Genetic types and ore-forming laws of copper deposits in southwestern Henan Province

The southwestern Henan Province is an important polymetallic mineralization area. To further achieve breakthrough in copper ore exploration in this region, the authors conducted the study based on the typical copper deposits data in the southwestern Henan Province, and the exploration work at typical deposits and mineral occurrences. The mineral sources and ore-forming fluids were compared in this research to explore the different genesis types of the copper deposits in this area and summarize the mineralization laws of the copper deposits in the southwestern Henan Province. The research indicated that copper deposits in the southwestern Henan Province contained three different genetic types. The first one is blocky sulfide type, whose ore bodies are mainly produced in the diabase quartz porphyry series of Erlangping Group, and are controlled by the NWW-trending compressive-torsional fault, ductile shear metamorphic zone and secondary fault zones. The second one is porphyry-skarn type, whose ore bodies are mainly produced in Qinling Group Yanlinggou Formation marble, plagioclase amphibolite gneiss, granite gneiss. The secondary fault zone is a favorable location for ore control and storage, while Yanshanian granite and granite porphyry veins and their surrounding areas are favorable locations for mineralization. The third one is medium low temperature hydrothermal filling type, whose ore bodies are all controlled by structures, and its occurrence is consistent with the tectonic fracture zone. The mineralization time of copper deposits in the southwestern Henan Province is concentrated in Caledonian period and Yanshanian period, with Yanshanina period being the main one. Finally, based on the structure and the ore-controlling patterns of the rock mass, four favorable areas for mineralization were identified. This research could provide references for copper prospecting in the southwestern Henan Province.