The Research On The Geological Characteristics And Mineralization Of Taoxikeng Tungsten Deposit, South JiangXi

The Taoxikeng tungsten deposit is located in the eastern slope ofZhuguangshan-Wanyangshan mineralization belt with S-N trend, in the north-centralpart of Chongyi-Dayu-Shang, the mineralization condition is perfect, and it is easy toform large ore cluster area. Up to2005, proven reserves of tungsten trioxide wereabout60000tons, which has constituted a large-scale tungsten deposit accompaniedby Sn、Cu、Ag、Mo etc., with great research and economic significance. This paper isa summary of characteristics of mineralogy, petrology, deposit, deposit geochemistryand ore-forming mechanism of Taoxikeng tungsten deposit based on former scientificresearch, exploration data, field work and indoor chemical analysis mainly achievedthe following results：1．The genesis of studied deposit belongs to the granite-related hydrothermalvein-type tungsten ore, Magmatic rocks played an important role in the mineralizationprocess. Previous and the present study showed that the concealed rock in the deepdeposit was the same period product to Jiulongnao rock, it was a part of Jiulongnaorock, had a close relationship with the mineralization, and also was the source ofmaterial and energy of the mineralization.2、The ore type of Taoxikeng tungsten deposit was divided into wolframitequartz vein type and greisen type，mainly was wolframite quartz vein type. Accordingto the output characteristics of the ore body, a combination of ore minerals, themineralization is divided into seven stages within two ore-forming period; in space,shows a clear vertical zoning, that is, the upper part is cassiterite-wolframite ore belt,the central part is wolframite-chalcopyrite （molybdenite）, the deep part is wolframite-molybdenite （chalcopyrite）, with the appropriate combination of ore-formingelements from the upper to deep part under the performance of W, Sn�'W and Cu（Mo）�'W, Mo,（Cu）.3．The results of study showed，the wolframite was main tungsten manganeseiron in region，had a certain amount of Nb2O5and Ta2O5，the Nb⁵⁺、Ta⁵⁺and W inwolframite maybe presents the possible incomplete isomorphism replacement；the contents of Nb, Ta in the same veins of different section had a decreasing trend fromdeep to shallow, but the contents had a great change in the same veins of differentsection；The change of Sr、Zr、Sc、Y was alike Nb、Ta，Maybe reflect the migrationof the mineralizing solution was not a simple law changes along the verticaldirection，may exist oblique insertion along the different favorable direction. Rareearth elements analysis results showed that heavy rare earth elements relativelyenriched in minerals such as wolframite，also showed that the orebody output waswith the relevant acidic granitoids，preferential access to the ore-forming melt in therock and ore melt differentiation，but the heavy rare earth elements tend to enrichmentin the ore-forming fluids.4、The studies of the granite, wall rock, ore geochemistry within the mining areashowed that， W, Sn, showed a higher peak in wall rock，illustrated Cambrian andSinian were important source of W, Sn deposits；Buried granite belonging to Kcalc-alkaline series，contents of Ore-forming elements such as W, Sn were more thanthe average of the acid rock，and the content of the ore-forming elements in thegreisen has some increase，Reflected with the evolution of the granitic magma, someminerals in granite enter into the hydrothermal fluid, provideing the material basis forthe mineralization。In the REE chondrite-normalized distribution diagram, Reflectedthe ore and the region buried granite showing light rare earth mild enrichment, withstrong negative Eu anomaly REE patterns, The wall rock of the ore showing light rareearth strongly enriched，With significant negative abnormality of δE, moderate toweak δCe unusual "V"-type distribution pattern；This apparent difference, reflectingthe forming material is not from the surrounding rock of the ore, should be magmaticdifferentiation product.5．Sulfide sulfur isotope studies have shown that the Precipitation of sulfidessulfur source in hydrothermal fluids is single，and H2S accounted for an absoluteadvantage in the ore-forming hydrothermal，or had a unique and narrow range ofphysical and chemical conditions.Sulfur isotope values of pyrite, chalcopyrite andarsenopyrite are near zero，and sulfur value of pyrite represented the total sulfur value of the ore-forming solution，illustrated ore-forming fluids mainly associated withburied granite body. The results of Hydrogen and oxygen isotope composition showedthat：all sample points fell between magmatic water and meteoric water line，reflectingthe hydrothermal characteristics of ore-forming fluids was from the deep magmaticwater，and also the trend of evolution to the precipitation, that there may be a smallamount of atmospheric precipitation in mixed，the main mineralization phase of theore-forming fluid mixing in magmatic water and meteoric water。6．Through the integrated study on geological features, output and standardfeatures of the main ore minerals, ore deposit geochemistry, isotope geochemistry,mineral sources and mineralization, Established deposit evolution model andmetallogenic model, carryed out a comparative study with geological characteristicsand metallogenic mechanism of the important tungsten deposits in the region. Theresults achieved by this study has certain practical guidance for the follow-up mineralexploration.