GSA Today
Volume 32, Issue 6

Cover image

Topographic map of central North America outlining the extent of its three major failed rifts: the Mesoproterozoic Midcontinent Rift, and the Ediacaran-Cambrian Southern Oklahoma Aulacogen and Reelfoot Rift. Dashed lines indicate possible extensions of rift arms.

© The Geological Society of America, Inc.