Columbia, also known as Nuna or Hudsonland, is a hypothetical ancient supercontinent. It was first proposed by John J.W. Rogers and M. Santosh in 2002[1] and is thought to have existed approximately 2,500 to 1,500 million years ago (Ma), in the Paleoproterozoic era. The assembly of the supercontinent was likely completed during global-scale collisional events from 2,100 to 1,800 Ma.[2]
Columbia consisted of proto-cratons that made up the cores of the continents of Laurentia, Baltica, Ukrainian Shield, Amazonian Craton, Australia, and possibly Siberia, North China, and Kalaharia as well. The evidence of Columbia's existence is provided by geological[2][3] and paleomagnetic data.[4]