Hydrogeologic framework bottom elevations and thicknesses of Permian, Upper Pennsylvanian, Lower Pennsylvanian, and Mississippian units in the Appalachian Plateaus Physiographic Province

As part of the U.S. Geological Survey Water Availability and Use Science Program study of Appalachian Plateaus aquifers, bottom elevations and thicknesses were determined for Permian, Upper Pennsylvanian, Lower Pennsylvanian, and Mississippian hydrogeologic framework units in the Appalachian Plateaus, covering parts of Pennsylvania, Maryland, Ohio, West Virginia, Kentucky, Virginia, Tennessee, Georgia, and Alabama. Thickness values for these units were compiled at point locations from available sources (Martens, 1945; McKee and Crosby, 1975; Craig and Connor, 1979; Ryder and others, 2008, 2009, 2012, 2015) and used to interpolate surfaces representing thicknesses, contact elevations, and outcrop elevations using earthVision software (Dynamic Graphics, Inc., 2014). Unit contact and outcrop elevations at cell centers from the earthVision rasters were used as the primary source to create geodatabase rasters representing bottom elevations and thicknesses of the Permian, Upper Pennsylvanian, Lower Pennsylvanian, and Mississippian framework units.