胶东金矿金成色及其指示意义

THE FINENESS OF NATIVE GOLD AND ITS INDICATIVE SIGNIFICANCE IN JIAODONG GOLD MINES

影响金成色的因素较多，包括矿床成因类型、形成深度、变质程度、成矿时代、成矿温度和矿化阶段等，其中金矿床形成深度是最关键的因素。矿床形成深度大，成矿的物化参数变化慢，形成的金成色高；形成深度小，成矿的物化参数变化快，形成的金成色低。以胶东金矿为例，统计并定性分析了这种关系，证明胶东金矿区存在类似的规律，据此可以推广，以矿床金的成色来判断矿床的形成深度和矿体的延深情况。胶东金矿金成色较低，以５５０～７５０居多，反映了金矿成矿以中浅成为主。南张家金矿金成色最低，暗示其形成深度最浅（小于１．５ｋｍ）。

The fineness of native gold is influenced by many factors, such as genetic type, formation depth, the degree of metamorphism, mineralizing temperature and stages etc. Of all the factors, the formation depth of gold deposit is the most important. If a gold deposit formed in a very deep place, the physical and chemical parameter would changed slowly, and then produced native gold with high fineness, on the contrary, the fineness of gold would be low. Taking the gold mines in Jiaodong as example, the authors analyzed the relation between fineness of native gold and the formation depth and the similar rules was discovered in gold mines of Jiaodong. With the help of this rule, it would be more efficient to determine the situation of mineralization extention and the formation depth of gold mine. Generally the fineness of native gold averages 550￣750, which suggests that the gold mines are middle or shallowed seated, specially the fineness of gold in Nanzhangjia gold mine is the lowest, which means it formed in a shallowest place (<1 5 km).