Analysis On Metallogenic Model About Xiaosanjiaotan Ore Districts In Chuankou Tungsten Orefield, Hunan Province

There is a large-scale tungsten orefield in terrain Chuakou, South China. It is characteristic of excellent metallogenic condition, large scale, high grade and convenience to mining. In which, the Xiaosanjiaotan tungsten deposit is the poly-metal type containing scheelite and wolframite. The genetic type belongs to post- magmatic metasomatic-filling- type large-vein tungsten deposit.Based on the analysis of the results of the other geologists, the effective field geological survey has been done, such as collecting plenty geological information, sampling all kinds of rocks and minerals. Apart from analyzing regional metallogenic background and stress development as well as putting multi-theories and methods into practice, the characteristics of strata, structure and magmatite has been deeply discussed. And the relationship between mineralization and strata, structure and magnetite has been intensively analyzed. In order to conclude the metallogenic rule and factors of Xiaosanjiaotan tungsten deposit, some gas-liquid components are analyzed, some specimens of exploration geochemistry are systematically sampled and all of the metallogenic conditions are fully discussed.From above, a distinct geological metallogenic period is carried out in the thesis, which differs from traditional description of tungsten deposit. Then the most important conclusion is deduced, which is the metallogenic model of Xiaosanjiaotan deposit:During the stretching process in Early Yanshanian, attenuation and decompression of the crust happened, and then deep strata were remelted. And the "Chuankou Uplift" was a channel and a space for granite (mother rock) intruding, and the lift also molded axis-like shape of granite. There were so many magma ore-bearing fluid mixed with mineral of extraction of strata, because the process of magma intrusion accompanying its differentiation. Because of cooling and shrinking of magma, a series of spaces of dilatanacy and cross (tension) joints were created, which provide spaces for reservoir ore. And compact slate was the barrier screen to the ore-bearing fluid, which resulted in the fluid flowed from the top down and produced a series of metasomatic-filling mineralization in the cross joints. With the accumulation of fluid bit by bit, the splitting by ore-bearing fluid was happened, and then the large-shape tungsten deposit was created.