Mammoth Cave National Park
A quintessential example of karst topography
What is Mammoth Cave?
Mammoth Cave is the longest cave system in the world. It is a heavily visited national park and is known for the overlying karst topography and long winding caverns within.
Mammoth Cave is located in central Kentucky
What defines Karst Topography?
Topographic Map of Mammoth Cave National Park (USGS)
- Karst topography is defined by specific geologic landforms and drainage patterns.
- These landforms include but are not limited to sinking streams, springs, monadnocks, sinkholes, and caves.
- Karst landscapes develop on soluble rock layers creating poor surface drainage and typically diverts water underground.
- Mammoth Cave and the surrounding region is a good example because of the plethora of features within the area.
What do these landforms look like?
What do karst landforms look like in the Mammoth Cave region?
Sinking Streams are streams that flow into a permeable layer of rock "disappearing" into the ground and reappearing as springs downstream.
Springs are the counterpart of sinking streams that occur when the water table intersects with the ground surface.
Monadnocks are remnants of the overlying impermeable capstone that was once laying over the permeable layer of rock.
Sinkholes are depressions that typically occur in multiples as a sinkhole plain.
Dry Valleys are valleys that have down cut into a permeable rock unit making the water flow directly into the ground instead of running along the bottom of the valley.
Caves form under the overlying resistant caprock and can develop in the phreatic (saturation) zone or the vadose (aeration) zone creating pits, corridors, and speleothems (stalagmites, stalactites, etc.)
Where and why does karst topography occur?
- Karst topography only occurs when permeable rock layers are near the ground surface and can be dissolved by rainwater.
- As this process occurs, landforms such as sinkholes, disappearing streams, caves and dry valleys form.
DePauw Nature Park (photo taken by Chris Lynch via AllTrails)
- The Midwest is known for its limestone which is a permeable and soluble rock layer, so its not surprising to find karst landforms nearby.
- In fact, DePauw's Nature Park was once a limestone quarry.
- You can find Karst topography all over the world. The US is a great place to find different types of karst landscapes.
Karst topography is all over the US and can be found with a variety of bedrocks
Sinkhole Plain 3-D imaging
Sinkhole plains can be best shown using 3-D imaging and exaggerating the vertical scale. The model below shows a sinkhole plain southeast of Mammoth Cave National Park heavily pockmarked with sinkholes at a 3x vertical scale.
Mammoth Cave Area Sinkhole Plain
