Hydrology of Mountain Blocks in Arizona and New Mexico as Revealed by Isotopes in Groundwater and Precipitation
AffiliationUniv Arizona, Dept Geosci
Univ Arizona, Lab Tree Ring Res
MetadataShow full item record
CitationEastoe, C.J.; Wright, W.E. Hydrology of Mountain Blocks in Arizona and New Mexico as Revealed by Isotopes in Groundwater and Precipitation. Geosciences 2019, 9, 461.
RightsCopyright © 2019 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
Collection InformationThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at firstname.lastname@example.org.
AbstractMountain-block groundwater in the Southern Basin-and-Range Province shows a variety of patterns of delta O-18 and delta H-2 that indicate multiple recharge mechanisms. At 2420 m above sea level (masl) in Tucson Basin, seasonal amount-weighted means of delta O-18 and delta H-2 for summer are -8.3, -53 parts per thousand, and for winter, -10.8 and -70 parts per thousand, respectively. Elevation-effect coefficients for delta O-18 and delta H-2 are as follows: summer, -1.6 and -7.7 parts per thousand per km and winter, -1.1 and -8.9 parts per thousand per km. Little altitude effect exists in 25% of seasons studied. At 2420 masl, amount-weighted monthly averages of delta O-18 and delta H-2 decrease in summer but increase in winter as precipitation intensity increases. In snow-banks, delta O-18 and delta H-2 commonly plots close to the winter local meteoric water line (LMWL). Four principal patterns of (delta O-18, delta H-2) data have been identified: (1) data plotting along LMWLs for all precipitation at >1800 masl; (2) data plotting along modified LMWLs for the wettest 30% of months at <1700 masl; (3) evaporation trends at all elevations; (4) other patterns, including those affected by ancient groundwater. Young, tritiated groundwater predominates in studied mountain blocks. Ancient groundwater forms separate systems and mixes with young groundwater. Recharge mechanisms reflect a complex interplay of precipitation season, altitude, precipitation intensity, groundwater age and geology. Tucson Basin alluvium receives mountain-front recharge containing 50%-90% winter precipitation.
NoteOpen access journal
VersionFinal published version
SponsorsU.S. National Parks Service