GEOLOGY OF THE CHICKASAW NATIONAL RECREATION AREA, SOUTH-CENTRAL OKLAHOMA: A MULTIDISCIPLINARY GEOLOGIC APPROACH

The Arbuckle-Simpson aquifer in the Arbuckle Mountains of south-central Oklahoma is a critical groundwater resource and the Chickasaw National Recreation Area (CHIC) contains numerous freshwater and mineral springs that discharge in the park’s Rock Creek and its principal tributary, Travertine Creek. This study of the geology of the Arbuckle-Simpson aquifer in and around CHIC has been an important part of the state- and federally-funded, 5-year Arbuckle-Simpson Hydrology Study. Therefore, a multidisciplinary geologic approach was needed to improve our understanding of CHIC’s surface and subsurface geology, which includes: (1) map compilation and new geologic mapping at 1:24,000-scale, (2) airborne helicopter electromagnetic (HEM) and ground geophysical surveys, and (3) a waterborne electromagnetic (WEM) survey of CHIC’s Lake of the Arbuckles. The park’s geology is also represented in the western part of a 3-D EarthVision model of the Hunton anticline area (USGS Open-File Report 2010-1123).

Geospatial registration of existing, smaller-scale (1:72K- and 1:100K-scale) geologic maps of CHIC and surrounding areas, and construction of an accurate GIS database, was followed by new geologic mapping over a two-year period. Included in the new CHIC map database is a digital 1:24,000-scale map layer with geology, topography and shaded relief, a National Agriculture Imagery Program 2008, 1-meter photo mosaic data layer, and merged, 15-meter resolution Landsat 7 ETMplus and Advanced Spaceborne Thermal Emission and Reflection Radiometer data sets.

Ground geophysical surveys in the park focused on mapping fresh-/saline-groundwater and investigating areas of complex fault geometry. Audiomagnetotelluric (AMT) stations in areas of spring water discharge mapped the transition between fresh-water springs in the east and saline springs in the west. One AMT transect across a mapped fault confirmed it as a thrust fault. An experimental WEM geophysical survey of the Lake of the Arbuckles was carried out in August, 2009, in a proof-of-principal application using an airborne bird on a towed raft to map sub-bottom geology. The resulting electromagnetic imaging will complement CHIC mapping by providing additional unit contact and fault control.