CENTRAL COLORADO GEODATABASE, AN EXAMPLE OF REGIONAL GEOSCIENCE INTEGRATION

We have compiled a regional geodatabase in Central Colorado that integrates geologic mapping, structural attitudes, geochemistry-based crystalline rock names, geochronology, and general geochemical rock properties. The geologic map database was compiled at a nominal 1:100,000 scale from the best available published and unpublished maps, including recent geologic mapping by the Colorado Geological Survey and the U.S. Geological Survey National Geologic Mapping Program as well as thesis maps and some of our own reconnaissance mapping. Rock units were recoded from the source maps using a unified nomenclature developed for this database. Rock unit polygons are coded with geologic age and the best available absolute ages based on published data (also summarized in a point layer) and from our recently completed U-Pb and Ar³⁹/Ar⁴⁰ geochronology. Fold and fault line layers contain information on fault or fold type, displacement, and published names. Rock geochemistry from U.S. Geological Survey studies and graduate theses were compiled in point layers and used to attribute polygons for rock names and petrologic classification. Bedrock polygons were classified using an empirically-derived generalized chemical classification to allow investigations of the influence of bedrock chemistry on water chemistry and biota. A point file containing stream sediment geochemistry allows evaluation of regional geochemical baselines. Derivative views of the timing and compositional variation of plutonism and volcanism can be easily compiled from the age- and rock composition-attributed polygons. Structural attitudes can be exported to other programs for analysis, for example, structural data for specific rock units or geographic areas can be extracted for domain analysis. This database provides access to these diverse data types for use in land management, resource assessment and geoscience investigations in a geospatial framework.