最近在河南灵宝小秦岭地区大湖金矿及其附近的泉家峪含金石英脉中发现了具有工业价值的钼矿化。为了研究小秦岭金矿集中区钼矿的成矿时代,笔者选取大湖金(钼)矿床及泉家峪石英脉型金钼矿体中的辉钼矿进行了Re-Os法同位素定年,在大湖钼金矿石中获得3个辉钼矿样品的Re-Os模式年龄,分别为(223.0±2.8)Ma、(223.7±2.6)Ma和(232.9±2.7)Ma;泉家峪钼金矿石中2个辉钼矿样品的Re-Os模式年龄分别为(129.1±1.6)Ma和(130.8±1.5)Ma。这些年龄数据表明,该区的成矿作用不仅发生于燕山期,而且还发生在印支期。与金堆城、黄龙铺等典型钼矿床不同,大湖和泉家峪矿床中辉钼矿含铼很低,可能表明它们的成矿物质来自壳源。
Molybdenum mineralization with economic value was recently discovered in the Dahu gold deposit and its nearby Quanjiayu gold-bearing quartz veins in the Xiaoqinling gold ore district, Henan Province. For the purpose of studying the chronology of the molybdenum mineralization in this district, the authors purified molybdenite from the Dahu gold deposit and the Quanjiayu gold-bearing quartz veins. Re-Os dating of these molybdenite minerals yielded modal ages of (223.0 ±2.8)Ma, (223.7 ± 2.6)Ma and (232.9 ± 2.7)Ma for the three samples from Dahu and (129.1 ± 1.6)Ma and (130.8 ± 1.5)Ma for the two samples from Quanjiayu. These results indicate that Au-Mo mineralization in the Xiaoqinling gold ore district took place not only at the Yanshanian stage but also at the Indo-Chinese stage. Different from things of Jinduicheng, Huanglongpu and other Mo deposits, the molybdenites from the Dahu and Quanjiayu deposits have a very low content of Re, showing a crustal source for ore-forming materials.