High resolution mapping of alteration zones in Daghbag and Bakriya gold occurrences (Central Eastern Desert, Egypt) using field, mineralogical-geochemical, and remote sensing data


Hagag W., Khalıl A. A. A.

ARABIAN JOURNAL OF GEOSCIENCES, vol.14, no.14, 2021 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 14 Issue: 14
  • Publication Date: 2021
  • Doi Number: 10.1007/s12517-021-07490-9
  • Journal Name: ARABIAN JOURNAL OF GEOSCIENCES
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Aquatic Science & Fisheries Abstracts (ASFA), Geobase, INSPEC
  • Keywords: Hydrothermal alteration, Gold mineralization, ASTER, Landsat-8 OLI, Daghbag, Bakriya, Central Eastern Desert (Egypt), SPACEBORNE THERMAL EMISSION, REFLECTION RADIOMETER ASTER, HYDROTHERMALLY ALTERED ROCKS, PRINCIPAL COMPONENT ANALYSIS, IMAGERY DATA, LANDSAT TM, DEPOSITS, AREA, MINERALIZATION, IDENTIFICATION
  • Istanbul Technical University Affiliated: No

Abstract

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.