{"id":{"repo_id":"unm","oai_identifier":"oai:digitalrepository.unm.edu:eps_etds-1099"},"canonical_url":"https://search.dev.ndltd.org/etd/unm/oai:digitalrepository.unm.edu:eps_etds-1099","repository":{"repo_id":"unm","name":"University of New Mexico","base_url":"https://digitalrepository.unm.edu/do/oai/"},"display":{"title":"An aqueous geochemical and hydrologic study of the springs and wells of the Sevilleta National Wildlife Refuge : evaluating hydrochemical pathways","abstract":"The Rio Grande is a regionally important water source, but the smaller rift springs are also a vital resource for livestock and wildlife. Several springs are located on rift-bounding faults and exhibit a mixing of larger volume meteoric recharge with small volume, chemically potent \"endogenic\" fluids. It has been hypothesized that deep-seated faults within the rift provide conduits for the ascent of deeply derived fluids, possibly from the lithospheric/asthenospheric mantle, while others have proposed that upwelling sedimentary basin brines at interbasin constrictions represent a significant salinity input to the modern Rio Grande. This study (a) provides the first hydrochemical data on a comprehensive suite of springs and wells, and (b) tests and refines existing models for water quality in the rift using hydrochemistry (major, minor and trace elements, Cl/Br ratios, δ18O, δD, δ13C, and 87Sr/86Sr ratios) and geochemical modeling along a series of transects within the Sevilleta National Wildlife Refuge. In the rift, several potential flow systems can be envisioned: 1) exogenic fluids in shallow unconfined aquifers with recent meteoric recharge, which are characterized by low temperatures, CO2 values, and 87Sr/86Sr ratios, 2) mesogenic fluids, categorized as subregional basin fluids in Tertiary rift fill, 3) regional/intermediate waters residing in the confined aquifers of Paleozoic/Mesozoic sedimentary strata, 4) deep sedimentary basin brines, also in confined strata, and 5) endogenic waters, defined as deeply-circulating regional fluids that may have mantle derivation, source from faults, and are characterized by elevated temperatures, salinity, CO2 values, and 87Sr/86Sr ratios. Major ions indicate the interaction of five fluids with distinct hydrochemical facies: 1) Na-Cl, 2) mixed ion-HCO3, 3) Ca-SO4, 4) mixed cation/anion (corresponds with local precipitation chemistry), and 5) Na-mixed anion. δ18O and δD indicate mixing between brines and the Rio Grande, and δ13C values suggest a mixing of organic C and a mantle-derived C input in springs. Radiogenic 87Sr/86Sr ratios indicate mixing between endogenic fluids and meteorically-derived waters and principal component analysis indicates a common deeply-derived source in select waters. These tracers conclude that endogenic fluids are a volumetrically small but potent addition to middle Rio Grande rift springs, and may contribute to river salinization.","abstract_html":"The Rio Grande is a regionally important water source, but the smaller rift springs are also a vital resource for livestock and wildlife. Several springs are located on rift-bounding faults and exhibit a mixing of larger volume meteoric recharge with small volume, chemically potent "endogenic" fluids. It has been hypothesized that deep-seated faults within the rift provide conduits for the ascent of deeply derived fluids, possibly from the lithospheric/asthenospheric mantle, while others have proposed that upwelling sedimentary basin brines at interbasin constrictions represent a significant salinity input to the modern Rio Grande. This study (a) provides the first hydrochemical data on a comprehensive suite of springs and wells, and (b) tests and refines existing models for water quality in the rift using hydrochemistry (major, minor and trace elements, Cl/Br ratios, δ18O, δD, δ13C, and 87Sr/86Sr ratios) and geochemical modeling along a series of transects within the Sevilleta National Wildlife Refuge. In the rift, several potential flow systems can be envisioned: 1) exogenic fluids in shallow unconfined aquifers with recent meteoric recharge, which are characterized by low temperatures, CO2 values, and 87Sr/86Sr ratios, 2) mesogenic fluids, categorized as subregional basin fluids in Tertiary rift fill, 3) regional/intermediate waters residing in the confined aquifers of Paleozoic/Mesozoic sedimentary strata, 4) deep sedimentary basin brines, also in confined strata, and 5) endogenic waters, defined as deeply-circulating regional fluids that may have mantle derivation, source from faults, and are characterized by elevated temperatures, salinity, CO2 values, and 87Sr/86Sr ratios. Major ions indicate the interaction of five fluids with distinct hydrochemical facies: 1) Na-Cl, 2) mixed ion-HCO3, 3) Ca-SO4, 4) mixed cation/anion (corresponds with local precipitation chemistry), and 5) Na-mixed anion. δ18O and δD indicate mixing between brines and the Rio Grande, and δ13C values suggest a mixing of organic C and a mantle-derived C input in springs. Radiogenic 87Sr/86Sr ratios indicate mixing between endogenic fluids and meteorically-derived waters and principal component analysis indicates a common deeply-derived source in select waters. These tracers conclude that endogenic fluids are a volumetrically small but potent addition to middle Rio Grande rift springs, and may contribute to river salinization.","abstract_has_math":false,"creators":["Williams, Amy"],"institution":null,"degree_name":"Earth and Planetary Sciences","degree_level":"Masters","degree_discipline":"Department of Earth and Planetary Sciences","degree_department":null,"school":null,"contributors":["Crossey, Laura","Karlstrom, Karl","Dahm, Clifford"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2009,"date_issued":"2009-08-27T07:00:00Z","date_published":"2009-08-27T07:00:00Z","updated_at":"2026-07-24T05:26:22Z","subjects":["aqueous geochemistry","Rio Grande Rift","Sevilleta"],"languages":["English"],"rights":[],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["https://digitalrepository.unm.edu/eps_etds/100"],"render_values":[{"text":"https://digitalrepository.unm.edu/eps_etds/100","href":"https://digitalrepository.unm.edu/eps_etds/100","code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/1928/9787","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Crossey, Laura","Karlstrom, Karl","Dahm, Clifford"]},{"key":"dc:creator","label":"Author","values":["Williams, Amy"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"thesis:degree_discipline","label":"Discipline","values":["Department of Earth and Planetary Sciences"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Masters","Thesis"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Earth and Planetary Sciences"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["aqueous geochemistry","Rio Grande Rift","Sevilleta"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["English"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/1928/9787","https://digitalrepository.unm.edu/eps_etds/100"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["The Rio Grande is a regionally important water source, but the smaller rift springs are also a vital resource for livestock and wildlife. Several springs are located on rift-bounding faults and exhibit a mixing of larger volume meteoric recharge with small volume, chemically potent \"endogenic\" fluids. It has been hypothesized that deep-seated faults within the rift provide conduits for the ascent of deeply derived fluids, possibly from the lithospheric/asthenospheric mantle, while others have proposed that upwelling sedimentary basin brines at interbasin constrictions represent a significant salinity input to the modern Rio Grande. This study (a) provides the first hydrochemical data on a comprehensive suite of springs and wells, and (b) tests and refines existing models for water quality in the rift using hydrochemistry (major, minor and trace elements, Cl/Br ratios, δ18O, δD, δ13C, and 87Sr/86Sr ratios) and geochemical modeling along a series of transects within the Sevilleta National Wildlife Refuge. In the rift, several potential flow systems can be envisioned: 1) exogenic fluids in shallow unconfined aquifers with recent meteoric recharge, which are characterized by low temperatures, CO2 values, and 87Sr/86Sr ratios, 2) mesogenic fluids, categorized as subregional basin fluids in Tertiary rift fill, 3) regional/intermediate waters residing in the confined aquifers of Paleozoic/Mesozoic sedimentary strata, 4) deep sedimentary basin brines, also in confined strata, and 5) endogenic waters, defined as deeply-circulating regional fluids that may have mantle derivation, source from faults, and are characterized by elevated temperatures, salinity, CO2 values, and 87Sr/86Sr ratios. Major ions indicate the interaction of five fluids with distinct hydrochemical facies: 1) Na-Cl, 2) mixed ion-HCO3, 3) Ca-SO4, 4) mixed cation/anion (corresponds with local precipitation chemistry), and 5) Na-mixed anion. δ18O and δD indicate mixing between brines and the Rio Grande, and δ13C values suggest a mixing of organic C and a mantle-derived C input in springs. Radiogenic 87Sr/86Sr ratios indicate mixing between endogenic fluids and meteorically-derived waters and principal component analysis indicates a common deeply-derived source in select waters. These tracers conclude that endogenic fluids are a volumetrically small but potent addition to middle Rio Grande rift springs, and may contribute to river salinization."]},{"key":"dc:title","label":"Title","values":["An aqueous geochemical and hydrologic study of the springs and wells of the Sevilleta National Wildlife Refuge : evaluating hydrochemical pathways"]}]}],"canonical_facts":{"dc:contributor":["Crossey, Laura","Karlstrom, Karl","Dahm, Clifford"],"dc:creator":["Williams, Amy"],"dc:description.abstract":["The Rio Grande is a regionally important water source, but the smaller rift springs are also a vital resource for livestock and wildlife. Several springs are located on rift-bounding faults and exhibit a mixing of larger volume meteoric recharge with small volume, chemically potent \"endogenic\" fluids. It has been hypothesized that deep-seated faults within the rift provide conduits for the ascent of deeply derived fluids, possibly from the lithospheric/asthenospheric mantle, while others have proposed that upwelling sedimentary basin brines at interbasin constrictions represent a significant salinity input to the modern Rio Grande. This study (a) provides the first hydrochemical data on a comprehensive suite of springs and wells, and (b) tests and refines existing models for water quality in the rift using hydrochemistry (major, minor and trace elements, Cl/Br ratios, δ18O, δD, δ13C, and 87Sr/86Sr ratios) and geochemical modeling along a series of transects within the Sevilleta National Wildlife Refuge. In the rift, several potential flow systems can be envisioned: 1) exogenic fluids in shallow unconfined aquifers with recent meteoric recharge, which are characterized by low temperatures, CO2 values, and 87Sr/86Sr ratios, 2) mesogenic fluids, categorized as subregional basin fluids in Tertiary rift fill, 3) regional/intermediate waters residing in the confined aquifers of Paleozoic/Mesozoic sedimentary strata, 4) deep sedimentary basin brines, also in confined strata, and 5) endogenic waters, defined as deeply-circulating regional fluids that may have mantle derivation, source from faults, and are characterized by elevated temperatures, salinity, CO2 values, and 87Sr/86Sr ratios. Major ions indicate the interaction of five fluids with distinct hydrochemical facies: 1) Na-Cl, 2) mixed ion-HCO3, 3) Ca-SO4, 4) mixed cation/anion (corresponds with local precipitation chemistry), and 5) Na-mixed anion. δ18O and δD indicate mixing between brines and the Rio Grande, and δ13C values suggest a mixing of organic C and a mantle-derived C input in springs. Radiogenic 87Sr/86Sr ratios indicate mixing between endogenic fluids and meteorically-derived waters and principal component analysis indicates a common deeply-derived source in select waters. These tracers conclude that endogenic fluids are a volumetrically small but potent addition to middle Rio Grande rift springs, and may contribute to river salinization."],"dc:identifier":["http://hdl.handle.net/1928/9787","https://digitalrepository.unm.edu/eps_etds/100"],"dc:language":["English"],"dc:subject":["aqueous geochemistry","Rio Grande Rift","Sevilleta"],"dc:title":["An aqueous geochemical and hydrologic study of the springs and wells of the Sevilleta National Wildlife Refuge : evaluating hydrochemical pathways"],"thesis:degree_discipline":["Department of Earth and Planetary Sciences"],"thesis:degree_level":["Masters","Thesis"],"thesis:degree_name":["Earth and Planetary Sciences"]},"updated_at":"2026-07-24T05:26:22Z"}