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

Abstract

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 oc-curred 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 elements. Additionally, a brief summary of the geological evolution process of the deposit was provided, offering references for future work in the Guanshan Copper deposit.