| 藏北美多锑矿带地质地球化学特征及其地球动力学背景探讨 |
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| 关键词:northern Tibet plateau antimony deposit helium and argon isotope collisional orogen post-collision stage |
| 基金项目:国家重点基础研究规划973项目(编号:2001CB409807)，国土资源部定向基金 |
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| Geology and Geochemistry of the Meiduo Antimony Ore Belt in Northern Tibet: Its Origin and Geodynamic Setting |
| The EW-trending Meiduo antimony ore-forming belt,200 km in length and 40 km in width, is distributed along the sou- thern edge of the TanggulaMountains in the northern part of Tibet. More than ten deposits have been founded in this area, of which Meiduo is the largest one. The antimony orebody is hosted in the siliceous rocks of the Tumengela Group and controlled jointly by the NW-andNE-striking faults. The antimony ores are mainly composed of such minerals as stibnite, quartz, opal and calcite. Four types of ores could be identified, namelydisseminated siliceous rocks, stibnite-quartz veins, brecciated siliceous rocks, and stibnite-calcite veins. Isotopic compositions of the sulfur, lead, heliumand argon indicate that the ore-forming fluids were mainly meteoric water, theore metals seemed unlikely to be provided mainly by the wall rocks, and some mantle-derived materials obviously participated in the ore-forming process. The metallogenic age is about 20.2 m.y., suggesting the post-collision stage of the Qinghai-Tibet Cenozoic continent collision orogen. The time-space coupling of theore-forming event with the tectonic-thermal event corresponding to the extensivealkali-rich lavas (30～10 m.y.) and the obvious participation of the mantle-derived materials in the ore-forming process suggest that the formation of the Meiduoantimony ore belt was most probably connected with the upwelling of the rheosphere or mantle diapir and the delaminating of the bottom part of the thickened lithosphere within the orogen since Miocene. |
| YAN Sheng-hao,YU Jin-jie,ZHAO Yi-xin,XU Zhi-zhong,WANG An-jian,TENG Rong-li.2004.Geology and Geochemistry of the Meiduo Antimony Ore Belt in Northern Tibet: Its Origin and Geodynamic Setting[J].Acta Geoscientica Sinica,25(5):541-548. |
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