GEOLOGY OF HURRICANE CREEK

Geologically, Hurricane Creek is interesting because it, like the rest of Tuscaloosa, is on the edge of Alabama’s fall line — the boundary between the older Appalachian ridge and valley area around Birmingham, and the Coastal Plain formed from an ancient seabed. 

The area of Hurricane Creek 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 to 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.



Honeycomb sandstone at Summerfield Bluff

The valley carved by Hurricane Creek along the eastern side of Tuscaloosa is one of the southernmost examples of a landform more commonly found much farther north. The tightly curved and steep-sided valley landform 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. Other erosional features include small caves formed by a combination of stream undercutting and seepage of rainwater into fractures in the rock.


Iced cliff cave

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 Period. The sandstone and organic-rich material was buried and covered by layers of sediment. This led to compaction, heating, and decomposition of organic materials, which were eventually reconstituted into coal.


Exposed Pottsville coal seam

Shortly after deposition of the Pottsville sediments, collision of North America with Africa caused faulting, folding, and uplifting 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, exposing 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 wore away 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 still be found along the cliffs above Hurricane Creek.


An abandoned belly mine from a distance


An abandoned belly mine up close

You can help us by taking photos and noting GPS coordinates for any other abandoned belly mines or mine shafts which you uncover while visiting Hurricane Creek. We would like to create a public map of abandoned mine shafts in the watershed and make this map available to the public.
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