Geologic History
The Hurricane Creek area on the east side of Tuscaloosa just north of Highway 216 includes beautiful erosional landforms, intriguing Paleozoic bedrock, and historic coal mines. The spectacular landforms in the area range from the steep-sided valley cut by the stream, huge blocks of solid sandstone that slumped or fell from the valley walls, to caves in softer layers of the bedrock and what is locally known as honeycomb weathering in the sandstone.
The steep-sided valley carved by Hurricane Creek along the eastern side of Tuscaloosa is one of the southernmost examples of a landform more commonly found much further north. The tightly curved and steep sided valley landform is an incised meander that results from extensive erosion by a sinuous or meandering stream. In the case of the Pottsville sandstone along Hurricane Creek, which is relatively resistant to erosion, the valley must have taken many thousands of years to form. Smaller scale erosional features include small caves formed by a combination of stream undercutting and seepage of rainwater into fractures in the rock.
The sandstone, coal and minor shale found along the sides of Hurricane Creek are all part of the Paleozoic age Pottsville Formation. This formation was deposited as sand bars, mud flats, and gravel by meandering rivers and streams flowing across a flat swampy plain during the Pennsylvanian Period of the Paleozoic about 300 million years ago.
The abundant fossil plants and coal found in this formation indicate that the area was covered by lush swampy vegetation during the Pennsylvanian. The sandstone and organic-rich material was buried and covered by layers of sediment. This led to compaction, heating, and decomposition of organic materials. As a result, the organic matter was eventually reconstituted into coal.
Shortly after deposition of the Pottsville sediments, collision of North America with Africa caused faulting, folding, and uplift of the Appalachian Mountains. The Pottsville rocks exposed along Hurricane Creek were on the western edge of the mountains where a few faults broke the layers into blocks. After mountain-building, many years of freeze-thaw cycles and rainfall broke the overlying rocks apart and eroded the pieces, exhuming the sandstone, shale, and coal layers now found along the creek. Finally, rivulets of water coalesced into the creek that we see today.
Thousands of years of erosion eroded the prominent cliffs now found along the creek. Native Americans explored the creek and used some of the caves found along its banks. These explorers were followed by early European settlers who exploited energy resources found in the Pottsville coals. They dug coal at the surface and then followed the thin seams into the cliffs in what are known as belly mines. Many of these crude mines can be found along the cliffs above Hurricane Creek.