This digital data release contains geospatial geologic and paleontological data of the 1° x2 °, 1:250,000 Limon quadrangle covering eastern Colorado and western Kansas. The dataset is a digital reproduction of previously published U.S. Geological Survey field mapping which illustrates the spatial configuration of primarily Quaternary surficial units overlying upper Miocene, Oligocene, Paleocene, and Upper Cretaceous bedrock (Sharps, 1980). This quadrangle contains numerous outcrop of the Ogallala Formation, which is a prolific freshwater aquifer throughout the broader great plains. A structure contour map of the top of the Dakota Sandstone are included, which was constructed using selected oil and gas well logs (Sharps, 1980). The Dakota Sandstone is a productive hydrocarbon reservoir within the Limon quadrangle, and the broader Denver-Julesburg Basin. Point data for Mesozoic invertebrate fossil collection localities are depicted on the map, depicted with either Denver or Washington D.C. U.S. Geological Survey catalog numbers (Sharps, 1980). Geologic map polygons, fossil points, faunal zones, and structure contours were digitized and attributed as GIS data sets as part of the U.S. Geological Survey’s ongoing studies on a regional and national scale. The geologic map polygons, fossil point features, faunal zone lines, and structure contour lines are distributed as separate feature classes within a geographic information system geodatabase. Contoured elevation values are given in feet, to maintain consistency with the original publication, and in meters. Nonspatial tables define the data sources used, define terms used in the dataset, and describe the geologic units. A tabular data dictionary describes the entity and attribute information for all attributes of the geospatial data and the accompanying nonspatial tables.
