


Geology of Brazil
Phanerozoic (542 - 0 Ma)

Compared to the relatively lifeless Precambrian, during the Phanerozoic, life suddenly exploded with staggering diversity and complexity. This was triggered by rising oxygen levels, which allowed the formation of an ozone layer in the upper atmosphere.
This layer acted as a shield against the deadly ultaviolet radiation, permitting ocean life - forms for the first time to come on land. It is believed that during the so - called Cambrian explosion there existed more different life forms than ever again in the planet's history.
During the Phanerozoic, Pangea including West Gondwana breaks up, the South American / Patagonian platform drifts westwards and the South Atlantic opens. In the east, the Nazca Plate subducts the South American Plate giving rise to the Andes. In the west, the Paraná Basin is flooded by voluminous basaltic lava flows and alkaline magmatism in southeast Brazil initiates the formation of the Southeast Rift and the mountain chains Serra do Mar and Mantiqueira – Geological Tours / Brazil.