The Primary Halo Characteristics of No.4 Vein and Related Depth Prospecting Prediction of the Qiaga Dtibnite deposit in Longzi County, Tibet

The Qiaga stibnite deposit is located in the central east of the Cuomei-Longzi Sb-Au metallogenic belt of Southern Tibet, where has favorable mineralization conditions and serves an excellent target to prospect Sb, Pb and Zn deposits.The research results show that:①The primary halos of ore bodies were developed very well, with a clearzonation of halo-formingelements.②The halo-formingelements can be divided into three categories, that is the front elements(Cd, Hg and As), near-ore elements (Pb and Zn in upper part, Sb in middle part, and Cu, Au and Ag in lower part) and rear halo elements (As, Sn, Bi, Mo and W) through analyzing the the situation of primary abnormal distribution and its relationship with the ore bodies. ③Through using the accumulation centermethod and the Zoning index method respectively, the similar zoning sequence (Pb-Zn-Mn-Bi-Mo-W-Sn-Cd-Hg-As-Sb-Cu-Au-Ag-Ba) has been obtained. ④As for the ore prospecting in depth, the ore bodies may extend downward or some blind ore bodies may be existed in the deep, and this stibnite deposit is hydrothermal metallic deposit. ⑤On the basis of primary halos system research, the indexes of (Cd×Hg×As×Sb)_D/(Bi×Mo×W×Sn)_D for estimating the deep ore have been constructed, and these indexes are regularly decreasing with the increasing of depth, which are effective criterions to evaluate the ore potential in depth.