The role of crustal-scale shear zones in SW Gondwana consolidation – transatlantic correlation

Abstract

Abstract We present the first correlation between South American and African shear zones based on a reconstruction model of SW Gondwana continental crust, correlating 57 Brasiliano–Pan-African crustal-scale shear zones that sutured this palaeocontinent at c. 500 Ma. The final amalgamation and consolidation of the SW Gondwana continental crust were attained by an anticlockwise rotation of three cratons (Kalahari, Angola and São Francisco) in relation to the clockwise rotation of the Río de la Plata Craton in the Early Paleozoic. These relative movements were accommodated by transcurrent shear zones active from 585 to 500 Ma within the Pan-African–Brasiliano belts that surround these cratons. This kinematic interaction resulted in the initiation of a long-term active margin starting with the Cambrian Pampean orogeny and ending with the Permian–Triassic Gondwanide orogeny.