Supercontinent

A supercontinent is a large area of land which has more than one continental core, or craton. They are formed by continental plates coming together. Continental plates have periodically collided and assembled in periods of orogeny (mountain-building) to form supercontinents. The cycle of supercontinents forming, breaking up, separating, and re-forming through plate tectonics happens about every 2000 million years.

Eurasia is certainly a supercontinent, but the Americas are usually thought of as separate continents. Even more clearly, Gondwana and Laurasia were supercontinents formed by the breakup of the global supercontinent Pangaea.

The land bridge between North and South America is geologically a rather temporary connection. Because of this, the Americas are usually not described as one supercontinent.

Ancient supercontinents

Throughout Earth's history, there have been many supercontinents. In order of age (oldest to newest), the ancient supercontinents were:

Supercontinent name	Age (Ma)	Period/Era Range	Comment
Vaalbara	3,636–2,803	Eoarchean-Mesoarchean	Also known as a supercraton or just a continent[1]
Ur	2,803–2,408	Mesoarchean-Siderian	Known as both a continent[2] and a supercontinent[3]
Kenorland	2,720–2,114	Neoarchean-Rhyacian	The continents may have also formed into two groupings Superia and Sclavia[4][5]
Arctica	2,114–1,995	Rhyacian-Orosirian	Not generally known as a supercontinent, depending on definition[2]
Atlantica	1,991–1,124	Orosirian-Stenian	Not generally known as a supercontinent, depending on definition[2]
Columbia (Nuna)	1,820–1,350	Orosirian-Ectasian	[4]
Rodinia	1,130–750	Stenian-Tonian	[4]
Pannotia	633–573	Ediacaran	[4]
Gondwana	550–175	Ediacaran-Jurassic	From the Carboniferous, formed part of Pangaea,[5] not always known as a supercontinent[6]
Pangaea	336–175	Carboniferous-Jurassic