REACTIVATED PALEOKARST IN NORTHERN AUDRAIN COUNTY, MISSOURI

In 2008, geologists from the Missouri Geological Survey investigated a collapsed man-made lake in northern Audrain County, Missouri. The investigation revealed that the lake was located in an area of thin, glacially-derived surficial materials overlying paleokarst that had developed in the Mississippian-age Burlington Limestone. Such features are not common in northern Missouri, where thick glacial soils are usually assumed to cover low-permeability Pennsylvanian-age shales. The reactivation of paleokarst in this region could impact the siting of surface structures such as waste disposal lagoons, as well as provide data on geologic processes that have affected paleokarst structures in the Quaternary Period.