Bedrock Geologic Database of the Indiana Portions of the Princeton, Evansville, Mount Vernon, and West Frankfort 30- x 60-minute Quadrangles
Authors: Padgett Penny , Ames Philip , Mastalerz Maria , Johnson Matthew , Hasenmueller Nancy 
Published: February 2024

Located in the eastern Illinois Basin, the Princeton 1:100,000-scale quadrangle comprises portions of Knox, Gibson, Pike, Dubois, Posey, Vanderburgh, Warrick, and Spencer Counties in Indiana as well as small portions of Edwards, Gallatin, Wabash, and White Counties in Illinois. The mapped area is situated in the rolling topography of the Wabash Lowland and dominated by Pennsylvanian-age coal-bearing strata. Pennsylvanian siliciclastics in the Princeton quadrangle host economically important coal seams. The most widespread coal beds occur in the Carbondale Group, but the Raccoon Creek Group hosts coal of superior quality (low sulfur, low ash) in Indiana. Surface and underground mining of these coals have been extensive, with expansive impacts on the landscape and subsequent reclamation. Bedrock outcrops are obscured mainly by glacial sediments and extensive fluvial deposits from the Wabash River that formed deep channels (paleo and active) filled with outwash and alluvium.
The geologic map of Gray and others (1970), the Compendium of Paleozoic Rock-Unit Stratigraphy in Indiana (1986), and Indiana Geologic Names Information System (IGNIS, https://legacy.igws.indiana.edu/ignis/) are the fundamental compilation of previous geological knowledge from this area. Additional data come from previous 1:24,000-scale mapping through the National Cooperative Mapping Program STATEMAP component. However, most information for the Bedrock Geologic Database of the Indiana Portions of the Princeton, Evansville, Mount Vernon, and West Frankfort 30- x 60-minute Quadrangles and, more broadly, the western corridor, is derived from Indiana-scale coal seam mapping conducted between 2011 and 2017 based on the National Coal Resources Data System (NCRDS), Indiana Coal Quality Database (ICQD), and geophysical logs from oil and gas wells archived in the Petroleum Database Management System (PDMS). The majority of these data were previously presented in Esri-based Indiana Coal Atlas StoryMaps for the entire western corridor.
This geologic mapping project was funded in part through the STATEMAP Program supported by the U.S. Geological Survey under Cooperative Agreement No. G22AC00424. The Bedrock Geologic Database of the Indiana Portions of the Princeton, Evansville, Mount Vernon, and West Frankfort 30- x 60-minute Quadrangles is a composite geodata set that conforms to "GeMS (Geologic Map Schema)--a standard format for the digital publication of geologic maps," available at http://ngmdb.usgs.gov/Info/standards/GeMS/. Metadata records associated with each element within the geodata set contain more detailed descriptions of their purposes, constituent entities, and attributes. An OPEN shapefile version of the data set is also available. It consists of shapefiles, DBF files, and delimited text files and retains all information in the native geodatabase, but some programming will likely be necessary to assemble these components into usable formats.