摘要
在1/5万内蒙古东乌旗狠麦温都尔地区的矿产远景调查工作中,首次按照岩性组合的差异,将宝力高庙组划分出以安山岩、安山质火山碎屑岩夹砂砾岩为主和以酸性火山岩-火山碎屑岩、炭质板岩、河流相砂砾岩为主的上、下段。在其中分别采集地层中的流纹岩、英安质晶屑凝灰岩和安山岩夹层样品,挑选其中的锆石进行U-Pb SHRIMP同位素测年,分别获得了上段303.4±6.7 Ma、304.9±3.1 Ma和下段320.1±7.2 Ma的年龄信息,地层时代为晚石炭世。该成果对研究古亚洲洋的闭合和晚华力西期成矿地质背景均具有十分重要的意义。
During the 1：50 000 mineral resource prospect investigation in the Mahonondor area of East Ujimqin Qi,Inner Mongolia,the authors firstly divided the Baoligaomiao Formation into two rock unite members： the lower member is made of the andesites,andesitic volcaniclastices and sandstone-conglomerates,and the upper member consists of the rhyolites,dacitic tuff,carbonaceous slate and the fluvial deposit sandstone-conglomerates.In this study,zircons were chosen from the andesite,rhyolites and dacitic tuff to analyse their U-Pb isotope.Their SHRIMP ages are 303.4±6.7 Ma,304.9±3.1 Ma in the upper member and 320.1±7.2 Ma in the lower member,which means they formed in late Carboniferous Period.This conclusion has a very important significance for studying the Paleo-Asian Ocean and ore-forming geological background in late Hercynian.
出处
《地质调查与研究》
2011年第1期1-9,共9页
Geological Survey and Research
基金
国家地质大调查:1/5万内蒙古东乌旗狠麦温都尔地区矿产远景调查(基[2010]矿评01-09-15和矿调[2006]11-5)
关键词
宝力高庙组
古亚洲洋
SHRIMP年龄
晚石炭世
Baoligaomiao Fm
the Paleo-Asian ocean
zircon SHRIMP U-Pb age
upper carboniferous
