Wetumpka Structure, Alabama

Steven Dutch, Professor Emeritus, Natural and Applied Sciences, Universityof Wisconsin - Green Bay


The Wetumpka Impact Structure, Alabama, is a small Tertiary structure just northof Montgomery. A casual visit will quickly show an unusual disturbance of therocks but little obvious evidence of impact. The upturned Paleozoic rocks lookat first glance like any other tectonic uplift. Brecciation is not widespreadand the mapped breccia bodies are not easily accessible by road. The mostobvious field evidence suggesting impact is the circular plan of the structure;laboratory petrographic studies confirm it.

Wetumpka Structure, Alabama 

Below: the structure (yellow) is just east of the town of Wetumpka on theopposite side of the Coosa River. U.S. 231 runs along the northwest margin ofthe structure.

Wetumpka Structure, Alabama 

Below: the northern half of the structure is clearly visible in topographyand stream patterns.

Wetumpka Structure, Alabama

Wetumpka Structure, Alabama Left and below: Tilted Paleozoic rocks along U.S. Highway 231
Wetumpka Structure, Alabama Wetumpka Structure, Alabama
Wetumpka Structure, Alabama Tilted Paleozoic rocks along U.S. Highway 231. What appears to be an overturn at the top is actually due to the way the cut is beveled; the rocks are actually uniformly dipping.
Wetumpka Structure, Alabama Brecciated and deformed sandstone in the interior of the structure
Wetumpka Structure, Alabama Brecciated and deformed sandstone in the interior of the structure
Wetumpka Structure, Alabama View northwest off the rim of the Wetumpka structure
Wetumpka Structure, Alabama View from Wetumpka across the Coosa River to the rim of the Wetumpka structure.
Wetumpka Structure, Alabama View from Wetumpka across the Coosa River to the rim of the Wetumpka structure.

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Created 14 July 2003, Last Update 06 June 2020