Panafrican brittle deformation and palaeostress superposition in northern Togo (West Africa)

In northern Togo, the nappes of the Panafrican Dahomeyide Belt display traces of an intense brittle deformation. These fractures are well represented on the aerial photographs or satellite images, and they stand out as a dense network of lineaments. The analysis of this fracture network, at the outcrop scale, leads to distinguish four compression episodes that can be correlated with four post-collisional and well-known Panafrican deformation phases (Dn + 1 to Dn + 4) of the Dahomeyide Belt. Two conjugated strike-slip microfault systems are associated with each episode and make it possible to determine the palaeostress directions. These directions underwent a progressive clockwise rotation of about 90°, whose meaning remains hypothetical.