Spatial Distribution Of Primary Halos In Jiaojia Orefield,Shandong Province

Previous research results show that the primary halo prospecting method is one of the most effective technical means to find concealed ore bodies and deep mineral prediction.As a typical gold field in China,Jiaojia gold field has considerable reserves.Jiaojia gold field in Shandong Province,as a mesothermal type ore field,has been used in this type of gold deposit for a long time.Therefore,this paper uses the method of primary halo prospecting to predict the depth of the orebody in Jiaojia,which provides strong support for the subsequent exploration work in the orefield and the subsequent resource potential evaluation.According to the relevant data of the study area,the main indicator elements of the primary halo in Jiaojia ore field are Ag,As,Au,Sb,Zn,W,Sn,Pb,Mo,Hg,Cu,Bi;the indicator elements of the front halo are Hg,Sb,As;the indicator elements of the near halo are Cu,Pb,Zn,Ag,Au;the indicator elements of the tail halo are Bi,Sn,Mo,W.Because the original element content value of the borehole is not evenly distributed in space,in order to facilitate the subsequent use of gray correlation and multifractal to solve geological problems,based on the original data,a three-dimensional model of the primary halo is established by using the inverse distance weighted interpolation algorithm in the Micromine software,and the data volume is cut,and the element content value of the grid is obtained.Based on the data obtained from three-dimensional modeling,the 152 exploration line in the north section of Jiaojia is selected in this paper.Based on the grey correlation theory,the axial zoning sequence of 152 lines is(Pb-Ag-Zn)-Bi-W-(Cu-As)-Sn-Sb-Au-(Mo-Hg).Meanwhile,the 152 axial zoning sequence is(Pb-Ag-Zn)-(W-BI)-Cu-(As-SN)-(Sb-Au)-(Hg-Mo)calculated by Grigorian zoning index method.Furthermore,the feasibility of the grey correlation method is verified.Based on the previous classification of 12 elements,the sequence is interpreted.There are some front halo elements at the end of the 152 line sequence and some tail halo elements at the beginning of the sequence,indicating that the ore body is not formed in a single period.It is speculated that there is another period of mineralization below-1300 m,that is to say,there is the possibility of mineralization.The geochemical data of primary halo are mostly non-linear due to its strong variability,which makes the conventional statistical methods show limitations.Here,based on the element content value obtained from Micromine 3D data volume cutting,multi fractal S-A algorithm and traditional cumulative frequency method are used to process the data to obtain geochemical anomalies.Through comparative comprehensive analysis,the 152 line profile anomalies are obtained.The results show that some of the front halo elements and the near halo elements have an increasing trend down to-1400 m,which indicates that the possibility of further mineralization is still very large.According to the rule of zoning and geochemical anomalies,it is predicted that there is a third enrichment zone extending about 500 m downward along the ore body side direction according to the rule of 1/3 of the controlled vein length extending to the depth.