Welcome to Leonard Springs Park. This beautiful 85 acre park perfectly exhibits the phenomenal powers of water and time. Walk the easy one mile loop trail and experience an amazing karst landscape and see how thousands of years of cascading water have formed a beautiful environment. There are interpretive signs along the trail describing the area, so pay attention to the signs as you walk, there will be a test at the end.
Karst topography is formed when water forms a mild acid that dissolves the rocks, in this case limestone, and makes small fissures and holes that over time form into the caves, sinkholes, and rock formations that can be found all around Leonard Springs Nature Park.
The limestone in this area was created around 335 million years ago during the Mississippian era when this part of Indiana was a shallow sea teeming with marine life. Most of these marine organisms had shells and exoskeletons made of calcite , a type of calcium carbonate, which was left behind after they died. When the shells mixed with the other materials on the sea floor they formed limestone. The limestone found around Monroe County is almost entirely made up of these small fossils. The chemical composition of this area's rock is 97% calcium carbonate (CaCO3) If you look closely at the limestone blocks on the buildings around Bloomington you can see the thousands of invertebrates that compose the limestone. The picture below is a good example of what some of the creatures looked like before they were broken up by the waves of the ancient sea and turned into limestone.
The carbonic acid that carved the karst features into the limestone was formed as rain passed through the atmosphere picking up carbon dioxide (CO2) which dissolved in the water. Once the rain reached the ground, it passed through the soil that provided much more CO2 to the rain water to form a weak acid solution which dissolved the calcium carbonate in the limestone. The mildly acidic water then began to dissolve the surface along fractures or bedding planes in the limestone bedrock. Over time, these fractures enlarged as the bedrock continued to dissolve. Openings in the rock increased in size, and an underground drainage system began to develop, allowing more water to pass through the area, and accelerating the formation of underground karst features.
As you will see during your short hike, Leonard Springs Nature Park has many geological features that have resulted from the shaping of the water passing through the limestone rock below your feet. As you walk the trail hopefully you'll enjoy the wonderful views provided by nature and learn a little something about karst geology.
To log this earthcache, please email me the answer to the following questions.
- What are the two types of limestone formations that are found in Leonard Springs Park?
- What are the names of the two sink holes that funnel water to Shirley Springs?
- How many years was this valley a reservoir?
According to the newer Earthcache rules, photos can no longer be required to log an Earthcache, but it would be great if you took a picture of your favorite spot in the park and shared the park's beauty with the rest of the geocaching community.