Specific features of the fluid regime during the formation of systems with copper-molybdenum-gold and copper-tin mineralizations (Iskra-Soboliny knot, Kavalerovo ore district, Primorye)

摘要

Specific features of the fluid regime in ore-magmatic systems located in the southwestern part of the Kavalerovo ore district (Primorye) are considered. One system is accompanied by mineralization of the porphyry copper type (Lazurnoe deposit); the other system, by tin (copper-tin) mineralization of the hydrothermal type (Iskra deposit). It is shown that the magmatic stages of these systems are distinguished mainly by the chlorophile nature of the copper-gold system and the fluorophile nature of the copper-tin system. The well-known distinction of these systems in terms of the redox parameter is confirmed, and its different evolution scenarios in the systems are shown. The results of the study of fluid inclusions in quartz of postmagmatic associations show that the processes of ore formation at the Lazurnoe deposit were characterized by a wide temperature range and the heterogeneity of the mineral-forming environment. The early period was marked by the coexistence of aqueous-saline brines (mainly of Na-Ca-Mg-chloride composition) and low-density fluid inclusions. The late period was dominated by ordinary hydrothermal solutions. The Iskra deposit formed in a relatively narrow temperature range from homogeneous fluids of essentially Na-chloride composition characterized by moderate and low salinity.