Description: <DIV STYLE="text-align:Left;"><DIV><P><SPAN>This digital map feature class represents the general distribution of karst geologic features, soluble carbonate bedrock geologic units, and surficial geologic units mapped in approximately 37.5 7.5-minute quadrangles in the northern Shenandoah Valley along the Interstate-81 corridor and U.S. Route 11 in Virginia. Sinkhole locations were derived using elevation data from a 1-meter LIDAR raster and an automated fill-difference raster geoprocessing toolset where the results were then manually edited. Geologic data were compiled from previously mapped or digitally compiled maps at a nominal scale of 1:24,000. A derived karst density raster map shows the density of karst features per square mile. The database delineates map units that are identified by general age and lithology, generally following the stratigraphic nomenclature of the U.S. Geological Survey (USGS). This metadata report provides an overview of the data content of this GeMS geodatabase and associated derivative files.</SPAN></P></DIV></DIV>