柴达木盆地西部地区构造演化的裂变径迹揭示  

Fission track evidences of tectonic evolution in west Qaidam basin

作　　者：孙国强[1,2] 苏龙[1,2] 王旭红 侯安平 郑建京[1] 

机构地区：[1]中国科学院地质与地球物理研究所气体地球化学重点实验室 [2]中国科学院研究生院 [3]中国石油青海油田勘探开发研究院

出　　处：《天然气工业》2009年第2期27-31,共5页Natural Gas Industry

基　　金：国家重点基础研究发展计划(973计划)(编号:2007CB209500);中国科学院知识创新工程重要方向项目(编号:KZCX3-SW-147)的联合资助

摘　　要：近年来,裂变径迹技术在研究沉积盆地的热历史、山脉的隆升速率、沉积盆地的物源分析、构造抬升及热演化以及测定活动断层的活动年龄等方面都得到了广泛的应用,但是用该方法来研究构造运动—热事件期次和发生时间的则很少。为此,采用该方法研究了柴达木盆地西部地区中新生代以来的构造运动学过程。实验样品采自柴达木盆地西部11口钻井的岩心,所选样品均位于渐新统顶部和中新统底部地层。对样品中的磷灰石和锆石矿物进行年龄测定后发现,磷灰石的测定年龄在距今8～13Ma之间,与地层的年龄一致;而锆石的测定年龄在距今45～150Ma之间。通过分析磷灰石和锆石的裂变径迹年龄数据,得出结论认为:柴达木盆地西部地区中生代末期以来发生了两次大规模的构造事件,分别发生在距今60～100Ma之间和距今35Ma以来,对应着柴达木盆地西部坳陷燕山运动以来的主要构造运动阶段。In recent years,fission tract technology is widely applied in the research of thermal history of sedimentary basins,uplifting rate of mountains,source of sedimentary basins,tectonic uplifting and thermal evolution as well as timing of fault activity,but seldom used in the study of the phases and timing of tectonic movement-thermal activities.It is used to study the process of tectonic movement since the Cenozoic in the western Qaidam basin.The laboratory samples are cores acquired from the top Oligocene and the bottom Miocene in 11 wells in the western Qaidam basin.Dating of apatite and zirconite in the samples shows that the age of apatite is 8 to 13Ma,which is in accordance with the age of the Earth,while that of zirconite is 45 to 150Ma.The following conclusion is obtained through analyzing the age of apatite and zirconite: the western Qaidam basin experienced two important tectonic events since the end of Mesozoic,which occurred in 100 to 60Ma and 35Ma respectively and correspond to the major tectonic movement phases since the Yanshan movement in the western depression of the Qaidam basin.

关 键 词：柴达木盆地 磷灰石裂变径迹 锆石裂变径迹 构造热事件 期次 发生时间 

分 类 号：P542[天文地球—构造地质学]