DIGITAL HYDROGEOLOGIC-FRAMEWORK MODEL OF THE SAN FRANCISCO RIVER BASIN, WEST-CENTRAL NEW MEXICO AND EAST-CENTRAL ARIZONA

This presentation describes development of a new digital hydrogeologic-framework model of basin-fill and bedrock aquifer systems in the San Francisco River (SFR) basin of west-central New Mexico and east-central Arizona The SFR is the only perennial tributary to the Upper Gila River, with their confluence located about 16 km south of the Clifton-Morenci (AZ) mining district, the site of the largest open-pit copper mine in North America. The model covers the 7,230 km² SFR drainage basin, which is located in the Datil-Mogollon section of the Transition Zone physiographic (and tectonic) province, and includes the Tularosa River (NM) and Blue River (AZ) watersheds. Our study and related hydrologic-hydrographic investigations were funded by the New Mexico Interstate Stream Commission, and are part of ongoing efforts to improve geohydrologic models used in management of surface-water and groundwater resources of the Gila River part of the “Lower Colorado River Basin.” This is the first synoptic integration of hydrogeologic information in the SFR basin; and our principal achievement has been development of a GIS-based, basin-scale digital hydrogeologic model using ARC-GIS® and Adobe Illustrator® for map and cross-section compilation, respectively. The hydrogeologic map and five schematic cross sections (msl base elevation; 5x vertical exaggeration) were compiled from published digital geologic-map databases (1:100,000 to 1:1,000,000-scale) acquired from the NM Bureau of Geology, Arizona Geological Survey, and the U.S. Geological Survey. The map shows the surface-distribution patterns of major bedrock and basin-fill mapping units, as well as large-scale tectonic and volcanic features. Detailed definitions of hydrostratigraphic mapping units (HSUs) and component lithofacies-assemblages (LFAs) are in a NMWRRI project completion report (6/30/09), which is available at ftp://water.nmsu.edu/pub/gila/hydrogeologic/.