Earth:Atlantica

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Short description: Ancient continent formed during the Proterozoic about 2 billion years ago
Atlantica at about 2 Ga. Archean cratons in grey.

Atlantica (Greek: Ατλαντικα; Atlantika) is an ancient continent that formed during the Proterozoic about 2,000 million years ago (two billion years ago, Ga) from various 2 Ga cratons located in what are now West Africa and eastern South America. [1] The name, introduced by Rogers 1996, was chosen because the parts of the ancient continent are now located on opposite sides of the South Atlantic Ocean. [2]

Formation

Atlantica formed simultaneously with Nena at about 1.9 Ga from Archaean cratons, including Amazonia in present-day South America, and the Congo, West Africa and North Africa Cratons in Africa.[3]

Breakup

Reconstruction of Earth 550 Ma ago showing the cratons of Atlantica forming West Gondwana

Atlantica separated from Nena between 1.6–1.4 Ga when Columbia — a supercontinent composed of Ur, Nena, and Atlantica — fragmented. [2] Atlantica and continents Nena and Ur and some minor plates formed the supercontinent Rodinia about 1 Ga ago. Between 1–0.5 Ga Rodinia split into three new continents: Laurasia and East and West Gondwana; Atlantica became the nucleus of West Gondwana. [1] During this later stage, the Neoproterozoic era, a Brasiliano-Pan African orogenic system developed. The central part of this system, the Araçuaí-West Congo orogen, has left a distinct pattern of deformations, still present on both sides of the Atlantic Ocean. [4][5]

See also

Notes

References