Do rock faces throughout southeastern Ohio share similar characteristics?
A Comparison of five different rock faces throughout Athens and Hocking counties.
Stroud’s Run State Park, Athens, Ohio. Rock type: Sandstone. Large fracture down the middle of the rock face, moderately sized. Most of the rock face is covered in mold growth and efflorescence. Takeaways: The mold growth and presence of efflorescence allow us to assume that this rock face is routinely exposed to the elements, the prominence of these growths also allows us to assume this rockface has been exposed to the elements for a relatively long time.
Sells Park, Athens, Ohio. Rock type: Sandstone. Rockface forms a rock house. Moderately sized, somewhat similar to set 1. An odd pillar-like formation within the rock house. The inside of the rockhouse features very bare sandstone, extremely minimal mold growth. Takeaways: The bare sandstone indicates that the interior rockhouse is both unexposed to elements but also suggests that the inside of the rockhouse has not been exposed for a relatively long time. The pillar-like formation also implies that at one point in time, a stone more susceptible to erosion once occupied what is now the empty space of the rock house.
Behind the Hampton Inn on East State Street in Athens, Ohio. Rock Type: Shale. The amount of exposed rock is much less when compared to other sets. Pieces of eroded shale lie on the ground before the rockface. Individual pieces of shale appear small and flat. shale is most often a dark gray to dark brown color. Takeaways: Shale is known as a brittle rock and from personal experience can be hard to find in large quantities like this as it erodes quickly. The fact that so much shale exists in this rock face tells us that it has only been exposed to the elements for a relatively short period of time.
Off of highway 33, just near Nelsonville, Ohio. The rockface has been clearly influenced by the creation of the highway, the coal vein creates a clear separation between layers of sandstone. The coal is black, while the sandstone is mostly its usual orange color. A lack of mold growth indicates that this rock has not been exposed for a relatively long amount of time. Takeaways: According to the Ohio Department of Natural Resources, coal bearing rocks in Ohio are generally from the Pennsylvanian and Permian Periods, which tells us that this portion of rock is about 320 to 245 million years old
Ash Cave, Hocking Hills, Ohio. Rock Type: Sandstone. By far the biggest rock formation of the project, Ash cave is a very large natural cavern that continues to be heavily influenced by erosion from water flow. We also observe honeycomb weathering in much of the rock. Mold growth creates many rich greens and shows how the rock has both been exposed for some time and is also very exposed to moisture. There also appears to be many red splotches of sandstone. Takeaways: The honeycomb weathering in much of the rock was caused by salt crystals and reminds us of how the area used to be covered in ocean water. The red within the rocks is due to the oxidation of iron, which tells us that the rock in Ash cave has been exposed for some time and might contain higher amounts of Iron oxide than other rock faces in the area.
A comparison of detail images of each rock face. Top row taken with 50mm lens and bottom taken with 135mm.