Characteristics Of Primary Halo Zoning And Prediction Of Deep Orebodies In No.43 Section Of Dulong Zn-In Polymetallic Deposit

The primary halo prospecting method has remarkable effect in searching for magmatic hydrothermal concealed deposits.It is one of the most important geochemical prospecting methods recognized by geologists at home and abroad.It can not only trace the blind ore body,but also determine the specific location of the ore body,which can provide scientific theoretical guidance for the exploration of new ore bodies.Laojunshan ore concentration area is located in the joint of South China fold system,Yangtze plate and Indosinian plate,with extremely complex structural position.Dulong tin zinc polymetallic deposit is located in the southwest of Laojunshan ore concentration area,belonging to magmatic hydrothermal type deposit,with multi-stage and multi-stage metallogenic characteristics,which is closely related to Laojunshan second stage granite.The ore body mainly occurs in Tianpeng formation,and the lithology is schist Marble.The core samples from three boreholes of No.43 exploration line of Dulo ng are used in the system,and the primary halo zoning is mainly studied.The n the mathematical statistical analysis method is used to analyze the geochemic al characteristics of the primary halo in the study area.Finally,the prediction mo del of the deep orebody is constructed.According to the study of 154 samples from No.43 exploration line of Dulong,it is shown that:(1)the primary halo of ore body is obviously developed,the concentration zoning is clear,and the distribution state of the primary halo anomalies of 15 chemical indicator eleme nts is approximately the same as the spatial distribution of ore body occurrenc e;(2)according to the calculation method of primary halo zoning of Gregorian,the axial zoning sequence of No.43 exploration line of Dulong is calculated(From shallow to deep):w-pb-zn-b-bi-f-sb-as-mo-ag-sn-in-cu-u-au,which is almo st the same as the standard axial zonation sequence on the whole;(3)based o n the zonation index,four groups of geochemical parameters are selected to pr edict the deep blind ore body,which are:(as×sb×f)_D/(Mo×Sn in)_D,(as)d/(MO)_D,,(as×b)_D/(Mo×BI)_D,(As×B×F)_D/(Mo×W)_D;The change trend of the four parameter indexes is the same.The value of this index is larger at t he head of the ore body,smaller in the middle of the ore body,and larger at the end of the ore body.The overall change trend is:the value decreases shar ply at first,and then increases sharply at the end of the ore body,indicating t hat there is a great possibility of blind ore body in the deep.Combined with t he specific geological characteristics of strata and structures in the study area,the prediction model of deep orebody is constructed,which provides scientific theoretical guidance for the prediction of orebody extending to the deep and bl ind orebody in the deep.