内蒙古卓资县大苏计钼矿辉钼矿铼-锇同位素定年及其地质意义

The Re-Os Isotopic Dating of Molybdenite from the Dasuji Molybdenum Deposit in Zhuozi County of Inner Mongolia and Its Geological Significance

摘要: 内蒙古卓资县大苏计钼矿是近年来华北陆块北缘中西部地区新发现的斑岩型钼矿床。通过对含辉钼矿石英斑岩中采集的辉钼矿样品进行铼-锇同位素年龄测定，获得铼-锇等时线年龄为(222.5±3.2) Ma，模式年龄变化于（222.1±3.2） Ma～（224.6±3.4） Ma，表明辉钼矿形成时代为晚三叠世。该铼-锇同位素年龄值指示华北陆块北缘存在着印支期成矿地质作用，对在该地区寻找印支期钼多金属矿床具有重要的指导意义。

Abstract: The Dasuji molybdenum deposit in Zhuozi County of Inner Mongolia is a porphyry molybdenum deposit discovered in the northern margin of North China Block in recent years. Through the ReOs dating of molybdenite from quartz porphyry, the isochron age of (222.5±3.2) Ma and the model age of (222.1±3.2) Ma～(224.6±3.4) Ma were obtained, which means molybdenite formed in late Triassic. It also means that the magmatism and mineralization took place in Indosinian in the northern margin of North China Block. This is significant to prospect the Indosinian molybdenum-polymetallic deposits in this area.