Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1753904 | International Journal of Coal Geology | 2009 | 5 Pages |
Abstract
The Middlesboro Basin, southeastern Kentucky, occurs on the Cumberland Overthrust Sheet and includes a ca. 5.5-km diameter impact structure. The Lower and Middle Pennsylvanian coal-bearing strata are faulted, with some evidence for shock metamorphism. The event post-dated the latest-Pennsylvanian-early-Permian thrusting and was likely prior to late-Mesozoic entrenchment of drainages. The impact of a 0.5-km meteor traveling at ca. 60,000Â km/h would release about 1Â EJ, the approximate equivalent of the instantaneous combustion of 30Â Mt of coal. The coal rank, while increased slightly above the regional level, still is within the upper portion of the high volatile A bituminous rank range. This helps to constrain the depth of burial at the time of the impact. The coal would have had to have been at a depth of a few kilometers to have avoided a more substantial rank increase. In addition, it is possible that some of the coal rank increase might be attributable to movements along the cross-cutting Rocky Face fault, unrelated to the impact.
Related Topics
Physical Sciences and Engineering
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Authors
James C. Hower, Stephen F. Greb, Kenneth W. Kuehn, Cortland F. Eble,