A study on genesis of the Tayuan Pb-Zn-Cu deposit in the northern Greater Xing'an Range,NE China
The Tayuan Pb-Zn-Cu deposit is located in the northern section of the Great Xing'an Range.In order to explore the ore-forming material sources and mineralization mechanism of the deposit,microthermometry and laser Raman spectroscopy of fluid inclusions hosted in the quartz which is closely associated with sulfides in the deposit,H-O isotopic composition analyses of the quartzs,and in-situ sulfur isotope analyses of sulfides by using the LA-MC-ICPMS have been conducted.The results show that TypeⅠ fluid inclusions have homogenization temperatures ranging from 232℃ to 340℃ and salinities ranging from 1.2%to 16.0%NaCleqv.Type Ⅱ fluid inclusions have homogenization temperatures varying from 355℃ to 418℃,and salinities varying from 2.6%to 11.6%NaCleqv.The laser Raman spectroscopy results show that the gas and liquid components in those two types of fluid inclusions are mainly H2O,with the bubble of some Type Ⅱ inclusions containing a small amount of CO2.The δ34S values of sulfides vary from+0.3‰ to+3.1 ‰.The δ18O和δD values of quartzs vary from+5.4‰ to+10.5 ‰ and from-97‰ to-102 ‰,respectively.Combined with the comprehensive study of geological and geochemical characteristics of the area,it is suggested that the Tayuan deposit is genetically related to the Yanshanian intrusive rocks.The metal-rich magmatic hydrothermal fluid,which was exsolved from the magma of Yanshanian intrusive rocks,migrated along the NE-NEE-and EW-trending bedded faults,had extensive metasomatic alteration with wallrocks,and mixed with meteoric water.These caused changes of physical and chemical conditions of the hydrothermal fluid,resulting in the precipitation of sulfides.
S-H-O isotopesfluid inclusionore genesisTayuanGreater Xing'an Range