THE CAVES, CANE, AND COAL OF KENTUCKY
“Paradise” is what the first European explorers called Kentucky. And Kentucky still fashions itself as a Commonwealth. But it was known to many people, plants, and animals long before Thomas Walker crossed the Cumberland Gap in 1750, Christopher Gist visited Lower Shawneetown in 1751, or John Findley showed Daniel Boone the abandoned Shawnee village of Eskippakithiki, in 1769.
Kentucky was actively managed for game by Native Americans maintaining prairies through fire. Those fields of canes and grasses were tasty tables to herds of stomping buffalo crossing over from the western prairies, crashing down toward the salt licks of Kentucky. One place they crossed was at the Falls of the Ohio, during low water. Kentucky was a paradise of food and minerals for many wild creatures then.
Around 1,200 A.D., the great corn cultures of the Mississippian Peoples thrived here. See their society at Wickliffe Mounds in Western Kentucky. Earlier still, the Hopewell Culture in Ohio built huge ceremonial mound complexes, including one that imaginatively extended south across the Ohio River from their great Earthworks at the mouth of the Scioto River. Thank the Cropper family for the preservation of that mystical place located in South Shore, Kentucky. The location of Lower Shawneetown was discovered nearby. The same one visited by Christopher Gist!
But even before the Hopewell, there were mounds built in Kentucky by the widespread Adena Peoples around 200 B.C. during the early Woodland Period. And even
earlier, more than 3,000 years ago, hungry Archaic Period peoples left heaps of mussel shell middens along the Green River of Kentucky.
And Giant Sloths, Mammoths and Mastodons once lived here, too. While Saber Tooth Tigers and Dire Wolves prowled the land! I can still see the trees that once fed them. The Paw Paw, Coffeetree, Honey Locust, and Hedge Apple trees. They were here before the climate changed and humans hunted the megafauna to extinction. Widows, with their animal partners who dispersed their seed, now dead.
That is why explorers were so excited to find Pleistocene Age bones of the Woolly Mammoth, the Mastodon, and Jefferson’s Giant Ground Sloth at Big Bone Lick in Northern Kentucky. Thomas Jefferson, and Georges Cuvier in Paris, knew the significance of those bones. They changed the course of natural history and religion in our culture. Jefferson thought those creatures might have still existed out west. He instructed Lewis and Clark to look for them. But none were found alive.
What is seen in Kentucky is spectacular, and spectacular to see, once you look down. Kentucky was covered by seas for hundreds of millions of years. And within the sediment- turned stone are the skeletons of the creatures of those times preserved for us to see. First in mud, muck and debris, and then detritus falling to the bottom of the sea. In time, all that material was pressed into sandstone, silt, limestone, and coal.
Just let your thoughts sweep into view those great ancient forests, on those ancient marshy edges. Huge Dragonflies soaring above. Fallen timbers that would become coal. Not too much for your imagination, when holding rocks with those forest fossil impressions So if you haven’t recently looked down outside, look now. You will be pleased. These are rocks laid down in those ancient geologic times. Here are some of Kentucky’s interesting timelines.
There are no mountains of metamorphic rock here, rising up from ruptures and continental collisions before. Just curtains of mud, muck and debris that gently floated down to the bottom of an ancient sea. And all of that sloshing around at the soupy sea edge bordered with those giant trees. Much time, it was. But when the waters retreated, Voila! Its ancient beds now stone!
So all of Kentucky’s exposed bedrock is sedimentary⎯first laid down as such sediment. There are some notable igneous intrusions, such as those found in the Fluorspar District in Western Kentucky, or in other rock faults across the state. But there are no volcanoes here.
And as the seas swept back out, and then swept back in, they became shallow, then deep again. Different types of material rained down to the bottom in discernable plates, visible as different layers of rock. Rocks through which rivers or roads now cut. One rock layer on top of another, just like a stack of paper plates or a wedding cake. And then time to change. Africa collided with North America again!
Those rock layers were squeezed by the collision. Buckled by the pressure, a ridge rose up in the rock layers between Lexington and Nashville. We call it the “Cincinnati Arch.” Being raised up higher, it was cut down harder, wind and water eroding and exposing the lower, older strata. Even though these different rock layers now appear flat as you drive across them, the exposed bedrock layers get younger as you drive away from the Arch in either direction.
And on the ground, as you move away from Lexington, you may find a “Cuesta”, a one-sided mountain, if the rocks of the upper, younger layers called strata, are more resistant to erosion. They often have outlying knobs, but soon give way to a sloping cliff face leading to more flat land beyond.
In Kentucky, the rocks now exposed at the surface are broken into six general geologic ages: The Ordovician, beginning roughly 510 million years ago (MYA); Silurian, 440 MYA; Devonian, 410 MYA; Mississippian, 360 MYA; Pennsylvanian, 325 MYA; and part of the Permian, 290 MYA. Oceans covered the land we called Kentucky during those times.
Here are the significant cuestas one will cross heading west from the Kentucky River Palisades near Lexington in the Inner Bluegrass. The oldest exposed rocks in Kentucky are at the base of those river palisades. They are of Middle Ordovician Age.
You first drive through the hilly Eden Shale Belt (Frankfort) to reach the Outer Bluegrass⎯Silurian Age rocks⎯at Shelbyville, Kentucky. Head southwest and you will climb up Muldraugh Hill (another cuesta) to the Pennyrile Plateau⎯Mississippian Age rocks full of Kentucky caves⎯then west up the Dripping Springs Escarpment⎯another significant cuesta, this one with Mammoth Cave buried inside. Then you rise up higher still, over the Pottsville Escarpment, into the Western Coalfields⎯Pennsylvanian Age rocks.
There you have it. A fossil travelogue. Over land that formed from sediment in an ocean covering Kentucky, starting 500 million years ago!
And don’t forget to stop at the Falls of the Ohio State Park in Indiana, just opposite the City of Louisville. There are found the great reefs of Devonian Age that form the only natural barrier to navigation on the Ohio River.
Maybe that is why your ancestors stopped here for a drink of famous Kentucky whisky. It is hard work carrying your flatboats around those rocky reefs and rapids!