Chronological record of the Early Mesozoic underplating in the northern margin of North China—U-Pb chronometry of zircons in the Late Mesozoic andesite from Western Liaoning  

作　　者：Shao Ji＇an Zhang Hongfu Liu Xiaoming Li Zhitong 

机构地区：[1]School of Earth and Space Sciences, Peking University, Beijing 100871, China [2]Institute of Geology and Geophysics and Key Laboratory of Mineral Resources, Chinese Academy of Sciences, Beijing 100029, China [3]Key Laboratory of Continental Dynamics,Northwestern University, Xi＇ an 710069, China [4]Institute of Geology and Mineral Resources of Shenyang, Shenyang 110032, China

出　　处：《Progress in Natural Science:Materials International》2007年第8期943-947,共5页自然科学进展·国际材料（英文版）

基　　金：Supported by National Natural Science Foundation of China (Grant Nos.40372103,40672039);Key Laboratory of Mineral Resources,Chinese Academy of Sciences

摘　　要：Cathodoluminescence spectroscopic analysis of zircons in the uppermost sanukites of the early Cretaceous Yixian Formation in Western Liaoning reveals zoning structures of the zircons in the volcanic rocks. LA-ICP-MS chronometry shows that the central part of the zircons is remnant zircon with a U-Pb dating of 254 Ma, which is consistent with the age of the Early Mesozoic underplating granulites, and that the periphery is zircon crystallizing out of the host magma with a U-Pb dating of 116 Ma, which is highly consistent with the Ar-Ar dating of the host volcanic rocks. Compositions of the clinopyroxenes xenocrystals in the sanukites are similar to those of the clinopyroxenes in the underplating granulites, indicating that the granulites accreted to the lower crust in the Early Mesozoic have been reformed and disrupted by the upwelling diapers of the asthenosphere and taken part in formation of the sanukites in the Late Mesozoic.锆石在的阴极射线发光分光镜的分析最高在西方的辽宁的早 Yixian 形成的 sanukites 在暴烈的岩石中揭示锆石的 zoning 结构。锆石的中央部分是残余锆石， U-Pb 254 妈标明日期的 LA-ICP-MS 测时学表演，与在 plating granulites 下面的早中生代的年龄一致，并且圆周是锆石从主人岩浆结晶， U-Pb 116 妈标明日期，它与 Ar-Ar 主人标明日期高度一致暴烈的岩石。在 sanukites 的 clinopyroxenes xenocrystals 的作文类似于 clinopyroxenes 在的那些在 plating granulites 下面，显示 granulites 在早中生代增大了到更低的外壳被改革了并且破坏由起来岩流圈的 welling 尿布并且在迟了的中生代参加 sanukites 的形成。

关 键 词：northern margin of North China Mesozoic volcanic rock U-Pb chronometry of zircon underplating granulite. 

分 类 号：P581[天文地球—岩石学]