| 西昆仑于田南部阿羌蛇绿构造混杂岩地质特征及意义 |
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| 引用本文： | 曹福根,冯红刚.西昆仑于田南部阿羌蛇绿构造混杂岩地质特征及意义[J].西北地质,2022(1). |
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| 作者姓名： | 曹福根 冯红刚 |
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| 作者单位： | 新疆地矿局第一区域地质调查大队 |
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| 基金项目： | 中国地质调查局项目“新疆西昆仑1∶5万J44E021018、J44E022017、J44E022018、J44E023017、J44E023018五幅区域地质调查”(1212011220634)。 |
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| 摘 要： | 近年的区调工作在西昆仑于田南部阿羌一带新填绘出一套具有蛇绿岩特征的变质橄榄岩、蛇纹岩、变辉长岩、辉绿岩和玄武岩等岩石组合。其中,变质橄榄岩、蛇纹岩具有低SiO2、高MgO、低稀土特征;辉长岩、辉绿岩和玄武岩绝大多数样品岩石化学具有低K2O<1%,TiO2含量为1.5%等特征;稀土元素及微量元素特征与N-MORB及E-MORB相似。综合分析认为,该蛇绿岩产于较大规模的洋盆中,属于地幔柱型(P型)蛇绿岩;辉长岩、玄武岩中2件锆石U-Pb SHRIMP定年样品加权平均年龄为(545.5±9.1)Ma和(440.0±4.8)Ma,结合其他证据,证实其形成时代为寒武—奥陶纪,与西邻区其曼于特蛇绿构造混杂岩同为昆中和昆北微地块早古生代洋陆转换事件的地质记录,对研究西昆仑构造演化具有重要意义。
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| 关 键 词： | 蛇绿构造混杂岩 寒武—奥陶纪 地幔柱型(P型) 阿羌 |
Geological and Tectonic Significance of Aqiang Ophiolitic Tectonic Melange in Southern Yutian,West Kunlun |
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| CAO Fugen,FENG Honggang.Geological and Tectonic Significance of Aqiang Ophiolitic Tectonic Melange in Southern Yutian,West Kunlun[J].Northwestern Geology,2022(1). |
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| Authors: | CAO Fugen FENG Honggang |
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| Institution: | (No.1 Regional Geological Survey Team, Bureau of Geology and Mineral Resources, Urumqi 830013, Xinjiang, China) |
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| Abstract: | In recent years,a set of metamorphic peridotite,serpentinite,metagabbro,diabase,basalt and other rock assemblages with ophiolite characteristics have been newly mapped in Aqiang of Southern Yutian,West Kunlun.Among them,the metamorphic peridotite and serpentine have the characteristics of low SiO2,high MgO and low REE.Most samples of gabbro,diabase and basalt are characterized by low K2O<1%and TiO2≈1.5%.The characteristics of rare earth elements and trace elements are similar to those of N-MORB and E-MORB.Comprehensive analysis shows that the ophiolite occurs in a large-scale ocean basin and belongs to mantle plume(P)origin.The average weighted ages of the dating samples are(545.5±9.1)Ma and(440.0±4.8)Ma,which confirm that the formation age is in Cambrian-Ordovician.The Qimanyute ophiolite melange in the adjacent western area is also the geological records of the Early Paleozoic ocean-continent transition events in the central and northern Kunlun block.The study is of great significance to the tectonic evolution of the west Kunlun. |
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| Keywords: | ophiolitic tectonic melange Cambrian-Ordovician mantle plume(P)origin Aqiang |
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