Abstract
The Bougmane complex represents the lower crustal section of a Neoproterozoic oceanic arc.Successive arc magmatic pulses triggered the ‘garnetisation’ of hydrous arc mafics and the in situ formation of tonalitic melt via dehydration and dehydration-melting reactions.Moroccan oceanic arc relics reached a significant crustal thickness (>30–35 km) via a combination of intra-oceanic magmatic and tectonic processes.