Research On Metallization Of The Dahutang Tungsten Multimetal Field, JiangXi Province, China

Dahutang tungsten deposit is located at the junction of Wuning, Xiushui, Jing’an county in the northwest Jiangxi province and lies in the Mesozoic copper molybdenum gold silver lead-zinc metallogenic belt of Jiangnan block in the lower Yangtze metallogenic province. It formed by the Yanshanian granite rock intruding into the granodiorite batholith in Jinningian (2.64 km2). The mineralization was found related to the Yanshanian granite. The proved reserves of WO3, copper, molybdenum, tin, silver in Dahutang tungsten deposit respectively is 1.1 million tons,650,000 tons, 50,000 tons,30,000 tons and 1,135 tons, shows it is one of the world’s largest tungsten deposits. There are three types mineralization type in this deposit, namely, disperse disseminated type, hydrothermal cryptoexplosion breccia type, quartz vein type. The main ore minerals are wolframite and scheelite, chalcopyrite and molybdenite, main gangue minerals are quartz-feldspar-albite-biotite-muscovite。Based on previous researches, the present study selected the magmatite related to metallogenesis of Shimen Temple ore district in Dahutang tungsten deposit as the key object, through systematic field geological survey, lithogeochemical and geochemistry research, systematically studied the large-scale magmatism, mineralization, genesis of metallic mineral deposit and the process of mineralization, at the same time obtained some new cognitions and achievements, confirmed that the metallogenic geological body related to scattered disseminated type ore body was Yanshanian biotite granite, related to the hydrothermal cryptoexplosion breccia type ore body was granite porphyry in Dahutang Shimen Temple mining area. The magmatic rocks related to mineralization in Dahutang Shimen Temlpe ore area included Jinningian biotite granodiorite, Yanshanian porphyritic biotite granite, fine-grained two-mica granite, granite-porphyry, muscovite granite. System dating (LA-ICP-MS zircon U-Pb) showed that the age of granodiorite was 835.6±1.5 Ma, the crystallization time of Yanshanian biotite granite, granite porphyry were almost the same, focused on 146 Ma±, indicated all of them were the product of magmatic differentiation in same period. Geochemical studies also showed that the Shimen Temple ore district in the Dahutang Tungsten deposit was S-type granites, it occurred different degrees of differentiation crystallization in the process of the formation, and the original rock mainly formed by the crust partial melting.Systematic geological and geochemistry study showed the typical granite-associated deposit features in different stages of the Dahutang tungsten deposit metallogenic systems. Systematic research of S and Pb isotope and trace analysis of rare earth of pegmatite shell also provided strong support for this understanding from another point of view. Re-Os dating methods of molybdenite indicated that the mineralization of Dahutang ore district occurred in the late Yanshanian.On the basis of the metallogenic geological body, metallogenic tectonic and metallogenic structural surface, characteristic symbol study, this article initially established a "geological prospecting prediction model" of Dahutang tungsten deposits and pointed out the direction for further ore prospecting.