• 首页
  • 学报简介
  • 编委会
  • 投稿指南
  • 订阅指南
  • 过刊浏览
  • 在线投稿
  • 联系我们
  • 网络预出版
  • English

本文将参加年度优秀论文评选,如果您觉得这篇文章很好,请投下您宝贵的一票,谢谢! 支持(0)   不支持(0)

张广才岭塔东岩群年代学研究及地质意义
投稿时间:2020-02-10  修订日期:2020-06-05  点此下载全文
引用本文:
DOI:10.19762/j.cnki.dizhixuebao.2020262
摘要点击次数: 172
全文下载次数: 259
作者单位地址
付俊彧 中国地质调查局沈阳地质调查中心 沈阳市黄河北大街280号
孙巍 中国地质调查局沈阳地质调查中心 
杨帆 吉林大学地球科学学院 
那福超 中国地质调查局沈阳地质调查中心 
葛锦涛 中国地质调查局沈阳地质调查中心 
钟辉 中国地质调查局沈阳地质调查中心 
基金项目:中国地质调查局项目:DD20190383, 1212011220435
中文摘要:塔东岩群是一套高绿片岩相-角闪岩相变质岩系,被认为是“松嫩-张广才岭地块”前寒武纪变质基底的一部分,但其形成时代一直没有定论。采用锆石U-Pb(LA-MC-ICP-MS)测试方法,对塔东岩群朱敦店岩组黑云二长片麻岩样品进行年代学研究; 105次测试中104个有效测点年龄介于239~2690Ma。年龄频谱图显示众多年龄组: 2690~2679Ma(n=2)、2509~2304Ma(n=8)、2287~2173Ma(n=5)、1924~1836Ma(n=4)、1428~1352Ma(n=2)、1171~1017Ma(n=3)、997~929Ma(n=12)、922~822Ma(n=40)、812~793Ma(n=14)、745~738Ma(n=2)、279~239Ma(n=8);其中早前寒武纪锆石占~18%、格林威尔造山期锆石占~53%、Rodinia超大陆裂解期锆石占~14%。锆石年龄谐和图反映前寒武纪锆石都有不同程度的Pb丢失,以239~1356Ma、1806~2576Ma两个年龄区段分别进行数据处理,获得前者不一致线下交点为476±84 Ma,后者不一致线下交点1711±210 Ma,可能反映两次重要构造热事件。年龄为晚古生代者,尽管锆石Th/U比值普遍大于0.1显示为岩浆锆石特点,但其复杂的CL图像特征,包括云雾状、流动状、楔状、冷杉叶状环带,并具有规则的外形,表明为后期热事件改造的结果。结合前人研究成果及区域地质建造特征,认为塔东岩群主体形成于新元古代晚期,可能是Rodinia超大陆裂解的响应;经历了~516Ma、~476Ma、~426Ma构造改造事件,可能为早古生代末的构造杂岩,于~260Ma又遭受后期强烈热事件的影响;大量早前寒武纪碎屑锆石的存在支持“松嫩-张广才岭地块”古老基底存在的认识。
中文关键词:塔东岩群  锆石U-Pb  LA-MC-ICP-MS  Rodinia  超大陆裂解  构造杂岩
 
Chronology study and geological significance of Tadong rock group of Zhangguangcailing
Author NameAffiliationAddress
Fu Junyu Shenyang Center of Geological Survey,China Geological Survey 沈阳市黄河北大街280号
Sun Wei Shenyang Center of Geological Survey,China Geological Survey 
Yang Fan College of Earth Sciences,Jilin University 
Na Fuchao Shenyang Center of Geological Survey,China Geological Survey 
Ge Jingtao Shenyang Center of Geological Survey,China Geological Survey 
Zhong Hui Shenyang Center of Geological Survey,China Geological Survey 
Abstract:Tadong group is a set of high greenschist facies - amphibolite facies metamorphic rock series, which is considered to be part of the Precambrian metamorphic basement of “Songnen – Zhangguangcailing block”. But the time of its formation has been uncertain. Using zircon U-Pb (LA-MC-ICP-MS)test method, the study was conducted on the chronology of the biotite monzogneiss of the Zhudundian formation in the Tadong rock group. In 105 tests, 104 effective measurement points were between 239 and 2690Ma. The age spectrum shows many age groups: 2690 ~ 2679Ma ( n = 2), 2509 ~ 2304Ma (n = 8), 2287 ~ 2173Ma ( n = 5), 1924 ~ 1836Ma (n = 4), 1428 ~ 1352Ma (n = 2), 1171 ~ 1017Ma (n = 3), 997 ~ 929Ma (n = 12), 922 ~ 822Ma (n = 40), 812 ~ 793Ma (n = 14), 745 ~ 738Ma ( n = 2), 279 ~ 239Ma (n = 8). Early Precambrian zircons accounted for ~ 18%, Grenville orogenic period zircons accounted for ~ 53%, Rodinia supercontinent cracking stage zircons accounted for ~ 14%. The age concordant of the zircons shows that the Precambrian zircons all lost Pb to varying degrees. Two age segments, 239-1356ma and 1806-2576ma, were respectively processed for data processing, and it was found that the incongruent offline intersection of the former was 476±84 Ma, while the incongruent offline intersection of the latter was 1711±210 Ma, which may reflect two important tectonic thermal events. Zircons of late Paleozoic age are characterized by magmatic zircons whose Th/U ratio is generally greater than 0.1. However, their complex CL image features, including cloud, flow, wedge and fir leaf-like rings, have regular shapes, indicating the result of modification for later thermal events. Based on previous research results and regional geological construction characteristics, it is suggested that the main body of the Tadong rock group was formed in the Neoproterozoic period of ~ 750Ma, which may be a response to the cracking of the Rodinia supercontinent and may have undergone structural transformation events of ~ 516Ma, ~ 476Ma and ~ 426Ma. It may be a structural complex rock at the end of the early Paleozoic period, which was influenced by strong thermal events in the later period of ~ 260Ma. The existence of a large number of early Precambrian detrital zircons supports the understanding of the existence of the ancient basement of the “ Songnen - Zhangguangcailing block ”.
keywords:Tadong rock group  zircon U-Pb  LA-MC-ICP-MS  Rodinia  Supercontinent cracking  structural complex rock
查看全文  查看/发表评论  下载PDF阅读器
您是第37393756位访问者  京ICP备05032737号-7  
版权所有:《地质学报》中文版
主管单位:中国科学技术协会 ; 主办单位:中国地质学会
地  址: 北京市西城区百万庄大街26号; 邮编:100037 ; 电话:010-68312410,010-68999025; E-mail: dizhixuebao@163.com
本系统由北京勤云科技发展有限公司设计 

京公网安备 11010202007916号

WeChat