Volume 21, Number 8 (August 2011)
About the cover:
The Three Sisters are iconic sandstone towers exposed above the Jamison Valley in the Blue Mountains, Australia. Erosion in the mountains is dominated by stream channels cutting through exposed joints and preferential erosion of weaker shale units interbedded within the Triassic-aged sandstone. Photo by Eric Portenga. See related article, p. 4–10.
© The Geological Society of America, Inc.