infer that the compressive stress generated from collision between Lhasa and the southern margin of Eurasia transmitted to the Tianshan mountain range through the rigid Tarim,which caused that the Tianshan mountain range underwent strong uplift and denudation in the Late Jurassic-Early Cretaceous,generating widely distributed conglomerate in the Early Cretaceous Yageliemu Formation and angular unconformity developed in the Late Jurassic-Early Cretaceous strata.During the Eocene,the Tianshan was subjected to rapid uplift and intensified deformation in response to the continuous collision of several plates on the southern margin of Eurasia.And the compressive stress propagated southward,which caused that the Kuqa depression underwent uplift in the Late Eocene.
作者
郭超
张志勇
吴林
项敦峰
王楠
肖文交
Guo Chao;Zhang Zhiyong;Wu Lin;Xiang Dunfeng;Wang Nan;Xiao Wenjiao(State Key Laboratory of Lithospheric Evolution,Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029,China;College of Earth and Planetary Science,University of Chinese Academy of Sciences,Beijing 100049,China;Xinjiang Research Center for Mineral Resources,Xinjiang Institute of Ecology and Geography,Chinese Academy of Sciences,Urumqi 830011,China)
出处
《地球科学》
EI
CAS
CSCD
北大核心
2022年第9期3417-3430,共14页
Earth Science
基金
国家自然科学基金项目(Nos.92055213,91855207,41888101).
关键词
天山
库车坳陷
磷灰石裂变径迹
隆升剥露
盆山耦合
地质年代学
Tianshan
Kuqa depression
apatite fission track
uplift and exhumation
basin‐mountain coupling
geochronology
