Archaean S-Type granites: petrology, geochemistry and geochronology of the Lekkersmaak and Willie plutons, Kaapvaal Craton, South Africa

Abstract S-type granites correspond to reworking of pre-existing continental material and form by partial melting (meta)sediments. Early-to-mid Archaean are rare more frequently found, usually as relatively small intrusions, during the Neoarchaean Archaean-Proterozoic transition. In context geology, their paucity is therefore significant, in that it matches uncommon nature processes this period. study, we focus on Late Mesoarchaean Willie pluton Lekkersmaak pluton, which crop out south Murchison Greenstone Belt Northern Kaapvaal Craton, South Africa. These intrusions represent oldest plutons known so far region. We constrain petrogenesis documenting petrology, mineralogy (mineral composition), geochemistry (major trace elements, Sr, Nd O isotopes) zircon U-Pb geochronology. The large smaller two sharing many geochemical characteristics; they both peraluminous, Ms-bearing although sodic less potassic than typical granites. granite was emplaced 2 816 ± 9 Ma ago while yielded an emplacement age 771 Ma. Therefore, S-Type magmatism area occurred twice at 2.82 Ga then 40 Myr later 2.77 Ga, involving comparable immature metasedimentary sources conditions melting. Finally, a sample from devoid features muscovite-free aluminum poor 734 11 ago. This confirms episodic magmatic activity Belt.