KARST 

Falling Spring discharges from a cave in the bluff of 
Hurricane Creek. The discharged water flows several 
hundred feet before sinking underground through the 
Hurricane Creek streambed.

The karstic Ozark aquifer supplies large quantities of water to springs and to domestic and municipal wells throughout southern Missouri. The term karst refers to a geologic terrain formed when carbonate rocks such as limestone and dolostone are dissolved by ground water. Karst terrain typically is characterized by the presence of sinkholes, caves, streams that lose water into the ground, springs, and complex underground drainage systems. Karst features are common throughout the exploration area and greatly increase the rate of ground-water flow through the aquifer and the potential for rapid transport of contaminants from upland areas to streams and springs and between surface-water basins.

Losing streams, a common feature in karst terrain of southern Missouri, occur where a combination of high streambed hydraulic conductivity and low ground-water levels cause a substantial part of the stream water to flow through the streambed into the bedrock. The presence of losing streams in the potential new mining area is of concern because contaminants released during mining activities or from stored mine waste (tailings piles) potentially can migrate through streambeds into the ground-water flow system.