Stratiform Ore of the Large Lengshuikeng Silver Deposit, China: Mineralogy, Fluid Inclusions, Stable O and C Isotopes

摘要

The composition of minerals from stratiform ores of the Lengshuikeng deposit, China was studied using contemporary techniques. Barite, enargite, and kutnohorite typical of postvolcanic mineralization have been identified for the first time at the studied deposit. The fluid inclusion study shows that the stratiform ore was formed at a temperature of 340-140℃ from homogeneous chloride solution with salinity of 0.2-11.7 wt % NaCl equiv. The O and C isotopic compositions of carbonates from the stratiform ore allowed us to calculate the oxygen isotopic composition of the H2O and the carbon isotopic composition of the CO2 in the ore-forming fluid. The data on ore minerals, fluid inclusions in quartz, and stable O and C isotopes show that two or more fluids derived from different sources could have mixed during formation of the stratiform ores.