What is it?
The knob of Central Kentucky our composed of loose shales near the top of the knobs that are of of the Mississippian age Borden formation --- these shales are much less resistant to erosion than the overlying limestones and sandstones that cap these hilltop. It is this combination of factors that create the steep sides of these knobs. The base of the Knobs commonly contain Devonian black shales (seen here in this creek bed). The Knobs physiographic region occurs along the outcrop belt of the Devonian-Mississippian contact. The knobs are usually associated with the outcrop belt of Silurian and Devonian rocks which commonly crop out nearby. Bernheim Forest is located in the Knobs Region of Kentucky. Below you will see an illustration of what these knobs are composed of along with this lower shale layer that is exposed in this creek bed.
"The Knobs" is the physiographic region that borders the Outer Bluegrass. It consists of hundreds of isolated, steep sloping, often cone-shaped hills. In physiographic terms, the hills are monadnocks or erosional remnants.
At this location
You will notice that the water from this creek has cut into the bank and exposed a layer of shale, this shale is the lower level of the adjacent knob
Your hike will take you through areas of dense trees, down the ridge to an area of many creek beds. Parts of the trail cross the creek and may be slippery when wet, so use caution.
To log this Earth Cache please answer the questions below:
1. How long is the area along the creek bed that is exposed?
2. How thick is this layer of shale here?
3. (Educational Question) In your own words, explain how water rushing through this area and freezing and thawing of the water might have caused the exposing of this layer here? *(optional) Please post a picture of yourself or your GPS at the rock feature.
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Earthcache Listing
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