3-dimensional Modeling And Characteristics Of Primary Haloes In The Zhunuo Porphyry Copper Deposit, In The Gangdese Belt, Southern Tibetan

Zhunuo porphyry copper deposit locates in the Gangdese Copper polymetallic metallogenic belt.So far, the Zhunuo deposit is not well researched, and it is currently in detailed investigation. This study establishes the 3-dimensional orebody model, and research its zoning characteristics. The main knowledge are as follows:By applying the mining modeling software Surpac, the drilling spatial distribution model of Zhunuo diggings and a 3-dimensional model (which including the surface, fault, orebodies and alteration zone) were established, and it eventually helps to realize the 3-dimensional visualization of the deposit and prospecting engineering in the mining area. The dominant alteration in drilling control area are both K-silicate zone, the quartz-sericite zone, and the propylitic zone, besides, the argillic alteration almost do not exist. The ore body locates in the K-silicate zone and the quartz-sericite zone.The primary haloes of Zhunuo porphyry copper mine is a composite anomaly zone predominantly in Cu element, the associated elements (Mo, Cu) show obvious characteristics of zonal distribution. The low temperature elements (e.g., Pb, Zn) lie in the lower part of the ore bodies with banded anomalies, it may indicate that there is another layer of deep orebody.The vertical zonation of elements (from top to bottom) are:Sb-As-F-W1-Mo-Cu-Cd-Zn-Ag-Pb-Bi-Au-W2-Co.To some extent, it differentiates with normal zoning sequence, such as, the front haloes elements’ distribution (e.g., Pb, Zn, Au, Ag) below the location of Cu. The occurrence of W repeated twice in the zoning sequence, shows that some characteristics of reverse zoning.All 21 kinds of elements were mainly divided into two groups through the R cluster analysis. Group 1 is composed of the elements of Pb, Zn, Cd, Se, As, Sb, Hg, Ag, Bi, Cu, Au, Sn, Mo and W, representing a set of hydrothermal-origin of ore-forming elements and associated elements combination. Meanwhile, group 2 is mainly composed by the elements of Cr, Ti, F, Li, Co, Be and Mn, it may suggest a set of elements came from the porphyry mass. Factor analysis was carried out on the elements of group 1, and then five major factors have been obtained, each of them respectively were used to represent several different stages of hydrothermal activity during the ore-forming evolution from high to low temperatures.Using the I=1g [1000x(AsxSbxF)/(CuxCoxMoxBi)] as a geochemical evaluation index, the author finds that the value of I is positive in the upper part of ore body, and is negative nearby or internally the orebody.And I become smaller Along with the depth increasing. Within the scope of ZK001, the value of I gradually reduce from the topside to downside.And it appears positive at the bottom of the ZKOOl,which shows that there may exist another layer of ore body under the ZK001.