"iLITH is a Microsoft Access database containing GIS capabilities that allows users to interact with a portion of the Indiana Department of Natural Resources (IDNR) Water-Well Record Database. iLITH differs from the IDNR database in that lithologic descriptions and drilling contractor names have been standardized, locational information for ~104,000 water-well logs has been verified, and the spatial information in the database has been standardized for use with USGS digital elevation data and US Census Bureau Tiger data. The iLITH graphical interface facilitates efficient interaction between the user and the database."
Using Microsoft Access, queries were constructed that summed the total thickness of sand and gravel units for each well. Units with the following designations were included in the summation: "sand," "sand and clay," "sand and gravel," "sand with clay," "sand with clay streaks," "sand with gravel," "silt and sand," "gravel," "gravel and clay," "gravel and stone," "gravel with boulders," "gravel with clay," "gravel with clay streaks," and "gravel with sand." Some inconsistencies in the database were eliminated. The resulting table was then exported from Microsoft Access and imported into ESRI ArcView to construct a point shapefile.