铜陵凤凰山铜矿南区构造地球化学异常的确定与评价

DETERMINATION AND EVALUATION OF TECTONIC-GEOCHEMICAL ABNORMITIES IN THE SOUTHERN AREA OF FENGHUANGSHAN COPPER DEPOSIT,TONGLING

凤凰山铜矿南区花岗闪长岩体与大理岩接触带附近的构造地球化学特征表明存在多个总体,即岩体、未受明显热液蚀变的大理岩和蚀变矿化大理岩,岩体与大理岩的Cu异常下限分别是562×10-6和51×10-6。构造地球化学Cu等值线上得到的贯穿岩体的大面积高值区只是一种虚假异常,实际上反映了岩体的高背景值。通过标准化处理后得到Cu的标准化参数S,以S=1.654(即总体累积概率95%)为异常下限,圈定了3个异常区,其中中部异常区沿外接触带分布长达近千米,宽数百米,具有蚀变、角砾岩化及方铅矿细脉等特征,是重要的找矿靶区。

Tectonic - geochemical characters of the contact zone between granodiorite stock and marble in the southern area of the Fenghuangshan copper deposit exhibit mixture of intrusion, marbles with and without hydrothermal alterations. The anomaly thresholds of copper for granodiorite and marble are 562 × 10^ -6 and 51 × 10^-6, respectively. Isopleth map of tectonic - geochemical copper contents reveals a widely distributed high - value area throughout intrusive body, which represents a higher copper background of granediorite rather than anomaly. Parameter S that standardize from Cu contents is used to determine three abnormal areas by a threshold value of 1. 654. Among them, the central abnormal are, spreading near 1000m long and several hundred meters wide along the exozone, is characterize by wallrock alterations, breeeiating and galena veinlets, and considered as a target area for copper prospecting.