湖北鸡笼山铜金矿区土壤地球化学特征及找矿潜力评价

Soil geochemical characteristics in Jilongshan Copper-Gold District in Hubei Province and evaluation of ore-prospecting potentials in the area

鸡笼山铜金矿床是长江中下游鄂东南地区铁铜金多金属成矿带内典型的矽卡岩型铜金矿床,目前虽仍在开采,但已属于危机矿山,取得找矿突破迫在眉睫。结合前人获得的土壤化探异常,在湖北鸡笼山地区开展了1∶1 000土壤地球化学剖面测量,获得的325个有效样品的测试结果表明,主成矿元素Au、Cu的异常区和实际地质剖面中的岩体与大冶组碳酸盐岩围岩的接触带具有较好的套合关系,与矿床整体的成矿空间分布规律相一致。Cu元素质量分数平均值为289.0×10-6,远高于地壳丰度,暗示研究区具有良好的铜金属成矿潜力。岩体北侧接触带是铜多金属的重要找矿有利地段,沿鸡笼山岩体北西侧,有找金的潜力。

Jilongshan Copper-Gold Deposit is a typical skarn type gold deposit on the Fe-Cu-Au polymetallic ore belt in southeastern Hubei Province of Lower Yangtze Region. It is already a crisis mine but still in operation,waiting urgently for prospecting breakthroughs. Based on the soil geochemical anomalies obtained from precedent work,a1∶ 1 000 soil geochemical profile survey was conducted in Jilongshan Region of Hubei Province. The statistics on the325 valid samples obtained showed that the anomalous areas of main ore-forming elements Au,Cu distribution corresponded to the contact boundary between the rock mass and the carbonatite wall rock of the Daye Formation in the geological section,which was consistent with the geochemical location of the ore deposit. The average value of Cu mass fraction was 289. 0 × 10-6,much higher than the crustal abundance,indicating great copper mineralization potentials in the area. The northern contact zone of the granodionite bore great potentials in copper mineralization. There were potentials in gold mineralization to the northwest of Jilongshan rock mass.