Ordovician of Caesar Creek, Ohio

[Italo40]

Hello dear members, 

in this post I'll show you the fossil bonanza of Caesar Creek State Park, near Waynesville, Ohio. This summer I spent a day collecting fossils in Ohio and I visited three sites: Trammell (I talk about it here http://www.thefossilforum.com/index.php?/topic/98830-trammel-fossil-park-ohio/), Oakes Quarry and Caesar Creek State Parks. The latter was the best, both for finds and general experience. It is in fact regarded as the most accessible fossil hunting locality on Ohio: over 150 m (500 ft) of fossiliferous rocks are exposed, due to the works for the constuction of an emergency spillway back in 1978. Since then it has attracted the attention of paleontologist and amateurs. In order to collect, you have to sign an authorization at the nearby Visitor Center and you cannot use tools or collect specimens that are larger than the palm of your hand. Nevertheless, you'll find and be able to keep some exceptional material and I consider my experience as the best ever in a fossiliferous locality!

Three formations crop out: Waynesville, Liberty and Whitewater formations. They date to the Upper Ordovician, a period when Ohio was covered by a shallow inland sea and was characterized by a tropical to subtropical climate. Beds of limestones and mudstones formed as the result of storm waves and currents; in a few cases the effects of super-hurricanes and tsunamis can be recorded. the fossil assemblage is dominated by clusters of brachiopods, bryozoans and horn corals. aragonitic fossils, such as bivalves, gastropods and nautiloids are preserved as internal molds. articulated and frequently enrolled trilobites can be found, as well as fragments of Isotelus, a very large trilobte and State Fossil of Ohio. In the Visitor Center a small diomara shows the Caesar Creek biota as it apparead in the Ordovician, alongside some fossils, including a perfectly-preserved Isotelus specimen. 

In the field, I collected fossils only from the ground, not on the walls (where you can only take pictures). i found a lot of isolated specimens, here I show the larger and more impressive clusters.

Let's start with a picture of a section of the exposure

 

And now the fossils! In the clusters, many kinds of fossils are preserved, in particular brachiopods and bryozoans, of which many species can be found.

Horn corals are easily distinguishable:

 

In this case, I think the cephalon of a trilobite can be seen:

 

This was a huge Bryozoan cluster!

 

And now, my favourite specimen, the genal spine of an Isotelus trilobite!

 

Finally, a picture of me holding a rock densely-packed with bryozoans and brachiopods.

 

all right, that's all! I hope you liked my post. I really loved the experience at Caesar Creek: everywhere you looked you could see museum-quality specimens. I spent only a couple hours at the site, but I have never seen so many fossils in a single place! I higly suggest anyone to pay visit, you wont't be disappointed.

Thank you,

Fabio

 

[Al Tahan]

That seems like a quality location! Excellent finds. Ohio is an 8 hour drive for me...someday lol

[Tidgy's Dad]

4 hours ago, Italo40 said:

Hello dear members, 

 

Nice report and some great finds and photos thereof. 

But why in this diorama are all the brachiopods dead? 

[FossilNerd]

Nice report as usual! I like the plate full of solitary rugose coral the best.  

[Italo40]

26 minutes ago, Tidgy's Dad said:

Nice report and some great finds and photos thereof. 

But why in this diorama are all the brachiopods dead? 

Oh, I didn't notice that. Maybe it points out that they formed large accumulations on the sea floor, much like those that we can see today in the fossil record!

[FossilDAWG]

It is a fun location, but it can be frustrating too.  When I visited, every time I got with 30 feet of the talus at the base of the walls of the spillway, a ranger (or maybe docent) appeared to rudely shoo me away.  I would not have been able to take a photo like the last one you show, that's for sure.  We were allowed to pick up small fossils that were loose on the ground towards the middle of the spillway, but if you could not pry them from the ground with your fingertips you had to leave them as the "no tools" rule was strictly enforced.  None of the rocks you show could have been collected, and I would certainly have been kicked out if I picked up a rock the size of the one you are holding.  I guess that ranger/docent just left a bad impression.  Nevertheless, I did get a nice assortment of brachiopods, bryozoans, and snails.

 

Don

[Italo40]

15 minutes ago, FossilNerd said:

Nice report as usual! I like the plate full of solitary rugose coral the best.  

Thanks for the nice words! I liked them the most too and I was fascinated because I had never found them before. I was able to take a couple of loose specimens back and now they proudly stand in my fossil showcase!

[Italo40]

7 minutes ago, FossilDAWG said:

It is a fun location, but it can be frustrating too.  When I visited, every time I got with 30 feet of the talus at the base of the walls of the spillway, a ranger (or maybe docent) appeared to rudely shoo me away.  I would not have been able to take a photo like the last one you show, that's for sure.  We were allowed to pick up small fossils that were loose on the ground towards the middle of the spillway, but if you could not pry them from the ground with your fingertips you had to leave them as the "no tools" rule was strictly enforced.  None of the rocks you show could have been collected, and I would certainly have been kicked out if I picked up a rock the size of the one you are holding.  I guess that ranger/docent just left a bad impression.  Nevertheless, I did get a nice assortment of brachiopods, bryozoans, and snails.

 

Don

Yeah I was very luck indeed. I visited in late August and there was only a couple of other collectors, but no one checking on us. Obviously I observed the regulations and I didn't keep any of the pictured material, but I couldn't resist in taking pictures!

[Uncle Siphuncle]

My first Caesar Creek bug, 1980.  I moved away from the area in 1993 and have never found another Isotelus in subsequent visits.  Somehow I managed not to lose this specimen I found as a 10 year old.

[Monica]

It looks like you had beautiful collecting weather that day, and found some really pretty fossils, too - congratulations!

[Shamalama]

I've been to the Caesar Creek spillway twice before and neither time did I register at the visitors center nor did I get yelled at for walking everywhere and climbing everything.  I never dug and did pick up fossils from the cliffs and ground.  It's a nice exposure and a great place to take kids as it has plenty of space to run around, unlike most roadcuts.

[erose]

It's been many moons since I last visited Caesar Creek Spillway. But it was always productive and I never had issues with the rangers. I pretty much followed the rules with no problem. I did explore the talus below the cliffs and I may have included all my outstretched fingers in the definition of "palm." 

 

I found the best stuff crawling the flat floor of the spillway. I'd move about looking for concentrations of the little Zygospira brachiopods and the itty bitty Flexicalymenes would be amongst them.   But there was other good stuff. I found a nice dime-sized Isotelus roller similar to Uncle Siphuncle's that way. But I have beautiful brachs, bryozoa, corals and more. There are some cool crinoids to be found there as well as rare starfish (bucket list!).

 

Fossil Dawg, you apparently were there on the day some ranger got up on the wrong side of the bed. Your experience I would characterize as the exception, not the norm.

[FossilDAWG]

It's good to know my experience was unusual.  Possibly I got someone who was new to the job and somewhat "overenthusiastic".  I may well give the place another try when I'm passing through the area.

 

Don

[erose]

10 minutes ago, FossilDAWG said:

It's good to know my experience was unusual.  Possibly I got someone who was new to the job and somewhat "overenthusiastic".  I may well give the place another try when I'm passing through the area.

 

Don

Definitely. 

 

We all know there are some folks who should never be given a uniform, or worse, a firearm.

[Kato]

It truly must be fun to have Ordovician jammed full of so many different fossils. I just completed a local New Mexico canyon hike with 50 vertical feet of Ordovician, spread along 2 miles of canyon floor, and could only find favosite coral. Interesting how the same geologic period separated by 1500 miles or so can be so different. Now if you love crinoids we literally have billions if not trillions of them here. haha.

 

Fortunately, a local friend, who still has a home in Ohio brought back a box full of Ordovician from his hometown that is as chock full of fossils as what you are sharing with us. I even found a small trilobite peeking out on one of the rocks.

 

Have fun!