Web-Based Glacial and Bedrock Geologic Map Products and Databases for Allen County, Indiana

Abstract

The Internet is becoming the medium of choice for delivering geologic information to both technical users and the general public. The Indiana Geological Survey (IGS) is currently creating a Web-based glacial and bedrock geologic map site for Allen County in northeastern Indiana. Allen County is the site of Fort Wayne, Indiana’s second largest city, and lies within IGS mapping and outreach priority areas based on population density and transportation corridors. This Web site provides detailed geologic information in an area that continues to experience pressure on natural resources by a large population and expanding transportation network. It is anticipated that the information from the Web site will be widely used by the general public and by industry and government entities. The Allen County Web site includes an Internet map server (IMS), as well as illustrations, educational summaries, and discussions of geologic maps, terrain images, and databases that complement the IMS. The site provides a front-end to the IGS enterprise geodatabases, which contain information used simultaneously for research and for viewing by the general public. The geodatabase systems allow maps and data to be efficiently created, managed, updated, and distributed. Maps provided on the Allen County Web site include: (1) digital elevation model terrain, (2) Landsat imagery, (3) surficial geology, (4) drift thickness, (5) bedrock topography, (6) bedrock geology, and (7) water-table elevation. Technical database information includes: (1) lithologic information compiled from water-well information in the Indiana Department of Natural Resources, Division of Water well records, (2) natural gamma-ray geophysical log data, (3) stratigraphic test hole data, and (4) petroleum-well data. The development of the Web site was funded by the IGS and the Central Great Lakes Geologic Mapping Coalition.