The Wetumpka impact crater is the only confirmed

impact crater An impact crater is a circular depression in the surface of a solid astronomical object formed by the hypervelocity impact of a smaller object. In contrast to volcanic craters, which result from explosion or internal collapse, impact craters ...

Alabama (We dare defend our rights) , anthem = "Alabama (state song), Alabama" , image_map = Alabama in United States.svg , seat = Montgomery, Alabama, Montgomery , LargestCity = Huntsville, Alabama, Huntsville , LargestCounty = Baldwin County, Al ...

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...

. It is located east of downtown

Wetumpka Wetumpka () is a city in and the county seat of Elmore County, Alabama, United States. At the 2020 census, the population was 7,220. In the early 21st century Elmore County became one of the fastest-growing counties in the state. The city is ...

in Elmore County. The crater is in diameter, and its age is estimated to be about 85 million years (late

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of th ...

), based on fossils found in the youngest disturbed deposits, which belong to the

Mooreville Chalk Formation The Mooreville Chalk is a geological formation in North America, within the U.S. states of Alabama and Mississippi, which were part of the subcontinent of Appalachia. The strata date back to the early Santonian to the early Campanian stage of t ...

. The crater is well preserved, including the original impact rim and

breccia Breccia () is a rock composed of large angular broken fragments of minerals or rocks cemented together by a fine-grained matrix. The word has its origins in the Italian language, in which it means "rubble". A breccia may have a variety of di ...

, but exposures are few owing to plant and soil cover, and nearly all are on private land. The

meteorite A meteorite is a solid piece of debris from an object, such as a comet, asteroid, or meteoroid, that originates in outer space and survives its passage through the atmosphere to reach the surface of a planet or Natural satellite, moon. When the ...

that caused the crater was estimated to be 1,100 feet in diameter and was likely to have impacted at a 30-45 degree angle from the Northeast, on a shallow sea that was about 300–400 feet deep.

Thornton L. Neathery Thornton or ''variant'', may refer to: People *Thornton (surname), people with the surname ''Thornton'' *Justice Thornton (disambiguation), judges named "Thornton" *Thornton Wilder, American playwright Places Australia *Thornton, New South Wale ...

discovered the Wetumpka Crater in 1969–70 during regional geological mapping and published the first article on the subject in 1976. However, conclusive evidence of impact origin was lacking until 1998 when David T. King, Jr. and colleagues discovered

shocked quartz Shocked quartz is a form of quartz that has a microscopic structure that is different from normal quartz. Under intense pressure (but limited temperature), the crystalline structure of quartz is deformed along planes inside the crystal. These pla ...

in a core drilled near the center of the structure. In 2002,

Auburn University Auburn University (AU or Auburn) is a public land-grant research university in Auburn, Alabama. With more than 24,600 undergraduate students and a total enrollment of more than 30,000 with 1,330 faculty members, Auburn is the second largest uni ...

researchers published evidence and established the site as an internationally recognized impact crater.

References

WetumpkaOnline City Information
{{Impact cratering on Earth Landforms of Elmore County, Alabama Impact craters of the United States Cretaceous impact craters Landmarks in Alabama