Tectonic Plates Come Apart at the Seams
The content you've requested is available without charge only to active Sigma Xi members and affiliates.
If you are an active member, affiliate or individual subscriber, please log in now in order to access this article. Be sure you've entered your member or subscriber number on your profile page. (You can access your profile page through the green box to the right.)
If you are not a member, affiliate or individual subscriber, you can:
At a rate of a few centimeters per year, the movement of continents is imperceptible to transient beings like ourselves. But over geologic time, the land masses that define the world of our senses have cruised around the globe, smashing together and ripping apart. Pangea, the supercontinent that broke up more than 100 million years ago, was only the most recent union of Earth's landmasses. Supercontinents and superoceans have been forming and disappearing for 3 billion years. But why do supercontinents split at one site and not another? The answer to this question is several hundred million years older than Pangea, dating back to the breakup of the previous supercontinent. The mountainous sutures of old continental collisions, it seems, carry the seeds of the next continental dispersion.