Bicarbonate, sulfate, and chloride water in a shallow, clastic-dominated coastal flow system, Argentina

Most of the cities southeast of Buenos Aires, Argentina, depend heavily on ground water for water supply. Whereas ground water quality is generally good in the region, economic development along the coastal plain has been constrained by high salinities. Fifty-four wells were sampled for major ions i...

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Autores principales: Logan, W.S., Auge, M.P., Panarello, H.O.
Formato: JOUR
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Acceso en línea:http://hdl.handle.net/20.500.12110/paper_0017467X_v37_n2_p287_Logan
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id todo:paper_0017467X_v37_n2_p287_Logan
record_format dspace
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Carbonates
Chlorine compounds
Discharge (fluid mechanics)
Estuaries
Hydrodynamics
Recharging (underground waters)
Salt water intrusion
Sulfur compounds
Water analysis
Water quality
Water supply
Water wells
Chloride
Sulfate
Groundwater resources
coastal aquifer
groundwater
water chemistry
water quality
Argentina
Buenos Aires
spellingShingle Carbonates
Chlorine compounds
Discharge (fluid mechanics)
Estuaries
Hydrodynamics
Recharging (underground waters)
Salt water intrusion
Sulfur compounds
Water analysis
Water quality
Water supply
Water wells
Chloride
Sulfate
Groundwater resources
coastal aquifer
groundwater
water chemistry
water quality
Argentina
Buenos Aires
Logan, W.S.
Auge, M.P.
Panarello, H.O.
Bicarbonate, sulfate, and chloride water in a shallow, clastic-dominated coastal flow system, Argentina
topic_facet Carbonates
Chlorine compounds
Discharge (fluid mechanics)
Estuaries
Hydrodynamics
Recharging (underground waters)
Salt water intrusion
Sulfur compounds
Water analysis
Water quality
Water supply
Water wells
Chloride
Sulfate
Groundwater resources
coastal aquifer
groundwater
water chemistry
water quality
Argentina
Buenos Aires
description Most of the cities southeast of Buenos Aires, Argentina, depend heavily on ground water for water supply. Whereas ground water quality is generally good in the region, economic development along the coastal plain has been constrained by high salinities. Fifty-four wells were sampled for major ions in zones of recharge, transport and discharge in an area near La Plata, 50 km southeast of Buenos Aires. The shallow, southwest to northeast coastal flow system is >30 km long but is only 50 to 80 m thick. It consists of Plio-Pleistocene fluvial sand overlain by Pleistocene eolian and fluvial silt and Holocene estuarine silty clay. Hydrochemical endmembers include HCO3, SO4, and Cl water. Bicarbonate-type water includes high plain recharge water (Ca-Na-HCO3) that evolves through cation exchange and calcite dissolution to a high pH, pure Na-HCO3 endmember at the southwest edge of the coastal plain. Similar Na-HCO3 water is also found underlying recharge areas of the central coastal plain, and a lens of Ca-HCO3 water is associated with a ridge of shell debris parallel to the coast. Mixed cation-Cl water near the coastline represents intruded sea water that has undergone cation exchange. Chemically similar water underlying the southwest coastal plain, however, can be shown isotopically to have formed from fairly dilute solutions concentrated many times by evapotranspiration. In the central coastal plain, Na-SO4-Cl water (up to 17,000 mg/L SO4) underlies hummocks and, at depth, forms plumes in the subsurface. The chemical controls are dissolution of gypsum precipitated during pyrite oxidation, evapotranspiration, and calcite precipitation. This extreme diversity of water chemistry in a shallow, clastic flow system is uncommon. It is made possible by (1) the presence of oxidized, originally pyritic, but slightly permeable sediments that have been exposed to evolving geochemical and hydrodynamic conditions, and (2) highly focused recharge that favors the development of fresh water bodies underlying recharge zones and stagnant, evaporated water underlying other areas. Most of the cities southeast of Buenos Aires, Argentina, depend heavily on ground water for water supply. Whereas ground water quality is generally good in the region, economic development along the coastal plain has been constrained by high salinities. Fifty-four wells were sampled for major ions in zones of recharge, transport and discharge in an area near La Plata, 50 km southeast of Buenos Aires. The shallow, southwest to northeast coastal flow system is >30 km long but is only 50 to 80 m thick. It consists of Plio-Pleistocene fluvial sand overlain by Pleistocene eolian and fluvial silt and Holocene estuarine silty clay. Hydrochemical endmembers include HCO3, SO4, and Cl water. Bicarbonate-type water includes high plain recharge water (Ca-Na-HCO3) that evolves through cation exchange and calcite dissolution to a high pH, pure Na-HCO3 endmember at the southwest edge of the coastal plain. Similar Na-HCO3 water is also found underlying recharge areas of the central coastal plain, and a lens of Ca-HCO3 water is associated with a ridge of shell debris parallel to the coast. Mixed cation-Cl water near the coastline represents intruded sea water that has undergone cation exchange. Chemically similar water underlying the southwest coastal plain, however, can be shown isotopically to have formed from fairly dilute solutions concentrated many times by evapotranspiration. In the central coastal plain, Na-SO4-Cl water (up to 17,000 mg/L SO4) underlies hummocks and, at depth, forms plumes in the subsurface. The chemical controls are dissolution of gypsum precipitated during pyrite oxidation, evapotranspiration, and calcite precipitation. This extreme diversity of water chemistry in a shallow, clastic flow system is uncommon. It is made possible by (1) the presence of oxidized, originally pyritic, but slightly permeable sediments that have been exposed to evolving geochemical and hydrodynamic conditions, and (2) highly focused recharge that favors the development of fresh water bodies underlying recharge zones and stagnant, evaporated water underlying other areas.
format JOUR
author Logan, W.S.
Auge, M.P.
Panarello, H.O.
author_facet Logan, W.S.
Auge, M.P.
Panarello, H.O.
author_sort Logan, W.S.
title Bicarbonate, sulfate, and chloride water in a shallow, clastic-dominated coastal flow system, Argentina
title_short Bicarbonate, sulfate, and chloride water in a shallow, clastic-dominated coastal flow system, Argentina
title_full Bicarbonate, sulfate, and chloride water in a shallow, clastic-dominated coastal flow system, Argentina
title_fullStr Bicarbonate, sulfate, and chloride water in a shallow, clastic-dominated coastal flow system, Argentina
title_full_unstemmed Bicarbonate, sulfate, and chloride water in a shallow, clastic-dominated coastal flow system, Argentina
title_sort bicarbonate, sulfate, and chloride water in a shallow, clastic-dominated coastal flow system, argentina
url http://hdl.handle.net/20.500.12110/paper_0017467X_v37_n2_p287_Logan
work_keys_str_mv AT loganws bicarbonatesulfateandchloridewaterinashallowclasticdominatedcoastalflowsystemargentina
AT augemp bicarbonatesulfateandchloridewaterinashallowclasticdominatedcoastalflowsystemargentina
AT panarelloho bicarbonatesulfateandchloridewaterinashallowclasticdominatedcoastalflowsystemargentina
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spelling todo:paper_0017467X_v37_n2_p287_Logan2023-10-03T14:15:01Z Bicarbonate, sulfate, and chloride water in a shallow, clastic-dominated coastal flow system, Argentina Logan, W.S. Auge, M.P. Panarello, H.O. Carbonates Chlorine compounds Discharge (fluid mechanics) Estuaries Hydrodynamics Recharging (underground waters) Salt water intrusion Sulfur compounds Water analysis Water quality Water supply Water wells Chloride Sulfate Groundwater resources coastal aquifer groundwater water chemistry water quality Argentina Buenos Aires Most of the cities southeast of Buenos Aires, Argentina, depend heavily on ground water for water supply. Whereas ground water quality is generally good in the region, economic development along the coastal plain has been constrained by high salinities. Fifty-four wells were sampled for major ions in zones of recharge, transport and discharge in an area near La Plata, 50 km southeast of Buenos Aires. The shallow, southwest to northeast coastal flow system is >30 km long but is only 50 to 80 m thick. It consists of Plio-Pleistocene fluvial sand overlain by Pleistocene eolian and fluvial silt and Holocene estuarine silty clay. Hydrochemical endmembers include HCO3, SO4, and Cl water. Bicarbonate-type water includes high plain recharge water (Ca-Na-HCO3) that evolves through cation exchange and calcite dissolution to a high pH, pure Na-HCO3 endmember at the southwest edge of the coastal plain. Similar Na-HCO3 water is also found underlying recharge areas of the central coastal plain, and a lens of Ca-HCO3 water is associated with a ridge of shell debris parallel to the coast. Mixed cation-Cl water near the coastline represents intruded sea water that has undergone cation exchange. Chemically similar water underlying the southwest coastal plain, however, can be shown isotopically to have formed from fairly dilute solutions concentrated many times by evapotranspiration. In the central coastal plain, Na-SO4-Cl water (up to 17,000 mg/L SO4) underlies hummocks and, at depth, forms plumes in the subsurface. The chemical controls are dissolution of gypsum precipitated during pyrite oxidation, evapotranspiration, and calcite precipitation. This extreme diversity of water chemistry in a shallow, clastic flow system is uncommon. It is made possible by (1) the presence of oxidized, originally pyritic, but slightly permeable sediments that have been exposed to evolving geochemical and hydrodynamic conditions, and (2) highly focused recharge that favors the development of fresh water bodies underlying recharge zones and stagnant, evaporated water underlying other areas. Most of the cities southeast of Buenos Aires, Argentina, depend heavily on ground water for water supply. Whereas ground water quality is generally good in the region, economic development along the coastal plain has been constrained by high salinities. Fifty-four wells were sampled for major ions in zones of recharge, transport and discharge in an area near La Plata, 50 km southeast of Buenos Aires. The shallow, southwest to northeast coastal flow system is >30 km long but is only 50 to 80 m thick. It consists of Plio-Pleistocene fluvial sand overlain by Pleistocene eolian and fluvial silt and Holocene estuarine silty clay. Hydrochemical endmembers include HCO3, SO4, and Cl water. Bicarbonate-type water includes high plain recharge water (Ca-Na-HCO3) that evolves through cation exchange and calcite dissolution to a high pH, pure Na-HCO3 endmember at the southwest edge of the coastal plain. Similar Na-HCO3 water is also found underlying recharge areas of the central coastal plain, and a lens of Ca-HCO3 water is associated with a ridge of shell debris parallel to the coast. Mixed cation-Cl water near the coastline represents intruded sea water that has undergone cation exchange. Chemically similar water underlying the southwest coastal plain, however, can be shown isotopically to have formed from fairly dilute solutions concentrated many times by evapotranspiration. In the central coastal plain, Na-SO4-Cl water (up to 17,000 mg/L SO4) underlies hummocks and, at depth, forms plumes in the subsurface. The chemical controls are dissolution of gypsum precipitated during pyrite oxidation, evapotranspiration, and calcite precipitation. This extreme diversity of water chemistry in a shallow, clastic flow system is uncommon. It is made possible by (1) the presence of oxidized, originally pyritic, but slightly permeable sediments that have been exposed to evolving geochemical and hydrodynamic conditions, and (2) highly focused recharge that favors the development of fresh water bodies underlying recharge zones and stagnant, evaporated water underlying other areas. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_0017467X_v37_n2_p287_Logan