by Amanda Rollason

On Saturday, February 19, 2022, many CCGMS members made their way to Monteagle, Tennessee and caravanned with other DMC groups to Ross Creek in Gruetli-Laager, about a 40 minute drive away. The part of Ross Creek where we were at was a shallow creek, with many little side creeks leading away and into the main creek. Most of us found something amazing to take home that day. I found a lot of very colorful shale and dark fern tree fossils. So, these fern tree fossils date back to the Pennsylvanian and Mississippian Periods where Carboniferous plant fossils come from. I didn’t know what this meant and decided to look it up. According to berke-ley.edu, the Pennsylvanian and Mississippian Periods were about 299 to 359.2 million years ago, and the Carboniferous Period is when plants cover the earth, where large trees covered with bark and huge ferns grew in the middle swamps. Carboniferous rocks in eastern North America largely consist of a repeated sequence of limestone, sandstone, shale and coal beds. The large coal deposits of the Carboniferous may owe their existence primarily to two factors. The first of these is the appearance of wood tissue and bark-bearing trees. The second factor was the low-er sea levels that promoted the development of extensive low-land swamps and forests in North America and Europe; this matters because large quantities of wood were buried during this period because animals and decomposing bacteria and fungi had not yet evolved enzymes that could effectively digest the bark, stems, and ferns. Fungi that could break those substances down effectively only became dominant towards the end of the period, making subsequent coal formation much rarer. This is the reason that coal is also called a ‘fossil fuel’. Mining and using fossils as fuel takes its toll, though; please see the nrdc.org website for more information.