A GEOLOGIC UNIT SCHEME FOR REGIONAL GEOLOGIC MAP INTEGRATION

Work on OneGeology map services for the United States has highlighted problems with lithologic portrayal schemes for regional maps. Basic information about lithology is most useful for many important applications in engineering and environmental management; these applications are the focus of this study. The variety and arrangement of rock types within the unit is key information, thus characterization using a single rock type category of the kind defined in the CGI simple lithology scheme is not optimal. A system of lithogenetic categories for regional geologic maps has been compiled based on frequency analysis of lithology/genesis categories in digital geologic map datasets for North America (Soller and Garrity, 2009 of Reed et al. 2005), Australia (Raymond, pers. comm., 2011), and the Arctic region (Harrison et al., 2008), and inspection of other regional maps. Categories lump related kinds of units with low frequency of occurrence, and provide finer distinction between kinds of units with extensive outcrop area. This is a work in progress. The goal is a lithogenetic unit category scheme that can be used for regional map portrayals from WMS services to achieve a high degree of visual harmonization. Such a scheme could be published with a community legend files, and if data providers mapped their geologic units into the regional data integration units, users could obtain geologic map images with a familiar legend, making use of geologic information easier. The goal is a lithogenetic unit category scheme that can be used for regional map portrayals from WMS services to achieve a high degree of visual harmonization. Development of an ontology to associate these units with properties of interest will increase utility in a linked data environment.