Geologic Map of Kentucky
(c) 2006 Andrew Alden, licensed to About.com, Inc. Original image courtesy Kentucky Geological Survey (fair use policy)
Kentucky extends from the inland side of the Appalachian Mountains on the east to the Mississippi River bed on the west. Its coverage of geologic time is spotty, having gaps in the Permian, Triassic, and Jurassic periods, and no rocks older than Ordovician (purple) are exposed anywhere in the state. Its rocks are mostly sedimentary, laid down in warm, shallow seas that have covered the central North American plate throughout most of its history.
Kentucky's oldest rocks crop out in a wide, gentle uplift in the north called the Jessamine Dome, a particularly high part of the Cincinnati Arch. Younger rocks, including thick deposits of coal laid down during later periods, used to be there but have been eroded away.
The coal measures of the American Midwest are so thick that the rocks known as the Carboniferous Series elsewhere in the world are subdivided here into the Mississippian (light blue) and Pennsylvanian (gray-blue). In Kentucky, these coal-bearing rocks are thickest in the gentle downwarps of the Appalachian Basin on the east and the Illinois Basin on the west.
Younger sediments (yellow and green) occupy the Mississippi River valley and the banks of the Ohio River along the northwestern border. The west end of Kentucky is in the New Madrid seismic zone and has a significant earthquake hazard.
The best copy of this map is available here in a 1400x600 pixel version weighing 370 KB. The original material is not all that high in quality, but it does have a key to the different colors. The Kentucky Geological Survey Web site has much more detail, including a simplified, clickable version of the state geologic map.
More Kentucky resources on About.com:
About Louisville
Kentucky Maps
Kentucky Geography, State Symbols & Facts
Kentucky Campgrounds
Kentucky National Parks
Kentucky State Parks
Kentucky Getaways
Kentucky Military History Sites
Kentucky Thoroughbred Farms
Kentucky Archaeology
Back to Geologic Maps of the States
