Middlesboro crater
Middlesboro Crater | |
---|---|
![]() The city of Middlesboro is built within the crater | |
Impact crater/structure | |
Confidence | Confirmed[1] |
Diameter | 6 kilometers (3.7 mi) |
Exposed | Yes |
Drilled | Yes |
Location | |
Location | Bell County, Kentucky, United States |
Country | United States |
Region | US-KY |
State | Kentucky |
Access | U.S. Route 25E |
The Middlesboro crater is a meteorite crater in Kentucky, United States.[2] It is named after the city of Middlesborough (both spellings are used), which today occupies much of the crater.
The crater is approximately 3 miles (about 5 km) in diameter and its age is estimated to be less than 300 million years (Permian).
History
The Middlesboro crater is located in the Appalachian Mountains, between the Cumberland Mountains and Pine Mountain. It forms part of the string of geological features that made the Cumberland Gap a critical westward passage during the settlement of Kentucky and the Ohio Valley in the late 18th and early 19th centuries.
Settlements
The town of Middlesboro, built in the crater, was established in 1886 to exploit iron and coal deposits,[dead link][3] although the town's founder, Alexander A. Arthur, apparently did not know of the crater's extraterrestrial origin. K. J. Englund and J. B. Roen, working for the U. S. Geological Survey, identified the impact basin in 1962.[4]
Geological features
The 12-mile (19 km) long Cumberland Gap consists of four geologic features: the Yellow Creek valley, the natural gap in the Cumberland Mountain ridge, the eroded gap in Pine Mountain, and Middlesboro crater.
Middlesboro crater is a 3-mile (4.8 km) diameter meteorite impact crater in which Middlesboro, Kentucky, is located. The crater was identified in 1966 when Robert Dietz discovered shatter cones in sandstone, which led to the further identification of shocked quartz. Shatter cones, a rock shattering pattern naturally formed only during impact events, are found in abundance in the area. In September 2003 the site was designated a Distinguished Geologic Site by the Kentucky Society of Professional Geologists.[5]
Without Middlesboro crater, it would have been difficult for packhorses to navigate this gap and improbable that wagon roads would have been constructed at an early date. Middlesboro is the only place in the world where coal is mined inside an impact crater. Special mining techniques must be used in the complicated strata of this crater. (Milam & Kuehn, 36).
![](http://upload.wikimedia.org/wikipedia/commons/thumb/a/a1/Cumberland_Gap_Pinnacle_Overlook.jpg/640px-Cumberland_Gap_Pinnacle_Overlook.jpg)
The gap was formed by an ancient creek, flowing southward, which cut through the land being pushed up to form the mountains. As the land rose even more, the creek reversed direction flowing into the Cumberland River to the north.[citation needed]
Industrial activity
While coal mining is still the town's primary economic driver, local leaders hope to turn the crater into a tourist destination.[6] In 2003, the Kentucky Society of Professional Geologists designated the area a Distinguished Geologic Site,[7] and the construction of the Cumberland Gap Tunnel makes the town a convenient source of supplies for visitors to Cumberland Gap National Historical Park.
References
- ^ "Barringer". Earth Impact Database. Planetary and Space Science Centre University of New Brunswick Fredericton. Retrieved 2013-08-26.
- ^ "Middlesboro". Earth Impact Database. Planetary and Space Science Centre University of New Brunswick Fredericton. Retrieved 2008-12-30.
- ^ [1][dead link]
- ^ K. A. Milam, J. Evenick, and B. Deane eds. "Field Guide to the Middlesboro and Flynn Creek Impact Structures" (PDF). Impact Field Studies Group. Retrieved November 13, 2012.
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(help)CS1 maint: multiple names: authors list (link) - ^ Kortenkamp, Steve (Summer 2004). "Impact at Cumberland Gap: Where Natural and National History Collide". PSI Newsletter. 5 (2): 1–2.
- ^ Associated Press (2003-09-20). "Kentucky town sees a future in its crater". St. Petersburg Times. Retrieved September 16, 2006.
- ^ Kortenkamp, Steve (Summer 2004). "Impact at Cumberland Gap: Where Natural and National History Collide" (PDF). PSI Newsletter. 5 (2): 1–2.