胶东牟平照岛山金矿蚀变矿化阶段及控矿要素

Identifying of alteration mineralization phase and analysis on ore-controlling factors of Zhaodaoshan gold deposit,Muping,eastern Shandong,China

照岛山金矿位于胶东牟平-乳山成矿带北段,矿体产于中生代燕山期昆嵛山二长花岗岩中,主要受NNE向金牛山断裂带的控制。对金的成矿背景、矿床地质、控矿因素和矿体隐伏特征的研究结果表明:围岩蚀变从近矿到远矿依次发育黄铁绢英岩化、绢英岩化和钾长石化;金的成矿分为黄铁矿石英、石英黄铁矿、多金属硫化物、石英碳酸盐矿物4个阶段;昆嵛山岩体和荆山群变质岩的接触带附近易于成矿;金牛山主断裂走向NE的拐折地段、不同期次断裂交会处和多期断裂破碎带部位都易于成矿;金品位高值区呈近似等距分布,32线以南有向SW侧伏的趋势,40线以北有向NE侧伏的趋势。总结了照岛山金矿的控矿因素,初步推测了深部找矿方向。

The Zhaodaoshan gold deposit, located in the north of the Muping-Rushan ore-forming belt, occurs in Mesozoic Kunyushan monzonitic granite. Ore bodies are controlled by the Jinniushan tectonic zones of NNE striking faults. Results of the metallogenic background, ore geology, ore-controlling factor and the characteristics of concealed orebody show that alterafons of wall rock from proximal to distal are pyrifization silicification-sericitization, silicification-sericitization and potash-alteration. It is concluded that the mineralizing processes of Zhaodaoshan gold deposit can be divided into four stages： pyrite-quartz stage, quartz-pyrite stage, polymetallic minerals stage and quartz-carbonate stage. The ore bodies occur in contact zone between Kunyushan granite and Archen- Lower proterozoic Jingshan Group metamorphic rock, and occur in the location of NE striking faults, at the cutting point of different faults and in the tectonic fracture zones. The gold enrichment localities distribute in accordance to an approximate equidistant rule. The gold orebodies incline to the SW direction in the south of No. 32 exploration line and to the NE direction in the north of No. 40 exploration line. The article sums up the ore-controlling factors and points out ore exploration prospecting in the deep area of Zhaodaoshan gold deposit.