首页 | 本学科首页   官方微博 | 高级检索  
     检索      

辽西北票—义县地区义县组顶部层位的年龄及其意义
引用本文:张 宏,柳小明 陈 文 李之彤  杨芳林.辽西北票—义县地区义县组顶部层位的年龄及其意义[J].中国地质,2005,32(4):596-603.
作者姓名:张 宏  柳小明 陈 文 李之彤  杨芳林
作者单位:1. 西北大学地质学系大陆动力学重点实验室,陕西,西安,710069;国土资源部沈阳地质研究所,辽宁,沈阳,110032
2. 西北大学地质学系大陆动力学重点实验室,陕西,西安,710069
3. 中国地质科学院地质研究所同位素开放实验室,北京,100037
4. 国土资源部沈阳地质研究所,辽宁,沈阳,110032
基金项目:科技部2000年度科技基础性工作第35专项、国土资源部专项(2000010403)和中国地质调查局地质大调查项目(200113000052-2、200413000024)资助.
摘    要:辽西义县组顶部层位为义县组金刚山层之上的黄花山角砾岩层或流纹岩(二者为同时异相).通过对该流纹岩样品中锆石的LA-ICP-MS的U-Pb测年,获得其加权平均年龄为(118.9±1.4)Ma~(119.8±1.9)Ma.通过Ar-Ar方法测年,测得了黄花山角砾岩层的下部岩石中灌入的英安斑岩的年龄,其坪年龄为(122.1±0.3)Ma,等时线年龄为(121.8±1.4)Ma.反映义县组顶部层位的形成时期应在122~119Ma.义县组顶部层位年龄的确定,不仅确定了义县组中热河动物群顶部层位(金刚山层)的上限年龄(约122Ma),同时也确定了义县组火山岩形成的上限年龄(118.9±1.4)Ma~(119.8±1.9)Ma.该地区义县组顶部层位的年龄,也是辽西乃至中国东北地区白垩纪大规模岩浆活动结束的年龄.

关 键 词:LA-ICP-MS  年龄  义县组顶部  辽西
文章编号:1000-3657(2005)04-0596-08
收稿时间:2004-05-03
修稿时间:2004-05-032005-09-15

The age of the top of the Yixian Formation in the area western Liaoning, BeipiaoYixian, and its importance
ZHANG Hong,LIU Xiaoming,CHEN Wen,LI YANG Zhitong,FangLin.The age of the top of the Yixian Formation in the area western Liaoning, BeipiaoYixian, and its importance[J].Chinese Geology,2005,32(4):596-603.
Authors:ZHANG Hong  LIU Xiaoming  CHEN Wen  LI YANG Zhitong  FangLin
Institution:ZHANG Hong1,3,LIU Xiao-ming1,CHEN Wen2,LI Zhi-tong3,YANG Fang-Lin3 1.Key Laboratory of Continental Dynamics,Department of Geology,Northwest University,Xi'an 710069,Shaanxi,China,2.Open Laboratory of Isotopic Geology,Chinese Academy of Geological Science,Beijing 100037,China,3.Shenyang Institute of Geology and Mineral Resources,Shenyang 110032,Liaoning,China)
Abstract:Abstract:The top of the Yixian Formation in the area western Liaoning, BeipiaoYixian, the Huanghuashan breccia or rhyolite above the Jingangshan bed of the Yixian Formation. Zircon of the rhyolite sample LAICPMS U-Pb dating gives weighted mean ages of 118.9 ± 1.4119.8 ± 1.9Ma. In addition, dacite porphyry injected into the lower part of the Huanghuashan breccia is dated by us Ing the 40Ar / 39Ar method, which has a plateau age of 122.1 ± 0.3Ma and an isochrone age of 121.8 ± 1.4Ma. These age data suggest that the top of the Yixian Formation in the area formed at BeipiaoYixian 122119 Ma. The determination of the age of the top of the Yixian Formation defines not only the upper age limit (~ 122 Ma) for the Rehe top part of the Yixian Formation Faunabearing (i. E. the Jingangshan bed) but also the upper age limit (- 118.9 ± 1.4Ma119.8 ± 1.9 Ma) of volcanic rocks of the Yixian Formation. The age of the top of the Yixian Formation in the area is also a very important ending age of Cretaceous magmatism in Western Liaoning Largescale and even Northeast China.
Keywords:LA-ICP-MS  age  top of the Yixian Formation  western Liaoning
本文献已被 CNKI 万方数据 等数据库收录!
点击此处可从《中国地质》浏览原始摘要信息
点击此处可从《中国地质》下载免费的PDF全文
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号