Shippingport Island || Louisville, KY

What is the first thing that pops in your head when you hear the words “Devonian fossil bed?” Probably something like, “Wow, that sounds sciency.” And you are totally correct. My travels (and my sister, Rachel) recently brought me to Louisville, Kentucky. On my final day there, I was eagerly waiting for Rachel to take me to the Zappos shoe outlet, when she informed me that it was too far away and we were going fossil hunting instead.

She drove us to Shippingport Island, which is right on the edge of Louisville and is FILLED WITH ACTUAL FOSSILS OF ACTUAL DEAD THINGS!

Fossils are found in sedimentary rock that is formed over millions of years through processes such as weathering, erosion, deposition, compaction and cementation. Basically, they are formed when any type of rock breaks down, is deposited and is pressed together for a super long time. The fossils here at Shippingport Island are from the Devonian period, which means they were deposited between 350 and 425 million years ago! Now, that might not be the coolest thing you have ever heard yet, but take a look at how long humans have been here:

(The Economist, 2011)

Not to make you feel unimportant, but in the scheme of things we’ve been here like a second*. In that tiny little dot, all of human existence has existed (Hippocrates, Aristotle, Ancient Egyptians, Mayans, Cher, ALL OF THE HUMANS). I mean, even that weird bird-dinosaur thing and all its buddies in the Palaeocene era were around longer than we have been!

*probably not scientifically accurate

During the Devonian period, Kentucky was covered by a shallow sea, as was most of North America. In the map from “The Paleontology of North America,” you can see that the United States was mostly ocean and was smooshed together with other continents that would, over millions of years and gradual tectonic movement (my favorite), form the continents we know and love today.

(The Paleontology of North America, n/d)

Since Kentucky was a sea, it was filled with sea organisms. Many sea organisms have hard parts (shells, for example) that are made of calcium carbonate and when these organisms died, they floated to rest on the bottom of the sea floor (#gravity). Sediment was gradually deposited and compacted and cemented together over millions of years which pushed all the dead sea things together and formed...limestone! That is INSANE. Next time you touch some limestone just know you are touching history...million year old history.

But why is Kentucky so special? Why can we see the limestone fossils there when much of North America was also covered in the shallow sea and probably has fossils also? Well that is because of the Ice Age, erosion and plate tectonics, obviously**.

**not obvious.

According to Stephen F. Greb, Richard Todd Hendricks and Donald R. Chestnut, Jr., my current heroes who wrote this amazingly interactive, understandable and detailed*** publication called Fossil Beds of the Falls of the Ohio, in the last 50,000 years glaciers were melting and moving south from Canada (thanks, Canada). Some of these glaciers reached all the way down to Kentucky where they began to melt. Since glaciers are HUGE and able to cut across land, they picked up lots of sediment (that’s a cute way to say it...some of the sediment was as large as boulders). When the glaciers melted, there was a ton of water that ran off and created the deep river valleys like the Ohio River Valley. Each time a glacier melted, it would change the way the land looked. One of these melting glaciers eroded the land and deposited sediment to form the Ohio River Valley that we currently see (thanks, glaciers!). (Greb, Hendricks & Chestnut, Jr., 1993).

***that sounds sarcastic, but it isn’t. The publication is so awesome. It even helps you identify the fossils you might see if you visit the Falls of the Ohio.

However, we can’t see fossils all over this area because the sediment from the glaciers covered most everything. So, why can we see them around Shippingport Island? Greb, Hendricks and Chestnut, Jr. say that it might be because of erosion. Possibly the areas around Louisville eroded more than others. Another prediction is because tectonic movement could have pushed the Devonian era rocks upward in this area. Geological evidence shows that some rocks in this area dip to the east, while some dip to the west meaning that something made them bulge upward (1993). Greb, Hendricks and Chestnut, Jr. say this is called an anticline and the internet and I believe them.

In conclusion, if you live in Kentucky, YOU ARE SO LUCKY! But if not, add this to your travels and you will not regret it. For a more touristy, reliable and preserved view of the fossils, check out the Falls of the Ohio right across the river.

Sources:

Greb, S.F., Hendricks, R.T., and Chestnut Jr., D.R. (1993). Fossil Beds of the Falls of the Ohio. Retrieved from http://kgs.uky.edu/kgsweb/olops/pub/kgs/kgsxisp19reduce.pdf on August 28, 2017.

The Economist. (2011). A Man-Made World: The Anthropocene. Retrieved from http://www.economist.com/content/anthropocene?fsrc=scn/fb/wl/dc/theanthropocene on August 28, 2017.

The Paleontology of North America. (n/d). The Devonian - 417 to 354 million years ago. Retrieved from http://paleoportal.org/kiosk/sample_site/period_13.html on August 28, 2017.

#Kentucky #Geology #Science #Travel