Columnar-jointed lava flow in the wall of the Yellowstone River canyon
By Yellowstone Volcano Observatory
2003 (approx.)
Detailed Description
A 1.5-million-year-old basaltic lava flow in the canyon wall of the Yellowstone River as viewed from Calcite Springs Overlook near Tower Junction in Yellowstone National Park. Slow cooling of this lava flow resulted in the formation of vertical columns. Glacial gravels are present above and below the lava flow.
Sources/Usage
Public Domain.