辽西地区燕山板内造山带早中生代构造变形的年代学限定  

Geochronological constrains for the early Mesozoic tectonic deformation of Yanshan intraplate orogen in northeastern China.

作　　者：胡健民[1] 刘晓文[2] 杨之青[3] 

机构地区：[1]中国地质科学院地质力学研究所,北京100081 [2]国土资源部事物地质资料中心,三河065201 [3]北京离子探针中心,北京100037

出　　处：《岩石学报》2007年第3期605-616,共12页Acta Petrologica Sinica

基　　金：国家重点基础研究973项目(2006CB403501);国家自然科学基金重点项目(40132020)

摘　　要：在辽西进行的构造研究确认了这里曾经在早中生代期间发生过几次重要的构造变形事件,地质上,这几次构造变形的时代被限定在中三叠世老虎沟组沉积之后到晚侏罗世髫髻山/蓝旗组火山岩喷发之前。期间,第一期逆冲推覆构造被水泉沟组不整合覆盖,第二期逆冲推覆构造被髫髻山组/蓝旗组不整合覆盖。本文通过对水泉沟组火山岩、邓杖子组火山岩砾石、髫髻山组底部火山岩以及侵位到逆冲构造岩片中的安山玢岩脉体进行锆石SHRIMP法U-Pb定年,比较准确地限定了燕山板内造山带早中生代几次构造变形的时代。这对于研究燕山板内造山带早期变形特征和变形历史、研究整个燕山造山带的变形过程都具有重要的意义。The study on the tectonics in the western Liaoning province has confirmed there occurred several times of thrusting and sliding. In geology, the time of the deformations were defined during after the sedimentation of the late Triassic Laohugou Formation to the evaporation of the volcanic rocks of the late Jurassic Tiaojishan Formation or Lanqi Formation. Especially, the early thrusts were covered by the Shuiquangou Formation and the late thrusts were covered by the Tiaojishan Formation or Lanqi Formation. In this paper, the authors obtained some SHRIMP U-Pb ages of zircons from the volcanic rocks of the Shuiquangou Formation, the volcanic gravels of Dengzhangzi Formation, the volcanic rocks of Tiaojishan Formation, and the andesitic-porphyrite vein intruded into the early thrust system. The ages constrain the times of the early Mesozoic deformations in Yanshan intraplate orogen. They are very important for the researching on the early deformational features and deformational evolution of Yanshan intraplate orogen.

关 键 词：燕山板内造山带 辽西-冀北地区 锆石U-PB定年 

分 类 号：P597.3[天文地球—地球化学] P542.2[天文地球—地质学]