Application of the zoning of ore-associated elements to exploration for volcanogenic massive sulphide deposits: A case study of the Pukkiharju Zn-Cu prospect, central Finland

Abstract

Abstract The zoning of ore-associated elements Volcanogenic massive sulphide deposits are characterized by mineralogical alteration zones that are associated with distinct geochemical zones. The geochemical zones commonly form larger exploration targets than do the observable alteration zones. Use has been made of the depletion of Na and Ca and enrichment of Mg, Fe, and sometimes of K as a standard procedure in lithogeochemical exploration. The enrichment of ore-associated minor or trace elements that are often found in a restricted zone in the area of most intense alteration are also used in locating orebodies, even though their halos are sometimes less distinct and well defined than those of the major elements. The concept of zoning of ore-associated elements in hydrothermal deposits has been extensively applied in the Soviet Union to interpret the level of erosion and type of deposit and also to detect blind mineralization. The direction of movement of the ore-bearing solutions is expressed as axial zoning, and the standard sequence for elements considered there is (from top to bottom): Ba-Ag-Pb-Zn-Au-Cu-Ni-Co. In this study, zoning is compared to features of volcanogenic massive sulpide deposits.