GSA Today
Volume 18, Number 12 (December 2009)

About the cover:
Recumbent chevron folds in Early Pennsylvanian graywacke and shale of the Bude Formation at Millook Haven on the north coast of Cornwall, southwestern Britain, record the development and deformation of the Varsican foreland basin — testifying to the closure of the Rheic Ocean during the mid- to Late Pennsylvanian Variscan orogeny. See “The Rheic Ocean: Origin, Evolution, and Significance” by R.D. Nance and U. Linnemann, p. 4-12.