阿尔金东段白垩纪以来阶段性隆升的裂变径迹年龄证据  

Fission Track Thermochronology Evidence of Stepwise Uplift Since Cretaceous in the Eastern Altyn, China

作　　者：郭怀军 王虎[1] 全守村[1] 闫旭光 贾伟航 GUO Huai-jun;WANG Hu;QUAN Shou-cun;YAN Xu-guang;JIA Wei-hang(Xi'an Center of Geological Survey,China Geological Survey,Xi'an 710054,Shaanxi,China;Xi'an Abbott Capital and Environmental Analysis and Testing Technology Co.,Ltd.,Xi'an 710018,Shaanxi,China;Gansu Coal Geology Survey Institute,Lanzhou 730099,Gansu,China)

机构地区：[1]中国地质调查局西安地质调查中心,陕西西安710054 [2]西安阿伯塔资环分析测试技术有限公司,陕西西安710018 [3]甘肃煤炭地质勘察院,甘肃兰州730099

出　　处：《地球科学与环境学报》2022年第2期243-256,共14页Journal of Earth Sciences and Environment

基　　金：中国地质调查局地质调查项目(DD20160005,DD20211398)。

摘　　要：阿尔金山处于青藏高原北缘,其中—新生代形成与演化过程研究是认识青藏高原隆升扩展的关键。以阿尔金东段拉配泉一带岩体为研究对象,通过锆石、磷灰石低温热年代学研究来揭示阿尔金东段白垩纪以来的抬升冷却过程,进而全面认识阿尔金中—新生代的隆升剥露史。结果表明:拉配泉地区锆石和磷灰石的裂变径迹中心年龄分别为116~108和47~19 Ma,记录了阿尔金东段地区早白垩世以来的冷却事件。热史模拟结果显示:阿尔金东段北缘在60~48和约10 Ma以来发生了两期快速降温事件;第1期事件,在印度板块向欧亚板块俯冲作用下,青藏高原北缘隆升并产生逆冲推覆作用,阿尔金断裂再次开始活动,阿尔金东段山体发生快速剥露;第2期事件,在印度板块和欧亚板块碰撞的远程效应下,阿尔金主断裂的大规模走滑运动导致了该地区的快速剥露;这两期事件的平均冷却速率分别为2.85℃·Ma^(-1)和4.84℃·Ma^(-1)。The research on Meso-Cenozoic formation and evolution process of Altyn Mountain,which locates at the northern margin of Qinghai-Tibet Plateau,is the key to understand the uplift and extension of Qinghai-Tibet Plateau.The rocks in Lapeiquan area,the eastern segment of Altyn was used to reveal its uplift and cooling process since Cretaceous through zircon and apatite fission track chronology,and then comprehensively understand Meso-Cenozoic uplift and exhumation history of Altyn.The results show that zircon and apatite fission track ages mainly are divided into two groups,including 116-108 Ma and 47-19 Ma,respectively.All of the data show a cooling history of the eastern segment of Altyn since Early Cretaceous.The thermal history simulation shows that the northern margin of the eastern segment of Altyn experiences two fast cooling events at 60-48 Ma and 10-0 Ma.In the first event,because of the subduction from Indian plate to Eurasian plate,Qinghai-Tibet Plateau experiences uplift and thrust nappe from south to north,the Altyn crack starts the activity again,the eastern segment of Altyn experiences fast uplift;in the second event,because of the remote effect by collision between Indian plate and Eurasian plate,the large-scale strike slip movement of the Altyn crack leads to its rapid cooling.The average uplift rates of these two events are estimated at 2.85℃·Ma^(-1) and 4.84℃·Ma^(-1),respectively.

关 键 词：磷灰石 裂变径迹 热演化史 白垩纪 锆石 隆升 阿尔金 

分 类 号：P542.2[天文地球—构造地质学] P597[天文地球—地质学]