Geology of Brazil
Precambrian (4,5 Ga - 542 Ma)

The Precambrian describes the time - span from the formation of earth about 4,5 billion years (Ga) ago to the evolution of abundant macroscopic hard - shelled fossils, which marked the beginning of the Cambrian, about 542 million years (Ma) ago. It is divided into the eons Hadean (4,5 - 3,8 Ga), Arquean (3,8 - 2,5 Ga) and Proterozoic (2,5 Ga - 542 Ma).

During the Precambrian, the prototypes of South America (the South American Platform) and Africa were formed. At the end of the Brasiliano - Pan African orogenic cycle both constitute the western part of supercontinent Gondwana.