How Do Supercontinents Assemble?
By R. Damian Nance
One theory prefers an accordion model; another has the continents travel the globe to reunite
This Article From Issue
July-August 2004
Volume 92, Number 4
Page 324
DOI: 10.1511/2004.48.324
For a strong dose of humility, consider that not even the land beneath our feet can be taken for granted. For example, geological data indicate with considerable certainty that between 300 and 200 million years ago all of the Earth's continental land masses were assembled into a supercontinent, which has been named Pangea (meaning "all lands"), surrounded by a superocean known as Panthalassa (meaning "all seas").
Figure 1. Plate tectonics, the theory that provides a comprehensive explanation for the forces that have shaped the Earth, suggests that the continents are more or less continuously on the march—rifting apart, colliding, grinding against one another. Moreover, in recent decades geoscientists have come to recognize that this dance is cyclical: Over time, the continents have amalgamated as supercontinents and broken apart again at least five times. The supercontinent cycle, as this process is known, poses a difficult question: Do the continents move apart and back together again like an accordion, or do they reunite on the other side of the planet? The authors have used a sophisticated type of isotopic analysis in an attempt to answer this question. In this satellite image, Africa can be seen colliding with Arabia, gradually closing the Persian Gulf and raising mountains in the process.
American Scientist Comments and Discussion
To discuss our articles or comment on them, please share them and tag American Scientist on social media platforms. Here are links to our profiles on Twitter, Facebook, and LinkedIn.
If we re-share your post, we will moderate comments/discussion following our comments policy.