| Recent work in Canada and Iran (Dowuona et al., 1992 and Khademi et al., 1997a; 1997b) suggested a correlation exists between the δ18 O and δD ratios of the hydration water of pedogenic gypsum and the δ18O/δD ratios of meteoric water. However, a pedogenic origin for the sampled gypsum was not clearly supported and the results from this procedure were not compared to other paleoclimatic indicators. Therefore, the goals of this study were, (1) evaluate the genesis and soil morphology of pedogenic gypsum in and to semi-arid regions and (2) determine the applicability of pedogenic gypsum as a paleoclimatic indicator.; Six profiles containing soils of late Pleistocene through Holocene age in the Tularosa and Jornada basins of Southern New Mexico were described and sampled for isotopic analysis. Gypsum soil morphology was expanded to include a new “snowball” morphology, as well as Stage I filaments and Stage II nodules, a classification scheme formerly only applied to carbonate morphology. A pedogenic origin for gypsum crystals found throughout the six profiles was determined using a scanning electron microscope. (Abstract shortened by UMI.)... |
