Chemistry and He isotope systematics of olivine as tracers of source in mantle xenoliths from Harrat Hutaymah and Harrat Kishb Cenozoic lava fields, Western Saudi Arabia - Ahmed Hasan Ahmed; Abdel-Kader M. Moghazi; Finlay M. Stuart; Shehta Abdallah; Moustafa Hashad; Kamal A. Ali (Geochemistry, 2025)