Fernandez-Alonso, M.,  Baudet, D.,  Tack, L.,  Thiéblemont, D. & Callec, Y. 2018. ‘The Araçuaí (Brasiliano) - West Congo (Pan African) orogenic system: an updated GIS compilation’. CAG 27 Portugal, Aveiro abstracts: 33.

Article in a scientific Journal / Article in a Journal

The Araçuaí (Brazil) - West Congo (Central Africa) Orogen is a branch of the Brasiliano - Pan African orogenic system formed during the Gondwana assembly in late Neoproterozoic and early Palaeozoic times. Since ca. 250 Ma after Pangaea breakup and sea-floor spreading, several segments of the Brasiliano-Pan African orogenic system have been exposed on both sides of the southern Atlantic ocean (e.g. Araçuaí, Ribeira and Dom Feliciano belts in South America; West Congo, Damara-Kaoko, Gariep and Saldanha belts in Africa). The Araçuaí and West Congo belts correspond to the northernmost branch of this orogenic system. Both belts are counterparts of a single, Wilson cycle-related orogen evolved in the embayment outlined by the São Francisco and Congo cratons. Problems arise with understanding the geodynamic processes controlling the roughly symmetric geometry as well as the peculiar confinement of the orogen. To clarify this, a GIS-based compilation to create a 1:1 million restitution of both complementary Araçuaí and West Congo counterparts in their original Gondwana position is in preparation. Work started in 2017 for the GEOSUDESTE 2017 initiative. We present here the first version of the compilation for the African – West-Congo part, spanning Gabon, Rep. Congo, DR. Congo and Angola, based on compilation of published geological maps at 1/200.000 scale and smaller, completed with recent fieldwork results from the authors in resp DR. Congo, R. Congo and Gabon. The integration is based on a proposed uniform lithostratigraphy for the belt, by correlating the mapped units in each country to a formalized sequence matching current lithostratigraphic rules and insights. The formalised lithostratigraphy was also adapted to reflect published works since 1970 and results from recent field work.