Pipe Creek Sinkhole
 http://www.professionalgeologistsofindiana.org/Portals/7/Gallery/Album/6/010922h.jpg The dark material (oxidized limestone) in this image is a remnant of the original sinkhole. |
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http://www.professionalgeologistsofindiana.org/Portals/7/Gallery/Album/6/010922k3Geos-on-rocks.jpg The sinkhole seen at a greater distance. Images are from the website of the Professional Geologists of Indiana. They were made by the Ball State University Department of Geology's Fall 2001 Field Trip. |
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http://www.irvmat.com/Articles/Images/PipeCrJr.jpg Camel bone found at Pipe Creek Sinkhole. Image from the website of the Irving Materials Company. |
Pipe Creek Sinkhole near Swayzee in Grant County, Indiana, is one of the most important paleontological sites in the interior of the eastern half of North America, preserved because it was buried by glacial till. Uncovered in 1996 by workers at the Pipe Creek Junior limestone quarry, the sinkhole has yielded a diverse array of fossils from the Pliocene epoch dating back five million years. Discoveries have been made there of the remains of camelids, bears, beavers, frogs, snakes, turtles and several previously unknown species of rodents. Two fish taxa, bullhead (Ameiurus) and sunfish (Centrarchidae), have also been found there.
Pipe Creek Sinkhole preserves an ancient wetland. It was created by the collapse of a limestone cave in a Silurian reef formation. That left a steep-sided depression about 75 meters (246 ft) long, 50 meters (164 ft) wide and 11 meters (36 ft) deep. When water collected in the depression, it became the habitat of the plants and animals whose remains were preserved there when the sinkhole was buried by glacial outwash and till during the , two million to 11,000 years ago.
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