ABSTRACT

Volcanogenic massive sulphide deposits (VMS) in norheastern Turkey are genetically and spatially associated with a rather thick dacitic volcanic pile that contains at least three main types of dacites known as the pyrite-bearing dacite, purple dacite and biotite dacite. The entire dataset obtained from these dacites was subjected to t test and one way variance analysis in combination with F test in order to test the hypothesis that the samples collected from different types of dacites are actually different. The t test indicates that A12O3, Fe2O3, MgO, MgO+Fe2O3, total S, Cu, Mo, Y, Zr/Ti*0.0001 and all REE contents of pyrite-bearing dacites differ from those of the purple dacites at a 5% significance level. Of these, Al2O3, TiO2, Y, total S and REE are the most discriminant elements in the dacites analysed. Therefore, the binary diagrams made of all these elements can be used to identify the type of dacite and thus help to outline the areas of dacite best favourable for VMS deposits.