焦家金矿带深部招贤北段重大找矿突破及构造叠加晕预测

Major Exploration Breakthrough and Structural Superimposed Halos Prediction in Northern Zhaoxian Section in the Deep Part of Jiaojia Gold Belt

摘要:

构造叠加晕方法在胶东金矿中浅部取得了良好的找矿应用效果，深部方法有效性有待验证。焦家金矿带2 000 m深度金矿勘查主要在招贤矿区开展，前期探获厚大金矿体分布于南段；北段在2024年完工的88ZK09和120ZK07钻孔探获厚大金矿体，其中120ZK07钻孔累计见矿真厚度达82.71 m，为焦家金矿带2 000 m深度见矿厚度最大的钻孔。北段Ⅰ1号主矿体产出于黄铁绢英岩化碎裂岩带内，产状与主裂面基本一致，倾向约295°，倾角20°左右；走向长2 368 m，倾斜延深2 139 m。构造叠加晕剖面上，Au原生晕异常与矿体相吻合、衬值高。根据剖面各元素叠加晕异常特征，建立深部构造叠加晕预测实用模型：前缘晕特征指示元素As、Sb、Hg，近矿晕元素Au、Ag、Cu、Pb、Zn，尾晕元素Mo、Bi；前缘晕异常及其强度、尾晕前缘晕异常共存等特征为重要构造叠加晕预测标志。构造叠加晕预测结果表明，与钻孔揭露矿体和蚀变带厚度强度等特征变化趋势一致，北段厚大金矿体向深部仍有较大的延深空间和成矿潜力。

Abstract:

The method of constructing superimposed halo has achieved good prospecting results in the shallow part of Jiaodong gold deposit. The effectiveness of deep exploration method needs to be verified. The exploration of gold deposits at a depth of 2000 meters in Jiaojia gold belt has mainly been carried out in Zhaoxian mining area. Thick and large gold deposits have been discovered in the southern section in the early stage, while thick and large gold deposits have been discovered in 88ZK09 and 120ZK07 boreholes in the northern section which have been completed in 2024. Among them, 120ZK07 borehole has accumulated a true thickness of 82.71 m. It is borehole with the largest thickness of mineral deposits at a depth of 2000 m in Jiaojia gold bel. Ⅰ1 ore body in the north occur in pyrite sericite quartzite fractured rock zone. The occurrence is basically consistent with main fracture plane. The dip angle is about 20 ° and the tendency angle is approximately 295 °. The strike length is 2368 m and the dip depth is 2139 m. On the structural overlay halo profile, the Au primary halo anomaly is consistent with the ore body and has a high lining value. Based on the anomalous characteristics of the superimposed halo of various elements in the profile, a practical model for predicting the superimposed halo of deep structures has been established. As, Sb and Hg are front halo features indicating elements; Au, Ag, Cu, Pb and Zn are near ore halo elements; Mo and Bi are the tail halo elements. The characteristics of abnormal front halo and its intensity, as well as the coexistence of tail halo and front halo anomalies are important indicators for predicting superimposed halo structures. As showed by the prediction results of the superimposed halo, it is consistent with the trend of changes in the thickness and intensity of the ore body and alteration zone revealed by drilling. The thick and large gold deposit in the northern section still has significant extension space and mineralization potential towards the deeper part.