## 1 Introduction  
Many peralkaline granites are considered specialized granites due to their distinct geochemical properties, including high concentrations of rare earth elements (REEs) and other elements such as Nb, Ta, Zr, Y, U, and Th [1, 2]. The composition of the parental magma is a crucial factor for the subsequent enrichment of rare metals in peralkaline granites and related pegmaties. In addition, the degree and type of magmatic differentiation and the transition from magmatic to hydrothermal processes can significantly influence the final enrichment of rare metals in the resulting magma. The study of alkaline/peralkaline granites and related pegmaties with rare metals is important because it provides valuable insights into the behavior of rare metals during late magmatic processes. These studies help scientists to understand the processes that control the concentration and dispersion of rare metals in igneous rocks. The origin and formation of the rare-metal alkaline and peralkaline granites in the Arabian Shield (AS) have been the subject of investigation in several studies [2, 3, 4, 5, 6, 7, 8, 9, 10]. Al-Ghurayyah, Jabal Hamara, Umm Al-Birak, Jabal Tawlah, Jabal Sayid, and the H Dayheen ring complex (referred to herein as the Dayheen intrusion) are indeed significant occurrences of rare metals in the AS (Figure 1). Both Jabal Sayid and Dayheen plutons were described earlier as A-type peralkaline granite that was produced in a within-plate tectonic setting [7; 8]. The granitic rocks and related pegmaties in Jabal Sayid and the Dayheen areas are characterized by the high content of certain elements, including Zr, Nb, U, Th, and REEs. In both areas, the final stages of magmatic evolution played an important role in the concentration of rare metals. The study by [4] proposes that the Dayheen peralkaline granite was formed through the partial melting of the juvenile lower crust. This melting event is thought to have occurred after the collision between the East and West Gondwana supercontinents during the final stages of the AS evolution. Ref. [6] discussed the U-Pb zircon dating and Nd-Hf-O isotopic analyses of the Dayheen ring complex. These findings suggest that the complex was primarily derived from juvenile crust formed during the Neoproterozoic period. Ref. [8] concluded that the variations in rare-metal mineralization between Jabal Sayid and Dayheen primarily occur from a magmatic to a hydrothermal stage, suggesting the influence of hydrothermal processes on mineralization. Similarly, ref. [9] concluded that both magmatic and hydrothermal processes contributed to the  
Figure 1: A simplified geological map of the ANS (modified after [11; 12; 13]) with the sites of the study areas and other rare-metal alkaline granites in the AS (red circles). formation of mineralization in the Dayheen complex. The study by [10] suggests that part of the Dayheen granitic rocks developed during an extension stage. Overall, these previous studies propose that the tectonic evolution of post-collision alkaline and peralkaline granites is closely linked to the assembly of the Arabian-Nubian Shield (ANS). The specific tectonic setting and processes that led to the emplacement of these granites are still subjects of ongoing study and debate among geologists and researchers in the field. To contribute to the understanding of the origin of rare-metal granites and pegmites, the present authors conducted investigations on the Jabal Sayid and Dayheen plutons in the Jeddah terrane (Figure 1). These plutons are known to host the significant mineralization of Nb, Zr, REEs, U, and Th. This article aims to address several fundamental questions concerning the evolution of rare-metal granite-pegmatite systems based on petrological and geochemical data. Here are the key questions that could be presented:  
1. What are the specific mechanisms involved in the petrogenesis of the peralkaline granites and related pegmatities in the Jabal Sayid and Dayheen areas? 2.