Factors affecting oxygen-18 concentrations in the Tucson basin and the Madrid basin
AdvisorDavis, Stanley N.
MetadataShow full item record
PublisherThe University of Arizona.
RightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
AbstractTwo regional aquifers are analyzed based on their stable isotope and hydrochemical data. The Tucson basin (Arizona) and Madrid basin (Spain), present similarities in their geologic patterns. The ground-water flow regimens, however, are different. Madrid basin presents local, intermediate and regional flow. Rivers in the Madrid basin are perennial, while Tucson washes only drain surface run-off. The winter precipitation is the main source for recharge in both basins. This was deduced by the difference in oxygen-18 content between winter and summer precipitation over both basins. Madrid basin presents a continental effect occurring from west to east and an altitude effect from northeast to southwest. Tucson basin presents an altitude effect. The oxygen-18 content decreases toward the higher elevations. Mixing of waters in discharge areas in both basins due to anthropogenic activity masked relationships, if any, among the stable isotopes and hydrochemical species.