Mantle xenoliths (lherzolites and a wehrlite) found in Cenozoic alkaline lavas from Azrou–Timahdite (Middle Atlas, Morocco) were petrographically studied with a particular emphasis on mineral chemistry. The most striking feature of these rocks is that plagioclase formed as a result of Al-rich spinel destabilization. This reaction is recorded in different steps and determined a variety of microstructures that allowed to identif...