New Mexico Geological Society Annual Spring Meeting & Ft. Stanton Cave Conference — Abstracts

As part of a U.S. Geological Survey study in cooperation with the Bureau of Reclamation and the Pueblos of Acoma and Laguna, a digital three-dimensional geologic framework model was constructed for the Rio San Jose and its surface-water drainage basin in west-central New Mexico. This model was constructed to define the elevation, thickness, and extent of 18 geologic units for use in a regional numerical hydrologic model. The model includes an undivided Precambrian basement layer, 13 consolidated rock units of Paleozoic and Mesozoic age, and 4 Cenozoic-aged units. Model input data were compiled from published cross sections, well data, structure contour maps, selected geophysical data, and data derived from geologic maps and structural features in the study area. These data were used to construct faulted surfaces that represent the upper and lower subsurface geologic unit boundaries. The digital three-dimensional geologic framework model is constructed through combining faults, the elevation of the tops of each geologic unit, and boundary lines depicting the subsurface extent of each geologic unit. The digital three-dimensional geologic model represents the generalized geometry of the subsurface geologic units, reproduces with reasonable accuracy the input geologic data, and is consistent with previously published subsurface conceptualizations of the region. The geologic framework model is at a scale and resolution appropriate for use as the foundation for a numerical hydrologic model of the study area. The numerical hydrologic model will provide a tool to help support long-term planning and management decisions regarding the basin’s surface-water and groundwater resources. The 18 geologic units from the geologic framework model were grouped into 9 hydrogeologic units based on similar age, lithology, and reported hydraulic properties and these hydrogeologic units were used to define the layering in the numerical hydrologic model.