This Earthcache is located in the Missouri Department of Conservation Paris Springs Conservation Area. The area is closed from 10 pm to 4 am.
When you drive to this location, you will find the Paris Springs CA just off historic old Route 66. You will have to cross a low water bridge to get to the designated parking lot.
If crops are fully grown, or under wet conditions, it might be best to hike along the edges of the field to get to the cave. Total hiking distance is around 1/2 mile round trip.
Since this is a conservation area, please use caution during hunting seasons.
Turnback Cave
Karst Topography
Karst topography is a geological formation shaped by the dissolution of a layer or layers of soluble bedrock, usually carbonate rock such as limestone, dolomite and gypsum. Many karst regions display distinctive surface features, with sinkholes being the most common. Some karst regions include thousands of caves and Missouri is well known for being a cave state. Karst topography also includes dolines which are shallow, usually funnel-shaped, depressions of the ground surface.
Types and Formation
A cave or cavern is a hollow place in the ground sometimes large enough for a human to enter. Caves form naturally by the weathering of rock and often extend deep underground.
Solution Caves
Solution caves are the most frequently occurring caves, and such caves form in rock that is soluble. The karst development occurs whenever acidic water starts to break down the surface bedrock near its cracks, or bedding planes. As the bedrock continues to break down, its cracks tend to get bigger. As time goes on, these fractures will become wider, and eventually a drainage system may start to form below the surface. If this underground drainage system does form, it will speed up the development of karst features due to the fact that more water will be able to flow through the area.
Primary Caves
Caves formed at the same time as the surrounding rock are called primary caves.
Lava tubes are formed through volcanic activity and are the most common primary caves. As lava flows downhill, its surface cools and solidifies. Hot liquid lava continues to flow under that crust and, if most of it flows out, a hollow tube remains.
How Caves Form
Cave formation begins when rainwater absorbs carbon dioxide as it falls through the atmosphere. Rainwater must have carbon dioxide to become acidic. It must be acidic to chemically react to the limestone bedrock. Rainwater is absorbed by the soil into the ground.
As rainwater comes through the soil it absorbs more carbon dioxide that is being produced by dead plants. This changes the ground water to a weaker form of carbonic acid (H2O + CO2 = H2CO3). As it travels down through the ground it comes into contact with solid rock. The water reacts chemically with the limestone rock and slowly a larger and larger space is formed. This happens because the rocks are made of calcium carbonate (CaCO3). This is what you call chemical erosion.
As the space becomes larger, even more water can flow through, and by physical erosion more rock and sand are washed away. This is what makes a cave larger and forms an underground stream system. Finally, over hundreds of thousands of years or even millions of years, the cave is formed.
To complete the requirements to log this Earthcache, please email me the answers to the following questions:
1. Estimate of the height and width of the cave opening.
2. Estimate the height of the cliff above the cave opening.
3. What colors are the rocks around and above the cave opening?
4. Is there evidence of stratification or layers on the cliff wall?
Permission granted by Frank Loncarich, Missouri Department of Conservation, Area Land Manager.