Research Into Both Halo Zonation And Deep Prognosis Of The East Of Laochang Sn Polymetallic Deposits,Gejiu,Yunnan Province,Southwestern China

Laochang ore segment is an important part of the world class of Gejiu tin-copper polymetallic deposits,which is located in the middle of the Wuzishan compound anticline,bounded by the Gejiu fault on west,and by the Beiyinshan fault on north and by the Laoxiongdong fault on south.Structures are developed in this study area.The mineral resources in the mining area are rich in copper,lead,zinc and molybdenum.The formation of these minerals are closely related to the late Yanshanian granite.This paper have a further explanation on how to predict hidden ore body by building a deep ore body prediction model in the process of measuring the sample content,extracting the geochemical anomalies and building the axial zonation in primary halos.Analyzing the raw date of the samples from five drilling cores,the results show as follows:(1)According to the 18 kinds of element data in the drilling,the original halo profile of each element was drawn out.The profiles figures show that the original halo of the ore body is relatively developed and the zoning is obvious,and the original halo zone shape of most elements are similar,which is consistent with the distribution of the ore body.(2)Using the method of Grigorian primary halo zonation,the exact axial zoning sequence(from head to tail of the ore body)of the east of Laochang A1 exploration line profile is obtained as follows: W-F-B-Ba-Cu-Sb-Be-Cr-Sn-Ni-Pb-Ag-Zn-Co-Mo-Bi-As.(3)Based on the study of zonation sequence,the index which is obtained by(B×Sb×F×Ba)D/(Mo×Co×Ni×Bi)D is not the same at different depths.The index is 63.67 at the head of the ore body,28.71 at the upper part,12.33 in the middle of the ore body,5.86 at the lower part of the ore body,17.83 at the tail of the ore body.The index decreases gradually with the depth of the ore body and suddenly increased at the tail of the ore body,which indicates that the blind ore body may exist in the deep.