Tectono-stratigraphic subdivision

The following broad subdivision of geological units is applicable to the whole region:

  1. Archean and/or Paleoproterozoic basement, older than 1.75 Ga;

  2. Metasedimentary sequences of intracontinental basins, with ages between 1.75 Ga and 1.0 Ga;

  3. Neoproterozoic metasedimentary and metavolcanic sequences, including rift and passive margin sequences, arc related sequences (back-arc and fore-arc basins) and collisional sequences (molasse and foreland basins).

  4. Neoproterozoic pre-collisional magmatic arc granitoids, either intra-oceanic or from active continental margins;

  5. Neoproterozoic syn-collisional granitoids;

  6. Neoproterozoic to Cambrian cover units related to late orogenic basins and post-collisional magmatism of Cambrian to Ordovician age.

Geographically the region is subdivided into three segments:

  1. The northern segment that corresponds to the Araçuaí Orogen;

  2. The central segment that includes the Ribeira Orogen, the interference zone between the Ribeira and southern Brasília Orogens, and the Apiaí-Guaxupé and Embú Terranes;

  3. The southern segment including the Dom Feliciano and São Gabriel Orogens.