Scouring the Mississippian of Alabama

Cam here-

I spend my time working on lectures, reading books, or annotating scientific papers. But, every once in a while, I get to collect fossils and do field work. I haven’t been out in the field since June of 2017. On January 13th and 14th of this year, I spent the weekend collecting fossils from Franklin County and Huntsville, Alabama. These areas around the state consists of limestones that date back during Mississippian period (Lower Carboniferous) ~355-325 million years old. These limestones formed in deep waters where at the time the geography of North Alabama was very different.

Stratigraphic chart in the area we were collecting in.

In these ancient shallows seas was a large diversity of sea life consisting of brachiopods, rugose corals, crinoids, blastoids, bryozoans, trilobites, and even a few early sharks. Now, their remains makeup the Lower Bangor Limestone Formation and the Lower/Upper Monteagle Limestone Formation of North Alabama. On January 13th the crew headed out to collect fossils from the Lower Bangor Limestone Formation. On our way the site, fossil collector Asa and I decided pull over at a local rock outcrop to save time. The outcrop is part of the Hartselle Formation which consists of fossiliferous and oolithic sandstones. Stratigraphically, the Hartselle Formation is right underneath the Bangor Limestone Formation. So, in other words, we were getting close to our main collecting site.

Debbie and Asa looking for fossils in the Lower Bangor Limestone Formation.

As we pulled up to the lakeshore, we began to pack up our tools and scout around to look for fossils. Limestones slabs were waiting for us to examine and chip away with our rock hammers. At the first site we found many fossils including a few crinoid calyces, trilobite fragments, Archimedes bryozoans, trace fossils, and one small shark tooth. Asa found a beautifully preserved echinoid and edrioasteroid. After the crew was done collecting at site one, we packed up and began to travel to site two of the Lower Bangor Limestone Formation. We pulled up to to the lakeshore once again. This time the men and women split up to look for fossils. Nathan, Asa, and Dylan scouted around to look for fossils.

Asa and I inspecting the Lower Monteagle Limestone Formation Site 1

It wasn’t until about 5 minutes later that I noticed that the the loose sediment on the ground contained a plethora of fossils that the lake water sifted back and forth over time. I spent a lot of my time lying on the ground picking up crinoid stems, ossicles, blastoid thecae (bodies), brachiopods, and even a few echinoid (sea urchin) fragments. After day one was over for fossil hunting, we began to day 2 of fossil collecting. On January 14th, Asa, Jess, and I went to fossil collect in the Upper/Lower portions of the Monteagle Limestone Formation. At location one we stopped by a small outcropping of limestone. We began looking up and down to look for fossils.

Upper Monteagle Limestone Formation Site 2

I found a good number of blastoids and great pieces of crinoidal limestone. After we collected material from site one, we began to travel to site two. Site two was much better for finding fossils. Asa and I began to inspect the very top of the rock outcrops. Fossiliferous sediment was then collected to sift through and use for educational purposes. I began to look for fossils from the bottom of the outcrop and collected crinoid stems and a large amounts of Pentremites, a common blastoid from the Mississippian. Just as we began to leave, Asa found a tooth from a Carboniferous aged cartilaginous fish called Chomatodus. The trip was a very successful one. We all spent the weekend and collecting fossils and enjoying each other’s company.

 

The echinoid Archaeocidaris hemispinifera that was found by Asa.
Four Asteriacites (star fish resting traces fossils) found by Jess.
Petaldus tooth. Found by Jess.
Blastoid (Pentremites sp.) that I found
Chomatodus sp. tooth

4 thoughts on “Scouring the Mississippian of Alabama

  1. Jimmy Williams August 30, 2018 / 11:25 am

    Where do you find these places? The formations and such? I keep looking online but I’m new to all this and don’t know what to look for. In what county and or city are the formations you are hunting in this article?

    • jenebauer August 30, 2018 / 11:36 am

      Hello! I can ask Cam how he went about looking for these fossil localities. There is a community for fossil enthusiasts called myFOSSIL.org. They have lots of forums to ask questions about getting started and some documentation on how to find fossils – some separated out by state: https://www.myfossil.org/resources/find-fossils/. Another good place to start is to study a bedrock geologic map of your area – figure out what time period you are in. Many great fossil localities are found along roadways because the Department of Transportation helps by cutting the rock for us. But not all states allow roadside collecting – so you have to be careful and look up restrictions for your state.

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