江苏观山铜矿III、VII和VIII矿脉矿化金属元素特征和成因  

Characteristics and Genesis of Mineralized Metal Elements in the III, VII, and VIII Ore Veins of Guanshan Copper Deposit, Jiangsu

作　　者：谢晓华 

机构地区：[1]江苏华东有色深部地质勘查有限责任公司,江苏 南京 [2]江苏省有色金属华东地质勘查局八一三队,江苏 南京

出　　处：《地球科学前沿（汉斯）》2023年第11期1252-1267,共16页Advances in Geosciences

摘　　要：江苏观山铜矿位于下扬子板块北缘沿江坳陷带内的溧水火山岩盆地大王山组地层中,III、VII和VIII矿脉产于观山铜矿西北角的粗安斑岩和角闪粗安斑岩中。为了查明三条矿脉矿化金属元素空间分布特征和共生关系,对主要成矿元素Cu、Au、Ag、Pb和Zn做了数学统计分析。在矿化金属元素丰度分析中,Cu在探槽样(TC) (2050 ppm)分别低于拨土样(BT) (2458 ppm)和钻孔样(ZK) (10,300 ppm);Ag在拨土样(BT) (7.25 ppm)低于钻孔样(ZK) (22.6 ppm);Au在拨土样(BT) (0.269 ppm)和钻孔样(ZK) (0.252 ppm)中相当;从拨土样(BT) (30.96 ppm)到钻孔样(ZK) (2332 ppm),Pb呈现逐渐富集;Zn在探槽样(TC) (327 ppm)和钻孔样(ZK) (346 ppm)类似。在矿化金属元素线性拟合中,Cu和Au在探槽样(TC)决定系数最高(0.754),线性拟合优度最好,Cu和Ag在拨土样(BT)决定系数为0.547,线性拟合优度次之,Cu和Pb、Zn决定系数分别低于0.5,线性拟合优度最差,无明显线性关系。通过对矿床地质年代学和同位素地球化学数据分析,显示该矿床形成于白垩纪早期(K1),成矿物质主要来自上地幔和下地壳,岩浆热液经过后期大气水的混合,在偏碱性、中低温度条件下成矿。通过以上对观山铜矿床内部III、VII和VIII矿脉主要矿化金属元素分析,阐明了主要矿化金属元素空间分布特征和共生关系,并对矿床演化地质过程进行简要概述,为后期在观山铜矿开展工作提供参考意见。Jiangsu Guanshan copper deposit, located in the Dawangshan Formation strata of Lishui volcanic basin in the Yanjiang depression zone on the northern edge of the lower Yangtze plate. III, VII and VIII ore veins occur in coarse andesite porphyry and hornblende coarse andesite porphyry in the Northwest Angle of Guanshan Copper Mine. In order to identify the distribution characteristics and co-exist of mineralized metal elements in three ore veins, it is based on mathematical statistical analysis of major ore-forming metal elements Cu, Au, Ag, Pb and Zn in three ore vein regions. The abundance of Cu in the trench sample (TC) (2050 ppm) is lower than that in the soil sample (BT) (2458 ppm) and the abundance of Cu in the borehole sample (ZK) (10,300 ppm);the abundance of Ag in BT (7.25 ppm) is lower than that in ZK (22.6 ppm);the abundance of Au in BT (0.269 ppm) is equivalent in ZK (0.252 ppm);Pb gradually enriched from BT (30.96 ppm) to ZK (2332 ppm);Zn has similar characteristics in TC (327 ppm) and ZK (346 ppm). In the analysis of the linear fitting of mineralized metal elements, Cu and Au have the highest determination coefficients (0.754) in the TC. The coefficient of determination for Cu and Ag in BT is 0.547. The determination coefficients for Cu, Pb, and Zn are all below 0.5, indicating a poor linear fit and no significant linear relationship. Based on the results from research and analysis of geological chronology and isotope geochemistry data of the deposit, it is indicated that the formation of this deposit occurred during the Early Cretaceous (K1) period. The ore-forming materials mainly originated from the upper mantle and lower crust. The mineralization took place under alkaline, medium to low-temperature conditions when magmatic hydrothermal fluids mixed with later atmospheric water. By analyzing the major ore-forming metal elements in internal veins III, VII, and VIII of the Guanshan Copper deposit, this study elucidated the spatial distribution characteristics and coexistence relationships of these el

关 键 词：观山铜矿 III、VII和VIII矿脉 铜 矿化元素 丰度 线性拟合 成因 

分 类 号：R28[医药卫生—中药学]