Characteristics of Primary Halo Zonation and Prediction Pattern of Deep Orebody of the Huaaobaote Pb-Zn-Ag Polymetallic Deposit,Inner Mongolia

The Huaaobaote Pb-Zn-Ag polymetalic deposit,tectonically located at the south segment of the Dahinggan Mountains ore-forming belt of the circum-western Pacific metallogenetic domain,is a buried hydrothermal vein deposit associated with early Cretaceous tectono-magma activities discovered in recent years.The following conclusions are drawn by studying on primary halos of ore bodies.(1) The ore and halos forming-elements exhibit a clear zonation.Based on their anomalous intensity the transverse element zonation of the ore deposit are established as follows (from high to low): Cd→Pb→Zn→Ag→Sb→In→Hg→As→Cu→Sn→W→Mo→Bi.The five elements (Cd、Pb、Zn、Ag、Sb) ranked in the front of this zoning sequence can be regarded as long range indicators;and the four elements (Sn、W、Mo、Bi)in the rear of this zoning sequence regarded as short range indicators.(2) The axial zonation of this ore deposits is as follows: Sb→Pb→Cd→Ag→Zn→Hg→Cu→In→As→Bi→Sn→Mo→W,which is similar to the standard zonation of hydrothermal ore deposits determined by S.V.Grigorian.(3) Indexes such as (Sb×Pb×Cd×Ag)D /(As×Sn×Mo×W)D are constructed as a criterion for evaluating the ore potential in depth,which is equal or greater than 1.30 on the top portion of the ore bodies,0.35-0.056 in the middle- upper portion,0.056-0.005 in the middle-lower portion and equal or lesser than 0.005 at the end portion of the ore bodies,illustrating that the criterion values decrease regularly and abruptly with depth,and they can be used for predicting the ore potentials at a given depth.