| 阿拉善北部查干础鲁—霍尔森蛇绿混杂岩带地质地球化学特征 |
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| 引用本文： | 王廷印,王士政,等.阿拉善北部查干础鲁—霍尔森蛇绿混杂岩带地质地球化学特征[J].甘肃地质学报,1993,2(1):46-53. |
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| 作者姓名： | 王廷印 王士政 |
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| 作者单位： | [1]兰州大学地质系，兰州730000 [2]宁夏地矿局区调队，贺兰 |
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| 基金项目： | 国家自然科学基金(9487001) |
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| 摘 要： | 查干础鲁—霍尔森蛇绿混杂岩带(CHOM)位于内蒙古阿拉善北部,它代表了一个消失了的边缘海。CHOM整体上北东东向延伸,由一系列向北逆冲推覆的叠瓦状构造岩片组成。可根据变形和产出特征划分出不同类型的构造岩块和基质。超镁铁质岩MgO/(MgO+FeO)平均比值为0.83,可区分成变质橄榄岩和堆积岩。辉长岩属LREE亏损型,地球化学特征相当于堆积辉长岩。玄武岩主元素特征类似于正常的大洋中脊玄武岩(N—MORB),但微量和稀土元素地球化学特征表明更接近于异常的大洋中脊玄武岩(E-MORB)。沉积于弧后盆地的碎屑岩其物质来源主要是火山弧。本文指出,查干础鲁—霍尔森边缘海是在华北古陆北缘西段破裂的背景上形成的,这个边缘海在晚二叠世—三叠纪初闭合。
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| 关 键 词： | 查干础鲁—霍尔森 混杂岩带 构造岩块 地球化学 |
GEOLOGICAL AND GEOCHEMICAL CHARACTERISTICS OF THE OPHIOLITIC MELANGE ZONE FOR CHAGANCHULU-HUOERSEN, NORTH OF ALAXA |
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| Wang Tingyin Wang Jinrong.GEOLOGICAL AND GEOCHEMICAL CHARACTERISTICS OF THE OPHIOLITIC MELANGE ZONE FOR CHAGANCHULU-HUOERSEN, NORTH OF ALAXA[J].Acta Geologica Gansu,1993,2(1):46-53. |
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| Authors: | Wang Tingyin Wang Jinrong |
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| Institution: | (Shenyang Institute of Geology and Mineral Resources Shenyang 110000) |
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| Abstract: | The ophiolite melange zone of Chaganchulu-Huoersen(CHOM) is located at north of Alaxa,in Nei Monggol, it represents a died marginal sea. The CHOM all extends in north-east-east direction, it is formed of series structural sheets of imbricated overthrusting to north. According to deformation and occurrence may be divided into structural blocks and matrixes of different types.
The average ratio of the MgO/(MgO+FeO* )for ultramafic rocks is 0. 83,they are divided into metamorphic peridotite and accumulative rock. The gabbro is loss for the LREE,it was characterized by the accumulative gabbro.. Character of major elements for basalts is similar to N-MORB,but geochemical character of trace elements and REE show that they was close to E-MORB. The material source of clastic rocks accumulated at retroarc basin mainly is of volcanic arc. This paper has to point out that marginal sea of Chaganchulu-Huoersen had been formed by bursted background at west part of northern margin on northern China ancient continent,and marginal sea had been closed at late Permian-early Triassic e-poch. |
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| Keywords: | Chaganchulu-Huoersen Melange zone Tectonic blocks Geochemistry |
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