## 6 Discussion  
### Tectonic Setting  
In the Ta, Hf, and Rb diagram of [47], the Jabel Al Bayda monzogranites are plotted within the volcanic-arc granite (VAG, Figure 8a), similarly to the monzogranites from the Wadi Um Sidra area, Egypt [48]. However, most of the alkali granites samples are plotted in the within-plate granite field (WPG), comparable to the alkaline granites of Saudi Arabia (e.g., Jabl Khur Dukhan, Jabl az Zuhd, Al-Hamra, and Al-Ghurayyah areas), and monzogranite from the Wadi Al-Baroud area, Egypt [43], while only one sample of the alkali granites is plotted within the post-COLG setting, similarly to alkali granites from the Wadi Um Sidra area, Egypt [48]. The Th/Ta ratio vs. Yb diagram helps to outline the tectonic environment of magmatism (Figure 8b). It is suggested that the alkali granites formed in an ensimatic rift setting, comparable to the alkaline granites of Saudi Arabia, e.g., the alkali feldspar granite from the Al-Hamra area [39], Jabl Sayid area [40], Idah area [37], and Jabl az Zuhd area [38]. On the other hand, the monzogranites are regarded as subduction-related arc granitoids at an active continental margin setting, similarly to Egyptian monzogranites from the El Fereyid area [33], Wadi Um Sidra area [48], and Wadi Al-Baroud area [43]. Figure 7: Chondrite-normalized REE patterns [46] for (**a**) the alkali granites, (**b**) the monzogranites. The mid-oceanic ridge granite normalized spider diagram of trace elements [4] for (**c**) the alkali granites and (**d**) the monzogranites, in comparison with the ANS alkali-feldspar granite and monzogranite patterns of selected areas showed in Figure 1.  
The Zr vs. (Nb/Zr)\({}_{\rm N}\) diagram enables a clear discrimination between two magmatic series (Figure 8c). The early magmatic series, represented by the Jabal Al Bayda monzogenites, is plotted in the subduction-related field, similarly to the Egyptian monzogranite from the Sukari area [42], Wadi Um Sidra area [48], Um Taghi area [32], and Feinan area, Jordan [41], whereas the late magmatic series of alkali granites falls within the field of intraplate granites, except three samples that belong to the collision-related granites, similarly to the alkali feldspar granites from Saudi Arabia, e.g., the Jabal Sayid area [40], Al-Hamra area [39], and Jabal az Suhda area [38]; A2 alkaline granites from Sahara area, Sinai [45]; and alkali feldspar granite from Egypt, e.g., the Qash Amir area [44] and Um Taghir area [32]. There are similarities between the studied granitoids and the 559 \(\pm\) 6 Ma Sukari monzogranite of [51]), the 556-572 Ma Feinan Ghuweir Magmatic Suite of [41], the 593 \(\pm\) 2.4 Ma Jabal Sayid alkali granite of [52], the 564 \(\pm\) 140 Ma Jabal az Zuhd alkali feldspar granite of [38], and the 608-578 Ma Sahara alkaline granites of [45]. The presence of two magmatic  
Figure 8: (**a**) Rb/30-Hf–Ta’3 ternary diagram of [47], for various tectonic environments in collision zones, (**b**) Th/Ta vs. Yb tectonic discrimination diagram of [49], (**c**) Zr vs. (Nb/Zr)\({}_{\rm N}\) diagram of [50], normalization values from [46], (**d**) Nb-Y-Ga’3 ternary diagram of [2]. VAG = volcanic arc granite; SYN-COLG = syn-collision granite; Post-COLG = post-collisional granite; WPG = within-plate granite. Symbols are as indicated in Figure 6.  
series may indicate a change in tectonic processes or conditions during the evolution of the magmatic system in the ANS. The observed transition from a subduction-related signature to a collision or intraplate signature from the early to late magmatic series provides valuable insights into the evolving tectonic processes and geodynamic history of the region.