This baked soil displays prominent columnar joints and is sandwiched between two basaltic lava flows. The temperature of the overlying lava flow was in the neighborhood of 1,100 Celsius when it buried the soil. The high temperature dried out the soil and caused the formation of the columnar joints. This outcrop occurs along I-17 near Flagstaff, Arizona. Photo by John Schieffer.
Photographer: John Schieffer
Photo Date: circa 2000
