Discovery of the Zhegucuo Au (As)-bearing fine granular quartz diorite in the eastern Tethyan Himalayan Belt and its significance
文献类型：期刊论文
| 作者 | Bian, QT; Ding, L |
| 刊名 | ACTA PETROLOGICA SINICA
 |
| 出版日期 | 2006-04-01 |
| 卷号 | 22期号:4页码:977-988 |
| 关键词 | An(As)-bearing Quartz Diorite Porphyry An(As) Deposit High-mg Adakite Geochemistry Tethyan Himalayan Belt |
| ISSN号 | 1000-0569 |
| 文献子类 | Article |
| 英文摘要 | This paper reports newly discovered An (As)-bearing fine granular high-Mg quartz diorites in the Zhegucuo hydrothermal Sb-Au deposit, in the eastern Tethyan Himalayan Belt. The rocks have been mostly altered and disseminated sulfide mineralized, and intruded in the Upper Triassic-Lower Jurassic black shale as veins or apophyses. Many gabbroid veins and few olivine websterite bodies are distributed in the Zhegucuo area. The geochemical characteristics of the An (As) -bearing fine granular high-Mg quartz diorites are similar to high-Mg adakite, such as SiO2 >= 56%, high Al2O3 content (> 15%), high Mg-# (48 similar to 59), high Cr (75 X 10(-6) similar to 130 x 10(-6)) and Ni content (54 X 10(-6) similar to 74 X 10(-6)), rich in large ion lithophile elements (LILE), relatively depleted in high strength field elements (HFSE) and HREE, (La/Yb)(N) > 12, weakly negative Eu anomaly (delta Eu = 0.81 similar to 0.91), relatively high and variable Sr content(209.28 X 10(-6) similar to 685.14 X 10(-6)), low Y and Yb content, Y < 16 X 10(-6), Yb < 1.7 X 10(-6), flat HREE pattern, (Ho/Yb)(N) approximate to 1, relatively high and variable Sr/Y (14.58 similar to 47.28). The Nd-Sr-Pb isotopic characteristics of the Au(As)-bearing fine granular high-Mg quartz diorites are high I-Sr(0.709726 similar to 0.711203), epsilon(Nd) (t) = -3.08 similar to -1.15, Pb-206/Pb-204 = 18.638 similar to 18.672, Pb-207/Pb-204 = 15.694 similar to 15.702, Pb-208/Pb-204 = 38.983 similar to 39.016. Two K-Ar isotopic ages of 42.54 +/- 0.94Ma and 43.21 +/- 1.14Ma for An (As)-bearing fine granular high-Mg quartz diorites have been obtained. The rocks were probably formed by the melting of underplated basaltic lower crust having the same geochemical characteristics as gabbroid occurred in the Zhegocuo area, and source of which was the continental mantle with weakly enriched in EMII matter. In Late Jurassic, a basaltic magma underplating took place in the eastern Tethyan Himalayan Belt. In Eocene (approximate to 43Ma), the thickness of crust in the studied area had been thickened more than 40km due to the collision between India and Asia continents (approximate to 65Ma). A tectonic event induced melting of the underplated basaltic lower crust in that time, by which the magma of An ( As) -bearing fine granular high-Mg quartz diorites was produced. Then the magma moved up and intruded shallow crust, along with the formation of the Au (As) -bearing fine granular high-Mg quartz diorites and the porphyry An (As) deposit. The An (As)-bearing fine granular high-Mg quartz diorites are favorable to An mineralization. It is approximately determined that the rocks contain porphyry-type An (As) mineralized bodies. The discovery indicates that a porphyry-type An (As) mineralized zone probably existed in the eastern Tethyan Himalayan Belt. It is also of significance for understanding tectonics and geodynamics of the Tethyan Himalayan Belt. |
| WOS关键词 | CONTINENTAL-CRUST ; TIBETAN OROGEN ; GENESIS ; EVOLUTION ; ARC ; ANDESITES ; GANGDESE ; PORPHYRY ; ORIGIN ; MAGMAS |
| WOS研究方向 | Geology |
| 语种 | 英语 |
| WOS记录号 | WOS:000238367700021 |
| 出版者 | SCIENCE CHINA PRESS |
| 源URL | [http://ir.iggcas.ac.cn/handle/132A11/66126]  |
| 专题 | 中国科学院地质与地球物理研究所 |
| 通讯作者 | Bian, QT |
| 作者单位 | 1.Chinese Acad Sci, Inst Geol & Geophys, Beijing 100029, Peoples R China 2.Chinese Acad Sci, Inst Tibetan Plateau Res, Beijing 100085, Peoples R China |
| 推荐引用方式 GB/T 7714 | Bian, QT,Ding, L. Discovery of the Zhegucuo Au (As)-bearing fine granular quartz diorite in the eastern Tethyan Himalayan Belt and its significance[J]. ACTA PETROLOGICA SINICA,2006,22(4):977-988. |
| APA | Bian, QT,&Ding, L.(2006).Discovery of the Zhegucuo Au (As)-bearing fine granular quartz diorite in the eastern Tethyan Himalayan Belt and its significance.ACTA PETROLOGICA SINICA,22(4),977-988. |
| MLA | Bian, QT,et al."Discovery of the Zhegucuo Au (As)-bearing fine granular quartz diorite in the eastern Tethyan Himalayan Belt and its significance".ACTA PETROLOGICA SINICA 22.4(2006):977-988. |
入库方式： OAI收割
来源：地质与地球物理研究所
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