Wetumpka Impact Crater

This post is going back.  Way, way back.  83 million years back, by some estimates.  You may have already guessed from the title of the post, but if not I'm going to go ahead and spill the beans.  There's a huge crater just east of downtown Wetumpka.  It's really, really big.  The crater is almost five miles across, it was created in the late Cretaceous period, and best estimates put the object that crashed at about 1000 feet wide.  Don't believe me?  Check out these maps.

First, we have a normal topographical map of the area.  Can you make out the crater?

Image courtesy of Auburn University

If your imagination needs a little nudge, here's another view, with the ridges around the crater highlighted.

Image courtesy of the Wetumpka Chamber of Commerce

People have noticed that something weird was happening in Wetumpka, geologically speaking, for nearly 150 years.  In 1891, University of Alabama professor Eugene Allen Smith was the first to note the abnormalities.

Now when one considers that the Mooreville Chalk sets in ... this range of hills ... these outlying tracts become difficult to explain except upon the supposition of a depression of several hundred feet, the whole thickness of the Eutaw strata
— Eugene Allen Smith - Report of the State Geologist, p. 552

It would be almost a century before anyone even considered the possibility that the abnormalities near Wetumpka could be explained by an impact event.  H.J. Melosh wrote the first major work on impact cratering in 1989, and the following excerpt from the preface helps explain why that was the case.

As recently as 1950 most astronomers believed that the lunar craters were giant volcanos, and all but a few geologists derided the idea that the Earth’s surface has been scarred by impact structures kilometers in diameter. A similar lack of appreciation led the eminent geologist G.K. Gilbert in 1896 to reject impact as the process that created Meteor Crater, Arizona. Impact cratering has risen from complete obscurity to become one off the most fundamental geologic processes. One meteoriticist has even suggested that future historians will accord the recognition of impact cratering as equal importance with the development of plate tectonics.
— H.J. Melosh, Impact Cratering: A Geologic Process

A team of geologists, led by Thornton L. Neatherly, visited the site in 1969, and they were the first to hypothesize that the structure was the result of a meteorite impact.  They published a paper in 1976 where they dubbed it the "Wetumpka Astrobleme", astrobleme being Greek for "star wound".  Another team led by Neatherly finally had the opportunity to prove the hypothesis in 1998, when they drilled 630 feet into the center of the crater.  Their findings were published in 1999, and the report showed that the samples of iridium and shocked quartz proved the impact theory.  The historical marker was erected three years later.

Wetumpka Impact Crater historical marker, Wetumpka, Elmore County, Alabama

Wetumpka Impact Crater

The ridges located here are the remnants of a six-mile diameter circular feature created some 85 million years ago by an estimated 1,000-foot diameter asteroid. The area at the time of impact was a shallow sea. The ridges consist of a variety of metamorphic rocks and surround a central area comprised of large jumbled blocks of younger geologic strata. Drilling in the central area of the crater recovered fragments of rocks showing characteristic mineral alteration only associated with impact structures. The structure, although known for more than a century, was first identified as an impact crater in the 1970s.
— Alabama Historical Association - 2002

Reverse of the Wetumpka Impact Crater historical marker, Wetumpka, Elmore County, Alabama

Site of the Wetumpka Impact Crater historical Marker, U.S. 231, Wetumpka, Elmore County, Alabama

Unfortunately, I spent several hours on two separate occasions looking for a spot to take a photo that really conveyed the size and existence of the crater, but I came away empty handed.  The crater is huge, and the entire structure is covered by trees on all sides, so it really just looks like hills.  I suspect that there are a few backyards up on those ridges that might have excellent vistas where you can get a real sense of the circular feature, but I wasn't willing to trespass to find out.  If you know anyone who owns property with that kind of view, let me know and we'll re-visit the topic.