Apparent age of ground water near the southeastern margin of the Tularosa Basin, Otero County, New Mexico
— G. F. Huff

Isotope data on hydrogen, oxygen, and carbon in ground and surface water combined with generalized directions of ground-water flow and published geochemical data were used to determine the apparent age and partial geochemical history of ground water near the southeastern margin of the Tularosa Basin. Dissolution of calcite and dolomite could account for part of the geochemical evolution of ground water, including possible dilution of ¹⁴C content, as it moves away from recharge areas. Dissolution of calcium sulfate also could account for a part of ground-water evolution. Apparent ¹⁴C ages, corrected for the effects of carbonate mineral dissolution, show ground water became closed with respect to ¹⁴C between 10,000 and 1000 yrs ago. These apparent ages are supported by hydrogen and oxygen isotope data that are consistent with the origination of ground water as Holocene age recharge. A general correlation between greater apparent ages of ground water and total depth of sampled wells is interpreted to correspond to longer travel times along deeper ground-water flow paths. Corrected apparent ages of ground water and inferred travel times will be used to assist in calibrating a ground water flow model of the Tularosa Basin that is currently being developed.