Geological characteristics and genesis analysis of Qincaitang graphite deposit in Guangxi
The Qincaitang graphite deposit is discovered for the first crystalline graphite deposit in Guangxi.TQincai-tang graphite ore body is produced in the lithofacies transition zone between the medium-grained hornblende biotite monzonitic granite and the medium-coarse-grained syenogranite in the Huashan composite rock mass.The orebody is in the form of a single vein,and the occurrence position is related to the residual carbonaceous strata in the transition zone of granite lithofacies.The fixed carbon content of the ore is 3.99%-12.37%,with an average of 6.01%.The graphite crystals are mainly microscopic flakes,flakes,flakes and plates,and the maximum sheet diameter can reach up to7 mm,with the crystalline graphite grade.Carbon isotope analysis result shows that δ13CV-PDB of the Qin-caitang graphite deposit is-4.28%o,indicating that the late stage is an inorganic carbon superimposed mineraliza-tion,which can be well correlated with the typical magmatic hydrothermal graphite deposit.The comprehensive study result shows that the formation of Qincaitang graphite deposit is affected by many factors,such as the develop-ment of carbonaceous strata in the mining area,the contact thermal metamorphism of granite intrusion and the trans-formation of magmatic hydrothermal fluid.In particular,the intrusion of the Late Jurassic Huashan rock mass plays a decisive role in the formation of industrial orebodies of graphite.The source of ore-forming materials is mainly or-ganic carbon in the early stage and inorganic carbon superposition in the late stage.The metallogenic process can be divided into two metallogenic stages,Middle Jurassic stage and Late Jurassic stage.The genetic type of the deposit can be defined as a contact metamorphic superimposed magmatic hydrothermal composite genesis crystalline graphite deposit.It can provides the theoretical guidance for the future exploration for crystalline graphite deposit in the Huas-han area of Guangxi.
Qincaitang graphite depositgeological characteristics of depositgenesis analysiscrystalline graphitecarbon isotopeGuangxi