The Primary Halo Research of Zhaishang Gold Deposit in Gansu Province

On the basis of geo-mathematic method and geochemical theories, this paper studied the elements distribution and the primary halo of the Zhaishang ultra-large carlin-like type gold deposit. It was held that the anomalies of Au, As, Sb were related to ore-forming process of gold and could be direct prospecting criteria for gold deposit. The front halo elements were Sb, As; the near-ore halo elements were Au, Ag, Pb, Zn; the rear halo elements were W, Mo. Two ore bodies of the ore veins in stage Ⅱ mineralization superposed in different exploration lines and altitudes. The ideal model of the primary superimposed halo of the northern No.10 ore vein and the southern No.32 ore vein was built. In the No.10 ore vein from the 2 650 m down to the 2 350 m, the tail of ore body A was superposed upon the top of ore body B, even extending deep down in 2 350 m. In the middle of No.32 ore vein from the 2 650 m down to the 2 300 m,ore body A and B were superposed in the middle and the tail, extending to the bottom of the ore body in 2 350 m.Three prospecting target areas were delineated depending on the primary halo prospecting principles.