Microstructural constraints on the Pan-African syn-kinematic magmatism in the Adamawa-Yade domain, Cameroon

Linte region, located within the Adamawa-Yade domain of the Central African Fold Belt (CAFB), is associated with the Pan-African orogeny in Cameroon. Magmatic (granular texture and suborientation of euhedral to subhedral feldspar crystals), sub-magmatic (intragranular fractures filled with quartz), and mostly solid-state (internal deformation, exsolution, and dynamic and static recrystallization) microstructures indicate that magmatic and metamorphic rocks of the Linte area were subjected to analogous tectonic manifestations during the Pan-African orogeny. Magmatic, sub-magmatic, and solid-state microstructural analyses combined with the existing age record reveal three phases of local deformation, namely D n , D n+1 , and D n+2 , which can be correlated with regional D 1 to D 4 deformation phases of the CAFB. The D n (ca. 660–600 Ma) marks the crystallization phase accompanied by magmatic and sub-magmatic microstructures. It is related to the regional D 1 -D 2 deformation. The D n+1 (ca. 600 Ma) represents a compressive tectonic setting related to the regional D 3 . The D n+2 (ca. 598 Ma), initiated during D 3 , represents a transpressive tectonic combined with brittle deformation, and marked by sinistral and dextral shearings episodes, grading into the regional D 4 stage. Collectively, microstructures recorded in the Linte igneous rocks can be correlated with the regional tectonic events, including crustal thickening, and successively sinistral wrench and regional dextral shear movements during the Pan-African orogeny in Cameroon.