Comprehensive assessment of A-type granite from south Sinai, Egypt: geochemistry, zircon geochemistry and geochronology

Abstract

The A-type granites are an important component of the Earth's continental crust and play a significant role in understanding crustal evolution and tectonic processes. This study presents a comprehensive assessment of A-type granites from Ataitir El Dehami granites (ADG), which are located in the northwestern part of the Wadi Seih area in South Sinai, using geochemistry, zircon geochemistry and geochronology characteristics. The geochemical analysis reveals that ADG are characterized by high silica content, relatively high FeO* and high alkali concentration, consistent with A-type granites derived from the melting of tonalite sources. Zircons from Ataitir El Dehami granites have high REE contents with Ce enrichment and depletion of Eu, which, together with the high U/Yb ratios, suggest that the studied granites were generated from melting of continental crustal rocks. Zircon U–Pb geochronological data indicate that the granite emplacement occurred around 575–603 Ma throughout continuous exhumation pulses. The isotopic analyses also indicate the presence of inherited zircon grains (735 ± 9 Ma). The present data suggest that the studied granites were formed in a post-collisional setting, and represent the transition stage from convergence to extension that occurred at 600 Ma.