河北半壁山金矿区地球化学异常特征及找矿预测

半壁山金矿床成因类型为变质热液型.通过地球化学勘查，获得面积约200 km²北北东向水系沉积物As、W、Au、Ag、Sb异常带、4个土壤金异常带和13个子异常.根据地球化学异常特征，在地表查证的基础上，分别对甲1-1和甲1-2异常进行了钻探深部验证，钻孔中见4条金矿体，并在-45 m标高发现盲矿脉.地球化学异常初步研究认为，金矿体前缘元素组合特征为As-Sb（-Au）-Ag；中部元素组合特征为Au-As-Sb-Pb（-Ag）-Cu-Zn；尾部元素组合特征为Co-Ni（-Ag）-Cu.经分析所见盲矿脉元素组合特征与前缘元素组合特征相同，由此预测其深部有第二成矿“标高”存在.

GEOCHEMICAL ANOMALIES AND PROSPECTING PREDICTION OF THE BANBISHAN GOLD FIELD IN HEBEI PROVINCE

The Banbishan gold deposit,located in the east of the Eastern Hebei metallogenic province,genetically belongs to metamorphic hydrothermal type.By geochemical survey,a NNE-trending As-W-Au-Ag-Sb anomalous belt of stream sediment covering 200 km2 is found,along with 4 soil Au anomalous belts and 13 sub-anomalous belts.According to the geochemical characteristics and on the basis of surface proving,two of the anomalies are verified by drilling.Four gold orebodies are seen in the drill holes.Blind ore veins are found at -45 m elevation.Study on the geochemical anomaly shows that the front element assemblage of gold orebody is characterized by As-Sb(-Au)-Ag,the middle by Au-As-Sb-Pb(-Ag)-Cu-Zn,and the tail by Co-Ni(-Ag)-Cu.By analysis,the element assemblage characteristics of the blind ore veins are the same as those of the front anomaly.So the second "metallogenic elevation" is predicted in the deep.