山东昆嵛山岩体中与细粒花岗岩有关的新类型金矿床地质特征及找矿方向——以下卧龙矿床为例

Geological Characteristics and Ore Prospecting Direction of A New Type Gold Deposit Hosted In Fine-grained Granite in Kunyushan Area in Shandong Province—Setting Xiawolong Gold Depostit as an Example

摘要:

昆嵛山地区位于胶东半岛东部牟平断裂和米山断裂之间，是苏鲁超高压变质带和华北克拉通两大不同地块的过渡地带。下卧龙金矿床位于昆嵛山地区东侧、米山断裂以西。矿体严格受细粒花岗岩脉控制，呈脉状产出，产状与其基本一致，围岩为玲珑序列郭家店单元。矿石类型为绿帘石化黄铁矿化黑云二长花岗岩，矿石矿物主要为黄铁矿，其次为磁黄铁矿、黄铜矿、辉钼矿、磁铁矿，金矿物主要为细粒自然金，赋存状态以晶隙金为主。根据矿床地质特征及矿体分布规律，认为（2）1矿体深部及矿区周边出露细粒二长花岗岩脉区域仍有较好的资源前景。下卧龙金矿床为昆嵛山地区首次发现的赋存于细粒花岗岩脉内的新类型金矿床，其特点为受构造控制不明显、岩石蚀变普遍较弱、载金矿物多样、矿体品位相对较高。该矿床的发现对昆嵛山及周边地区地质找矿具一定指导意义。

Abstract:

Kunyushan Mountain locates between Muping fault and Mishan fault in eastern Jiaodong peninsula. It is the transitional belt of Sulu UHP metamorphic belt and Northern China Craton. Xiawolong gold deposit is located in the east part of Kunyushan granites and west of Mishan fault. Ore bodies are strictly controlled by fine-grained granite with the vein form. The dip and strike are consistent with the attitude of the hosting rocks. The surrounding rock is Guojiadian formation of Linglong unit. Ore minerals include pyrite, pyrrhotite, chalcopyrite and molybdenite and magnetite，while gold minerals are natural gold occurred as crystal fractured gold. Based the geological characteristics and the occurrence regularity, it is believed that favorable prospecting potential can be expected in the depth of (2)-1 orebody and surrounding areas. Xiawolong gold deposit, with its ore body hosted in fine-grained granite,is a new type gold deposit verified for the first time in this area. The characteristic of structural ore-control is not obvious and rock alteration is generally weak. Meanwhile, Au-carrier minerals are varied and gold grade is quite high. The discovery of Xiawolong gold deposit will provide some references for ore prospecting in Kunyushan Mountain and the surrounding areas.