MAP COMPILATIONS: CREATING A SEAMLESS GEOLOGIC MAP FOR THE STATE OF WEST VIRGINIA

In effort to create a seamless statewide geologic map, the West Virginia Geological and Economic Survey (WVGES) is building an Enterprise Dataset, an internal WVGES database that seamlessly synthesizes all available geologic data for the state. This work dovetails with the U.S. Geological Survey’s goal of establishing a seamless nationwide geologic map. WVGES is mapping, organizing, and compiling 1:24,000 quadrangles by 1:100,000 sheets as part of an ongoing project for the U.S. GeoFramework Initiative of STATEMAP, a component of the National Cooperative Geologic Mapping Program. The goal is to have the geology of the state of West Virginia completely mapped at 1:24,000 scale. Presently, statewide geologic coverage exists as a combination of the 1:250,000 scale statewide geologic map published in 1968 and past and current 1:24,000 scale bedrock mapping of individual quadrangles. WVGES prioritizes bedrock mapping in areas of karst terrain, tourism, infrastructure development, and conservation, concentrated on the eastern state margin and New River Gorge area. While WVGES is organizing data by 1:100,000 sheets, the mapped geology retains 1:24,000 scale in the database. Presented are examples of this work in Silurian-Devonian bedrock units of the Elkins 100,000 sheet. Integrating different datasets resolves regional geology and provides a product useful for a broader range of studies. Important factors that improve resolution of geological maps include modern basemap data such as Lidar and systematic edge-matching of mapped quadrangles. Edge-matching ensures congruence of geologic features across map boundaries. Overlays are created for digitized bedrock maps in ArcGIS to assess severity and offer solutions for mismatches. Minor mismatches include offset in features and solutions are drawn in the overlay. Geologic groups on one quadrangle may be split into formations on adjacent quadrangles mapped by different authors. Major mismatches are managed by supplementary data analysis or field work. Such issues correspond to structural complexity or inconsistencies in stratigraphic interpretation. Examination and resolution of these geological problems will greatly enhance quality of bedrock mapping, providing new and updated mapping for West Virginia.