Proterozoic taphrogenic history recorded in the pre-collisional sedimentary basins of the Araçuaí Orogen, Southern Espinhaço Range, Southeastern Brazil

The Proterozoic pre-collisional basins of the Araçuaí orogen consist of a succession of superimposed basins that overlie the eastern margin of the São Francisco Craton. This report proposes new stratigraphic and tectonic models for the evolution of the pre-collisional basins of the Araçuaí orogen. They are younger than the Rhyacian orogeny and predate the Ediacaran orogeny. The Orosirian Costa Sena sineclisis was a submerged, N-S asymmetric basin. The onset of the Statherian Espinhaço rift system followed, consisting of four asymmetric rifts, bounded by N-S, west dipping normal faults. The faults are connected at depth to a detachment, exposed at the eastern border of the southern Espinhaço range. The taphrogenic process was caused by an asthenospheric heat flow, from underneath the São Francisco proto-Craton, moving eastward, below the Gouveia complex. After a geological hiatus greater than 400 Ma, the basin activity resumed when the temperature below the Gouveia complex was high enough to create a thermal heat flow, directed toward the east, below the Guanhães complex. Asthenospheric heat flow acting below a younger detachment zone governed the development of the remaining Stenian Tonian Cryogenian pre-collisional basins, continental breakup and oceanic crust generation.