The present study was carried out on commercial types of Aswan granite used as building and decorative materials. Nearly 29 granitic rocks samples from 11 classes (black Aswan, red Aswan, dark Rosa, light Rosa, yellow Verdi, grey Shirka, Gandolla, Forsan, red Nefertiti, Royal, and white Halayeb) were collected from three stations near Aswan city for petrographical description and assessment of natural radioactivity. The petrographical study of granites was conducted by polarized-light microscope in order to determine their mineralogical composition and investigate their texture; the activity of the natural radionuclides 238U, Ra226, 232Th, and 40K was measured by gamma-ray spectrometry with a NaI(Tl) detector. The average values of the activities, 52.2 Bq kg−1, 57.8 Bq kg−1, 31.2 Bq kg−1, and 1055.7 Bq kg−1 of U-238, Th-232, Ra-226, and K-40, respectively, were higher than that the world average values of 35 Bq kg−1, 30 Bq kg−1 and 400 Bq kg−1 for 226Ra, 232Th, and 40K, respectively, according to the recommended levels from UNSCEAR reports. The minimum and maximum values obtained were compared with the value ranges from other locations in the Eastern Desert, highlighting the fact that that the maximum values obtained in this work are higher than those in other areas. According to the radiological hazards indices results, most samples lie in the permissible level ranges, suggesting their favorability for use as building materials. In contrast to that, some samples have some environmental parameters higher than the international levels, indicating their unsuitability as building materials.

Gebel Filat granites form one of Egyptian younger granite intrusions in Wadi Allaqi region, South Eastern Desert of Egypt. They are perthitic monzogranites composed mainly of K-feldspars, plagioclase, and quartz with minor biotite. Plagioclase feldspars are Na-rich and have low anorthite content (An 2-3 ). Potash feldspars are mainly perthitic microcline and have chemical formula as (Or 96-96.6 Ab 3.4-4 An 0 ). Biotite is Mg-rich and seems to be derived from calc-alkaline magma. Chlorite is pycnochlorite with high Mg content, revealing its secondary derivation from biotite. The estimated formation temperatures of biotite and chlorite are (689-711°C) and (602-622°C), respectively. Gebel Filat monzogranites are metaluminous, high-K calcalkaline, I-type granites. They are late orogenic granites related to subduction-related volcanic arc magmatism. They are enriched in LILE and depleted in HSFE indicating highly differentiation character. The REE patterns display an enrichment in LREE due to presence of zircon and allanite as accessories and depletion in HREE with slight negative Eu anomaly Eu=Euà ¼ 0:51 À 0:97 ð Þ . The parent magma of Gebel Filat monzogranites were emplaced at moderate depths (20-30 km) under moderate conditions of watervapor pressure (1-5 kbar) and crystallization temperature [700-750°C]. The source magma of these granites seems to be derived from partial melting of lower crust material rather than upper mantle. The geochemical characteristics of pegmatites revealed that they are related to post orogenic within plate magmatism and not genetically related to the parent magma of Gebel Filat monzogranites. Distribution of radioactive elements (U and Th) in the studied rocks indicates normal U-Th contents for Filat monzogranites and U-Th bearing pegmatites. The positive correlations of each of Zr and Y versus U and Th are attributed to presence of zircon and allanite as accessories which incorporate U and Th in their crystal lattice.

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The present study deals with geochemical characteristics and petrogenesis of three younger granite varieties (coarse-grained biotite-muscovite granites (CBG), garnetiferous muscovite granites (GMG) and Abu Aggag biotite granites (AAG)) in El-Hudi area, east of Aswan, southeastern desert of Egypt. Mineral chemistry and whole rock chemistry data revealed that all granites have high SiO 2 (70.8-74.7 wt.%), Al 2 O 3 (12.8-14.3 wt.%), Na 2 O and K 2 O (>3.2 wt.%) contents with high Na 2 O/K 2 O ratios (∼>1). Plagioclase feldspars range in composition from albite to oligoclase (An 9-27 ) in CBG, oligoclase (An 13-18 ) in GMG and albite (An 2-6 ) in AAG. Potash feldspars are mainly perthitic microcline and exhibit chemical formulae as (Or 93-96 Ab 7-4 An 0 ) in CBG, (Or 95-98 Ab 5-2 An 0 ) in GMG and (Or 82-98 Ab 18-2 An 0 ) in AAG. Biotites from CBG and GMG are enriched in (Mg and Ti) and depleted in (Al, Fe, Mn and K) compared with those of AAG. Biotites from CBG and GMG had been derived from calc-alkaline magma, whereas those from AAG had been derived from peraluminous magma. Chlorites from CBG and GMG are Mg-Fe bearing, while that from AAG is Fe-rich chlorite (chamosite). The CBG and GMG are Mg-rich monzogranites originated from high-K calc-alkaline magma with metaluminous to mildly peraluminous nature. The AAG are Fe-rich monzogranites to syenogranites generated from high-K calc-alkaline peraluminous magma. Both CBG and GMG are late-to post-orogenic granites, while the AAG are post-orogenic granites. All three granite varieties are considered as evolved I-type granites, formed under low to moderate water pressures (∼ 0.5-7 kbars) and relatively high ranges of crystallization temperatures (∼700-890°C). They were generated from partial melting of crustal materials at lower (CBG >30 km depth) and intermediate (GMG & AAG ∼20-30 km depth) levels. The crystal fractionation was the predominant process during differentiation of parent magmas of these granites. Geochemical characteristics manifest that AAG represent the highly fractionated member of magma cycle differs from that produced CBG and GMG. The CBG are relatively enriched in both U and Th existing only within the accessory minerals such as zircon, sphene, and allanite.

Quartz-diorites, monzogranites and pegmatites are the main rock units in the studied area. The pegmatites occur as zoned pockets within monzogranites with zonal arrangement: border, wall, intermediate, and core zones. The wall zone have enrichment of radioactive and RREs-bearing minerals. K-feldspar, plagioclase and quartz are essential minerals, whereas uranothorite, columbite, zircon, xenotime, monazite, sphalerite and pyrite are accessories. Geochemically, the pegmatites of W. Ghadir have peraluminous character, ferroan with alkalic–calcic affinity and emplaced in within plate setting. These pegmatites revealed Li-bearing variety and high level of rare earth elements mineralization. The studied pegmatites exhibit high contents of Li, Nb, Cu, Ta, U, Th, Pb, Zr, Zn and Ga, can be from the previous data, the studied pegmatites can be classified as a Niobium–Yttrium–Fluorine (NYF) pegmatite or rare metal pegmatite. The trace elements ratio supports a low degree of fractionation and metasomatism in the evolutionary history of the pegmatites, and the very low Cs values (2.2–4.3 ppm) indicate paucity of alkali metal fractionation. Spectrometric investigation revealed that monzogranites are not uraniferous, while the radioactive anomaly is confined to the pegmatites. Applying the U mobilization equation proved that pegmatite samples have been originated from a late magmatic phase of magma very rich in radioelements, and the pegmatites affected with hydrothermal solutions rich in uranium than thorium which indicates uranium addition. Radioactive and important heavy minerals are represented by uranothorite, columbite, zircon, monazite, xenotime, sphalerite and pyrite.