Reports
Permanent link for this collectionhttps://hdl.handle.net/2022/3196
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Item Developing a Web Site to Provide Geologic Data and Map Products for Allen County, Indiana(U.S. Geological Survey, 2008) Rupp, Robin F.; Olejnik, Jennifer; Hasenmueller, Nancy R.; Walls, A. Chris; Radhakrishnan, Premkrishna; Karaffa, Marni D.; Eaton, Nathan K.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.Item GIS Tools for 3-D Surficial Mapping in Ohio(U.S. Geological Survey, 2008) McDonald, James; Pavey, Richard R.; Venteris, Erik R.; Wells, Joseph G.The Ohio Department of Natural Resources, Division of Geological Survey is currently mapping the surficial geology of Ohio in three dimensions (3-D) using a modified version of the stack-mapping technique of Kempton (1981). The stack-mapping technique depicts the geology for an area in 3-D by listing the unconsolidated (mostly glacial) geologic units from the surface to bedrock, the thickness of each unit, and the underlying bedrock unit. The new mapping of the surficial geology is intended to replace the older and smaller-scale mapping that was based upon generalized, two-dimensional mapping techniques. Three ArcMap-based software applications were developed to assist with the stack-unit mapping program. The first software application used the lithologies from water wells to create on-screen graphics representing the stratigraphic columns for each well record. These stratigraphic columns are interpreted by the geologist to assign a generalized stack unit for each polygon. The second software application consists of two tools used to attribute and label the stack-map polygons, which will capture the information in the GIS and for cartographic display. The first tool attributes a one-to-many relationship between a surficial-geology polygon and the lithology table. The second tool labels the surficial-geology polygons with the stack text for use in map publishing. The third application performs custom queries against the lithology table that can be used to create derivative mapping products, such as location and thickness of sand and gravel resources. These three applications allow the efficient creation of 3-D surficial-geology polygons and labels within a GIS database, and provide analysis tool to facilitate the use of the 3-D surficial geology maps for specific applications.Item Surface Terrain of Indiana—a Digital Elevation Model(U.S. Geological Survey, 2004) Rupp, Robin F.The surface terrain model of Indiana was created using part of the National Elevation Dataset (NED)—a digital elevation information product for the United States—and newly created digital elevation models (DEMs). New digital elevation data replaced 275 of the 710 Indiana 7.5-minute quadrangles. This report describes the processes of 1) creating new DEMs, 2) merging the new data and the original NED into a new grid, and 3) creating images from the final data set. The revised digital elevation model for Indiana and parts of the surrounding states is available on a CD-ROM as a raster in ESRI grid format. This report also provides the background for the Indiana Geological Survey (IGS) Poster 5 and the forthcoming terrain image series.