The Sunsás orogeny was an ancient orogeny active during the
Late Paleoproterozoic and
Mesoproterozoic
The Mesoproterozoic Era is a geologic era that occurred from . The Mesoproterozoic was the first era of Earth's history for which a fairly definitive geological record survives. Continents existed during the preceding era (the Paleoproterozoic), ...
and currently preserved as the Sunsás orogen in the
Amazonian Craton in
South America
South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the sou ...
. About 85% of the belt is covered by
Phanerozoic
The Phanerozoic Eon is the current geologic eon in the geologic time scale, and the one during which abundant animal and plant life has existed. It covers 538.8 million years to the present, and it began with the Cambrian Period, when anim ...
sediments. Among the remaining 15% of the orogen exposed at surface the best
outcrop
An outcrop or rocky outcrop is a visible exposure of bedrock or ancient superficial deposits on the surface of the Earth.
Features
Outcrops do not cover the majority of the Earth's land surface because in most places the bedrock or superficia ...
s lies around the Bolivia-Brazil border. It is thought that the original orogen once spanned an area from Venezuela to Argentina and Paraguay. The western and southeastern fringes of the Sunsás orogen have been incorporated into the
Andean orogeny
The Andean orogeny ( es, Orogenia andina) is an ongoing process of orogeny that began in the Early Jurassic and is responsible for the rise of the Andes mountains. The orogeny is driven by a reactivation of a long-lived subduction system along ...
and the
Brasiliano orogeny
Brasiliano orogeny or Brasiliano cycle ( pt, Orogênese Brasiliana and ''Ciclo Brasiliano'') refers to a series of orogenies of Neoproterozoic age exposed chiefly in Brazil but also in other parts of South America. The Brasiliano orogeny is a regi ...
respectively. The Sunsás orogeny was active during four separate phases:
*Santa Helena orogeny 1465–1427
Ma
*Candeias orogeny 1371–1319 Ma
*San Andrés orogeny ca. 1275 Ma
*Nova Brasilândia orogeny 1180–1110 Ma
References
Orogenies of South America
Geology of Colombia
Geology of Ecuador
Geology of Bolivia
Geology of Brazil
Geology of Peru
Mesoproterozoic orogenies
Precambrian South America
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