U.S. GEOLOGICAL SURVEY GEOLOGIC MAPPING IN THE OZARK NATIONAL SCENIC RIVERWAYS AREA, SOUTHEASTERN MISSOURI

In 1996 the USGS began geologic mapping with associated geologic studies in the Ozarks of southeastern Missouri. This work was performed under the FEDMAP component of the National Cooperative Geologic Mapping Program (NCGMP) with additional support from the National Park Service (NPS). This area of Missouri was the focus of government-sponsored studies because of concerns for potential groundwater contamination within a world-class karst aquifer and spring system due to proposed base metal exploration and production in the Mark Twain National Forest. In addition, there was a need for a comprehensive geologic inventory of the Ozark National Scenic Riverways (ONSR) for use in multidisciplinary studies of the park and surrounding lands that are drained by the upper Current and Eleven Point River systems. This project resulted in the publication of nineteen 7.5 minute geologic quadrangle maps (USGS, I and SIM series) and a 1:100,000 scale geologic map and comprehensive geologic report (SIM 3280). SIM 3280 encompasses the ONSR as well as the upper Current and Eleven Point River basins in southern Missouri, an area of 4,292 mi² (11,116 km²). The published 1:24,000 scale geologic map data have been combined with additional USGS field data and data published by the Missouri Geological Survey to produce a seamless GIS coverage of the entire ONSR and a surrounding buffer area extending 1 mile outside of the peripheral park boundaries. These data complete the NPS geologic inventory for the ONSR and will be used as the geologic database for future research, land classification, and land-management in the park. In addition to geologic maps, this project has resulted in multiple reports on aspects of the stratigraphy, paleontology, tectonic history, karst, speleogenesis, and geohydrologic framework of the region.