A History of Continents in the past Three Billion Years
The end-Paleozoic Pangea appears to have contained three continents that had grown in the Precambrian and remained intact until Mesozoic rifting: Ur, formed at ~3 Ga and accreted to most of East Antarctica in the middle Proterozoic to form East Gondwana; Arctica, an approximately 2.5-2 Ga continent...
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Published in: | The Journal of geology Vol. 104; no. 1; pp. 91 - 107 |
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Main Author: | |
Format: | Journal Article |
Language: | English |
Published: |
Chicago
University of Chicago Press
01-01-1996
University of Chicago, acting through its Press |
Subjects: | |
Online Access: | Get full text |
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Summary: | The end-Paleozoic Pangea appears to have contained three continents that had grown in the Precambrian and remained intact until Mesozoic rifting: Ur, formed at ~3 Ga and accreted to most of East Antarctica in the middle Proterozoic to form East Gondwana; Arctica, an approximately 2.5-2 Ga continent that contained Archean terranes of the Canadian and Siberian shields and Greenland; and Atlantica, formed at ~2 Ga of cratons of ~2 Ga age that now occur in West Africa and eastern South America. Arctica grew at ~1.5 Ga by accretion of most of East Antarctica plus Baltica to form the continent of Nena. Collision of Nena, Ur, and Atlantica, plus minor plates, formed the supercontinent of Rodina at ~1 Ga. Rifting of Rodinia between 1 and 0.5 Ga formed three continents: East Gondwana; Atlantica (which became the nucleus for West Gondwana); and Laurasia (which contained North America, Greenland, Baltica, and Siberia). Gondwana formed at ~0.5 Ga by amalgamation of its eastern and western parts. Various plates accreted to Laurasia during the Paleozoic, and collision of Gondwana with Laurasia created Pangea at ~0.3 Ga. |
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ISSN: | 0022-1376 1537-5269 |
DOI: | 10.1086/629803 |