PRIMARY HALO CHARACTERISTICS AND DEEP PROSPECTING PREDICTION OF NARAN TOLGOI GOLD DEPOSIT IN MONGOLIA

To predict and evaluate the metallogenic potential, the primary halo of Naran Tolgoi gold deposit is systematically studied by using multivariate statistical method combined with geochemical parameter information. The results show that the Clarke values of Au, Ag and Bi in the host rock granodiorite of the deposit are obviously high, which is closely related to the gold mineralization. Au is most closely correlated to Sb, Cu, Pb, Ag, Hg, Zn, As and Bi in the ores. There exists the superposition of rear halo elements(W and Sn) with front halo element(As) in the axial zoning sequence of primary halo. Besides, the turning of zonation indexes such as(As+Sb)/(Bi+Mo) and 100Sb/(Bi·Mo) indicates the existence of blind orebody in the deep. Based on the characteristics of primary halo, the prediction model of superimposed halo is established that the blind orebody is probably located near the contact zone between rock mass and strata below 710 m altitude.