July 24, 2004
This interesting photo of sandstone "blistering" was taken near Moab, Utah in April of this year. A number of similar patterns were observed on sandstone surfaces in this area. The shapes were frequently circular, but some denser forms are ram-head shaped. While it's not know for sure just what may have caused this deformation or blistering, it's possible that lichens weakened the rock, and physical weathering eroded it out.