Fluid Inclusion Petrography and Microthermometry of Zn and Pb Deposits of Rajpura-Dariba Bethumni Belt, Udaipur District (Rajasthan), India

Abstract

The Proterozoic Aravalli-Delhi orogenic complex hosts a large number of economically important stratabound base metal sulphide deposits. In the present work, rock samples taken from Outcrop and Underground Mine of Sindeskar Kalan, Vedanta Group, Rajpura Dariba-Bethumni Belt which is located at a distance of 76 kms from Udaipur city, Rajasthan have been studied. The chief litho units of the group which contain sulfide-bearing calc-silicate and graphite mica schist, dolomite marble, calc-biotite schist and quartzite are identified. An attempt has also been made to study/or hydrothermal in origin in the different types of fluid inclusions, hosted predominately in Geothermometry viz. heating and freezing study of entrapped palaeo-fluids (such as sedimentary and quartz host grain and a few in sphalerites). The quartz hosts are identified with four types of fluid inclusions, such as 1) monophase (gas/vapour), 2) gas-rich biphase, 3) liquid-rich biphase and 4) polyphase types. The primary types of fluid inclusions show that melting temperature of ice or depression freezing point (DFP) (ranging from -2.5 ° C to -7.2 ° C)/(salinity ranging from 4.5 - 13.25 wt% NaCl eq.) and temperature of homogenization into liquid phase (ranging from +188 ° C to +218 ° C) have been measured. Data from the fluid inclusions and salinity calculation (low salinity) reveal that rate of cooling is the important mechanism of ore deposition in the study area.