Remote sensing techniques and geochemical constraints on the formation of the Wadi El-Hima mineralized granites, Egypt: new insights into the genesis and accumulation of garnets

Abstract The Wadi El-Hima Neoproterozoic I- and A-type granites in the Southern Eastern Desert of Egypt are rich garnets (up to 30 vol%) cut by NW–SE strike-slip faults, as confirmed from structure lineament extraction maps. These mineralized garnet mineralization zones can be successfully discriminated using remote sensing techniques. Spectral angle mapper matched filtering techniques highly effective for mapping garnet-rich show that highest concentrations occur along intrusive contact zone striking faults. have high SiO 2 (73.5–75.1 wt%), Al O 3 (13.4–15.3 wt%) total alkali (6.7–8.7 contents, suggesting they were sourced peraluminous (A/CNK > 1) parental magmas. Garnet-bearing trondhjemites metasomatic origin formed after I-type tonalite-granodiorites, which originated a volcanic arc tectonic setting. Garnet-rich syenogranites alkali-feldspar both post-collisional granites: magmas generated partial melting lower crustal tonalite metasedimentary protoliths during lithospheric delamination, crystallized fractionated, felsic alkali-rich upper crust. Garnets three forms: (1) subhedral disseminated crystals, (2) vein-type (3) aggregated reflecting different mechanisms accumulation. All dominantly almandine composition (Alm 76 Sps 10 Prp 7 Grs 6 Adr 1 ) average heavy rare earth elements (HREE) (ΣHREE = 1636 ppm), Y (3394 Zn (325 Li (39.17 ppm) Ga (34.94 ppm). Garnet REE patterns strong negative Eu anomalies with HREE enriched relative LREE, indicating magmatic origin. late-stage crystallization products Al-rich hydrous magmas, at low temperature (680–730 °C) pressure (2.1–2.93 kbar) conditions continental Peculiar near feldspar related parent magma compositions. situ granite melts, alongside accumulation residual left behind host contact. Magmatic-fluid flow fault Najd system enhanced clots veins garnet.