Geochemical characteristics and genesis of niobium–yttrium–fluorine granite pegmatite from Hmrat El Sorwhyia area, North Eastern Desert, Egypt.

This article focuses on the geochemical characteristics and genesis of niobium–yttrium–fluorine (NYF) type granite pegmatites from the Hmrat El Sorwhyia area in the northern Egyptian-Nubian Shield. These pegmatites, hosted mainly within syenogranitic bodies, exhibit significant enrichment in rare metals including uranium (U), thorium (Th), rare earth elements (REE), zirconium (Zr), yttrium (Y), and niobium (Nb), with maximum equivalent uranium and thorium concentrations reaching 760 ppm and 5552 ppm, respectively. Geochemical and mineralogical analyses indicate that the pegmatites have a sub-alkaline, peraluminous composition with A-type granite affinity formed in a post-collisional, within-plate tectonic setting. Their formation involved fractional crystallisation and assimilation processes during late-stage magmatic evolution, leading to the crystallisation of minerals such as thorite, uranothorite, columbite, cerianite, and zircon. These findings highlight the mineralisation potential of the area and contribute to understanding the petrogenesis of rare-metal-enriched NYF pegmatites in post-collisional granitic environments.