About 83 million years ago, a cosmic object – an asteroid or comet estimated to have been about 1,250 feet in diameter – struck what is now Elmore County on the eastern side of the city of Wetumpka. All that remains of the meteoritic impact crater formed by the collision is a crescent-shaped ridge of hills rising up to 300 feet above the surrounding river plains.Scientists estimate that the energy released by the Wetumpka impact event was over 175,000 times the energy of the nuclear bomb detonated at Hiroshima, Japan in 1945 and would have destroyed all life for a radius of about 40 miles. The crater structure was first noted in 1969 by a group of geologists from the Geological Survey of Alabama, but its origin was not proven conclusively until 1999, when a team of scientists completed a 630-foot-deep drilling operation at the crater's center. The scientists found that the minerals contained in the subsurface samples revealed evidence of deformation characteristics resulting from high pressure and massive sudden impact. Such minerals are found only in structures formed by cosmic impacts and at nuclear-test sites. In addition to the physical analysis, the material was subjected to geochemical testing at a laboratory in Vienna, Austria, which revealed meteoritic elements such as iridium, cobalt, nickel, and chromium and confirmed their meteoric origin.
Info courtesy Encyclopedia of Alabama.