Super Sinkholes: Karst Topography in The Parklands
The Zoo, the Corvette Museum, all of Florida … The Parklands – what do all of these places have in common? We have sinkholes! Sure, our sinkholes are smaller, but that does not mean that they are any less interesting! If you have ever strolled through Highland Crossing or found yourself at the Doline Scape, you’ve seen some of our sinkholes!
So what causes a sinkhole? Underneath the beautiful flora that makes up the land around Floyds Fork, is bedrock made of limestone. Limestone is a sedimentary rock made of crushed and compacted sand and shells from 400 – 450 million years ago. This geologic time period, called the Devonian era, saw a Kentucky that was underneath a warm and shallow ocean. Today, we still see evidence of this time period when we find fossils in our rocks! To witness prehistoric fossils, check out the gravel bars on the Sycamore and Black Willow trails in Beckley Creek Park.
Limestone bedrock, like ours here in The Parklands, makes for an extremely unique but vulnerable landscape prone to water erosion. Geologic features such as caves, sinkholes (also known as dolines, hence our Doline Scape), springs, and fresh water aquifers occur frequently within limestone. Throughout Kentucky, we depend on underground karst aquifers for our drinking water!
Karst landscapes and features form when limestone comes in contact with weak acids such as carbonic acid, a simple compound formed when water combines with carbon dioxide from the air or soil. Carbonic acid easily dissolves and eats away at the limestone bedrock, causing cracks and crevasses to widen and deepen. Sometimes, the water percolating from the surface into the bedrock picks up sediment and carries it downward through the cracks, causing a depression in the surface known as a sinkhole. As time goes by and the crevasse grows wider from dissolution, more sediment is carried downward and the sinkhole grows!
One of the most important things to know about sinkholes is that they act like a door between everything on the surface and the water within the ground. Contamination or pollution that occurs near sinkholes can very easily get picked up by rain and flushed into our groundwater. It is important to make smart decisions around sinkholes because pollution within the groundwater can harm plants, animals, and humans that depend on the freshwater aquifer for life!
The karst landscape of Kentucky is famous around the world because of the sinkholes, caves, and springs that make it unique! Here at The Parklands, you have the chance to experience this exciting and unique landscape in person! Head over to Broad Run Park and visit the Karst Climb trail or the Limestone Gorge trail. To catch a glimpse of our karst sinkholes, stroll through Highland Crossing and catch the Doline Scape.