2026-04-01 JOURNAL OF AFRICAN EARTH SCIENCES 2026 236(卷), null(期), (null页)
The North Romite area, in the South Eastern Desert of Egypt, comprises a structurally controlled gold deposit (up to 8.8 g/t Au) that shares several characteristics with orogenic gold mineralization. This deposit has not received attention in geological studies because it is buried beneath Recent sand deposits. Here, we present new field, structural, and geochemical data for the North Romite deposit to investigate its mineralogical and geochemical characteristics, as well as its relationship to the regional tectonic context. The host rocks of gold mineralization in the study area are late Neoproterozoic arc metavolcanics and metagabbro-diorite, which underwent greenschist facies metamorphism and deformation. The mineralized zones are represented by sheared and folded quartz/ carbonate veins and wall rock alterations that extend along transpressional NNE-, NE- and NW-trending shear zones. These shear zones splay from the major post-accretionary N-S Hamisana zone that was formed by collisional tectonics during the final assembly of Gondwana -640-600 Ma. The wall rock alterations around the quartz veins contain chlorite and epidote in the distal zones and quartz-sericite-carbonate-pyrite-chalcopyritegold in the intermediate and proximal zones. The geochemical signature of the North Romite deposit is defined by a metallic association of Au- Ag-As, as indicated by the elevated contents of these elements in the proximal alteration zones. The lack of syn-tectonic magmatism and the intense deformation in the deposit area indicate that the fluids responsible for gold mineralization were produced by metamorphic devolatilization. Gold precipitation was most likely controlled by phase separation, accompanied by decreasing confining pressure and lowering pH.