On Geological Features And Genesis Study Of The Wangxia Gold Deposit In Changjiang Area Hainan Province

The Wangxiaya gold deposit in the Changjiang area is tectonically located at the boundarybetween the Wuzhishan fold zone of South China fold system, the Baisha depression zone and theBaoban doming area. It is middle-low temperature epithermal deposit and gold-bearingcalcite-quartz compound lodes mainly occur in the Permian strata. On the basis of the theoreticalknowledge of economic geology and mineralogy and the methods of petrology, petrochemistryand geochemistry, the geological characteristics and mineralization genesis of the Wangxiaya golddeposit was discussed in detail in this study.Trace and mineralization elements: the Permian strata enriched in gold and mafic and quartzdikes related to post-magmatic hydrothermal fluid exhibit higher gold contents than average valuesin the crust, indicating that the gold mineralization is directly related to post-magmatichydrothermal fluid of the Bawangling super-unit granites on the northern part of the Wangxiayagold deposit.Rare earth elemelts: many typical parameters suggest that the pluton were generated byperfect fractional crystallization processes, which provided the favorable condition for theformation of gold-bearing hydrothermal fluid.Isotope geochemistry: sulfur isotope compositions in the deposit are closed to those ofmeteorolite, indicating that they are primitive and the fractionation of sulfur isotope did not tookplace; the ratios of lead isotope suggests that the gold mineralization in the Wangxiaya area wasrelated to magma.On the basis of data of inclusions and their gas-liquid phases, the physical chemistryconditions for the formation of the Wangxiaya gold deposit are discussed in detail.In summary, the metallogenetic material of the Wangxiaya gold deposit was derived from thePermian strata and post-magmatic hydrothermal fluid, the metallogenesis was constrained by the emplacement of the Bawangling granite, and the mineralization was controlled by the Yalao fault.All gold lodes occur the fragmentation zone of the Yalao fault, the surrounding rocks exhibitepithermal alteration of pyrite sericitolite consisting of middle-low temperature epithermalminerals, e.g., quartz, calcite, sericite, pyrite, arsenopyrite etc. The Wangxiaya gold depositbelongs to the metallogenesis type of middle-low temperature epithermal calcite-quartzcompound lodes filling along the interbedded fragmentation fracture.