HR: 14:25h
AN: H33G-04    [Abstracts]
TI: Stable and Radiogenic Isotope Evidence Relating to Regional Groundwater Flow Ssystems Originating in the High Sacramento Mountains, New Mexico
AU: * Eastoe, C J
EM: eastoe@geo.arizona.edu
AF: SAHRA, Department of Geosciences, University of Arizona, Tucson, AZ 85721 United States
AU: Hibbs, B J
EM: bhibbs@calstatela.edu
AF: CEA-CREST, Dept of Geological Sciences, California State University-Los Angeles, Los Angeles, Los Angeles, CA 90032 United States
AB: Groundwater from the Sacramento Mountains and adjacent basin-fill sediments near Tularosa and Alamogordo has values of δ D , δ¹⁸O that plot in δ D vs. δ¹⁸O space on a linear trend of slope 5. Tritium is detectable in most samples. Carbon-14 content generally decreases downgradient from 80-90 pMC in the high mountains to 20-40 pMC in basin fill. Precipitation from areas above 2000 m elevation is the dominant water source. The O and H stable isotope data are best explained by mixing of non-evaporated water transmitted slowly through rock fractures with evaporated water of the same source transmitted rapidly as runoff to the point of recharge. Evaporation of surface water occurs from canyon-bottom sediment. Sacramento Mountains water replenishes the Tularosa basin aquifer by a combination of mountain-front and mountain-block recharge. It also replenishes a limestone-hosted aquifer extending 100 km southeast of Cloudcroft, New Mexico. Groundwater in basin fill at Dell City, Texas appears to have distinctive values of δ D, δ¹⁸O that are better explained by recharge of precipitation from high areas of the Diablo Plateau. Regional groundwater flow from the Sacramento Mountains to the Hueco Bolson aquifer is likely; however, O and H stable isotope data do not distinguish Sacramento Mountains water from other inputs to the Hueco Bolson.
DE: 1829 Groundwater hydrology
DE: 1830 Groundwater/surface water interaction
SC: Hydrology [H]
MN: Fall Meeting 2005