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Francis ML, Palcsu L, Molnár M, Kertész T, Clarke CE, Miller JA, van Gend J. Calcareous termite mounds in South Africa are ancient carbon reservoirs. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 926:171760. [PMID: 38537830 DOI: 10.1016/j.scitotenv.2024.171760] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Revised: 02/03/2024] [Accepted: 03/14/2024] [Indexed: 04/05/2024]
Abstract
Ecosystems that offer carbon sequestration by leaching bicarbonate to groundwater are valuable natural capital. One region that may offer this service is the west coast of South Africa. Over 20 % is covered by soil mounds ("heuweltjies") up to 40 m diameter, 2 m high, inhabited by the southern harvester termite Microhodotermes viator and enriched in soil organic and inorganic carbon and soluble minerals. We aimed to generate radiogenic and stable isotope data for soils and groundwater in a region where these data are absent, to 1) verify the atmosphere-soil-groundwater link, and 2) resolve the timing and pattern of calcite dissolution and water infiltration in the landscape. Results show that soil and groundwater sulfate have the same marine aerosol source. Episodic calcite dissolution in mound centers, which increased during periods of global cooling, has been set against background input of marine aerosols since before the Last Glacial according to radiocarbon (14C) ages. Our data push back soil organic carbon 14C ages of inhabited termite mounds to 13-19 ka (kiloannum, thousand years before present), nest carbonate 14C ages to 33 ka, and mound soil carbonate 14C ages to 34 ka, making these the oldest active termite features ever dated. These ages are consistent with soil organic carbon and carbonate 14C ages of regional, non-mound, coastal petrocalcic horizons formed by accumulation of carbonate leached from their overlying aeolian dune fields. Harvesting activities of termites inject younger organic material around nests >1 m deep, leading to continuous renewal of important soil carbon reservoirs at depth. Termite bioturbation increases the system's ability to dissolve carbonate. The central, bioturbated part of the mounds have greater infiltration depths and greater calcite dissolution, whereas surrounding soils experienced more surface runoff. Calcareous termite mounds offer a mechanism to sequester CO2 through dissolution and leaching of soil carbonate-bicarbonate to groundwater.
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Affiliation(s)
- M L Francis
- Department of Soil Science, Stellenbosch University, Private Bag X1, Matieland, South Africa.
| | - L Palcsu
- Isotope Climatology and Environmental Research Center, Institute for Nuclear Research, Bem ter 18/c, Debrecen, Hungary
| | - M Molnár
- Isotope Climatology and Environmental Research Center, Institute for Nuclear Research, Bem ter 18/c, Debrecen, Hungary
| | - T Kertész
- Isotope Climatology and Environmental Research Center, Institute for Nuclear Research, Bem ter 18/c, Debrecen, Hungary
| | - C E Clarke
- Department of Soil Science, Stellenbosch University, Private Bag X1, Matieland, South Africa
| | - J A Miller
- Department of Earth Sciences, Stellenbosch University, Private Bag X1, Matieland, South Africa
| | - J van Gend
- Department of Earth Sciences, Stellenbosch University, Private Bag X1, Matieland, South Africa
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Wang H, Peng Y, Li C, Cao X, Cheng M, Bao H. Sulfate triple-oxygen-isotope evidence confirming oceanic oxygenation 570 million years ago. Nat Commun 2023; 14:4315. [PMID: 37463883 DOI: 10.1038/s41467-023-39962-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Accepted: 07/05/2023] [Indexed: 07/20/2023] Open
Abstract
The largest negative inorganic carbon isotope excursion in Earth's history, namely the Ediacaran Shuram Excursion (SE), closely followed by early animal radiation, has been widely interpreted as a consequence of oceanic oxidation. However, the primary nature of the signature, source of oxidants, and tempo of the event remain contested. Here, we show that carbonate-associated sulfate (CAS) from three different paleocontinents all have conspicuous negative 17O anomalies (Δ'17OCAS values down to -0.53‰) during the SE. Furthermore, the Δ'17OCAS varies in correlation with its corresponding δ34SCAS and δ18OCAS as well as the carbonate δ13Ccarb, decreasing initially followed by a recovery over the ~7-Myr SE duration. In a box-model examination, we argue for a period of sustained water-column ventilation and consequently enhanced sulfur oxidation in the SE ocean. Our findings reveal a direct involvement of mass-anomalously 17O-depleted atmospheric O2 in marine sulfate formation and thus a primary global oceanic oxygenation event during the SE.
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Affiliation(s)
- Haiyang Wang
- International Center for Isotope Effects Research, Nanjing University, Nanjing, China
- State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation & Institute of Sedimentary Geology, Chengdu University of Technology, Chengdu, China
- International Center for Sedimentary Geochemistry and Biogeochemistry Research, Chengdu University of Technology, Chengdu, China
| | - Yongbo Peng
- International Center for Isotope Effects Research, Nanjing University, Nanjing, China.
- Frontiers Science Center for Critical Earth Material Cycling and State Key Laboratory for Mineral Deposits Research, School of Earth Sciences and Engineering, Nanjing University, Nanjing, China.
| | - Chao Li
- State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation & Institute of Sedimentary Geology, Chengdu University of Technology, Chengdu, China.
- International Center for Sedimentary Geochemistry and Biogeochemistry Research, Chengdu University of Technology, Chengdu, China.
- Key Laboratory of Deep-time Geography and Environment Reconstruction and Applications of Ministry of Natural Resources, Chengdu University of Technology, Chengdu, China.
| | - Xiaobin Cao
- International Center for Isotope Effects Research, Nanjing University, Nanjing, China
- Frontiers Science Center for Critical Earth Material Cycling and State Key Laboratory for Mineral Deposits Research, School of Earth Sciences and Engineering, Nanjing University, Nanjing, China
| | - Meng Cheng
- State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation & Institute of Sedimentary Geology, Chengdu University of Technology, Chengdu, China
- International Center for Sedimentary Geochemistry and Biogeochemistry Research, Chengdu University of Technology, Chengdu, China
- Key Laboratory of Deep-time Geography and Environment Reconstruction and Applications of Ministry of Natural Resources, Chengdu University of Technology, Chengdu, China
| | - Huiming Bao
- International Center for Isotope Effects Research, Nanjing University, Nanjing, China.
- Frontiers Science Center for Critical Earth Material Cycling and State Key Laboratory for Mineral Deposits Research, School of Earth Sciences and Engineering, Nanjing University, Nanjing, China.
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Triple oxygen isotope constraints on atmospheric O 2 and biological productivity during the mid-Proterozoic. Proc Natl Acad Sci U S A 2021; 118:2105074118. [PMID: 34911756 PMCID: PMC8713798 DOI: 10.1073/pnas.2105074118] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/02/2021] [Indexed: 12/16/2022] Open
Abstract
Reconstructing the history of biological productivity and atmospheric oxygen partial pressure (pO2) is a fundamental goal of geobiology. Recently, the mass-independent fractionation of oxygen isotopes (O-MIF) has been used as a tool for estimating pO2 and productivity during the Proterozoic. O-MIF, reported as Δ'17O, is produced during the formation of ozone and destroyed by isotopic exchange with water by biological and chemical processes. Atmospheric O-MIF can be preserved in the geologic record when pyrite (FeS2) is oxidized during weathering, and the sulfur is redeposited as sulfate. Here, sedimentary sulfates from the ∼1.4-Ga Sibley Formation are reanalyzed using a detailed one-dimensional photochemical model that includes physical constraints on air-sea gas exchange. Previous analyses of these data concluded that pO2 at that time was <1% PAL (times the present atmospheric level). Our model shows that the upper limit on pO2 is essentially unconstrained by these data. Indeed, pO2 levels below 0.8% PAL are possible only if atmospheric methane was more abundant than today (so that pCO2 could have been lower) or if the Sibley O-MIF data were diluted by reprocessing before the sulfates were deposited. Our model also shows that, contrary to previous assertions, marine productivity cannot be reliably constrained by the O-MIF data because the exchange of molecular oxygen (O2) between the atmosphere and surface ocean is controlled more by air-sea gas transfer rates than by biological productivity. Improved estimates of pCO2 and/or improved proxies for Δ'17O of atmospheric O2 would allow tighter constraints to be placed on mid-Proterozoic pO2.
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Aroskay A, Martin E, Bekki S, Montana G, Randazzo L, Cartigny P, Chabas A, Verney-Carron A. Multi O- and S-isotopes as tracers of black crusts formation under volcanic and non-volcanic atmospheric conditions in Sicily (Italy). THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 750:142283. [PMID: 33182218 DOI: 10.1016/j.scitotenv.2020.142283] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Revised: 09/04/2020] [Accepted: 09/07/2020] [Indexed: 06/11/2023]
Abstract
The deterioration of monument or building stone materials is mostly due to the growth of black crusts that cause blackening and disaggregation of the exposed surface. This study reports on new oxygen (δ17O, δ18O and Δ17O) and sulphur (δ33S, δ34S, δ36S, Δ33S and Δ36S) isotopic analyses of black crust sulphates formed on building stones in Sicily (Southern Italy). The measurements are used to identify the possible influence of volcanic emissions on black crust formation. Black crusts were mostly sampled on carbonate stone substrate in different locations subject to various sulphur emission sources (marine, anthropogenic and volcanic). Unlike atmospheric sulphate aerosols that mostly exhibit Δ33S > 0‰, here most of the analysed black crust sulphates show negative Δ33S. This confirms that black crust sulphates do not result from deposition of sulphate aerosols or of rainwater but mostly from the oxidation of dry deposited SO2 onto the stone substrate. The δ34S and δ18O values indicate that most of black crust sulphate originates from anthropogenic activities. Δ17O values are found to be related to the sampling location. The largest 17O-anomalies (up to ~4‰) are measured in black crust from areas highly influenced by volcanic emissions, which demonstrates the strong involvement of ozone in the formation of black crusts in volcanically influenced environments.
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Affiliation(s)
- A Aroskay
- Institut des Sciences de la Terre de Paris (ISTeP), Sorbonne Université, Paris, France.
| | - E Martin
- Institut des Sciences de la Terre de Paris (ISTeP), Sorbonne Université, Paris, France
| | - S Bekki
- Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Sorbonne Université, Paris, France
| | - G Montana
- Dipartimento di Scienze della Terra e del Mare (DiSTeM), Università degli Studi di Palermo, Palermo, Italy
| | - L Randazzo
- Department of Biology, Ecology and Earth Sciences (DiBEST), Università della Calabria, Italy
| | - P Cartigny
- Institut de Physique du Globe de Paris (IPGP), Université de Paris, Paris, France
| | - A Chabas
- Laboratoire Interuniversitaire des Systèmes Atmosphériques (LISA), Université Paris-Est-Créteil, Université de Paris, Institut Pierre Simon Laplace (IPSL), Créteil, France
| | - A Verney-Carron
- Laboratoire Interuniversitaire des Systèmes Atmosphériques (LISA), Université Paris-Est-Créteil, Université de Paris, Institut Pierre Simon Laplace (IPSL), Créteil, France
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Abstract
The mass-independent minor oxygen isotope compositions (Δ'17O) of atmospheric O2 and [Formula: see text] are primarily regulated by their relative partial pressures, [Formula: see text]/[Formula: see text] Pyrite oxidation during chemical weathering on land consumes [Formula: see text] and generates sulfate that is carried to the ocean by rivers. The Δ'17O values of marine sulfate deposits have thus been proposed to quantitatively track ancient atmospheric conditions. This proxy assumes direct [Formula: see text] incorporation into terrestrial pyrite oxidation-derived sulfate, but a mechanistic understanding of pyrite oxidation-including oxygen sources-in weathering environments remains elusive. To address this issue, we present sulfate source estimates and Δ'17O measurements from modern rivers transecting the Annapurna Himalaya, Nepal. Sulfate in high-elevation headwaters is quantitatively sourced by pyrite oxidation, but resulting Δ'17O values imply no direct tropospheric [Formula: see text] incorporation. Rather, our results necessitate incorporation of oxygen atoms from alternative, 17O-enriched sources such as reactive oxygen species. Sulfate Δ'17O decreases significantly when moving into warm, low-elevation tributaries draining the same bedrock lithology. We interpret this to reflect overprinting of the pyrite oxidation-derived Δ'17O anomaly by microbial sulfate reduction and reoxidation, consistent with previously described major sulfur and oxygen isotope relationships. The geologic application of sulfate Δ'17O as a proxy for past [Formula: see text]/[Formula: see text] should consider both 1) alternative oxygen sources during pyrite oxidation and 2) secondary overprinting by microbial recycling.
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Wang H, Zhang Q. Research Advances in Identifying Sulfate Contamination Sources of Water Environment by Using Stable Isotopes. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2019; 16:ijerph16111914. [PMID: 31151187 PMCID: PMC6603547 DOI: 10.3390/ijerph16111914] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Revised: 05/22/2019] [Accepted: 05/23/2019] [Indexed: 12/02/2022]
Abstract
As the main anion of groundwater, the content of sulfate affects the drinking water safety and ecological security directly. In recent years, with the acceleration of industrialization and urbanization development, the problem of sulfate pollution in water environments is becoming more and more serious. It is critical to effectively identify the sulfate sources of water environment to ensure human health and the benign evolution of water environment. Due to its “fingerprints” feature, the sulfur and oxygen isotopes of SO42− have been widely used to identify sources of sulfate contamination in water environment. However, research advances in tracing sulfate contamination sources of water environment by using stable isotopes are rarely reported. This paper reviewed the research advances of sulfate isotope technology domestically and abroad, which was used to trace the sources of sulfate pollution in water environment, compared different pre-treatment methods for analyzing the δ34S and δ18O of sulfate, and compiled the ranges of typical values of δ34S and δ18O from different potential sources of sulfate contamination. In this review, the limitation of the technique in traceability of sulfate pollution was also discussed, and the future traceability techniques of sulfate pollution were prospected.
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Affiliation(s)
- Huiwei Wang
- Hebei and China Geological Survey Key Laboratory of Groundwater Remediation, Institute of Hydrogeology and Environmental Geology, Chinese Academy of Geological Sciences, Shijiazhuang 050061, China.
| | - Qianqian Zhang
- Hebei and China Geological Survey Key Laboratory of Groundwater Remediation, Institute of Hydrogeology and Environmental Geology, Chinese Academy of Geological Sciences, Shijiazhuang 050061, China.
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A case for low atmospheric oxygen levels during Earth's middle history. Emerg Top Life Sci 2018; 2:149-159. [PMID: 32412619 DOI: 10.1042/etls20170161] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Revised: 05/29/2018] [Accepted: 05/31/2018] [Indexed: 11/17/2022]
Abstract
The oxygenation of the atmosphere - one of the most fundamental transformations in Earth's history - dramatically altered the chemical composition of the oceans and provides a compelling example of how life can reshape planetary surface environments. Furthermore, it is commonly proposed that surface oxygen levels played a key role in controlling the timing and tempo of the origin and early diversification of animals. Although oxygen levels were likely more dynamic than previously imagined, we make a case here that emerging records provide evidence for low atmospheric oxygen levels for the majority of Earth's history. Specifically, we review records and present a conceptual framework that suggest that background oxygen levels were below 1% of the present atmospheric level during the billon years leading up to the diversification of early animals. Evidence for low background oxygen levels through much of the Proterozoic bolsters the case that environmental conditions were a critical factor in controlling the structure of ecosystems through Earth's history.
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Vicars WC, Bhattacharya SK, Erbland J, Savarino J. Measurement of the 17O-excess (Δ17O) of tropospheric ozone using a nitrite-coated filter. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2012; 26:1219-1231. [PMID: 22499198 DOI: 10.1002/rcm.6218] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
RATIONALE The (17)O-excess (Δ(17)O) of tropospheric ozone (O(3)) serves as a useful marker in studies of atmospheric oxidation pathways; however, due to the complexity and expense of currently available analytical techniques, no systematic sampling campaign has yet been undertaken and natural variations in Δ(17)O(O(3)) are therefore not well constrained. METHODS The nitrite-coated filter method is a new technique for O(3) isotope analysis that employs the aqueous phase NO(2)(-) + O(3) → NO(3)(-) + O(2) reaction to obtain quantitative information on O(3) via the oxygen atom transfer to nitrate (NO(3)(-)). The triple-oxygen isotope analysis of the NO(3)(-) produced during this reaction, achieved in this study using the bacterial denitrifier method followed by isotope-ratio mass spectrometry (IRMS), directly yields the Δ(17)O value transferred from O(3). This isotope transfer process was investigated in a series of vacuum-line experiments, which were conducted by exposing coated filters to O(3) of various known Δ(17)O values and then determining the isotopic composition of the NO(3)(-) produced on the filter. RESULTS The isotope transfer experiments revealed a strong linear correlation between the Δ(17)O of the O(3) produced and that of the oxygen atom transferred to NO(3)(-), with a slope of 1.55 for samples with bulk Δ(17)O(O(3)) values in the atmospheric range (20-40‰). This finding is in agreement with theoretical postulates that place the (17) O-excess on only the terminal oxygen atoms of ozone. Ambient measurements yield average Δ(17)O(O(3))(bulk) values in agreement with previous studies (22.9 ± 1.9‰). CONCLUSIONS The nitrite-coated filter technique is a sufficiently robust, field-deployable method for the determination of the triple-oxygen isotopic composition of tropospheric O(3). Further ambient measurements will undoubtedly lead to an improved quantitative view of natural Δ(17)O(O(3)) variation and transfer in the atmosphere.
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Affiliation(s)
- William C Vicars
- Laboratoire de Glaciologie et Géophysique de l'Environnement, Université Joseph Fourier-Grenoble 1/CNRS, Grenoble, France.
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Massive volcanic SO2 oxidation and sulphate aerosol deposition in Cenozoic North America. Nature 2010; 465:909-12. [DOI: 10.1038/nature09100] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2009] [Accepted: 04/13/2010] [Indexed: 11/09/2022]
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Guo Z, Li Z, Farquhar J, Kaufman AJ, Wu N, Li C, Dickerson RR, Wang P. Identification of sources and formation processes of atmospheric sulfate by sulfur isotope and scanning electron microscope measurements. ACTA ACUST UNITED AC 2010. [DOI: 10.1029/2009jd012893] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Hannon JE, Böhlke JK, Mroczkowski SJ. Effects of nitrate and water on the oxygen isotopic analysis of barium sulfate precipitated from water samples. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2008; 22:4109-4120. [PMID: 19021238 DOI: 10.1002/rcm.3832] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
BaSO(4) precipitated from mixed salt solutions by common techniques for SO(4) (2-) isotopic analysis may contain quantities of H(2)O and NO(3) (-) that introduce errors in O isotope measurements. Experiments with synthetic solutions indicate that delta(18)O values of CO produced by decomposition of precipitated BaSO(4) in a carbon reactor may be either too low or too high, depending on the relative concentrations of SO(4) (2-) and NO(3) (-) and the delta(18)O values of the H(2)O, NO(3) (-), and SO(4) (2-). Typical delta(18)O errors are of the order of 0.5 to 1 per thousand in many sample types, and can be larger in samples containing atmospheric NO(3) (-), which can cause similar errors in delta(17)O and Delta(17)O. These errors can be reduced by (1) ion chromatographic separation of SO(4) (2-) from NO(3) (-), (2) increasing the salinity of the solutions before precipitating BaSO(4) to minimize incorporation of H(2)O, (3) heating BaSO(4) under vacuum to remove H(2)O, (4) preparing isotopic reference materials as aqueous samples to mimic the conditions of the samples, and (5) adjusting measured delta(18)O values based on amounts and isotopic compositions of coexisting H(2)O and NO(3) (-). These procedures are demonstrated for SO(4) (2-) isotopic reference materials, synthetic solutions with isotopically known reagents, atmospheric deposition from Shenandoah National Park, Virginia, USA, and sulfate salt deposits from the Atacama Desert, Chile, and Mojave Desert, California, USA. These results have implications for the calibration and use of O isotope data in studies of SO(4) (2-) sources and reaction mechanisms.
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Affiliation(s)
- Janet E Hannon
- U.S. Geological Survey, 431 National Center, 12201 Sunrise Valley Drive, Reston, VA 20192, USA
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Michalski G, Kasem M, Rech JA, Adieu S, Showers WS, Genna B, Thiemens M. Uncertainties in the oxygen isotopic composition of barium sulfate induced by coprecipitation of nitrate. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2008; 22:2971-2976. [PMID: 18763262 DOI: 10.1002/rcm.3687] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Coprecipitation of nitrate and sulfate by barium has probably resulted in significant error in numerous studies dealing with the oxygen isotopic composition of natural sulfates using chemical/thermal conversion of BaSO(4) and analysis by isotope ratio mass spectrometry. In solutions where NO(3) (-)/SO(4) (2-) molar ratios are above 2 the amount of nitrate coprecipitated with BaSO(4) reaches a maximum of approximately 7% and decreases roughly linearly as the molar ratio decreases. The fraction of coprecipitated nitrate appears to increase with decreasing pH and is also affected by the nature of the cations in the precipitating solution. The size of the oxygen isotope artifact in sulfate depends both on the amount of coprecipitated nitrate and the delta(18)O and Delta(17)O values of the nitrate, both of which can be highly variable. The oxygen isotopic composition of sulfate extracted from atmospheric aerosols or rain waters are probably severely biased because photochemical nitrate is usually also present and it is highly enriched in (18)O (delta(18)O approximately 50-90 per thousand) and has a large mass-independent isotopic composition (Delta(17)O approximately 20-32 per thousand). The sulfate delta(18)O error can be 2-5 per thousand with Delta(17)O artifacts reaching as high as 4.0 per thousand.
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Affiliation(s)
- Greg Michalski
- Department of Earth & Atmospheric Sciences, Purdue University, West Lafayette, IN 47907-2051, USA.
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Triple oxygen isotope evidence for elevated CO2 levels after a Neoproterozoic glaciation. Nature 2008; 453:504-6. [DOI: 10.1038/nature06959] [Citation(s) in RCA: 181] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2007] [Accepted: 03/31/2008] [Indexed: 11/08/2022]
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Pack A, Toulouse C, Przybilla R. Determination of oxygen triple isotope ratios of silicates without cryogenic separation of NF3- technique with application to analyses of technical O2 gas and meteorite classification. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2007; 21:3721-3728. [PMID: 17955569 DOI: 10.1002/rcm.3269] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
A novel technique is described to determine Delta'(17)O(TFL) with high accuracy and precision by using infrared (IR) laser fluorination with F(2) as the reaction gas. The technique includes precise monitoring of the intensity ratio of the (14)NF(2)+ (m/z 52) to O(2) signals. The correlation between the intensity of (14)NF(2) + and positive error in delta(17)O(VSMOW) allows correction of measured data to obtain reliable Delta'(17)O(TFL) values. The resultant error in Delta'(17)O(TFL) of a single measurement after correction is in the range of +/-0.06 per thousand, i.e. sufficiently small to permit the technique to be useful for meteorite classification. Our data for technical O(2), in combination with literature data, suggest a negative anomaly of tropospheric air O(2) with Delta'(17)O(TFL) = -0.344 +/- 0.015 per thousand (1sigma).
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Affiliation(s)
- Andreas Pack
- Universität Göttingen, Geowissenschaftliches Zentrum, Goldschmidtstrasse 1, D-37077 Göttingen, Germany.
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Bao H, Marchant DR. Quantifying sulfate components and their variations in soils of the McMurdo Dry Valleys, Antarctica. ACTA ACUST UNITED AC 2006. [DOI: 10.1029/2005jd006669] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Savarino J, Bekki S, Cole-Dai J, Thiemens MH. Evidence from sulfate mass independent oxygen isotopic compositions of dramatic changes in atmospheric oxidation following massive volcanic eruptions. ACTA ACUST UNITED AC 2003. [DOI: 10.1029/2003jd003737] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Joël Savarino
- Laboratoire de Glaciologie et Géophysique de l'Environnement; Université Joseph Fourier, CNRS; St. Martin d'Hères France
| | - Slimane Bekki
- Service d'Aéronomie; Université Pierre et Marie Curie, CNRS; Paris France
| | - Jihong Cole-Dai
- Department of Chemistry and Biochemistry; South Dakota State University; Brookings South Dakota USA
| | - Mark H. Thiemens
- Department of Chemistry and Biochemistry; University of California, San Diego; La Jolla California USA
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Bao H. Multiple oxygen and sulfur isotopic analyses on water-soluble sulfate in bulk atmospheric deposition from the southwestern United States. ACTA ACUST UNITED AC 2003. [DOI: 10.1029/2002jd003022] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Miller MF, Franchi IA, Thiemens MH, Jackson TL, Brack A, Kurat G, Pillinger CT. Mass-independent fractionation of oxygen isotopes during thermal decomposition of carbonates. Proc Natl Acad Sci U S A 2002; 99:10988-93. [PMID: 12167677 PMCID: PMC123197 DOI: 10.1073/pnas.172378499] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Nearly all chemical processes fractionate 17O and 18O in a mass-dependent way relative to 16O, a major exception being the formation of ozone from diatomic oxygen in the presence of UV radiation or electrical discharge. Investigation of oxygen three-isotope behavior during thermal decomposition of naturally occurring carbonates of calcium and magnesium in vacuo has revealed that, surprisingly, anomalous isotopic compositions are also generated during this process. High-precision measurements of the attendant three-isotope fractionation line, and consequently the magnitude of the isotopic anomaly (delta17O), demonstrate that the slope of the line is independent of the nature of the carbonate but is controlled by empirical factors relating to the decomposition procedure. For a slope identical to that describing terrestrial silicates and waters (0.5247 +/- 0.0007 at the 95% confidence level), solid oxides formed during carbonate pyrolysis fit a parallel line offset by -0.241 +/- 0.042 per thousand. The corresponding CO2 is characterized by a positive offset of half this magnitude, confirming the mass-independent nature of the fractionation. Slow, protracted thermolysis produces a fractionation line of shallower slope (0.5198 +/- 0.0007). These findings of a 17O anomaly being generated from a solid, and solely by thermal means, provide a further challenge to current understanding of the nature of mass-independent isotopic fractionation.
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Affiliation(s)
- Martin F Miller
- Planetary and Space Sciences Research Institute, The Open University, Walton Hall, Milton Keynes MK7 6AA, United Kingdom.
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Gao YQ, Marcus RA. On the theory of the strange and unconventional isotopic effects in ozone formation. J Chem Phys 2002. [DOI: 10.1063/1.1415448] [Citation(s) in RCA: 138] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Farquhar J, Savarino J, Airieau S, Thiemens MH. Observation of wavelength-sensitive mass-independent sulfur isotope effects during SO2photolysis: Implications for the early atmosphere. ACTA ACUST UNITED AC 2001. [DOI: 10.1029/2000je001437] [Citation(s) in RCA: 370] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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Zhu XK, Guo Y, O'Nions RK, Young ED, Ash RD. Isotopic homogeneity of iron in the early solar nebula. Nature 2001; 412:311-3. [PMID: 11460156 DOI: 10.1038/35085525] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The chemical and isotopic homogeneity of the early solar nebula, and the processes producing fractionation during its evolution, are central issues of cosmochemistry. Studies of the relative abundance variations of three or more isotopes of an element can in principle determine if the initial reservoir of material was a homogeneous mixture or if it contained several distinct sources of precursor material. For example, widespread anomalies observed in the oxygen isotopes of meteorites have been interpreted as resulting from the mixing of a solid phase that was enriched in 16O with a gas phase in which 16O was depleted, or as an isotopic 'memory' of Galactic evolution. In either case, these anomalies are regarded as strong evidence that the early solar nebula was not initially homogeneous. Here we present measurements of the relative abundances of three iron isotopes in meteoritic and terrestrial samples. We show that significant variations of iron isotopes exist in both terrestrial and extraterrestrial materials. But when plotted in a three-isotope diagram, all of the data for these Solar System materials fall on a single mass-fractionation line, showing that homogenization of iron isotopes occurred in the solar nebula before both planetesimal accretion and chondrule formation.
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Affiliation(s)
- X K Zhu
- Department of Earth Sciences, University of Oxford, UK.
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Abstract
The puzzling mass-independent isotopic enrichment in ozone formation contrasts markedly with the more recently observed large unconventional mass-dependent ratios of the individual ozone formation rate constants in certain systems. An RRKM (Rice, Ramsperger, Kassel, Marcus)-based theory is used to treat both effects. Restrictions of symmetry on how energy is shared among the rotational/vibrational states of the ozone isotopomer, together with an analysis of the competition between the transition states of its two exit channels, permit the calculation of isotope effects consistent with a wide array of experimental results.
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Affiliation(s)
- Y Q Gao
- Noyes Laboratory of Chemical Physics, Mail Code 127-72, California Institute of Technology, Pasadena, CA 91125, USA
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Bogard DD, Clayton RN, Marti K, Owen T, Turner G. Martian Volatiles: Isotopic Composition, Origin, and Evolution. SPACE SCIENCES SERIES OF ISSI 2001. [DOI: 10.1007/978-94-017-1035-0_17] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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26
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Savarino J, Lee CCW, Thiemens MH. Laboratory oxygen isotopic study of sulfur (IV) oxidation: Origin of the mass-independent oxygen isotopic anomaly in atmospheric sulfates and sulfate mineral deposits on Earth. ACTA ACUST UNITED AC 2000. [DOI: 10.1029/2000jd900456] [Citation(s) in RCA: 121] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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Hathorn BC, Marcus RA. An intramolecular theory of the mass-independent isotope effect for ozone. II. Numerical implementation at low pressures using a loose transition state. J Chem Phys 2000. [DOI: 10.1063/1.1321045] [Citation(s) in RCA: 95] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
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28
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Bao H, Campbell DA, Bockheim JG, Thiemens MH. Origins of sulphate in Antarctic dry-valley soils as deduced from anomalous 17O compositions. Nature 2000; 407:499-502. [PMID: 11028998 DOI: 10.1038/35035054] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The dry valleys of Antarctica are some of the oldest terrestrial surfaces on the Earth. Despite much study of soil weathering and development, ecosystem dynamics and the occurrence of life in these extreme environments, the reasons behind the exceptionally high salt content of the dry-valley soils have remained uncertain. In particular, the origins of sulphate are still controversial; proposed sources include wind-blown sea salt, chemical weatherings, marine incursion, hydrothermal processes and oxidation of biogenic sulphur in the atmosphere. Here we report measurements of delta18O and delta17O values of sulphates from a range of dry-valley soils. These sulphates all have a large positive anomaly of 17O, of up to 3.4/1000. This suggests that Antarctic sulphate comes not just from sea salt (which has no anomaly of 17O) but also from the atmospheric oxidation of reduced gaseous sulphur compounds, the only known process that can generate the observed 17O anomaly. This source is more prominent in high inland soils, suggesting that the distributions of sulphate are largely explained by differences in particle size and transport mode which exist between sea-salt aerosols and aerosols formed from biogenic sulphur emission.
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Affiliation(s)
- H Bao
- Department of Chemistry & Biochemistry, University of California San Diego, La Jolla 92093-0356, USA.
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Clayton RN. Rock signature from the sky. Nature 2000; 406:136-7. [PMID: 10910337 DOI: 10.1038/35018193] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- R N Clayton
- Enrico Fermi Institute, University of Chicago, Illinois 60637-1433, USA.
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