东秦岭东段新发现的沙坡岭细脉浸染型钼矿地质特征、Re-Os同位素年龄及其地质意义

Geological Features and Re-Os Isotopic Dating of Newly Discovered Shapoling Veinlet-Disseminated Mo Deposit in the Eastern Section of East Qinling Mountains and Its Geological Significance

豫西洛宁沙坡岭钼矿床位于华北克拉通南缘东秦岭钼矿带东段,是新近发现的赋存于太古宇太华群变质岩中的细脉浸染型钼矿床。本文对其地质特征进行了研究,并初步测定了1个辉钼矿样品的Re-Os同位素年龄,获得模式年龄为126.8±1.7Ma,表明沙坡岭钼矿形成于燕山期,接近金堆城、雷门沟钼矿的形成时代,Re同位素含量显示其地幔来源的特征。沙坡岭钼矿形成机制错综复杂,有待进一步研究,特别是深部钻孔工程验证工作,对于验证深部是否隐伏着与成矿相关的斑岩体、储量更大的斑岩型钼矿有着重要作用,找矿潜力巨大。

The Shapolin Mo deposit in Luoning, western Henan Province, is tectonically located at the eastern part of East Qinling molybdenum ore belt in the southern margin of the North China craton. It is a veinlet- disseminated type molybdenite deposit newly discovered in the hypometamorphic rocks of Archean Taihua Group. The research of geological features was carried out in this area. The Re-Os isotopic dating of one quartz vein sample yielded a model age of 126.8±1.7 Ma. This indicates that the Shapoling molybdenum deposit formed mainly in the Yanshanian, the same as Jinduicheng and Leimengou Mo deposits. The content of Re isotope also shows its material mainly derived from upper mantle. Considering the complication of formation mechanism of the Shapoling molybdenum deposit, further research, especially deep drilling, is needed. It is of great significance to verify the existence of deep-concealed porphyry bodies and porphyry-type Mo ore field with large reserves and the potential of prospecting.