地物化综合找矿方法在青海和洛佳地区金多金属矿勘查中的应用

Application of intergrated geological,geophysical and geochemical prospecting methods in gold polymetallic deposit in Heluojia area,Qinghai

都兰县和洛佳地区金多金属矿是近年来1∶2.5万地球化学测量新方法试点中新发现的矿床。基于该地区属于高寒深切割区,总体地貌为山脊处碎石流广泛发育,低缓处第四系黄土覆盖严重的特点,1∶25万和1∶5万化探扫面均未在该地区圈出具有找矿价值的综合异常。在系统研究评价1∶2.5万地球化学测量异常特征→地质—岩石地球化学特征→物探及工程验证的组合方法在找矿成果应用的基础上,发现1∶2.5万地球化学测量异常浓集中心可以较为准确地控制异常高含量段及含矿地质体的位置;1∶1万地质草测工作将研究区内各类地质体之间的接触关系及分布有了较为明确的划分,重点是对金成矿有利的断裂构造从分布位置、性质、交切关系及含矿性方面有了较为系统的认识;1∶5000地化综合剖面测量缩小了找矿靶区,确定了含矿构造的位置;1∶5000激电中梯剖面进一步查明了含矿构造在走向上的延伸情况,为进一步工程验证并发现矿(化)体提供了直接的物探依据。通过研究认为其方法组合具有经济、有效,且快速发现矿体的特征,可为成矿带内类似地貌特征的地区在找矿评价方面起到示范作用。

The Heluojia gold polymetallic deposit of Dulan county is a newly discovered deposit through the new 1 ∶ 25000 geochemical survey method in recent years. This area belongs to high-and-cold and dissected mountain regions,the characteristics of overall landscape is debris flow is widely developed on the ridge and Quaternary loess covered serious in the lower,1 ∶ 250000 and 1 ∶50000 geochemical survey didn＇t find comprehensive anomalies which have prospecting value in this area. On the basis of systematic research and evaluation of the 1 ∶ 25000 geochemical survey anomaly characteristics-geology-rock geochemistry-geophysical prospecting and engineering verification for prospecting application,it is found that 1 ∶ 25000 geochemical anomaly concentration center can control accurately the abnormally high content and location of ore bodies; 1 ∶ 10000 geology preliminary survey have definite partition the contact relation and distribution of various geologic bodies of the study area,The emphasis is on the systematic understanding of the favorable fracture structures of gold mineralization in terms of distribution position,properties,intersecting relations and ore bearing properties; 1 ∶ 5000 geochemical comprehensive measurement reduced the target area for prospecting and determined the location of the ore-bearing structure,but the extension is not clear along the strike because of serious cover; 1 ∶ 5000 induced polarization intermediate gradient survey further find out the extension of the ore bearing structure along the strike; It provides a direct basis for further engineering verification and the discovery of ore bodies. It is considered that the combination of the method is the most economical,most effective and the most rapid for finding ore bodies; It can play an exemplary role in mineral prospecting evaluation with similar landscape area in the metallogenic belt.