Construction of a 3D Conceptual Model of Subsurface Sulfide Mineralizations Using Integrated Geophysical Survey in Saint Catherine, South Sinai, Egypt

Abstract

The genesis and mode of occurrence of sulfide mineralizations located within the quartz monzonite rocks of Saint Catherine Area, Egypt have divided researchers who studied them into 2 main groups. One group believes that the mineralizations belong to the porphyry copper type of deposits, while the other group thinks that the mineralizations are formed by deposition of sulfides-rich hydrothermal solution in the structural lineaments. This is the reason for conducting an integrated geophysical survey using magnetic, radiometric, very low frequency and turam electromagnetic methods to provide possible solutions to the conflict. Incorporating the results of the geophysical surveys with the previously available geological and geochemical data helped building up a realistic conceptual 3D model of the subsurface sulfide mineralizations. The model proposes that the mineralizations were formed through 2 stages of upward migration of hydrothermal solutions. The early stage resulted in the deposition of a deep massive heap of mineralizations, creating features that support porphyry copper deposits. In the later stage, some of these hydrothermal solutions traveled farther upward, along fault planes and dykes, forming shallower linear mineralized deposits controlled by the NW-SE structural lineaments. Both mineral deposits were deformed, displaced, and dissected by faults and dykes trending NE-SW, creating the present complicated situation, and showing contradicting evidences on their mode of occurrence. The proposed conceptual model accommodates all previously introduced evidences, solves the conflict between existing contradicting hypotheses, and presents a reasonable evidence-based view of the geometry and mode of formation of these mineralizations.