Daghbag and Bakriya gold occurrences are located at the western part of the central Eastern Desert of Egypt belonging to
Barramiya gold district. This work presents comprehensive geological, structural, and new mineralogical data to define the
different alteration types related to the gold mineralization at these occurrences. Moreover, in order to reduce the field and
additional costs, ASTER and Landsat-8 OLI data are used at the initial exploration stages to elucidate the spread of alteration
zones associated with the auriferous quartz veins at the Daghbag and Bakriya gold mines. Two alteration types are defined in the
studied areas: type 1 (sericitic/muscovitization) and type 2 (propylitic). The Daghbag gold mineralization is mainly related to
NW- milky, brownish, and smoky quartz veins and veinlets having pyrite, chalcopyrite goethite and malachite with gold. While
Bakriya gold mineralization occurs within NNW–SSE and NW–SE quartz veins and alteration zones at the mining areas
including pyrite and chalcopyrite, magnetite, hematite, malachite, and goethite with gold. Mass balance calculations and
Gresens’isocon diagrams revealed that Au was added with Cu along mainly with K2O, Fe2O3, MgO, CaO to the sericitic and
some propylitic with ferriginated altered wallrocks. Although alteration types do not show regular distribution pattern, several
band combinations, and multiplications, developed selective principal component analysis and image transformations were
developed for detecting the hydrothermal alteration zones associated with gold mineralization using ASTER and Landsat-8
OLI data. In which, the gold mineralization at the studied area is related to pervasive sericitic (±muscovite) alteration types with
some propylitic and ferrugination at Bakriya mine areas. |
