| 东天山前寒武纪基底若干问题的讨论 |
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| 引用本文： | 李铨,于海峰,修群业.东天山前寒武纪基底若干问题的讨论[J].新疆地质,2002,20(4):346-351. |
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| 作者姓名： | 李铨 于海峰 修群业 |
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| 作者单位： | 中国地质调查局天津地质矿产研究所,天津,300170 |
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| 基金项目： | 中国地质调查局国土资源调查大调查项目(DK9902043)资助 |
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| 摘 要： | 东天山前寒武纪基底由星星峡群和卡瓦布拉克群组成。通过其物质组成、同位素年龄资料并与邻区－库鲁克塔格和甘肃北山前寒武纪基底对比，提出东天山前寒武纪基底是由已变质的深成岩侵入体（包括奥长花岗岩等）和表壳岩组成，与库鲁克塔格和甘肃北山前寒武纪基底有着显著差别，绝不是同一地质环境的产物。年龄数据显示它有晚太古代和早元古代的成分，其岩石组合反映具有早前寒武纪结晶基底特征，应暂将其置于一个单独的大地构造单元，建议将星星峡群和卡瓦布拉克群暂分别称为星星峡杂岩和卡瓦布拉克岩群。
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| 关 键 词： | 东天山地区 前寒武纪 大地构造单元 岩石组合 同位素年龄 地质环境 |
| 文章编号： | 1000-8845(2002)04-346-06 |
| 修稿时间： | 2002年4月15日 |
ON PRECAMBRIAN BASEMENT OF THE EASTERN TIANSHAN MOUNTAINS, XINJIANG |
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| LI Quan,YU Hai-feng,XIU Qun-ye.ON PRECAMBRIAN BASEMENT OF THE EASTERN TIANSHAN MOUNTAINS, XINJIANG[J].Xinjiang Geology,2002,20(4):346-351. |
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| Authors: | LI Quan YU Hai-feng XIU Qun-ye |
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| Abstract: | The Precambrian basement in the eastern Tianshan mountains (PBETM) is located in a narrow belt trending E-W from Dikaner to Xingxingxia. It consists of Xingxingxia Group and Kawatiulak Group with lithotectonic assemblages metamorphosed to greenschist facies and amphibolite fades, including numerous metamorphic plutonic intrusions and some supra-crustal rocks. Its tectonic setting has been hotly debated. Currently we consider that it belongs to an individual tectonic unit formed in a rift or rift zone with early Precambrian crystalline features which are inferred from isotopic ages of Archean and early Proterozoic. PBETM obviously differs from its adjacent Precambrian basements at Kuruktag in northern Tarim Block and at Beishan in Gansu province. The latter two belong to Changcheng System and Jixian System, and formed in different tectonic settings by comparison with their lithotectonic assemblages, isotopic ages and crustal evolutions. Therefore, PBETM was not a massif separated from Kuruktag Precambrian block. Two units, named as Xingxingxia complex and Kawabulak Group complex are further divided according to its lithotectonic assemblages. |
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| Keywords: | eastern Tianshan mountains Precambrian basement tectonic unit lithotectonic assemblage isotopic age |
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