Geo 730: March 27, Day 451: Eroded Cross Bedding

Dune deposition occurs as wind carries sand grains up the fore side (facing into the direction the wind is blowing), then drops the sand on the lee side (the downwind side). This results in a series of cross beds, which slope down in the same general direction the wind was blowing at the time. Here, subsequent wind erosion has beveled off the original surface, exposing the cross beds. As we'll see later, this same process can lead to some surprisingly beautiful abstract "art."

Photo unmodified. July 10, 2012. FlashEarth location (approximate).