It cuts through Permian rock, and according to the Geological Society of America, may actually be a complex fault.

Basic volcanism is recognized in the Carboniferous and Permian rock.

Most of the Permian rocks in Kansas were deposited in marine environments.

Permian rocks are the best-known of the Texas Paleozoic.

Below are Permian sedimentary rocks including measures of coal.

The last trilobites are found in Permian rocks, and before the Triassic they had disappeared forever.

Acanthodian fishes generally resembling this one are known from quite complete specimens from Devonian to Permian rocks.

Permian rocks predominantly consist of limestones, shales and evaporites.

The Permian rocks in the central and southeastern expanse of the Lower Hunter Valley were formed when the area was underneath a shallow marine estuary.

These stratigraphic sequences are among the thickest collections of Permian rocks in the world.