Petrographical and Geochemical Features of Sulfide Mineralization in the Walash Group, Gallala Area, Kurdistan Region of Iraq

Abstract

In this article, a Fe-rich sulfide mineralization hosted within the Walash Group in the Gallala area, on the northwestern side of the Zagros Orogen is investigated for the first time. The mineralization occurs as massive sulfide veins and veinlets, as well as disseminated within volcanic lithologies. The objective of the study is to characterize the sulfide-rich mineralization using petrographical and geochemical methods, applied in both the ores and the corresponding host formations, including the characterization of volcanic rock alteration. Petrographic data indicates the presence of Fe-rich sulfide mineralization in altered basaltic andesite to andesite rocks, which are affected by hydrothermal alteration such as actinolization, chloritization, sericitization, and epidotization. The geochemical analysis of the fresh rock samples reveals enrichment of iron in the suture zones, but low copper and zinc concentrations. The mineralogical and textural signatures of sulfide minerals lead to inferring that the ore mineralization origin is volcanogenic to the hydrothermal type of deposits.