秦岭西部地区泥盆系层控铅锌矿带同位素地球化学研究及其成矿物质来源探讨

ISOTOPIC GEOCHEMISTRY AND SOURCES OF THE ORE-FORMING MATERIALS OF THE DEVONIAN STRATABOUND LEAD-ZINC METALLOGENIC BELT IN THE WEST QINLING

系统地研究了秦岭西部地区泥盆系层控铅锌矿带的同位素地球化学特征,结果表明该区矿石硫和铅主要分别取自海水硫酸盐和基底地层,而成矿流体则主要为渗流加热的大气降水.

The Devonian stratabound Pb-Zn metallogenic belt in the west Qinling consists of the Xicheng and Fentai orefields. This paper deals with the isotopic geochemical characteristics of sulfur, lead, carbon, hydrogen and oxygen, through which the following conclusions have been reached: 1) the ore-forming metals in this area are mainly derived from the basement strata and not from the ore-bearing strata (the Middlle Devonian). This view has been corroborated by the systematic studies of the stratigraphic geochemistries; 2) the source of the ore sulfur seems rather complex, as the ore sulfur of the Xicheng ore field is mainly derived from marine sulphate through biogenic reduction, and one of the Fentai orefield is formed by mixture of the reduced sulfur of marine sulphate and the plutonic sulfur which made δ^(34)S values of the ore sulphides more lower; 3) the water of the oreforming fluid of the deposits in the belt is mainly derived from the heated meteoric water and partialy from the recharge sea water.