## 5 Geochemistry
### Major and Trace Element Characteristics
The alkaline/peralkaline character of the Jabal Sayid and Dayheen peralkaline granites is in agreement with the presence of aegirine and ribeckite as deduced from a petrographical study (Figures 3e,f and 4c,d). On the other hand, the Dayheen granodiorite-diorite samples are placed in the calc-alkaline field (Figure 7b). This indicates that these rocks have a different geochemical composition compared to the peralkaline granites and monzogranites. The change in alkalinity observed from calc-alkaline through alkaline to peralkaline in these rocks suggests a variation in the source of the magma and the tectonic setting in which they formed. In the K\({}_{2}\)O vs. SiO\({}_{2}\) diagram of [27], the peralkaline granite samples from Jabal Sayid and Dayheen, as well as the monzogranite samples from Dayheen, are plotted within the fields of the high-K calc-alkaline and shoshonite series (Figure 7c). However, it is also mentioned that granodiorite-diorite samples fall within the medium-K calc-alkaline. The change in magma composition from medium-K calc-alkaline to high-K calc-alkaline and shoshonite series indicates a progressive evolution of the magmas. This evolution can involve fractional crystallization, the assimilation of crustal rocks, or mixing between different magma sources. These processes can modify the chemical composition of the magma and result in observed variations in potassium content. Figure 6: The classification of the studied granitic samples according to the R1-R2 diagram [24]. The FeO\({}_{\rm t}\)/(FeO\({}_{\rm t}\) + MgO) versus SiO\({}_{2}\) diagram of [28] provides insights into the composition and characteristics of the studied granitoids (Figure 7d). Samples of the peralkaline granites from Jabal Sayid and Dayheen fall within the ferroan field, whereas the monzogranite and graniodiorite-difice samples fall within the magnesium field. The ferroan nature of the peralkaline granites, similar to most of the rare-metal A-type granite in the ANS, suggests a higher iron content compared to magnesium. On the other hand, the positioning of the monzogranite and graniodiorite-diorite samples within the magnesium field may be indicative of different source materials or differentiation processes that favor the incorporation of magnesium-rich minerals. The change from the magnesium field to the ferroan field can indicate a transition in the source rocks or the conditions under which these granitoids formed. The trace element profiles of the peralkaline granites and their related pegmatites from Jabal Sayid and Dayheen exhibit similar patterns, as normalized to the ocean ridge granite (ORG, [29]). In general, these rocks are enriched in most trace elements (Figure 8a,b), except for Ba, which is depleted and exhibits values lower than one, specifically in the peralkaline granites. However, there are a few samples where the concentrations of Zr, Sm, Y, and Yb are lower than one. The enrichment of most trace elements suggests a significant contribution from crustal materials to the composition of these granites and related pegmatites. Figure 8c illustrates that the trace elements in monzogranites can be divided into two distinct groups based on their concentrations. The first group includes elements such as K, Rb, Ba, Th, Ta, Nb, Sr, and Ce, which are enriched relative to the values of ORG. The second group comprises elements like Zr, Sm, Y, and Yb, which have concentrations lower than one. The trace element patterns observed in the monzogranites align with those typically found in monzogranites associated with island or continental arc settings in the ANS context. In Figure 8d, a typical saw-tooth pattern of magma related to  
Figure 7: Magma-type diagrams of Jabal Sayid and Dayheen granites.