This Earthcache was part of the worlds First Earthcache GeoTour put on by AFK and the Earthcaching 101 Team.
Experience this EarthCache
Welcome to Trammel Fossil Park! In this Earthcache, we would like to introduce you to some of the stratigraphy (rock layers) of Cincinnati geology. More important, we want you to explore these rock layers yourself and search for fossils! Please feel free to share pictures of your findings!
Here is a brief description of the rock layers exposed here, from the bottom (oldest rocks) to the top (youngest rocks).
Fairview Formation
Named after the hillsides exposed at Fairview Heights in Cincinnati, the limestone layers of the Fairview typically ranges from 7 to 15 inches in thickness. The tops and bottoms of these layers are in soft shale and thus provide easily worked slabs that were used for building stones. You will see ripple marks caused by water moving across the surface of the sea, forever frozen in time. In some places you can see holes in the rocks, probably made by worms burrowing into the mud.
Miamitown Formation
The formation lying on top of the Fairview is called the Miamitown Shale, named after rocks first studied near Miamitown in western Hamilton County. The Miamitown Formation accumulated in a trough that had extended into Ohio from the West. The seafloor of this trough was generally mud filled. At Trammel Park, shell layers colonized the mud filled though and were subsequently buried by mudslides, preserving the fossils in time.
Bellevue Formation
The Bellevue formation was named for the rocks first studied around Bellevue, Kentucky. These rocks are recognized by close layering of limestone indicating a shallower, more stirred up sea at the time of formation. Out of all the formations view-able at Trammel Park, Bellevue reflects a time with the shallowest water, perhaps within ten foot of the surface. Bellevue layers have rippled appearances and plenty of fossils indicating a favorable environment for all kinds of animals.
Corryville Formation
The Corryville Formation is named after the Corryville neighborhood of Cincinnati, near the University of Cincinnati. Fine particles settling out of the seas formed the shale layers that you see in Corryville. These fine particles resulted from erosion and runoff from the uplifted Appalachian Mountains, east of this region. From the Corryville shale, some of the most rare fossils have been found. In many other local areas, the soft shale has eroded away. Trammel Park is unique in that the Correyville Formation is exposed and undisturbed.
What about all of those fossils?
When animals, plants and other organisms die, they typically decay completely. But sometimes, when the conditions are just right, they're preserved as fossils.
Most of the fossils at Trammel Fossil Park form from molds and casts. If an organism completely dissolves in sedimentary rock, it can leave an impression of its exterior in the rock, called an external mold. If that mold gets filled with other minerals, it becomes a cast.
An internal mold forms when sediments or minerals fill the internal cavity of an organism, such as a shell or skull, and the remains dissolve.
* Source research and text by LtStabos.
Logging Requirement:
Once you log this Earthcache as "FOUND" please message us the answer to the following question within 1 hour.
- Find the sign describing the Fairview formation. In what conditions does limestone form? In what conditions does shale form?
- Find the Corryville Formation on the hillside (look for the colored signs that go up the hill). Pick up a rock from this section. What color is it? What else do you observe about this rock? What do the fossils look like?
EarthCaching 101 Locations:
This Earthcache was part of the worlds First Earthcache GeoTour put on by AFK and the Earthcaching 101 Team.
