摘要
对甘肃北山地区芨芨台子蛇绿岩组成单元中辉长岩进行LA-ICP-MS锆石U-Pb年龄测定,结果表明,芨芨台子蛇绿岩形成于321.2Ma±3.7Ma,相当于早石炭世;结合近年来对其东部小黄山蛇绿岩的测年结果,认为芨芨台子-小黄山蛇绿岩带形成于早石炭世。它们是北山早古生代洋盆俯冲消减和碰撞造山后裂谷拉伸的产物。
LA-ICP-MS zircon U-Pb dating of gabbro from Jijitaizi ophiolite in Beishan area of Gansu Province shows that Jijitaizi ophiolite was formed at 340.3Ma＋3Ma. In combination with the dating of Xiaohuangshan in eastern Jijitaizi, the authors consider that the Jijitaizi-Xiaohuangshan ophiolite belt was formed in Early Carboniferous. The Jijitaizi-Xiaohuangshan ophiolite belt represented the subduction of early Paleozoic ocean basin. It is therefore held that the Jijitaizi-Xiaohuangshan ophiolite belt resulted from colli- sional orogeny and rift extension.
出处
《地质通报》
CAS
CSCD
北大核心
2012年第12期2025-2031,共7页
Geological Bulletin of China
基金
中国地质调查局地质调查项目<北山-祁连成矿带地质矿产综合研究>(编号:1212011085077)
<亚洲构造演化过程中几个关键时段火山岩研究>(编号:1212011120133)
<北祁连成矿带成矿条件研究与找矿靶区优选>(编号:1212010818090)
