Caves and Karst
RESEARCH
CHEROKEE CAVE
07.22.22
If there is one truly defining geological feature of our region it must be the Caves. With more than 7,000 caves, Missouri is known as "the Cave State." This is because much of Missouri is a karst landscape of porous limestone and dolomite, where caves, springs, sinkholes, and natural bridges form. St. Louis is one of the most cave and karstic urban areas in the world.
The word karst is the German name for the Krš (or Kras) region of Europe near the Dolomite Mountain Range which has a similar limestone topography. It’s used to describe this type of unique geology of caves, sinkholes, and springs, no matter where on Earth it occurs.Karstic features appear every from Southeaster China, to Central Europe, to back here in the foothills of the Ozark Plateau and Highlands.
Most nearby caves are in the Ozark Highlands ecoregion, where they occur in soluble dolomite or limestone. Caves also occur in sandstone or igneous rocks and may be found in the Osage Plains and Central Dissected Till Plains ecoregions. There are almost no caves in northwestern Missouri and in the Bootheel lowlands.
The Karst Cycle
Slightly acidic groundwater flows through cracks in limestone or dolomite, slowly dissolving the rock. The cracks widen to form cavities and eventually a subterranean drainage system. The creeks that flow through caves come from surface water that has seeped downward.
When a cave is below the water table, it is filled entirely with water. When the cave is above the water table, the cave has air in it and its water flows ever downward. Wherever cave water exits the rock and flows into the open air, it is called a spring.
Some of our largest caves formed ages ago as completely water-filled cavities. Over geologic time, the Ozark Plateau was uplifted, and rivers carved valleys ever deeper into the bedrock, creating bluffs and causing cave passages to be above the water table and to drain.
Locally in Saint Louis, the most notable cave system is the Cherokee Cave. The cave system known today as the Cherokee Cave is a natural limestone cave that was formed over a million years ago when slightly acidic rainwater made its way into small cracks and fissures in the limestone bedrock. Over time, as the acid began to eat away at the limestone, larger channels were created, admitting more water and accelerating the formation of the cave. Geological features created in this manner are referred to as Karst Topography. The Cave was used as a beer cellar for the 19th Breweries which utilized the climate controlled spaces for refrigeration. There is also evidence that the Caves were used as part of the Underground Railroad, the escape for Slaves before and during the Civil War to the Northern portion of the United States.
Sources:
Missouri Department of Conservation; Cherokee Cave, St. Louis, Missouri, Missouri Speleology, Volume VI, Number 3. July 1964; Bats/Cherokee Cave, Missouri Speleology, Volume VI, Number 4. October 1964; Hubert Rother, Charlotte Rother (1964): The Lost Caves of St. Louis; (2018): History of the Lemp Brewery Caverns & Cherokee Cave, Missouri Speleology, The Journal of the Missouri Speleological Survey, Volume 58, 2018