地球学报2026，Vol.47Issue(2)：307-320,14.DOI:10.3975/cagsb.2026.011601
西藏冈底斯中段南缘曲水地区早中新世隆升剥露历史及控制机制
Early Miocene Uplift and Exhumation History of the Southern Margin in Central Gangdese,Quxu Area,Tibet,and Its Governing Mechanisms:Evidence from Apatite(U-Th)/He Thermochronology
摘要
Abstract
The Quxu area,is located in the southern margin of the central Gangdese Magmatic Arc.The Cenozoic uplift and exhumation history of this area holds significant implications for deciphering the tectono-geomorphic evolution of the Gangdese Magmatic Arc and even the entire Tibetan Plateau.This study focuses on the uplift and exhumation history of the Quxu area.Nine samples were systematically collected at equal intervals along a 950 m vertical profile through Paleocene-Eocene granodiorites.Apatite(U-Th)/He thermochronology analyses of these samples produced ages ranging from 13.7 Ma to 12.6 Ma.The combination of thermochronological data and thermal history modeling indicated that the Quxu area underwent a rapid cooling event during the Early Miocene(19.0-11.5 Ma).During this interval,the total cooling was 299.4 ℃ at a cooling average rate of 40.0 ℃/Ma,corresponding to an exhumation magnitude of 9.8 km and average exhumation rate of 1.3 km/Ma.Since 11.5 Ma,the area has undergone a phase of slow cooling,characterized by a total cooling of 11.7 ℃ at a rate of 1.0 ℃/Ma that corresponds to an exhumation magnitude of 0.35 km and rate of 0.03 km/Ma,respectively.The study proposes that the Early Miocene rapid exhumation in the Quxu area was predominantly controlled by the Xietongmen-Quxu Shear Zone.South-directed thrusting along this shear zone drove crustal shortening and thickening,which induced isostatic adjustment and consequently led to intense regional exhumation.After 11.5 Ma,the exhumation rate in the Quxu area decreased significantly,driven by cessation of the Xietongmen-Quxu Shear Zone activity,regional transition to an extensional tectonic regime,and climate aridification induced by the rapid uplift of the southern Himalayas.关键词
曲水地区/磷灰石(U-Th)/He/剥露历史/冈底斯/谢通门—曲水剪切带Key words
Quxu area/apatite(U-Th)/He/exhumation history/Gangdese/Xietongmen-Quxu shear zone分类
天文与地球科学引用本文复制引用
侯淡平,周敖日格勒,贺海洋,毕文军,曾涛,李朋刚,冯佳伟..西藏冈底斯中段南缘曲水地区早中新世隆升剥露历史及控制机制[J].地球学报,2026,47(2):307-320,14.基金项目
本文由国家重点研发计划项目(编号:2022YFC2905001)、西藏玉龙铜业股份有限公司技术服务项目(编号:HX2024-42)、中央引导地方科技发展资金项目(编号:XZ202401YD0006-08)、湖南省研究生科研创新项目(编号:CX20251436)、西藏玉龙铜业股份有限公司"玉龙铜矿外围地质找矿潜力研究"(编号:中地科合同 2024-342)和"玉龙铜矿与甘龙拉、纳加扎地区矿产资源潜力综合研究"项目(编号:XKYL/D-FW-14.2025.07.01)联合资助. The study was supported by the National Key Research and Development Program of China(No.2022YFC2905001),the Technical Service Project of Yulong Copper Industry(No.HX2024-42),the Cen-tral Government Guides Local Science and Technol-ogy Development Fund Project(No.XZ202401YD0006C),the Hunan Province Graduate Research and Innovation Project(No.CX20251436),and the Technical Service Project of Yulong Copper Industry(Nos.Zhongdike Contract No.2024-342 and XKYL/D-FW-14.2025.07.01). （编号:2022YFC2905001）
