云南者桑金矿床富金矿石类型与地球化学特征研究

Study on Types and Geochemical Characteristics of Gold-enriched Ore of Zhesang Gold Deposit in Yunnan Province

摘要:

云南富宁者桑金矿床位于我国滇黔桂“金三角”区域，是该区的大型卡林型金矿床之一。为了更为详细地了解卡林型金矿在富金矿石中的赋存状态以及地球化学特征，该文以者桑金矿床中几种不同类型赋金矿石：辉绿岩型矿石、泥质板岩或粉砂岩型矿石、泥灰岩型矿石的载金黄铁矿及毒砂为研究对象，进行矿物特征观察和地球化学特征分析。结果表明：辉绿岩型矿石中，破碎状毒砂、细粒自形毒砂、拉长菱形毒砂的尖端含金性较优；泥质板岩或粉砂岩型矿石中，脉状黄铁矿集合体、粗粒自形五角十二面体含金性较优；泥灰岩型矿石普遍含金，其中细粒菱形毒砂的含金性尤为显著。不同矿石类型中载金矿物的含金性与硅化、炭化、绢云母化等密切相关；黄铁矿w(Fe)、w(S)关系，黄铁矿、毒砂晶形特征以及微量元素Co/Ni 关系，揭示者桑金矿床属中—低温热液成因；AuAs关系表明者桑金矿床金主要是以“不可见”形式的晶格金和纳米金赋存于赋金矿石中。

Abstract:

Zhesang gold deposit in Funing county of Yunnan province is located in the “Golden Triangle” region of Yunnan province, Guizhou province and Guangxi province. It is one of the major Carlin-type gold deposit. In order to understand the occurrence and geochemical characteristics of Carlin-type gold deposits in gold ore in detail, regarding different types of gold-bearing iron ore, such as diabase type ore, argillaceous slate or siltstone ore, marl type ore in Zhesang gold deposit as the research object, observation of mineral characteristics and analysis on mineral and geochemical characteristics have been carried out. It is found that among the diabase type ores, fractured arsenopyrite, fine-grained self-shaped arsenopyrite, elongated rhombic arsenopyrite have superior gold-bearing properties. In argillaceous slate or siltstone-type ores, vein-like pyrites aggregates and coarse-grained self-shaped pentagonal dodecahedrons have good gold-bearing properties. Marlstone-type ores generally contain gold, and fine-grained rhombic arsenopyrites have the best gold-bearing properties. The gold content of gold-bearing minerals in different ore types is closely related to silicification, carbonization, sericitization and carbonation. The relationship between main elements of pyrite. The relationship of w(Fe) and w(S), the crystal form of pyrite, arsenopyrite and the Co/Ni reveals the meso-low temperature hydrothermal genesis of Zhesang gold deposit. The Au-As relationship indicates that the gold in Zhesang gold deposit is mainly in the form of "invisible" lattice gold and nano gold.