## 4 Results and Discussion  
### Petrographical Examination  
The Homrit Waggat area comprises several granitic rocks according to their mineralogical composition. They include older granites (tonalite and granodiorite) and younger granites (syenogranite, alkali-feldspar granite, and abitized granite).  
Tonalite is medium-grained (2-4 mm) and characterized by propidiumorphic texture. It is composed essentially of plagioclase, quartz, as well as hornblende with traces (or minor) of K-feldspar. Plagioclase occurs as subhedral crystals that exhibit moderate to extensive turbidity surface because of saussuritization processes (Figure 3a). Thus, their twinning is extinct. Quartz exhibits undulose extinction and occurs in two generations (fine- to medium-grained). Relics of hornblende are recorded due to extensive chloritization. Perthitetexture is abundant with a clear worm-like shape,  
Figure 2: Field photographs showing general views of Homrit Waggat area from its core, revealing the contact between older granitic (OG) rocks and younger granites (YG).  
Granodiorite is medium-grained (2-4 mm) and consists mainly of plagioclase, K-feldspar, quartz, and biotite as major minerals, whereas allanite, titanate and zircon are the main accessory minerals. Plagioclase occurs as tabular crystals exhibiting both lamellar and zoned twinning. It shows a slightly turbid surface because of alteration (kaolinitization) processes. Patchy perthite (intergrowth texture between K-feldspar and albite) occurs commonly enclosing small plagioclase crystals. Quartz is present as fine- to medium-grained crystals. Flaky biotite crystals are partially altered to chlorite. Titanite occurs as  
Figure 3: Crossed-polar photomicrographs showing (**a**) Extensive plagioclase saussiritization (PI) in tonalite; (**b**) Allanite (Aln) associated with biotite (Bt) crystals in granodiorite; (**c**) Pristine patchy perthite (Pr) in synogenrainite; (**d**) Coarse-grained muscovite (Ms) associated with perthite and quartz (Qz) in alkali-feldspar granites; (**e**) Coarse-grained plagioclase engulfing fine-grained muscovite in alkali-feldspar granites; and (**f**) Turbal albite plagioclase crystals in albite granites.  
wedge-shaped crystals. Moreover, allanite is present as reddish-brown crystal associated with biotite crystals (Figure 3b).  
Svenogranite is coarse-grained (>5 mm), composed mainly of quartz, K-feldspar, and plagioclase as major minerals. Zircon and iron oxide (hematite) are the main accessory phases. These rocks exhibit hypodiomorphic textures. Quartz shows normal extinction and occasionally is engulfed in plagioclase crystals. Microcline shows clear crosshatching. Orthoclase-perthite is abundant with simple twinning (Figure 3c) and is either pristine or slightly kaolinitized. Moreover, biotite crystals (flaky) are partially altered to chlorite forming rims. Zircon crystals are disseminated and enclosed in other minerals such as biotite.  
Alkali-feldspar granites are coarse-grained (>6 mm), comprising mainly quartz, K-feldspars, plagioclase, and muscovite. Quartz crystals are fine- to medium-grained and show normal extinction. Flamy as well as patchy perthitic textures are recorded. Subhedral crystals of plagioclase reveal slight saussuritization. Fine- to coarse-grained muscovite crystals with clear cleavage are present (Figure 3d,e).  
Albitic granites are fine-grained (<1 mm), have a white color and comprise albite and quartz crystals with minor K-feldspar. Albite forms subhedral and tabular grains that are rarely fractured. It reveals a completely turbid surface as a result of kaolinitization process (Figure 3f). Quartz occurs as anhedral crystals with normal extinction. K-feldspar occurs as fine-grained perthite crystals. Zircon is the main accessory mineral with pleochroic haloes and is commonly enclosed in albite.