Columbia (supercontinent)

Columbia, also known as Nuna and Hudsonland, was one of Earth's ancient supercontinents. It was first proposed by Rogers & Santosh 2002 and is thought to have existed approximately 1,820 to 1,500 million years ago in the Paleoproterozoic Era.Zhao et al. 2002 proposed that the assembly of the supercontinent Columbia was completed by global-scale collisional events during 2.1–1.8 Ga.

Columbia consisted of proto-cratons that made up the cores of the continents of Laurentia, Baltica, Ukrainian Shield, Amazonian Shield, Australia, and possibly Siberia, North China, and Kalaharia as well.

The evidence of Columbia's existence is based upon geological and paleomagnetic data.

Columbia is estimated to have been approximately 12,900 km (8,000 mi) from North to South at its broadest part. The eastern coast of India was attached to western North America, with southern Australia against western Canada. In this era most of South America was rotated such that the western edge of modern-day Brazil lined up with eastern North America, forming a continental margin that extended into the southern edge of Scandinavia.

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