甘肃滴水山金矿床原生晕特征及深部成矿预测

摘要

Dishuishan gold deposit,related to ductile-brittle shear zone of altered rock-host,is primarily occurred in littoral facies-neritic phase acidic volcanic clastic rock.On the basis of field geological work,the paper analyzes the trace elements of the samples of the drill hole in different geologic section,which located in Au2 orebody, with using geological and mathematical analysis methods,the paper carries through the analysis on the spatial distribution characteristics,the primary halo feature and the elemental association characterisitics of trace elements.The results showed that:On the basis of Grigoryan’s zonation indexes,the primary halo axial zoning sequence from the top to the deep part in No.141 and 175 geologic section are(Pb-As)-Au-Cu-Zn-Bi-Hg-Sb-Ag-Mo and (Hg-As-Au-Sb-Pb-Cu)-Zn-Mo-Ag-Bi respectively,which exists the mutual superposition of the front halo elements,proximal elements and tail halo elements;The correlation analysis,cluster analysis and factor analysis reveal that Au is closely related to Ag,and followed by the As,Sb in Au2 orebody,and determine the F1 main factors of Au in the Au2 orebody is Sb-As-Ag-Cu-Au-(Pb-Zn),which is the most favorable combination of elements for mineralization.According to the space distribution characteristics of each element,we consider that the mineralization is prospective in the deep portion of the Au2 orebody.%滴水山金矿床是一个主要赋存于滨海—浅海相中酸性火山碎屑岩中，与脆—韧性剪切带有关的蚀变岩型金矿床。在野外地质工作的基础上，对 Au2号矿体不同勘探线钻孔中所采样品进行微量元素分析，并利用地质和数学分析方法，对微量元素的空间分布特征、原生晕特征及元素组合特征进行了分析。结果表明：根据格里戈良分带指数法，141号勘探线原生晕轴向分带序列为（Pb-As）-Au-Cu-Zn-Bi-Hg-Sb-Ag-Mo，175号勘探线分带序列为（Hg-As-Au-Sb-Pb-Cu）-Zn-Mo-Ag-Bi，存在前缘晕、近矿晕、尾晕元素重叠的现象；通过相关分析、聚类分析和因子分析，认为 Au2号矿体中与 Au 关系较密切的元素为 Ag，其次为 As 和 Sb，并确定了Au 元素所在的 F1主因子元素组合 Sb-As-Ag-Cu-Au-（Pb-Zn）为成矿最有利的元素组合。根据元素分布特征，对深部成矿进行了预测，认为 Au2号矿体深部仍有较好的成矿前景。