【作者】 王银喜； 顾连兴； 张遵忠； 张开均； 李惠民； 吴昌志； 杨杰东；

【Author】 WANG Yinxi~1,2) GU Lianxing~2,3) ZHANG Zunzhong~2,3) ZHANG Kaijun~3,4) LI Huimin~1,2) WU Changzhi~2,3) YANG Jiedong~1,2)1)Center of Modern Analysis,Nanjing University,Nanjing,Jiangsu,210093; 2)State Key Laboratory of Mineral Deposit Research,Nanjing University,Nanjing,Jiangsu,210093;3)Department of Earth Science,Nanjing University,Nanjing,Jiangsu,210093;4)Guangzhou Institute of Geochemistry,Laboratory of Marginal Sea Geology,Chinese Academy of Sciences,Guangzhou,Guangdong,510640

【机构】 南京大学现代分析中心； 南京大学内生金属矿床成矿作用国家重点实验室；

【摘要】 博格达造山带位于准噶尔和吐鲁番-哈密两个前寒武纪地块之间,是晚古生代的大陆裂谷。经研究,博格达大石头-色皮口地区的流纹岩Rb-Sr 同位素年龄为307.1±1.3 Ma,表明博格达地区火山活动由早石炭世持续到晚石炭世。该年龄可视为博格达裂谷闭合和区域隆什之后造山阶段产物的形成年龄。该区流纹岩其源区物质主要来自于亏损地幔或是由玄武岩浆演化经分离结晶作用形成的流纹岩这一特征是十分罕见的。更多还原

【Abstract】 The Bogda Mountain,with Junggar basin on the north and Turpan-Hami basin on the south,is a part of the East Tian-shan Mountains.The Rb-Sr isotope age and the⁸⁶Sr/⁸⁸Sr ratio of ten rhyolite samples from the Dashitou-Sepigou belt are 307.1±1.3 Ma and 0.703296±32,respectively.The age data indicate that the volcanic activities of Bogda area lasted from Early and Mid-dle Carboniferous to Late Carboniferous,and also imply that the age can be regarded as the age of Bogda rift closure and regional uplift.Sr isotopes of the rhyolites suggest that the volcanic rocks were chiefly derived from the depleted mantle source.Such a character-istic of rhyolites is very rarely seen.更多还原