地质通报2012，Vol.31Issue(8)：1267-1278,12.
新疆东准噶尔卡拉麦里蛇绿岩的形成和侵位时限——来自辉绿岩和凝灰岩LA-ICP-MS锆石U-Pb年龄的证据
Formation and emplacement age of Karamaili ophiolite: LA-ICP-MS zircon U-Pb age evidence from the diabase and tuff in eastern Junggar, Xinjiang
摘要
Abstract
The Karamaili ophiolite is one of the representative ophiolites in the Central Asian Orogenic Belt (CAOB). The time limits of the opening and closure of the Karamaili oceanic basin remain a key problem due to the lack of high accuracy isotopic ages. The LA-ICP-MS zircon U-Th-Pb dating of diabase in Karamaili ophiolite yielded an age of 416.7±3.2 Ma, recording the generation of the oceanic crust. Sedimentary rocks conformably overlies Karamaili ophiolite. The 343.0±5.0Ma zircon U-Pb age from the tuff overlying the strata constrains the upper limit of the emplacement age of the Karamaili ophiolite and suggests that the sedimentary cover is Early Carboniferous in age. Therefore these ages indicate that the Karamaili oceanic basin was opened in the Lochkovian stage during Early Devonian and closed before the Tourmaisian stage during Late Carboniferous. Accurate constraints on the formation and emplacement age of Karamaili ophiolite provide important constraints for the tectonic evolution of the eastern Junggar Orogenic Belt and the tectonic framework of the CAOB during the Palezoic period.关键词
东准噶尔/卡拉走里蛇绿岩/辉绿岩/凝灰岩/LA-ICP-MS锆石U-Pb年龄Key words
eastern Junggar/ Karamaili ophiolite/ diabase/ tuff/ LA-ICP-MS zircon U-Pb age分类
天文与地球科学引用本文复制引用
黄岗,牛广智,王新录,郭俊,宇峰..新疆东准噶尔卡拉麦里蛇绿岩的形成和侵位时限——来自辉绿岩和凝灰岩LA-ICP-MS锆石U-Pb年龄的证据[J].地质通报,2012,31(8):1267-1278,12.基金项目
中国地质调查局地质矿产调查专项评价项目《阿尔泰成矿带地质矿产调查》(编号:2010010101) （编号:2010010101）
