| 任 涛.贵州水银洞金矿的几点新认识[J].地质与勘探,2013,49(2):217-223 |
| 贵州水银洞金矿的几点新认识 |
| Some New Grasp of the Shuiyindong Gold Deposit in Guizhou Province |
| 投稿时间：2012-05-07 修订日期：2012-10-24 |
| DOI： |
| 中文关键词: 卡林型金矿 黄铁矿 水银洞 贵州 |
| 英文关键词: Shuiyindong, Carlin-type gold deposit, pyrite, Guizhou |
| 基金项目:本文为国家自然科学基金项目（编号 41203039）和昆明理工大学成矿动力学及隐伏矿预测创新团队（2008）联合资助的成果 |
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| 中文摘要: |
| [摘 要]水银洞金矿是滇黔桂“金三角”已知最富的、特大型卡林型金矿床，矿体赋存于二叠统龙潭组的大孔隙度生物碎屑灰岩中。镜下观察发现水银洞金矿含有五种不同类型的黄铁矿：草莓状黄铁矿、细粒黄铁矿、粗粒黄铁矿、生物状黄铁矿和长条状黄铁矿。草莓状黄铁矿为沉积成因，与金矿化关系不大；细粒黄铁矿、生物状黄铁矿和条带状黄铁矿为热液型黄铁矿；而粗粒黄铁矿由沉积型和热液型黄铁矿共同组成，内核为沉积型黄铁矿(Py1)，被外带的热液型黄铁矿包裹(Py2)，成环带构造。电子探针波谱分析发现该矿床中Au主要赋存于热液黄铁矿（含砷黄铁矿）中。本研究从新的视角分析了黄铁矿形成和含金硫化物分解的相互制约，吸附作用，电化学作用可能是卡林型金矿床中金沉淀的主要机制。 |
| 英文摘要: |
| Abstract: The Shuiyindong gold mine is one of the largest and richest Carlin-type deposit in the Yunnan-Guizhou-Guangxi “gold triangle” area, whose orebodies occur in the high-porosity bioclastic limestone of the Permian Longtan Fm.. Microscope observations see five kinds of pyrites: framboidal, fine-grained, coarse-grained, bioelastic and banding ones. The framboidal pyrite is of sedimentary genesis, little related with the gold mineralization. The fine-grained, bioclastic and banding pyrites are of hydrothermal genesis, while the coarse-grained pyrite is of sedimentary and hydrothermal genesis. The coarse-grained euhedral pyrite has a sedimentary-type core that is enclosed by the hydrothermal arsenic pyrite. The backscattered images show that the gold mainly occurs in the hydrothermal arsenic-rich pyrite. The distribution of pyrites and gold-bearing sulfide suggests that adsorption and electrochemical processes are the possible mechanism for the formation of the Carlin-type gold deposits. characteristics and lateral facies distribution of more than ten typical Cambrian profiles in the upper Yangtze region, the lithofacies palaeogeography of the Qingxudong epoch, Duyun stage, Cambrian Period has been studied with the isochronal dominant facies method and a stratigraphic map is prepared. The paleogeography in the study area is characterized by high in the west and low in the east, deep water in the south and shallow water in the north. The sediments overlapped from NW to SE, and exhibit diachrononism with increasing depth. The differences of the lithology, thickness, color and sedimentary facies are due to the sedimentary facies change and diachrononism. Vertically, the stratigraphic succession from the dolomite member and the limestone member of the Qingxudong Formation makes up of a large-scale upward-shoaling sedimentary facies succession and demonstrates a growth process of a ramp carbonate platform. Horizontally, the principal lithofacies palaeogeographic units in the upper Yangtze region, i.e., carbonate tidal flat, shallow ramp facies, middle ramp facies, deep ramp facies, shallow shelf facie, and deep shelf facies as well as basin facies from the northern to the southern have been described. The lithofacies palaeography exerts a key control on the stratabound-type lead-zinc deposits, which are distributed in the middle- and shallow ramp facies of the restricted platform, and the assemblage making up of turbidite and micrite mounds (algal bioherm) and rudstone is a well developed succession for lead-zinc deposits. |
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