The Fodjomekwet-Fotouni shear zone (FFSZ) belongs to the western part of the Central Cameroon Shear Zone (CCSZ). From the border to the core, the FFSZ is made of: (i) protomylonites, (ii) garnet-sillimanite mylonites and (iii) garnet-sillimanite ultramylonites. Structural data indicate (1) a N40°E mylonitic foliation trend (strongly dipping toward NE or SW) with st...