Comparative Study on the Geological and Geochemical Characteristics of Some Rare-Metal Granites, Southeastern Desert, Egypt

Abstract

The Egyptian younger granites are characterized by the presence of more than 14 exposures of raremetal granites. The studied granites are included into three geological modes of occurrence. The first includes Igla and Abu Dabbab plutons, which occur as small stocks of circular, ovoid, or apophyses and leucocratic outcrops. The second comprises the plugs and dyke-like bodies intruded peralkaline granites of Bir Um Hibal. The third includes Homrit Waggat and Muweilha plutons. They cover small areas and exhibit obvious pervasive post magmatic alterations. The petrographic and mineralogical studies are confirmed by the geochemical investigations indicating that the concerned rare-metal granites being broadly distinguished into magmatic and metasomatic associations. The magmatic granite associations are further subdivided into two subgroups; i) peraluminous granites (Li-mica rich) including Igla and Abu Dabbab plutons and ii) peralkaline granites including Um Hibal pluton. The studied peraluminous granites are generally enriched in Nb, Rb, Ta, Li, F, Y, Zr, U and Th elements. The peralkaline granites are enriched in K 2 O oxide as well as Zr, Nb, F, U, Th and Ta elements. On the other hand, the metasomatic granite associations are represented by Homrit Waggat and Muweilha plutons. They are characterized by high contents of Na 2 O oxide as well as Nb, Ta, U, Th and Rb elements. Igla pluton has highest average U & Th contents (42 ppm & 58 ppm respectively), while Um Hibal pluton has lowest average U & Th contents (14 ppm & 26 ppm respectively)

Assessment of magmatic versus post-magmatic processes in the Mueilha rare-metal granite, Eastern Desert of Egypt, Arabian-Nubian Shield

“…Salem et al, 1985;Morsy and J o u r n a l P r e -p r o o f Journal Pre-proof Mohamed, 1992;Abou El Maaty and Ali Bik, 2000) or metasomatic origins (e.g. El-Galy et al, 2016;Abu El-Rus et al, 2017). In fact, the distinction between magmatic and metasomatic processes may not be as absolute as once thought (Lundstrom, 2016;, and transitional models may provide a path to reconciling the available evidence.…”

“…Rare-metal bearing granites in the Eastern Desert of Egypt have been attributed to various magmatic processes (Morsy and Mohamed, 1992;Mohamed, 1993;Jahn, 1996;Helba et al, 1997;Abou El Maaty and Ali Bik, 2000), to post-magmatic hightemperature metasomatism (El-Galy et al, 2016;Abu El-Rus et al, 2017), or to a combination of magmatic and post-magmatic processes (Abuamarah et al, 2019;Heikal et al, 2019).…”

Genesis of Rare Metal Granites in the Nubian Shield: Tectonic Control and Magmatic and Metasomatic Processes

“…Several studies have examined the genesis of rare metals (Figure 7; Supplementary Table S2) in the ANS, and three hypotheses include: (1) metasomatic origin (e.g., [83,84]), (2) magmatic origin (e.g., [16,51]), and (3) both magmatic and metasomatic origins (the hybrid origin) ( [7,8,11,13,85]). The Igla Ahmr rare metal-bearing granites are mainly magmatic in origin, even with the involvement of subsequent metasomatic processes and formation of some rare metals (e.g., [8]).…”

Magmatic and post-magmatic evolution of post-collisional rare-metal bearing granite: The Neoproterozoic Homrit Akarem Granitic Intrusion, south Eastern Desert of Egypt, Arabian-Nubian Shield

“…The rare-metal bearing granites in the Eastern Desert of Egypt have been attributed by many authors to post-magmatic high-temperature metasomatic origins (e.g., Sabet et al, 1976; J o u r n a l P r e -p r o o f El-Tabal, 1979;Riad, 1979;Kamel and El Tabbal, 1980;El-Galy et al,2016),while others have preferred magmatic origins (e.g., Asran, 1985;Morsey and Mohamed, 1992;Jahn, 1996;Helba et al, 1997;Arslan et al, 1997;Renno, 1997;Abou El Maaty and Ali Bik, 2000) or hybrid models that note significant roles for both magmatic and post-magmatic processes (Azer et al, 2019;Heikal et al, 2019;Seddik et al, 2020;Zoheir et al, 2020;Abuamarah et al, 2021).…”