广西芹菜塘晶质石墨矿床成矿特征与成因分析  

Geological characteristics and genesis analysis of Qincaitang graphite deposit in Guangxi

作　　者：韦鹏翔 黄启明 付伟[2] 蒋松林 李赛赛[2] 陈子龙 白晓 WEI Pengxiang;HUANG Qiming;FU Wei;JIANG Songlin;LI Saisai;CHEN Zilong;BAI Xiao(Regional and Geological Survey Institute of Guangxi Zhuang Autonomous Region,Guilin 541003,Guangxi,China;Guilin University of Technology,Guilin 541004,Guangxi,China)

机构地区：[1]广西壮族自治区区域地质调查研究院,广西桂林541003 [2]桂林理工大学,广西桂林541004

出　　处：《矿产与地质》2024年第4期670-677,共8页Mineral Resources and Geology

基　　金：广西自然资源厅科技计划项目“桂东北稀有金属和战略性非金属矿产成矿作用及成矿规律综合研究”(编号:桂自然资函[2020]1639号);广西自然资源厅找矿突破战略行动项目“广西石墨矿资源调查及潜力评价”(编号:桂国土资函[2017]333号);“广西恭城县芹菜塘矿区晶质石墨矿普查”(编号:桂自然资函[2019]594号)共同资助。

摘　　要：芹菜塘石墨矿床是广西发现的首个晶质石墨矿床,该矿体产于花山复式岩体中粒角闪黑云二长花岗岩与中粗粒正长花岗岩之间的岩相过渡带。矿体呈单体脉状,产出位置与花岗岩岩相转折带内残存的炭质地层有关。矿石固定碳含量为3.99%~12.37%,平均6.01%。石墨晶体主要呈显微鳞片状、鳞片状和片状、板状,最大片径可达7 mm,达到晶质石墨品级。碳同位素分析指示,芹菜塘石墨矿的δ^(13)C_(V-PDB)为-4.28‰,表明晚期为无机碳叠加成矿,与典型的岩浆热液成因石墨矿床可进行对比。综合研究结果表明,芹菜塘石墨矿的形成受矿区内炭质地层发育、花岗岩体侵入接触热变质作用以及岩浆热液改造作用的多因素影响,尤其是晚侏罗世花山岩体的侵入对石墨形成工业矿体起到决定性作用。成矿物质来源早期以有机碳为主,晚期出现无机碳叠加。成矿过程可分为中侏罗世和晚侏罗世两个成矿期。该矿床的成因类型可界定接触变质叠加岩浆热液型复合成因晶质石墨矿床,为今后在广西花山地区寻找晶质石墨矿床提供理论指导。The Qincaitang graphite deposit is discovered for the first crystalline graphite deposit in Guangxi.TQincaitang 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 thatδ^(13)C_(V-PDB)of the Qincaitang graphite deposit is-4.28‰,indicating that the late stage is an inorganic carbon superimposed mineralization,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 development of carbonaceous strata in the mining area,the contact thermal metamorphism of granite intrusion and the transformation 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 organic 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 Huashan area of Guangxi.

关 键 词：芹菜塘石墨矿 矿床成矿特征 成因分析 晶质石墨 碳同位素 广西 

分 类 号：P619.25[天文地球—矿床学]