胶东牟乳成矿带金青顶矿床构造叠加晕研究

Study on tectonic superimposed halo of the Jinqingding deposit in Mouru metallogenic belt,Jiaodong

金青顶金矿床是牟平—乳山金成矿带最大的石英脉型金矿床,矿脉严格受构造控制,已探明储量为32 t,平均品位为6.44×10^(-6)。为探讨金青顶金矿床深部成矿潜力,本文在分析矿区成矿地质条件及矿床地质特征的基础上,对金青顶金矿床II号主矿体开展了构造叠加晕研究。结果表明:金青顶金矿床II号矿体的前缘晕特征指示元素组合为As、Sb、Hg,近矿特征指示元素组合为Au、Ag、Cu、Pb、Zn,尾晕特征指示元素组合为Bi、Mo、Co。II号矿体特征指示元素的分带序列由上至下为Sb→Cu、Ni→Au→Sn→W→Hg→As、Co→Ag→Zn→Pb、Mo→Bi,结合地球化学参数确定了II号矿体在-195 m、-435 m和-945 m中段深部存在金成矿作用叠加,并据此建立了II号矿体的构造叠加晕理想模型。综合矿脉品位等值线图、数据统计学分析、元素轴向分带序列、地球化学参数变化规律、构造叠加晕成矿模式以及井下地质现象观察分析,显示出金青顶金矿床II号矿体向深部的延伸较差,说明在深部存在矿体的可能性不是很大。因此,今后在本区开展找矿工作时,应重点关注矿区内的空白区及矿床外围。

Jinqingding gold deposit is the largest quartz vein type gold deposit in the Mouting-Rushan gold metallogenic belt.The vein is strictly controlled by structure.The proven reserves are 32 t with an average grade of 6.44×10^(-6).In order to explore the deep ore-forming potential of Jinqingding gold deposit,this paper has carried out a study on the structural superposition halo of No.II main orebody of Jinqingding gold deposit on the basis of analyzing the ore-forming geological conditions and geological characteristics of the deposit.The results show that the frontal halo characteristics indicate the element combination of As,Sb and Hg,the near-ore characteristics indicate the element combination of Au,Ag,Cu,Pb and Zn,and the tail halo characteristics indicate the element combination of Bi,Mo and Co.The characteristics of orebody II indicate that the zonation sequence of elements is Sb→Cu,Ni→Au→Sn→W→Hg→As,Co→Ag→Zn→Pb,Mo→Bi from top to bottom.Combined with geochemi⁃cal parameters,it is confirmed that there is gold mineralization superposition in the depth of orebody II at-195 m,-435 m and-945 m.Based on this,the ideal model of structural superimposed halo of No.II main orebody is established.Comprehensive analysis of ore vein grade contour map,statistical data analysis,element axial zona⁃tion sequence,geochemical parameter variation law,tectonic superposition halo mineralization model and observa⁃tion and analysis of underground geological phenomena show that the extension of No.II ore body to the depth of Jinqingding gold deposit is poor,indicating that the possibility of deep ore body is not very large.Therefore,we should pay more attention to the blank area in the mining area and the periphery of the deposit when prospecting in this area in the future.