Study For The Micro-Disseminate Gold Deposit, Geological And Metallogenic In Southeastern Yunnan Area

The southeast of Yunnan is located the boundries of Yunnan, Guizhou and Guangxi provinces,Tectonics in the southwest margin of Yangtze Platform and the China fold system occupies a position CALEDONIAN.It's an important area of multi-metallic minerals, ranging from different size of gold deposits (points) distribution, and Guizhou and Guangxi provinces of gold deposits constitute a well-known micro-disseminated gold deposits of the "Golden Triangle" area. In this paper, southern Yunnan region micro-disseminated type gold will be the research object, the typical deposit and mineralization will be the starting point for research, the deposit - Structure - Fluid - forming will be the main line, the studied regional mineralization geological conditions and geological mineralization features, builded the metallogenic model, prospecting indications, and prospecting was predicted. This paper acquired the main research progress, results and conclusions are as follows:1. Discussed in southeast micro-fine disseminated gold mineralization geological background. According to the research,summarized in southeast micro-disseminated gold deposits with multi-age, multi-layer characteristics, which are mainly produced in the last, Paleozoic and Mesozoic, Triassic, the current statistics ORE-BEARING reached more the eight, while the gold and near east-west faults with the existence of a very close link into the health, in other words, nearly east-west extensional faults to become a major gold ore-controlling structure.2. Through the evolutionary history of Yunnan, Guizhou rift study reveals rift development, the migration and precipitation of mineral provides the basis for the space and lithology, as the deep auriferous hydrothermal fluids migrated upward to provide a channeland thermal driving force, but also the deep gold-bearing hydrothermal mineral precipitation to provide an environment and to promote the activation and concentration of trace gold. 3. Analysis of the characteristics of a typical gold deposit, ore body through the characteristics of the structure and composition of mineral ore, rock alteration and other studies, initially revealed the stratum, and the structure, magmatic activity, the relationship between the wall rock alteration, etc. to identify the primary ore and oxide ore geochemical characteristics and variety.4. Based on the southeast Yunnan grained model deposit area geology, mining and geological features, especially mineralization, rock alteration and geochemical characteristics of the detailed study; particularly minerals and fluid into sources are analyzed, the main ore-forming hydrothermal ore-forming fluid composition of the various stages of physical and chemical characteristics and ore-forming conditions and thermodynamic conditions were discussed, the area of micro-fine gold deposit formation mechanism is analyzed to obtain the corresponding results.5. Through research, first proposed in the area of mineralization model, summarized as follows: Devonian to Middle Triassic rift with the development and evolution, as well as deep fault and magmatic activities in the development and mantle uplift, the formation of ore source fluid storage library, gathering a large number of volatile-rich ore fluid elements and activities; the crust of the basement and cover plays a barrier role, so that closed in the upper mantle and lithosphere-forming fluids in the strong state of balance; into the Jurassic After the late Yanshan Ji Luo, strong orogeny, so that the original closed deep faults were revived, and the formation of super deep faults, trigger differentiation of the upper mantle, forming fluid through the crust - mantle boundary into the crust; in strong reducing conditions , due to the joint action of high pressure and steam, the fluid nature of the Au particles were gold migration; with fluid account of the crust, local or part of the crust ingredients into the reaction part of the gold - silicon and Au - S complex formation and migration in a certain range. On the other hand, these three forms of it may move with the fluid, quartz, sulfides and precipitation of clay minerals crystal-induced changes in fluid composition factors such as the role of the natural decomposition of the gold particles, while dispersed adsorption or wrapped in crystal out sulfides and clay minerals, eventually form a micro-disseminated gold deposit.6. Based on many years in southeast Yunnan to find gold or gold mining area known geological, physical and chemical characteristics, or by means of a variety of prospecting, exploration and prospecting methods to implement the results achieved, and of the direct and indirect access to the comprehensive summary of information for mineral exploration, prospecting criteria proposed; the basis of these results, on the southeast Yunnan micro-disseminated gold prospecting forecast, look for gold in the region to provide a geological basis of the actual work has an important role in guiding.