内蒙古查干敖包钼矿Re-Os同位素年龄及成矿作用研究

摘要

The Qagan Obao molybdenum deposit was discovered in the northern part of the Langshan Mountain. It is a porphyry muscovite quartz vein type deposit, and the ore-forming rock bodies are mainly K-feldspar granite, fine-grained granite and granite porphyry, with the zircon U-Pb mean age of(53.5 ± 3.3)Ma. Molybdenite 187Re-187Os isochron age of the Qagan Obao molybdenum deposit is(239.2 ± 5.8)Ma, with the rock-forming and ore-forming time difference being about 13 Ma, suggesting that the formation of the Qagan Obo molybdenum deposit experienced a long rock-forming and ore-forming evolution history. The Qagan Obo molybdenum deposit has the characteristics of the porphyry deposit, the ore deposit occurs in the inner contact zone with the country rock, but the mineralization took plade in muscovite quartz veins, mainly related to hydrothermal mineral muscovite. The deposit is therefore a special kind of porphyry molybdenum deposit.%提内蒙古查干敖包钼矿是宝音图钼矿区矿床之一，为狼山北段发现的斑岩白云母石英脉型钼矿,成矿岩体主要为钾长花岗岩、细晶花岗岩和花岗斑岩,岩体锆石U-Pb平均年龄为(253.5±3.3) Ma。本次研究测得查干敖包辉钼矿的187Re-187Os等时线年龄为(239.2±5.8) Ma,与成矿岩体时代相差约13 Ma,反映钼矿床的形成经历了较长的成岩成矿演化历史。查干敖包钼矿床具有斑岩矿床特点,矿床产于成矿岩体内接触带,但是矿化形成于白云母石英脉中,主要与白云母热液矿物有关,因此是一种特殊的斑岩型钼矿床。