PHY SICO-CHEMICAL CHARACTERISTICS OF MINERALIZING FLUIDS AT THE KAMARMEHDI MINE, TABAS REGION, IRAN

The data obtained from field and geothermometric studies and also the REE composition of fluorites associated with lead mineralization at the Kamar-Mehdi mine are compatible with a structurally controlled, fissure filling, epigenetic, hydrothermal origin. Homogenization and last ice melting temperatures for primary fluid inclusions trapped in fluorite crystals indicate that the mineralization of fluorite and the associated (cogenetic ?) lead has taken place over a temperature range of 1 15- 125OC. The mineralizing fluids were dilute and do not show any apparent change in temperature and salinity with depth. Salinities of inclusion fluids range from 0.7 to 3.7 equivalent wt.% NaCl, and Na/Ca atomic ratio of inclusion leachates is low with all leachates containing appreciable amounts of K and Mg. The daughter minerals are mostly Ca, K, Al, Si, C1 phases