甘肃寨上金矿综合信息找矿模型研究

摘要

This paper systematically researched some prospecting information of the Zhaishang gold deposit,which included the geological,the geophysical and the geochemical.(1)The geological prospecting information:The Zhai-shang gold deposit is located at the Xicheng-Fengtai-Zhenxun extensional rift basin, in the middle sector of the west Qinling Moutains.The ore is controlled by fault and fold structures,and the ore-bearing horizon are the clastic rocks and carbonate rocks of middle Devonian Anjiacha Formation and lower part of Lower Permian Shilidun Formation.It also produces in the NWW interlaminar faults.Silicification,pyritization,arsenopyrite and brown iron mineralization developed in gold deposit are the direct prospecting marks.(2)The geophysical prospecting informa-tion:Electrical measurement shows that the gold veins have low resistivity and high polarization.Electrical ore bodies and country rocks have big differences.Therefore,both of polarization anomaly, fracture zone and metal sulfide coexist in the Low resistivity zone,the prospecting is more significant.(3)The geochemical prospecting inf-ormation:1∶200 000 and 1 ∶50 000 stream sediment anomaly in this area are in good agreement with the gold deposits.Moreover,Au,As,Sb,Hg anomaly obvious combined and strongly repeated.It plays an important role in the Zhaishang gold deposit discovery.By the way,the 1 ∶10 000 soil anomaly is more effective to prospecting mining.Summary of the above prospecting information,we established the prospecting model of the Zhaishang gold deposit and mine regional area.%　　寨上金矿床位于西秦岭岷礼成矿带西段，属于中低温热液矿床，文章对寨上金矿的地质、物探和化探等找矿信息进行了总结研究，从而建立了该区找矿综合模型。（1）地质找矿信息：寨上金矿大地构造位置处于西秦岭中带的西成—凤太—镇旬拉张裂陷盆地内，成矿受断裂和褶皱构造双重控制，赋矿层位为中泥盆统安家岔组和下二叠统十里墩组下段碎屑岩和碳酸盐岩，矿体产于 NWW 向的层间断裂中，硅化、黄铁矿化、毒砂化和褐铁矿化发育，是直接的找矿标志。（2）地球物理找矿信息：大量的电法测量表明，该区金矿脉具有低阻高极化特征，围岩与矿体电性差异较大，因此处于低阻带中的极化率异常、破碎带和金属硫化物同时存在时，找矿的指示意义较大。（3）地球化学找矿信息：该区1∶20万、1∶5万水系沉积物异常与金矿床吻合较好，Au、As、Sb 和 Hg元素异常套合明显，重现性强，为寨上矿区的发现起到了重要的指示作用；1∶1万土壤异常对矿区找矿的作用更为有效。