Geochemistry Of Primary Halos And Evaluation Of Deep Mineralization In The Gaosongshan Gold Deposit,Heilongjiang Province

The Gaosongshan gold deposit, discovered in Northeast China recently, is a largeepithermal deposit. Geochemical studies of primary halos indicate that, the primarygeochemical anomalies of Au, As, Mo and Hg are obvious three-grade zoning inexploration line No.32and No.23, the ones of Sb, Ag, Cu and Pb occur middle andouter zones, while the ones of Sn, Zn, Se and Tl only have outer zone. In thelongitudinal direction, whether at eastern part of theⅠ-1ore-body, or at its middlepart, or at its western part, all occur the coexistence phenomenon of ore-formingelement, front halo elements, near-ore hole elements and tail halo elements, showingthe superposition characteristics of multi-stage mineralization. In which, theanomalies of ore-forming element (Au), front halo elements (As, Sb, Hg), near-orehole elements (Ag, Pb) and tail halo elements (Mo, Sn) overlapped well, belonging toore-forming anomalies. The primary halo abnormal distributions of exploration lineNo.32and No.23in theⅠ-1ore-body show that this ore-body inclined towards south,and their distributions in the longitudinal direction suggest that the western part of thisore-body has undergone relatively strong erosion, followed by its middle part, and itseastern part has evidenced minor denudation, or that this ore-body inclined to east inthe longitudinal direction.The axial zoning sequences of exploration line No.32and No.23have beenobtained through using zoning index and center of gravity method, they are(Cu-Zn-Ag-Au)-(Sb-Sn-As-Pb)-(Hg-Tl or Tl-Hg)-(Mo-Se) and Zn-Cu-Ag-Au-Sn-Pb-Hg-Tl-Sb-Se-As-Mo,(Cu-Pb-Sn)-(Hg-Mo-Sb-Ag-As-Au-Tl-Se-Zn) and Pb-Cu-Hg-Mo-Zn-Sb-Au-Ag-Sn-As-Se-Tl, respectively. These zoning sequences have similaroverall distribution trends, and they are basically normal zoning, but the distributionsequence of some elements occur large differences.The results of correlation analysis show that Au is related with Ag well, and thatAg is a good indicator element for gold mineralization. By using cluster analysis, theore-forming elements and its associated elements of theⅠ-1ore-body can be dividedinto six groups, such as, As-Sb, Au-Ag, Pb-Sn-Mo, Hg, Se-Tl-Zn and Cu. Fourelement combinations can be obtained by factor analysis, that is, As-Sb-Pb, Sn-Se-Tl,Au-Ag-Se-Tl and As-Sb-Cu. In which, the element combination of Sn-Se-Tl showthat this mineral deposit had the characteristic of the multi-stage mineralization, the element combination of Au-Ag-Se-Tl reflects that the gold mineralization hadcontemporaneous and homologous characteristics with polymetallic sulphides. As, Sb,Se and Tl are occurred in both two factors, indicating they are the results ofsuperposition of multi-stage mineralization.According to comprehensively analyzing the study results mentioned above, thecharacteristics of primary halos of theⅠ-1ore-body in the Gaosongshan gold deposithave been evaluated, and the prospecting of deep mineralization of this ore-body andits denudation degree have been speculated. The results show that, the front haloelements are coexistent with the tail halo elements in the deep section of explorationline No.32and No.23in theⅠ-1ore-body, and their geochemical parameters havestrong fluctuations, indicting the good mineralization perspective exist in the deepsection of these two exploration lines, but the mineralization prospecting ofexploration line No.32is better than the ones of exploration line No.23.