Erosion forms of limestone on a rock shelter at Rough Trail. Red River Gorge, Kentucky, November 6, 1999.
Erosion forms of limestone in a rock shelter at Rough Trail. Red River Gorge, Kentucky, November 6, 1999.
Erosion of a limestone rock at Rough Trail. Red River Gorge, Kentucky, November 6, 1999.
Limestone rocks, view from Sheltowee Trail near Chimney Top Rock. Red River Gorge, Kentucky, November 6, 1999.
Tree roots and erosion forms on a limestone rock at Rough Trail. Red River Gorge, Kentucky, November 6, 1999.
Ruffle lichen (Parmotrema) on a mossy limestone rock in a red cedar forest in Pedernales Falls State Park. Johnson City, Texas, January 11, 2019
Rock shield lichen (Xanthoparmelia) on limestone in a red cedar forest in Pedernales Falls State Park. Johnson City, Texas, January 11, 2019