The triple argon isotope composition of groundwater on ten-thousand-year timescales

Seltzer, Alan M.; Krantz, John A.; Ng, Jessica; Danskin, Wesley R.; Bekaert, David V.; Barry, Peter H.; Kimbrough, David L.; Kulongoski, Justin T.; Severinghaus, Jeffrey P.

doi:10.1016/j.chemgeo.2021.120458

Cited by 9 publications

(11 citation statements)

References 69 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We also show that new Δ 40 Ar data from Arizona and Oregon contribute to an emerging compilation of high precision Δ 40 Ar measurements 11 that exhibit increasing Δ 40 Ar with decreasing 14 C activity, i.e., increasing age (Figure 6B). Weathering of old potassium‐bearing minerals is understood to be the main control on Δ 40 Ar, 11 with variable lithology contributing to a wide range in Δ 40 Ar in low 14 C waters.…”

Section: Discussion: Application To Groundwater Field Samplesmentioning

confidence: 66%

“…The first application of this method to the San Diego aquifer in Southern California revealed a 20‐m water table decline across the last deglaciation, in alignment with other proxies suggesting a wetter glacial climate across the southwestern United States 8 . High‐precision measurements of triple Ar isotopes used to quantify radiogenic 40 Ar content in groundwater additionally serve as a new tracer of groundwater age, rock composition, and rock weatherability 11 . In seawater, dissolved Kr and Xe isotopes offer promising new constraints on ventilation processes that contribute to observed deep ocean inert gas disequilibria 5,12 …”

Section: Introductionmentioning

confidence: 74%

“…We conducted interlaboratory comparisons of replicate field samples between SIO and three other laboratories: a dynamic noble gas mass spectrometry laboratory at WHOI that employs a similar LVE method 21 (Seltzer laboratory, WHOI-S), a static mass spectrometry laboratory at WHOI that employs the CT method (Jenkins laboratory, WHOI-J), and the University of Utah noble gas laboratory (UofU) that uses the CT method and static mass spectrometry (Figure 5 and We also show that new Δ 40 Ar data from Arizona and Oregon contribute to an emerging compilation of high precision Δ 40 Ar measurements 11 that exhibit increasing Δ 40 Ar with decreasing 14 C activity, i.e., increasing age (Figure 6B). Weathering of old potassiumbearing minerals is understood to be the main control on Δ 40 Ar, 11 with variable lithology contributing to a wide range in Δ 40 Ar in low…”

Section: Interlaboratory Comparisonsmentioning

confidence: 80%

See 2 more Smart Citations

A new large‐volume equilibration method for high‐precision measurements of dissolved noble gas stable isotopes

Tyne

Seltzer

et al. 2023

Rapid Comm Mass Spectrometry

Self Cite

View full text Add to dashboard Cite

Rationale: Noble gases are widely used as physically based climate proxies, notably in dissolved water samples as tracers of past recharge temperature in groundwater and air-sea gas exchange processes in seawater. Recent advances in measuring largevolume samples of dissolved noble gas isotopic ratios at high precision have expanded the range of climate parameters that can be interpreted. Methods:We build on prior methods for measuring noble gas stable isotopes at high precision with a new large-volume equilibration (LVE) method wherein sample gases are equilibrated in the sample flask between the dissolved phase and the headspace.The original dissolved gas composition is determined by measuring the headspace gases and correcting for the equilibrium dissolved gas content of the discarded water using known solubilities and fractionation factors. We evaluate the accuracy and precision of this method with air-equilibrated water standards of known noble gas composition.Results: Replicate air-equilibrated water standards and field measurements demonstrate that the LVE method achieves comparable precision to prior methods, with major advantages of measuring the Ne content as a constraint on excess air and allowing for long-term sample storage. Isotope ratios measured with the LVE method in replicate samples were consistent between two laboratories, and LVE elemental noble gas abundances agreed closely with replicate samples measured using established copper-tube methods and static noble gas mass spectrometry. Conclusions:The new LVE method enables reconstruction of past water table depths at ±1 m precision along with excess air, recharge temperature, and age and hydrogeochemical indicators. It has wide application to investigating climate signals and physical gas exchange processes in groundwater and seawater. | INTRODUCTIONNoble gases are valuable physical tracers of past climate and gas exchange processes due to their chemical and biological inertness, and their presence in various terrestrial, marine, and polar climate archives. In groundwater and ice cores, noble gases are a wellestablished tool to reconstruct paleotemperatures at the time of recharge or air-bubble closure in ice based on their temperaturedependent solubilities. [1][2][3] In seawater, noble gas measurements help distinguish physical processes of air-sea gas exchange from biogeochemical ones. 4,5 Dissolved noble gases in groundwater or seawater are typically sampled in 10-50-ml copper tubes for measurement of elemental abundances via static mass spectrometry (herein, the CT method). 6 Recently, high-precision measurements of dissolved argon (Ar), krypton (Kr), and xenon (Xe) stable isotope ratios-alongside their elemental concentrations-have allowed for reconstructions of additional paleoclimatic parameters beyond traditional

show abstract

Section: Discussion: Application To Groundwater Field Samplesmentioning

confidence: 66%

Section: Introductionmentioning

confidence: 74%

Section: Interlaboratory Comparisonsmentioning

confidence: 80%

See 1 more Smart Citation

A new large‐volume equilibration method for high‐precision measurements of dissolved noble gas stable isotopes

Tyne

Seltzer

et al. 2023

Rapid Comm Mass Spectrometry

Self Cite

View full text Add to dashboard Cite

show abstract

“…The relatively low excess 40 Ar in Ordovician formations can likely be attributed to the limited release of radiogenic Ar to porewaters. The weathering of K-bearing minerals has been confirmed as an important factor influencing Ar release. , This may be due to minimal lattice damage given the weak energy of β decay compared with the release of 4 He from α decay of 238 U, and given the larger atomic radius of 40 Ar when compared to 4 He. This results in the preferential retention of radiogenic 40 Ar over 4 He in clay minerals.…”

Section: Resultsmentioning

confidence: 99%

Crustal Noble Gas Isotopic Characteristics in Low-Permeability Ordovician Sedimentary Rock, Eastern Flank of the Michigan Basin

Zuo

Lapp

Jautzy

et al. 2021

ACS Earth Space Chem.

View full text Add to dashboard Cite

This study presents noble gas characteristics of porewater in the Ordovician low-permeability drill cores, which were vacuum-sealed in Al-foil bags and collected over a decade ago on the eastern flank of the Michigan Basin. Noble gas ratios and concentrations reveal crustal noble gas features as well as radiogenic 4He, 40Ar, and 136Xe components. The measured noble gas ratios in this study agree with measurements previously made in the Ordovician brine samples from the western flank of the Michigan Basin. However, unlike water samples from the western Michigan Basin, no mantle-featured noble gas components are found in the Ordovician rock porewater from this site. The Ordovician porewater residence time is quantitatively estimated with both He and Xe radiogenic ingrowth, yielding an average of 251 million years (m.y.). This porewater residence time estimate is comparable with the previous He accumulation time estimate at the same study site that yielded 260 m.y. The radiogenic noble gas ingrowth demonstrates long-term confinement of porewater and concomitant gases within the Ordovician low-permeability rock investigated. The remarkable preservation of gases in these well-sealed vapor-barrier Al-foil bags provides an economical and efficient possibility for noble gas out-diffusion sampling from drill cores.

show abstract

“…In addition to the traditional 14 C, 3 H and 18 O isotopes widely used in groundwater traceability analysis (Craig, 1961;Zhang et al, 2006), isotopes such as 32 Si, 37 Ar, 85 Kr, 87 Sr, 226 Ra and 222 Rn are gaining more and more popularity in terms of groundwater source and age analysis (Knies et al, 2000;Bauer et al, 2001;Krall et al, 2017;Danish et al, 2020;Seltzer et al, 2021), which makes the research on GCE more diversified. Isotope mixing model and Bayesian mixing model are also widely used in the identification of pollutants and the calculation of pollutant contribution rate (Zhang et al, 2022).…”

Section: New Methods Of Groundwater Chemical Evolutionmentioning

confidence: 99%

Theoretical progress of groundwater chemical evolution based on Tóthian theory: A review

Dong

Gao²

2022

Front. Mar. Sci.

View full text Add to dashboard Cite

Tóthian theory refers to the gravity driven groundwater flow system (GFS) theory represented by Tóth, which mainly expounds the driving and distribution law of groundwater. The establishment and development of this theory not only deepened people’s understanding of the driving and distribution law of groundwater, but also greatly promoted the study of groundwater chemical evolution (GCE). Modern GCE research is mostly based on Tóthian theory, characterized by combining with advanced scientific and technological means. Based on the clue of time, this paper is divided into two parts. The first part mainly summarizes the establishment and development of Tóthian theory, including the exploration of groundwater driving force and distribution form by hydrogeologists before Tóthian theory, and the enrichment, development and application of Tóthian theory by geologists after its establishment. The second part mainly combs the main theories and application progress of GCE mechanism research, including the main theories and findings of GCE research before the emergence of Tóthian theory, as well as the research progresses of GCE after the emergence of Tóthian theory. With the flow of groundwater in GFS, groundwater undergoes continuous chemical evolution, which eventually leads to the transformation of hydrochemical types and the gradual increase of total dissolved solids (TDS). The distribution of GFS and GCE complement each other. The distribution of GFS directly determines the model of GCE, and the results of GCE also play a certain role in the distribution of GFS. GCE mainly includes dissolution, precipitation, cation exchange and adsorption, which is affected by the physical and chemical conditions of permeable media, organic matter content and microorganisms. GCE has the characteristics of universality, sustainability and diversity. With the increasing global population and the progresses of science and technology, the impact of human life, industrial and agricultural production on groundwater is deepening. The aggravation of pollution directly changes the chemical compositions of groundwater, resulting in changes of the law of GCE.

show abstract

The triple argon isotope composition of groundwater on ten-thousand-year timescales

Cited by 9 publications

References 69 publications

A new large‐volume equilibration method for high‐precision measurements of dissolved noble gas stable isotopes

A new large‐volume equilibration method for high‐precision measurements of dissolved noble gas stable isotopes

Crustal Noble Gas Isotopic Characteristics in Low-Permeability Ordovician Sedimentary Rock, Eastern Flank of the Michigan Basin

Theoretical progress of groundwater chemical evolution based on Tóthian theory: A review

Contact Info

Product

Resources

About