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Sample records for 32s 33s 34s

  1. Determination of the sulfur isotope ratio in carbonyl sulfide using gas chromatography/isotope ratio mass spectrometry on fragment ions 32S+, 33S+, and 34S+.

    PubMed

    Hattori, Shohei; Toyoda, Akari; Toyoda, Sakae; Ishino, Sakiko; Ueno, Yuichiro; Yoshida, Naohiro

    2015-01-06

    Little is known about the sulfur isotopic composition of carbonyl sulfide (OCS), the most abundant atmospheric sulfur species. We present a promising new analytical method for measuring the stable sulfur isotopic compositions (δ(33)S, δ(34)S, and Δ(33)S) of OCS using nanomole level samples. The direct isotopic analytical technique consists of two parts: a concentration line and online gas chromatography-isotope ratio mass spectrometry (GC-IRMS) using fragmentation ions (32)S(+), (33)S(+), and (34)S(+). The current levels of measurement precision for OCS samples greater than 8 nmol are 0.42‰, 0.62‰, and 0.23‰ for δ(33)S, δ(34)S, and Δ(33)S, respectively. These δ and Δ values show a slight dependence on the amount of injected OCS for volumes smaller than 8 nmol. The isotope values obtained from the GC-IRMS method were calibrated against those measured by a conventional SF6 method. We report the first measurement of the sulfur isotopic composition of OCS in air collected at Kawasaki, Kanagawa, Japan. The δ(34)S value obtained for OCS (4.9 ± 0.3‰) was lower than the previous estimate of 11‰. When the δ(34)S value for OCS from the atmospheric sample is postulated as the global signal, this finding, coupled with isotopic fractionation for OCS sink reactions in the stratosphere, explains the reported δ(34)S for background stratospheric sulfate. This suggests that OCS is a potentially important source for background (nonepisodic or nonvolcanic) stratospheric sulfate aerosols.

  2. Photoabsorption cross-section measurements of 32S, 33S, 34S, and 36S sulfur dioxide from 190 to 220 nm

    NASA Astrophysics Data System (ADS)

    Endo, Yoshiaki; Danielache, Sebastian O.; Ueno, Yuichiro; Hattori, Shohei; Johnson, Matthew S.; Yoshida, Naohiro; Kjaergaard, Henrik G.

    2015-03-01

    The ultraviolet absorption cross sections of the SO2 isotopologues are essential to understanding the photochemical fractionation of sulfur isotopes in planetary atmospheres. We present measurements of the absorption cross sections of 32SO2, 33SO2, 34SO2, and 36SO2, recorded from 190 to 220 nm at room temperature with a resolution of 0.1 nm (~25 cm-1) made using a dual-beam photospectrometer. The measured absorption cross sections show an apparent pressure dependence and a newly developed analytical model shows that this is caused by underresolved fine structure. The model made possible the calculation of absorption cross sections at the zero-pressure limit that can be used to calculate photolysis rates for atmospheric scenarios. The 32SO2, 33SO2, and 34SO2 cross sections improve upon previously published spectra including fine structure and peak widths. This is the first report of absolute absorption cross sections of the 36SO2 isotopologue for the C1B2-X1A2 band where the amplitude of the vibrational structure is smaller than the other isotopologues throughout the spectrum. Based on the new results, solar UV photodissociation of SO2 produces 34ɛ, 33Ε, and 36Ε isotopic fractionations of +4.6 ± 11.6‰, +8.8 ± 9.0‰, and -8.8 ± 19.6‰, respectively. From these spectra isotopic effects during photolysis in the Archean atmosphere can be calculated and compared to the Archean sedimentary record. Our results suggest that broadband solar UV photolysis is capable of producing the mass-independent fractionation observed in the Archean sedimentary record without involving shielding by specific gaseous compounds in the atmosphere including SO2 itself. The estimated magnitude of 33Ε, for example, is close to the maximum Δ33S observed in the geological record.

  3. Combined 34S, 33S and 18O isotope fractionations record different intracellular steps of microbial sulfate reduction

    NASA Astrophysics Data System (ADS)

    Antler, Gilad; Turchyn, Alexandra V.; Ono, Shuhei; Sivan, Orit; Bosak, Tanja

    2017-04-01

    Several enzymatic steps in microbial sulfate reduction (MSR) fractionate the isotope ratios of 33S/32S, 34S/32S and 18O/16O in extracellular sulfate, but the effects of different intracellular processes on the isotopic composition of residual sulfate are still not well quantified. We measured combined multiple sulfur (33S/32S, 34S/32S) and oxygen (18O/16O) isotope ratios of sulfate in pure cultures of a marine sulfate reducing bacterium Desulfovibrio sp. DMSS-1 grown on different organic substrates. These measurements are consistent with the previously reported correlations of oxygen and sulfur isotope fractionations with the cell-specific rate of MSR: faster reduction rates produced smaller isotopic fractionations for all isotopes. Combined isotope fractionation of oxygen and multiple sulfur isotopes are also consistent with the relationship between the rate limiting step during microbial sulfate reduction and the availability of the DsrC subunit. These experiments help reconstruct and interpret processes that operate in natural pore waters characterized by high 18O/16O and moderate 34S/32S ratios and suggest that some multiple isotope signals in the environment cannot be explained by microbial sulfate reduction alone. Instead, these signals support the presence of active, but slow sulfate reduction as well as the reoxidation of sulfide.

  4. 34S/32S fractionation in sulfur cycles catalyzed by anaerobic bacteria

    NASA Technical Reports Server (NTRS)

    Fry, B.; Gest, H.; Hayes, J. M.

    1988-01-01

    Stable isotopic distributions in the sulfur cycle were studied with pure and mixed cultures of the anaerobic bacteria, Chlorobium vibrioforme and Desulfovibrio vulgaris. D. vulgaris and C. vibrioforme can catalyze three reactions constituting a complete anaerobic sulfur cycle: reduction of sulfate to sulfide (D. vulgaris), oxidation of sulfide to elemental sulfur (C. vibrioforme), and oxidation of sulfur to sulfate (C. vibrioforme). In all experiments, the first and last reactions favored concentration of the light 32S isotope in products (isotopic fractionation factor epsilon = -7.2 and -1.7%, respectively), whereas oxidation of sulfide favored concentration of the heavy 34S isotope in products (epsilon = +1.7%). Experimental results and model calculations suggest that elemental sulfur enriched in 34S versus sulfide may be a biogeochemical marker for the presence of sulfide-oxidizing bacteria in modern and ancient environments.

  5. 34S/32S fractionation during sulfate reduction in groundwater treatment systems: reactive transport modeling.

    PubMed

    Gibson, Blair D; Amos, Richard T; Blowes, David W

    2011-04-01

    Isotope ratio measurements provide a tool for indicating the relative significance of biogeochemical reactions and for constraining estimates of the extent and rate of reactions in passive treatment systems. In this paper, the reactive transport model MIN3P is used to evaluate sulfur isotope fractionation in column experiments designed to simulate treatment of contaminated water by microbially mediated sulfate reduction occurring within organic carbon-based and iron and carbon-based permeable reactive barriers. A mass dependent fractionation model was used to determine reaction rates for 32S and 34S compounds during reduction, precipitation, and dissolution reactions and to track isotope-dependent mass transfer during SO4 removal. The δ34S values obtained from the MIN3P model were similar to those obtained from the Rayleigh equation, indicating that there was not a significant difference between the conceptual models. Differences between the MIN3P derived α value and the Rayleigh equation derived value were attributed to minor changes in the dissolution and precipitation rate of gypsum and mathematical differences in the fitting models. The results indicated that the prediction of δ34S was fairly insensitive to differences in the fractionation factor at the concentration ranges measured in the current study. However, more significant differences would be expected at low sulfate conditions.

  6. The (32)S/(33)S abundance as a function of galactocentric radius in the Milky Way

    NASA Technical Reports Server (NTRS)

    Greenhouse, M. A.; Thronson, H. A., Jr.

    1986-01-01

    Astration of heavy elements by the stars of the Milky Way forms a fossil record which may preserve spacial distribution of the mass function for the stars in the galaxy. Sulfur is among the last common element for which the relative abundance of its various isotopes have yet to be completely measured within our galaxy. Explosive oxygen burning in massive stars is thought to be the process which dominates sulfur production within stars. There models predict that the various isotopes (S-32, S-33, S-34) are formed in relative abundance which depend strongly upon the mass of the parent star. This relative abundance is thought to be unaffected by subsequent stellar procesing since all important sinks of sulfur destroy it without regard for isotopic form. Hence the spacial variation of the mass function (MF) can be studied by measuring the abundance variation of sulfur isotopes in the galaxy provided that the product yields for these isotopes are known accurately as a function of stellar mass.

  7. δ34S and Δ33S records of Paleozoic seawater sulfate based on the analysis of carbonate associated sulfate

    NASA Astrophysics Data System (ADS)

    Wu, Nanping; Farquhar, James; Strauss, Harald

    2014-08-01

    This study updates the δ34S and Δ33S temporal records of Paleozoic and early Mesozoic seawater sulfate using analysis of carbonate associated sulfate of biogenic and whole rock carbonate. The time resolution of carbonate samples studied here is on the order of millions of years which is longer than the timescale for homogenization of seawater sulfate-sulfur (one tenth of a million years), but is comparable to the timescale for isotope evolution of sulfate in the oceans. This δ34S record confirms the long-term decreasing trend that is discernible over the 250 million year timescale of sampling, and the Δ33S record of seawater sulfate for the Paleozoic is consistent with an average value of -0.002±0.004‰ (2σ, 540-251 Ma) that is distinct from the positive Δ33S observed today and inferred for the rest of the Cenozoic. Both δ34S and Δ33S records of seawater sulfate suggest the presence of shorter-timescale variations that occur on timescales of tens of millions of years, arguably driven by changes in intensity of sulfide oxidation in cycling of sulfur and/or by rapid changes in sulfur influx to the oceans and its associated sulfur isotopes. The Permian-Triassic boundary marks a transition in co-trajectories of δ34S and Δ33S from in-phase to anti-phase. The biogeochemical forcing that causes this is unclear. This newly calibrated record remains consistent with an earlier assertion (Wu et al., 2010) that the sulfur isotope fractionation (Δ34SSW-PY) between oceanic sulfate (δ34SSW) and coeval sedimentary pyrite (δ34SPY) was smaller during the Paleozoic than in the Cenozoic, and reached lowest values during the Carboniferous. The δ34SIN and Δ33SIN estimates of influx sulfur to the oceans afforded by the isotope mass balance model for each geologic period throughout the Paleozoic reveal a change from higher positive values of δ34SIN (more negative values of Δ33SIN, approximately -0.030‰) to lower positive values of δ34SIN (slightly negative values of

  8. /sup 34/S//sup 32/S fractionation in sulfur cycles catalyzed by anaerobic bacteria. [Chlorobium vibrioforme; Desulfovibrio vulgaris

    SciTech Connect

    Fry, B.; Gest, H.; Hayes, J.M.

    1988-01-01

    Stable isotopic distributions in the sulfur cycle were studied with pure and mixed cultures of the anaerobic bacteria, Chlorobium vibrioforme and Desulfovibrio vulgaris. D. vulgaris and C. vibrioforme can catalyze three reactions constituting a complete anaerobic sulfur cycle: reduction of sulfate to sulfide (D. vulgaris), oxidation of sulfide to elemental sulfur (C. vibrioforme), and oxidation of sulfur to sulfate (C. vibrioforme). In all experiments, the first and last reactions favored concentration of the light /sup 32/S isotope in products (isotopic fractionation factor ..sigma.. = -7.2 and -1.7 per thousand, respectively), whereas oxidation of sulfide favored concentration of the heavy /sup 34/S isotope in products (..sigma.. = +1.7 per thousand). Experimental results and model calculations suggest that elemental sulfur enriched in /sup 34/S versus sulfide may be a biogeochemical marker for the presence of sulfide-oxidizing bacteria in modern and ancient environments.

  9. The abundance of 28Si32S, 29Si32S, 28Si34S, and 30Si32S in the inner layers of the envelope of IRC+10216

    PubMed Central

    Fonfría, J. P.; Cernicharo, J.; Richter, M. J.; Fernández-López, M.; Prieto, L. Velilla; Lacy, J. H.

    2016-01-01

    We present high spectral resolution mid-IR observations of SiS towards the C-rich AGB star IRC+10216 carried out with the Texas Echelon-cross-Echelle Spectrograph mounted on the NASA Infrared Telescope Facility. We have identified 204 ro-vibrational lines of 28Si32S, 26 of 29Si32S, 20 of 28Si34S, and 15 of 30Si32S in the frequency range 720 – 790 cm−1. These lines belong to bands v = 1 – 0, 2 – 1, 3 – 2, 4–3, and 5–4, and involve rotational levels with Jlow ≲ 90. About 30 per cent of these lines are unblended or weakly blended and can be partially or entirely fitted with a code developed to model the mid-IR emission of a spherically symmetric circumstellar envelope composed of expanding gas and dust. The observed lines trace the envelope at distances to the star ≲ 35R⋆(≃ 0″.7). The fits are compatible with an expansion velocity of 1+2.5(r/R⋆ −1) km s−1 between 1 and 5R⋆, 11 km s−1 between 5 and 20R⋆, and 14.5 km s−1 outwards. The derived abundance profile of 28Si32S with respect to H2 is 4.9 × 10−6 between the stellar photosphere and 5R⋆, decreasing linearly down to 1.6 × 10−6 at 20R⋆ and to 1.3 × 10−6 at 50R⋆. 28Si32S seems to be rotationally under LTE in the region of the envelope probed with our observations and vibrationally out of LTE in most of it. There is a red-shifted emission excess in the 28Si32S lines of band v = 1 – 0 that cannot be found in the lines of bands v = 2 – 1, 3 – 2, 4 – 3, and 5 – 4. This excess could be explained by an enhancement of the vibrational temperature around 20R⋆ behind the star. The derived isotopic ratios 28Si/29Si, and 32S/34S are 17 and 14, compatible with previous estimates. PMID:26997679

  10. The abundance of 28Si32S, 29Si32S, 28Si34S, and 30Si32S in the inner layers of the envelope of IRC+10216

    NASA Astrophysics Data System (ADS)

    Fonfría, J. P.; Cernicharo, J.; Richter, M. J.; Fernández-López, M.; Velilla Prieto, L.; Lacy, J. H.

    2015-10-01

    We present high spectral resolution mid-IR observations of SiS towards the C-rich AGB star IRC+10216 carried out with the Texas Echelon-cross-Echelle Spectrograph mounted on the NASA Infrared Telescope Facility. We have identified 204 ro-vibrational lines of 28Si32S, 26 of 29Si32S, 20 of 28Si34S, and 15 of 30Si32S in the frequency range 720-790 cm-1. These lines belong to bands v = 1-0, 2-1, 3-2, 4-3, and 5-4, and involve rotational levels with Jlow ≲ 90. About 30 per cent of these lines are unblended or weakly blended and can be partially or entirely fitted with a code developed to model the mid-IR emission of a spherically symmetric circumstellar envelope composed of expanding gas and dust. The observed lines trace the envelope at distances to the star ≲35R⋆ (≃0.7 arcsec). The fits are compatible with an expansion velocity of 1 + 2.5(r/R⋆ - 1) km s-1 between 1 and 5R⋆, 11 km s-1 between 5 and 20R⋆, and 14.5 km s-1 outwards. The derived abundance profile of 28Si32S with respect to H2 is 4.9 × 10-6 between the stellar photosphere and 5R⋆, decreasing linearly down to 1.6 × 10-6 at 20R⋆ and to 1.3 × 10-6 at 50R⋆. 28Si32S seems to be rotationally under local thermodynamic equilibrium (LTE) in the region of the envelope probed with our observations and vibrationally out of LTE in most of it. There is a red-shifted emission excess in the 28Si32S lines of band v = 1-0 that cannot be found in the lines of bands v = 2-1, 3-2, 4-3, and 5-4. This excess could be explained by an enhancement of the vibrational temperature around 20R⋆ behind the star. The derived isotopic ratios 28Si/29Si, and 32S/34S are 17 and 14, compatible with previous estimates.

  11. High-precision measurements of (33)S and (34)S fractionation during SO2 oxidation reveal causes of seasonality in SO2 and sulfate isotopic composition.

    PubMed

    Harris, Eliza; Sinha, Bärbel; Hoppe, Peter; Ono, Shuhei

    2013-01-01

    This study presents high-precision isotope ratio-mass spectrometric measurements of isotopic fractionation during oxidation of SO2 by OH radicals in the gas phase and H2O2 and transition metal ion catalysis (TMI-catalysis) in the aqueous phase. Although temperature dependence of fractionation factors was found to be significant for H2O2 and TMI-catalyzed pathways, results from a simple 1D model revealed that changing partitioning between oxidation pathways was the dominant cause of seasonality in the isotopic composition of sulfate relative to SO2. Comparison of modeled seasonality with observations shows the TMI-catalyzed oxidation pathway is underestimated by more than an order of magnitude in all current atmospheric chemistry models. The three reactions showed an approximately mass-dependent relationship between (33)S and (34)S. However, the slope of the mass-dependent line was significantly different to 0.515 for the OH and TMI-catalyzed pathways, reflecting kinetic versus equilibrium control of isotopic fractionation. For the TMI-catalyzed pathway, both temperature dependence and (33)S/(34)S relationship revealed a shift in the rate-limiting reaction step from dissolution at lower temperatures to TMI-sulfite complex formation at higher temperatures. 1D model results showed that although individual reactions could produce Δ(33)S values between -0.15 and +0.2‰, seasonal changes in partitioning between oxidation pathways caused average sulfate Δ(33)S values of 0‰ throughout the year.

  12. Evaluation of the 34S/32S ratio of Soufre de Lacq elemental sulfur isotopic reference material by continuous flow isotope-ratio mass spectrometry

    USGS Publications Warehouse

    Qi, H.P.; Coplen, T.B.

    2003-01-01

    Soufre de Lacq elemental sulfur reference material (IAEA-S-4) isotopically is homogeneous in amounts as small as 41 ??g as determined by continuous flow isotope-ratio mass spectrometry. The ??34S value for this reference material is +16.90 ?? 0.12??? (1??) on a scale (Vienna Can??on Diablo troilite, VCDT) where IAEA-S-1 Ag2S is -0.3??? and IAEA-S-2 Ag2S is +22.67???. Published by Elsevier Science B.V.

  13. Fusion near and below the barrier for the systems 32,34S+24,25,26Mg and 32S+27Al

    NASA Astrophysics Data System (ADS)

    Berkowitz, G. M.; Braun-Munzinger, P.; Karp, J. S.; Freifelder, R. H.; Renner, T. R.; Wilschut, H. W.

    1983-08-01

    Excitation functions are reported for total fusion near and below the Coulomb barrier of the systems 32,34S+24,25,26Mg and 27Al. The data cannot be reproduced by one-dimensional barrier penetration calculations. The enhancement of the cross sections at low energies is compared to predictions of models taking into acount the static deformation or zero point vibration of the reaction partners. Calculations including zero point motion do not reproduce the observed variations of the measured cross sections with respect to the neutron number of target and projectile. Reasonable agreement is obtained when calculating fusion between statically deformed nuclei. Finally, the fusion process is described in a quantum mechanical coupled channels model, indicating the importance of dynamical effect on sub-barrier fusion. NUCLEAR REACTIONS 24,25,26Mg, 27Al(32,34S, Fusion) 0.9

  14. Empirical infrared line lists for five SO2 isotopologues: 32/33/34/36S16O2 and 32S18O2

    NASA Astrophysics Data System (ADS)

    Huang, Xinchuan; Schwenke, David W.; Lee, Timothy J.

    2015-05-01

    Using the latest published, empirically refined potential energy surface (PES) Ames-1 and purely ab initio CCSD(T)/aug-cc-pV(Q+d)Z dipole moment surface (DMS), we have computed infrared line lists for five symmetric isotopologues of sulfur dioxide: 32S16O2 (626), 33S16O2 (636), 34S16O2 (646), 36S16O2 (666), and 32S18O2 (828). The line lists are based on J = 0-80 rovibrational variational calculations with E‧ ⩽ 8000 cm-1. The 34S16O2 and 33S16O2 line lists are compared to the experiment-based models in the HIgh-resolution TRANsmission molecular absorption database (HITRAN2012,

  15. New {sup 34}Cl proton-threshold states and the thermonuclear {sup 33}S(p,{gamma}){sup 34}Cl rate in ONe novae

    SciTech Connect

    Parikh, A.; Faestermann, T.; Kruecken, R.; Behrens, T.; Bildstein, V.; Bishop, S.; Eppinger, K.; Herlitzius, C.; Hinke, C.; Schlarb, M.; Seiler, D.; Wimmer, K.; Hertenberger, R.; Wirth, H.-F.; Schafstadler, D.

    2009-07-15

    Analysis of presolar grains in primitive meteorites has shown isotopic ratios largely characteristic of the conditions thought to prevail in various astrophysical environments. A possible indicator for a grain of ONe nova origin is a large {sup 33}S abundance: nucleosynthesis calculations predict as much as 150 times the solar abundance of {sup 33}S in the ejecta of nova explosions on massive ONe white dwarfs. This overproduction factor may, however, vary by factors of at least 0.01-3 because of uncertainties of several orders of magnitude in the {sup 33}S(p,{gamma}){sup 34}Cl reaction rate at nova peak temperatures (T{sub peak}{approx}0.1-0.4 GK). These uncertainties arise due to the lack of nuclear physics information for states within {approx}600 keV of the {sup 33}S+p threshold in {sup 34}Cl (S{sub p}({sup 34}Cl) = 5143 keV). To better constrain this rate we have measured, for the first time, the {sup 34}S({sup 3}He,t){sup 34}Cl reaction over the region E{sub x}({sup 34}Cl) = 4.9-6 MeV. We confirm previous states and find 15 new states in this energy region. New {sup 33}S(p,{gamma}){sup 34}Cl resonances at E{sub R}=281(2), 301(2), and 342(2) keV may dominate this rate at relevant nova temperatures. Our results could affect predictions of sulphur isotopic ratios in nova ejecta (e.g., {sup 32}S/{sup 33}S) that may be used as diagnostic tools for the nova paternity of grains.

  16. Discrimination between 34S and 32S during bacterial metabolism of inorganic sulfur compounds.

    PubMed Central

    Fry, B; Cox, J; Gest, H; Hayes, J M

    1986-01-01

    Sulfur isotope effects during the oxidation of thiosulfate by Thiobacillus versutus were found to be negligible. This result is considered in relation to other oxidative and reductive processes to assess which reactions are most likely to control the isotopic compositions of sulfur compounds in microbial sulfureta. PMID:3941049

  17. Constraining nova observables: Direct measurements of resonance strengths in 33S(p,γ)34Cl

    NASA Astrophysics Data System (ADS)

    Fallis, J.; Parikh, A.; Bertone, P. F.; Bishop, S.; Buchmann, L.; Chen, A. A.; Christian, G.; Clark, J. A.; D'Auria, J. M.; Davids, B.; Deibel, C. M.; Fulton, B. R.; Greife, U.; Guo, B.; Hager, U.; Herlitzius, C.; Hutcheon, D. A.; José, J.; Laird, A. M.; Li, E. T.; Li, Z. H.; Lian, G.; Liu, W. P.; Martin, L.; Nelson, K.; Ottewell, D.; Parker, P. D.; Reeve, S.; Rojas, A.; Ruiz, C.; Setoodehnia, K.; Sjue, S.; Vockenhuber, C.; Wang, Y. B.; Wrede, C.

    2013-10-01

    The 33S(p,γ)34Cl reaction is important for constraining predictions of certain isotopic abundances in oxygen-neon novae. Models currently predict as much as 150 times the solar abundance of 33S in oxygen-neon nova ejecta. This overproduction factor may vary by orders of magnitude due to uncertainties in the 33S(p,γ)34Cl reaction rate at nova peak temperatures. Depending on this rate, 33S could potentially be used as a diagnostic tool for classifying certain types of presolar grains. Better knowledge of the 33S(p,γ)34Cl rate would also aid in interpreting nova observations over the S-Ca mass region and contribute to the firm establishment of the maximum endpoint of nova nucleosynthesis. Additionally, the total S elemental abundance which is affected by this reaction has been proposed as a thermometer to study the peak temperatures of novae. Previously, the 33S(p,γ)34Cl reaction rate had only been studied directly down to resonance energies of 432 keV. However, for nova peak temperatures of 0.2-0.4 GK there are seven known states in 34Cl both below the 432-keV resonance and within the Gamow window that could play a dominant role. Direct measurements of the resonance strengths of these states were performed using the DRAGON (Detector of Recoils And Gammas of Nuclear reactions) recoil separator at TRIUMF. Additionally two new states within this energy region are reported. Several hydrodynamic simulations have been performed, using all available experimental information for the 33S(p,γ)34Cl rate, to explore the impact of the remaining uncertainty in this rate on nucleosynthesis in nova explosions. These calculations give a range of ≈20-150 for the expected 33S overproduction factor, and a range of ≈100-450 for the 32S/33S ratio expected in ONe novae.

  18. Intermittency in {sup 32}S + S and {sup 32}S + Au collisions at the CERN SPS

    SciTech Connect

    Bloomer, M.A.; Jacobs, P.; WA80 Collaboration

    1991-12-01

    Nonstatistical or ``intermittent`` fluctuations of charged particle multiplicities have been investigated at the CERN SPS with the WA80 multiplicity array for {sup 32}S+S and {sup 32}S+Au collisions of varying centrality. Within the phase space domain studied there is no evidence for intermittency in these collisions beyond that accounted for by FRITIOF filtered through a full detector simulation.

  19. Intermittency in sup 32 S + S and sup 32 S + Au collisions at the CERN SPS

    SciTech Connect

    Bloomer, M.A.; Jacobs, P.

    1991-12-01

    Nonstatistical or intermittent'' fluctuations of charged particle multiplicities have been investigated at the CERN SPS with the WA80 multiplicity array for {sup 32}S+S and {sup 32}S+Au collisions of varying centrality. Within the phase space domain studied there is no evidence for intermittency in these collisions beyond that accounted for by FRITIOF filtered through a full detector simulation.

  20. Delta34S measurements of sulfur by multicollector inductively coupled plasma mass spectrometry.

    PubMed

    Clough, Robert; Evans, Peter; Catterick, Tim; Evans, E Hywel

    2006-09-01

    An accurate and precise method for the determination of delta34S measurements by multicollector inductively coupled plasma mass spectrometry has been developed. Full uncertainty budgets, taking into consideration all the uncertainties of the measurement process, have been calculated. The technique was evaluated by comparing measured values with a range of isotopically enriched sulfur solutions prepared by gravimetric addition of a 34S spike. The gravimetric and measured results exhibited a correlation of R2 >0.999. Repeat measurements were also made after adding Na (up to 420 microg g(-1)) and Ca (up to 400 microg g(-1)) salts to the sulfur standard. No significant deviations in the delta34S values were observed. The Russell correction expression (Ingle, C.; Sharp, B.; Horstwood, M.; Parrish, R.; Lewis, D. J. J. Anal. At. Spectrom. 2003, 18, 219) was used to correct for mass bias on the 34S/32S isotope amount ratio from the mass bias observed for the 30Si/28Si isotope amount ratio. Consistent compensation for instrumental mass bias was achieved. Resolution of the measured delta34S values was better than 1 per thousand after consideration of all uncertainty components. The technique was evaluated for practical applications by measurement of delta34S for a range of mineral waters by pneumatic nebulization sample introduction and the analysis of genuine and counterfeit pharmaceuticals using both laser ablation sample introduction and liquid chromatography. For the former two cases polyatomic interferences were resolved by operating the MC-ICPMS in medium resolution, while for the chromatographic analyses polyatomic interferences were minimized by the use of a membrane desolvator, allowing the instrument to be operated at a resolution of 400.

  1. High-Resolution Spectra of Carbon Disulfide (12)C(32)S(2) in the Region of 2 µm.

    PubMed

    Blanquet; Walrand; Bredohl; Dubois

    1999-11-01

    By Fourier transform, spectra were recorded for carbon disulfide (12)C(32)S(2) in the region of weak absorption near 5200 cm(-1). The data were fitted and new molecular constants were determined. We also observed a band of the isotopomer (12)C(32)S(34)S. A self-broadening coefficient gamma(0) of 0.120 cm(-1). atm(-1) was obtained by recording two lines of the nu(3)-nu(1) band with a tunable diode laser. Copyright 1999 Academic Press.

  2. Determination of the δ34S of sulfate in water; RSIL lab code 1951

    USGS Publications Warehouse

    Revesz, Kinga; Qi, Haiping; Coplen, Tyler B.

    2006-01-01

    The purpose of the Reston Stable Isotope Laboratory (RSIL) lab code 1951 is to determine the δ(34S/32S), abbreviated as δ34S, of dissolved sulfate. Dissolved sulfate is collected in the field and precipitated with BaCl2 at pH 3 to 4 as BaSO4 in the laboratory. However, the dissolved organic sulfur (DOS) is oxidized to SO2, and the carbonate is acidified to CO2. Both are degassed from the water sample before the sulfate is precipitated. The precipitated BaSO4 is filtered and dried before introduction into an elemental analyzer (EA) Carlo Erba NC 2500. The EA is used to convert sulfur in a BaSO4 solid sample into SO2 gas, and the EA is connected to a continuous flow isotope-ratio mass spectrometer (CF-IRMS), which determines the differences in the isotope-amount ratios of stable sulfur isotopes (34S/32S) of the product SO2 gas. The combustion is quantitative; no isotopic fractionation is involved. Samples are placed in a tin capsule and loaded into the Costech Zero Blank Autosampler of the EA. Under computer control, samples are dropped into a heated tube reaction tube that combines the oxidation and reduction reactions. The combustion takes place in a helium atmosphere containing an excess of oxygen gas at the oxidation zone at the top of the reaction tube. Combustion products are transported by a helium carrier through the reduction zone at the bottom of the reaction tube to remove excess oxygen and through a separate drying tube to remove any water. The gas-phase products, mainly CO2, N2, and SO2, are separated by a gas chromatograph. The gas is then introduced into the isotope-ratio mass spectrometer (IRMS) through a Finnigan MAT (now Thermo Scientific) ConFlo II interface, which also is used to inject SO2 reference gas and helium for sample dilution. The IRMS is a Thermo Scientific Delta V Plus CF-IRMS. It has a universal triple collector with two wide cups and a narrow cup in the middle. It is capable of measuring mass/charge (m/z) 64 and 66 simultaneously

  3. Determination of the δ34S of Total Sulfur in Solids: RSIL Lab Code 1800

    USGS Publications Warehouse

    Revesz, Kinga; Coplen, Tyler B.

    2006-01-01

    The purpose of Reston Stable Isotope Laboratory Lab (RSIL) Code 1800 is to determine the δ(34S/32S), abbreviated as δ34S, of total sulfur in a solid sample. A Carlo Erba NC 2500 elemental analyzer (EA) is used to convert total sulfur in a solid sample into SO2 gas. The EA is connected to a continuous flow isotope-ratio mass spectrometer (CF-IRMS), which determines the relative difference in stable sulfur isotope-amount ratio (34S/32S) of the product SO2 gas. The combustion is quantitative; no isotopic fractionation is involved. Samples are placed in tin capsules and loaded into a Costech Zero-Blank Autosampler on the EA. Under computer control, samples are dropped into a heated tube reaction tube that combines both the oxidation and the reduction reactions. The combustion takes place in a He atmosphere that contains an excess of oxygen gas at the oxidation zone at the top of the reaction tube. Combustion products are transported by a He carrier through the reduction zone at the bottom of the reaction tube to remove excess oxygen and through a separate drying tube to remove any water. The gas-phase products, mainly CO2, N2, and SO2, are separated by a gas chromatograph (GC). The gas is then introduced into the isotope-ratio mass spectrometer (IRMS) through a Thermo-Finnigan ConFlo II interface, which also is used to inject SO2 reference gas and He for sample dilution. The IRMS is a Thermo-Finnigan DeltaPlus CF-IRMS. It has a universal triple collector with two wide cups and a narrow cup in the middle. It is capable of measuring mass/charge (m/z) 64 and 66 simultaneously. The ion beams from SO2 are as follows: m/z 64 = SO2 = 32S16O16O; and m/z 66 = SO2 = 34S16O16O primarily.

  4. Improving the 33S(p,γ)34Cl Reaction Rate for Models of Classical Nova Explosions

    NASA Astrophysics Data System (ADS)

    Parikh, A.; Faestermann, Th.; Krücken, R.; Bildstein, V.; Bishop, S.; Eppinger, K.; Herlitzius, C.; Lepyoshkina, O.; Maierbeck, P.; Seiler, D.; Wimmer, K.; Hertenberger, R.; Wirth, H.-F.; Fallis, J.; Hager, U.; Hutcheon, D.; Ruiz, Ch.; Buchmann, L.; Ottewell, D.; Freeman, B.; Wrede, Ch.; García, A.; Delbridge, B.; Knecht, A.; Sallaska, A.; Chen, A. A.; Clark, J. A.; Deibel, C. M.; Fulton, B.; Laird, A.; Greife, U.; Guo, B.; Li, E.; Li, Z.; Lian, G.; Wang, Y.; Liu, W.; Parker, P. D.; Setoodehnia, K.

    2011-10-01

    Reduced uncertainty in the thermonuclear rate of the 33S(p,γ)34Cl reaction would help to improve our understanding of nucleosynthesis in classical nova explosions. At present, models are generally in concordance with observations that nuclei up to roughly the calcium region may be produced in these explosive phenomena; better knowledge of this rate would help with the quantitative interpretation of nova observations over the S-Ca mass region, and contribute towards the firm establishment of a nucleosynthetic endpoint. As well, models find that the ejecta of nova explosions on massive oxygen-neon white dwarfs may contain as much as 150 times the solar abundance of 33S. This characteristic isotopic signature of a nova explosion could possibly be observed through the analysis of microscopic grains formed in the environment surrounding a nova and later embedded within primitive meteorites. An improved 33S(p,γ)34Cl rate (the principal destruction mechanism for 33S in novae) would help to ensure a robust model prediction for the amount of 33S that may be produced. Finally, constraining this rate could confirm or rule out the decay of an isomeric state of 34Cl (Ex = 146 keV, t1/2 = 32 m) as a source for observable gamma-rays from novae. We have performed several complementary experiments dedicated to improving our knowledge of the 33S(p,γ)34Cl rate, using both indirect methods (measurement of the 34S(3He,t)34Cl and 33S(3He,d)34Cl reactions with the Munich Q3D spectrograph) and direct methods (in normal kinematics at CENPA, University of Washington, and in inverse kinematics with the DRAGON recoil mass separator at TRIUMF). Our results will be used with nova models to facilitate comparisons of model predictions with present and future nova observables.

  5. 33S nuclear magnetic resonance spectroscopy of biological samples obtained with a laboratory model 33S cryogenic probe.

    PubMed

    Hobo, Fumio; Takahashi, Masato; Saito, Yuta; Sato, Naoki; Takao, Tomoaki; Koshiba, Seizo; Maeda, Hideaki

    2010-05-01

    (33)S nuclear magnetic resonance (NMR) spectroscopy is limited by inherently low NMR sensitivity because of the quadrupolar moment and low gyromagnetic ratio of the (33)S nucleus. We have developed a 10 mm (33)S cryogenic NMR probe, which is operated at 9-26 K with a cold preamplifier and a cold rf switch operated at 60 K. The (33)S NMR sensitivity of the cryogenic probe is as large as 9.8 times that of a conventional 5 mm broadband NMR probe. The (33)S cryogenic probe was applied to biological samples such as human urine, bile, chondroitin sulfate, and scallop tissue. We demonstrated that the system can detect and determine sulfur compounds having SO(4)(2-) anions and -SO(3)(-) groups using the (33)S cryogenic probe, as the (33)S nuclei in these groups are in highly symmetric environments. The NMR signals for other common sulfur compounds such as cysteine are still undetectable by the (33)S cryogenic probe, as the (33)S nuclei in these compounds are in asymmetric environments. If we shorten the rf pulse width or decrease the rf coil diameter, we should be able to detect the NMR signals for these compounds.

  6. The chemical conditions of the late Archean Hamersley basin inferred from whole rock and pyrite geochemistry with Δ33S and δ34S isotope analyses

    NASA Astrophysics Data System (ADS)

    Gregory, Daniel D.; Large, Ross R.; Halpin, Jacqueline A.; Steadman, Jeffery A.; Hickman, Arthur H.; Ireland, Trevor R.; Holden, Peter

    2015-01-01

    The well-preserved late Archean sedimentary rocks of the Fortescue and Hamersley Basins in Western Australia offer fascinating insights into early earth ocean chemistry prior to the Great Oxidation Event (GOE). In this study, we use a combination of whole rock geochemistry, LA-ICPMS trace element analysis of sedimentary pyrite and pyrrhotite and SHRIMP-SI sulfur isotope analyses to elucidate the chemical changes in these sedimentary rocks. These proxies are used to examine chemical conditions of the ocean during the late Archean. Two to three periods of oxygen enrichment prior to the deposition of banded iron formations (BIF) can be identified. One minor stage of general increase in whole rock enrichment factors and trace element content of pyrite is observed up stratigraphy in the Jeerinah Formation, Fortescue Basin and a more substantial stage is present in the Paraburdoo and Bee Gorge Members of the Wittenoom Formation, Hamersley Basin. Some of the trace element enrichments indicate organic matter burial flux (Ni, Cr, Zn, Co and Cu) which suggests an increase in biological productivity. If the increased biological activity reflects an increase in cyanobacteria activity then an associated increase in oxygen is likely to have occurred during the deposition of the Bee Gorge Member. An increase in atmospheric oxygen would result in continental weathering of sulfide and other minerals, increasing the trace element content of the water column via erosion and avoiding excessive depletion of trace elements due to drawdown in seawater. Since some of these trace elements may also be limiting nutrients (such as Mo and Se) for the cyanobacteria, the degree of biological productivity may have further increased due to the increasing amount of trace elements introduced by oxygenation in a positive feedback loop. These periods of increased productivity and oxygen rise stopped prior to the onset of BIF deposition in the Hamersley Basin. This may be due to the ocean reaching an oxidation threshold, enabling the precipitation of hematite and magnetite BIF. The BIF deposition caused depletion of ocean nutrients such as phosphate, severely limiting the growth of cyanobacteria, and thus limiting further oxygen production.

  7. Oxygen isotope corrections for online δ34S analysis

    USGS Publications Warehouse

    Fry, B.; Silva, S.R.; Kendall, C.; Anderson, R.K.

    2002-01-01

    Elemental analyzers have been successfully coupled to stable-isotope-ratio mass spectrometers for online measurements of the δ34S isotopic composition of plants, animals and soils. We found that the online technology for automated δ34S isotopic determinations did not yield reproducible oxygen isotopic compositions in the SO2 produced, and as a result calculated δ34S values were often 1–3‰ too high versus their correct values, particularly for plant and animal samples with high C/S ratio. Here we provide empirical and analytical methods for correcting the S isotope values for oxygen isotope variations, and further detail a new SO2-SiO2 buffering method that minimizes detrimental oxygen isotope variations in SO2.

  8. The performance of single and multi-collector ICP-MS instruments for fast and reliable 34S/32S isotope ratio measurements†

    PubMed Central

    Pröfrock, Daniel; Irrgeher, Johanna; Prohaska, Thomas

    2016-01-01

    The performance and validation characteristics of different single collector inductively coupled plasma mass spectrometers based on different technical principles (ICP-SFMS, ICP-QMS in reaction and collision modes, and ICP-MS/MS) were evaluated in comparison to the performance of MC ICP-MS for fast and reliable S isotope ratio measurements. The validation included the determination of LOD, BEC, measurement repeatability, within-lab reproducibility and deviation from certified values as well as a study on instrumental isotopic fractionation (IIF) and the calculation of the combined standard measurement uncertainty. Different approaches of correction for IIF applying external intra-elemental IIF correction (aka standard-sample bracketing) using certified S reference materials and internal inter-elemental IIF (aka internal standardization) correction using Si isotope ratios in MC ICP-MS are explained and compared. The resulting combined standard uncertainties of examined ICP-QMS systems were not better than 0.3–0.5% (uc,rel), which is in general insufficient to differentiate natural S isotope variations. Although the performance of the single collector ICP-SFMS is better (single measurement uc,rel = 0.08%), the measurement reproducibility (>0.2%) is the major limit of this system and leaves room for improvement. MC ICP-MS operated in the edge mass resolution mode, applying bracketing for correction of IIF, provided isotope ratio values with the highest quality (relative combined measurement uncertainty: 0.02%; deviation from the certified value: <0.002%). PMID:27812369

  9. The performance of single and multi-collector ICP-MS instruments for fast and reliable (34)S/(32)S isotope ratio measurements.

    PubMed

    Hanousek, Ondrej; Brunner, Marion; Pröfrock, Daniel; Irrgeher, Johanna; Prohaska, Thomas

    2016-11-14

    The performance and validation characteristics of different single collector inductively coupled plasma mass spectrometers based on different technical principles (ICP-SFMS, ICP-QMS in reaction and collision modes, and ICP-MS/MS) were evaluated in comparison to the performance of MC ICP-MS for fast and reliable S isotope ratio measurements. The validation included the determination of LOD, BEC, measurement repeatability, within-lab reproducibility and deviation from certified values as well as a study on instrumental isotopic fractionation (IIF) and the calculation of the combined standard measurement uncertainty. Different approaches of correction for IIF applying external intra-elemental IIF correction (aka standard-sample bracketing) using certified S reference materials and internal inter-elemental IIF (aka internal standardization) correction using Si isotope ratios in MC ICP-MS are explained and compared. The resulting combined standard uncertainties of examined ICP-QMS systems were not better than 0.3-0.5% (uc,rel), which is in general insufficient to differentiate natural S isotope variations. Although the performance of the single collector ICP-SFMS is better (single measurement uc,rel = 0.08%), the measurement reproducibility (>0.2%) is the major limit of this system and leaves room for improvement. MC ICP-MS operated in the edge mass resolution mode, applying bracketing for correction of IIF, provided isotope ratio values with the highest quality (relative combined measurement uncertainty: 0.02%; deviation from the certified value: <0.002%).

  10. Determination of the δ34S of low-concentration sulfate in water; RSIL lab code 1949

    USGS Publications Warehouse

    Revesz, Kinga; Qi, Haiping; Coplen, Tyler B.

    2006-01-01

    The purpose of the Reston Stable Isotope Laboratory (RSIL) lab code 1949 is to determine the δ(34S/32S), abbreviated as δ34S, of dissolved sulfate having a concentration less than 20 milligrams per liter. Dissolved sulfate is collected on an anion-exchange resin in the field, eluted in the laboratory with 3 M KCl, and precipitated with BaCl2 at pH 3 to 4 as BaSO4. The precipitated BaSO4 is filtered and dried before introduction into an elemental analyzer (EA) Carlo Erba NC 2500. The EA is used to convert sulfur in a BaSO4 solid sample into SO2 gas, and the EA is connected to a continuous flow isotope-ratio mass spectrometer (CF-IRMS), which determines differences in the isotope-amount ratios of stable sulfur isotopes (34S/32S) of the product SO2 gas. The combustion is quantitative; no isotopic fractionation is involved. Samples are placed in a tin capsule and loaded into the Costech Zero Blank Autosampler of the EA. Under computer control, samples are dropped into a heated reaction tube that combines the oxidation and reduction reactions. The combustion takes place in a helium atmosphere containing an excess of oxygen gas at the oxidation zone at the top of the reaction tube. Combustion products are transported by a helium carrier through the reduction zone at the bottom of the reaction tube to remove excess oxygen and through a separate drying tube to remove any water. The gas-phase products, mainly CO2, N2, and SO2, are separated by a gas chromatograph. The gas is then introduced into the isotope-ratio mass spectrometer (IRMS) through a Finnigan MAT (now Thermo Scientific) ConFlo II interface, which is also used to inject SO2 reference gas and helium for sample dilution. The IRMS is a Thermo Scientific Delta V Plus CF-IRMS. It has a universal triple collector with two wide cups and a narrow cup in the middle. It is capable of measuring mass/charge (m/z) 64 and 66 simultaneously. The ion beams from SO2 are as follows: m/z 64 = SO2 = 32S16O16O; m/z 66 = SO2 = 34S

  11. The possible role of thiosulfate in the precipitation of 34S-rich barite in some Mississippi Valley-type deposits

    USGS Publications Warehouse

    Spirakis, C.S.

    1991-01-01

    The precipitation of extremely 34S-rich barite in the late stage of mineralization in the Mississippi Valleytype deposits of the Illinois-Kentucky district (U.S.A.) may be explained by reactions involving thiosulfate (S2O3=). Inorganic processes are known to concentrate 34S in the sulfonate site of thiosulfate and 32S in the sulfate site. In the mineralizing solution, these inorganic processes may have fractionated sulfur between the two sites by about 40 per mil. At the low temperatures of the late barite stage of mineralization, bacteria are known to metabolize thiosulfate by various reactions. In one of these, dissimilatory reduction, hydrogen sulfide and sulfite are produced. Isotopically light sulfite is preferentially reduced to sulfide by bacteria to leave a residual sulfite enriched in 34S. Part of the residual sulfite may be oxidized to form isotopically heavy sulfate; part may recombine with hydrogen sulfide to form thiosulfate. The recombination also enriches the sulfonate site in 34S and the sulfane site in 32S. Recycling the newly formed thiosulfate through the above steps further enriches sulfite and sulfate from oxidation of sulfite in 34S. During genesis of the ores, the aggregate effect of these reactions may have been the precipitation of extremely 34S-rich barite. The sequence of reactions suggested above requires the presence of organic matter. Previously proposed reactions to account for the precipitation of sulfide minerals and fluorite and for the carbonate paragenesis also require the presence of organic matter. Thus, organic matter in the host rocks may cause the various ore-zone reactions and account for the localization of the ores. ?? 1991 Springer-Verlag.

  12. Resonance strengths of the 34S + α reaction

    NASA Astrophysics Data System (ADS)

    O'Malley, P. D.; Connolly, Devin; Greife, Uwe; Hager, Ulrike; Ilyushkin, Sergey; Buchmann, Lothar; Christian, Greg; D'Auria, John; Davids, Barry; Fallis, Jennifer; Hutcheon, Dave; Martin, Lars; Ruiz, Chris; Chen, Alan; Setoodehnia, Kiana; Akers, Charles; Fulton, Brian; Laird, Alison; Erikson, Luke

    2014-09-01

    Late in their evolution, particularly massive stars undergo a stage of explosive oxygen burning. The free α-particle density will rapidly increase and initiate a network of reactions among nuclides ranging from 28Si to 40Ca. Next there will be a abrupt rise in the abundances of 34S and 38Ar where the small excess of neutrons reside. The final abundances of nuclei in this mass region depend on the reaction cross sections involving these two nuclei. Currently there are large discrepancies in the strengths of the 34S + α resonances in the energy range of interest for this astrophysical environment. A new measurement was performed at DRAGON to resolve these discrepancies. Preliminary data will be shown and tentative results discussed.

  13. δ(34)S values in recent sea sediments and their significance using several sediment profiles from the western Baltic Sea.

    PubMed

    Hartmann, Martin; Nielsen, Heimo

    2012-01-01

    The isotope ratios of various sulphur components (total sulphur content in the sediment, sulphate and H(2)S in the pore-water) were measured in a number of cores from recent marine sediments taken from the Kieler Bucht (Kiel Bay) region in the western Baltic Sea. Additionally, the quantitative contents of total sulphur, sulphate, sulphide, chloride, organic carbon, iron and water in the sediment and in the pore-water solutions, respectively, were determined. These investigations provided the following results: 1. The sulphur contained in the sediment (∼ 0.3-2% of the dry sample) was for the most part introduced only after sedimentation. This confirms the deliberations of Kaplan et al. [The Distribution and Isotopic Abundance of Sulfur in Recent Marine Sediments off Southern California, Geochim. Cosmochim. Acta 27, 297 (1963)]. The organic substance contributes to the sulphur content of the sediment only to an insignificant degree (in our samples with ∼5-10% of the total sulphur). 2. The sulphate in the pore-waters has been identified as a source for sulphur in the sediment. During normal sedimentation, the exchange of sulphate by diffusion significant for changes in the sulphur content goes down to a sediment depth of 4-6 cm. In this process, the sulphate consumed by reduction and formation of sulphide or pyrite is mostly replaced. The uppermost sediment layer thus represents a partially open system for the total sulphur. The diagenesis of the sulphur is allochemical. At depths below 4-6 cm, we are dealing with a closed system. The further diagenesis of sulphur here is isochemical. 3. The isotope values of the sediment sulphur are influenced primarily by sulphur which comes into the sediment by diffusion and which is bound by subsequent bacteriological reduction as either sulphide or pyrite. As a consequence of the prevailing reduction of (32)S and reverse-diffusion of sulphate into the open sea water, a (32)S enrichment takes place in the uppermost layer of

  14. Highly accurate potential energy surface, dipole moment surface, rovibrational energy levels, and infrared line list for 32S16O2 up to 8000 cm-1

    NASA Astrophysics Data System (ADS)

    Huang, Xinchuan; Schwenke, David W.; Lee, Timothy J.

    2014-03-01

    A purely ab initio potential energy surface (PES) was refined with selected 32S16O2 HITRAN data. Compared to HITRAN, the root-mean-squares error (σRMS) for all J = 0-80 rovibrational energy levels computed on the refined PES (denoted Ames-1) is 0.013 cm-1. Combined with a CCSD(T)/aug-cc-pV(Q+d)Z dipole moment surface (DMS), an infrared (IR) line list (denoted Ames-296K) has been computed at 296 K and covers up to 8000 cm-1. Compared to the HITRAN and CDMS databases, the intensity agreement for most vibrational bands is better than 85%-90%. Our predictions for 34S16O2 band origins, higher energy 32S16O2 band origins and missing 32S16O2 IR bands have been verified by most recent experiments and available HITRAN data. We conclude that the Ames-1 PES is able to predict 32/34S16O2 band origins below 5500 cm-1 with 0.01-0.03 cm-1 uncertainties, and the Ames-296K line list provides continuous, reliable and accurate IR simulations. The Ka-dependence of both line position and line intensity errors is discussed. The line list will greatly facilitate SO2 IR spectral experimental analysis, as well as elimination of SO2 lines in high-resolution astronomical observations.

  15. Highly Accurate Potential Energy Surface, Dipole Moment Surface, Rovibrational Energy Levels, and Infrared Line List for (32)S(16)O2 up to 8000 cm(exp -1)

    NASA Technical Reports Server (NTRS)

    Huang, Xinchuan; Schwenke, David W.; Lee, Timothy J.

    2014-01-01

    A purely ab initio potential energy surface (PES) was refined with selected (32)S(16)O2 HITRAN data. Compared to HITRAN, the root-mean-squares error (RMS) error for all J=0-80 rovibrational energy levels computed on the refined PES (denoted Ames-1) is 0.013 cm(exp -1). Combined with a CCSD(T)/aug-cc-pV(Q+d)Z dipole moment surface (DMS), an infrared (IR) line list (denoted Ames-296K) has been computed at 296K and covers up to 8,000 cm(exp -1). Compared to the HITRAN and CDMS databases, the intensity agreement for most vibrational bands is better than 85-90%. Our predictions for (34)S(16)O2 band origins, higher energy (32)S(16)O2 band origins and missing (32)S(16)O2 IR bands have been verified by most recent experiments and available HITRAN data. We conclude that the Ames-1 PES is able to predict (32/34)S(16)O2 band origins below 5500 cm(exp -1) with 0.01-0.03 cm(exp -1) uncertainties, and the Ames-296K line list provides continuous, reliable and accurate IR simulations. The Ka-dependence of both line position and line intensity errors is discussed. The line list will greatly facilitate SO2 IR spectral experimental analysis, as well as elimination of SO2 lines in high-resolution astronomical observations.

  16. A mantle origin for Paleoarchean peridotitic diamonds from the Panda kimberlite, Slave Craton: Evidence from 13C-, 15N- and 33,34S-stable isotope systematics

    NASA Astrophysics Data System (ADS)

    Cartigny, Pierre; Farquhar, James; Thomassot, Emilie; Harris, Jeffrey W.; Wing, Bozwell; Masterson, Andy; McKeegan, Kevin; Stachel, Thomas

    2009-11-01

    In order to address diamond formation and origin in the lithospheric mantle underlying the Central Slave Craton, we report N- and C-stable isotopic compositions and N-contents and aggregation states for 85 diamonds of known paragenesis (73 peridotitic, 8 eclogitic and 4 from lower mantle) from the Panda kimberlite (Ekati Mine, Lac de Gras Area, Canada). For 12 peridotitic and two eclogitic sulfide inclusion-bearing diamonds from this sample set, we also report multiple-sulfur isotope ratios. The 73 peridotitic diamonds have a mean δ13C-value of - 5.2‰ and range from - 6.9 to - 3.0‰, with one extreme value at - 14.1‰. The associated δ15N-values range from - 17.0 to + 8.5‰ with a mean value of - 4.0‰. N-contents range from 0 to 1280 ppm. The 8 eclogitic diamonds have δ13C-values ranging from - 11.2 to - 4.4‰ with one extreme value at - 19.4‰. Their δ15N ranges from - 2.1 to + 7.9‰ and N-contents fall between 0 and 3452 ppm. Four diamonds with an inferred lower mantle origin are all Type II (i.e. nitrogen-free) and have a narrow range of δ13C values, between - 4.5 and - 3.5‰. The δ34S of the 14 analyzed peridotitic and eclogitic sulfide inclusions ranges from - 3.5 to +5.7‰. None of them provide evidence for anomalous δ33S-values; observed variations in δ33S are from +0.19 to - 0.33‰, i.e. within the 2 sigma uncertainties of mantle sulfur ( δ33S = 0‰). At Panda, the N contents and the δ13C of sulfide-bearing peridotitic diamonds show narrower ranges than silicate-bearing peridotitic diamonds. This evidence supports the earlier suggestion established from eclogitic diamonds from the Kaapvaal that sulfide-(±silicate) bearing diamonds sample a more restricted portion of sublithospheric mantle than silicate-(no sulfide) bearing diamonds. Our findings at Panda suggest that sulfide-bearing diamonds should be considered as a specific diamond population on a global-scale. Based on our study of δ34S, Δ 33S, δ15N and δ13C, we find no

  17. Simultaneous N, C, S isotopic analyses using purge and trap EA technology. Application to δ34S analyses of natural phosphate material NBS120c and BCR32

    NASA Astrophysics Data System (ADS)

    Fourel, F. P.; Lecuyer, C.; Martineau, F.

    2013-12-01

    The first example of stable isotope analyses in continuous flow mode by Preston et al in 19861 involved Elemental Analyser Isotopic Ratio Mass Spectrometry (EA-IRMS) dedicated to carbon isotopes in combustion mode. EA-IRMS has since then evolved to allow 34S/32S determinations still in combustion mode and mainly to access pyrolysis reaction for O and H isotopes. As far as combustion EA-IRMS is concerned the technique itself has remained unchanged since the development of 'purge and trap' separation techniques online with IRMS instruments. Here we have used a high-precision, easy, low-cost and rapid method of simultaneous carbon, nitrogen and sulphur isotope analysis using this new type of elemental analyser based on 'purge and trap' technology 2,3. Simultaneous determinations, performed on the same aliquot of 13C, 15N and 34S are demonstrated. Emphasis is put on the high quality of 34S/32S determinations. First concentrating on peak shapes, yields of conversion and preliminary results. Then the reliability and accuracy of such a technique is illustrated using analyses from various international reference materials. Alongside international reference material working NCS calibrated material has been selected and characterized prior to apply this technology to calibrate natural phosphate material used as compositional reference material BCR32 and NBS120c. δ34S values of respectively 15.62×0.32‰ and 16.5×0.17‰ are proposed for those samples with sulphur concentrations below the 1% level. The possibility to reliably measure S isotopes on that kind of samples opens up new fields of investigation especially for paleoenvironmental reconstructions. Keywords: carbon, nitrogen, sulfur, isotope, combustion, phosphate, elemental-analyser 1. T. Preston, N.J.P. Owens: Preliminary 13C Measurements using a Gas Chromatograph Interfaced to an Isotope Ratio Mass Spectrometer. Biomedical. Mass Spectrom. 1985, 12-9, 510. 2. H.P. Sieper, H.J. Kupka, L. Lange, A. Rossmann, N. Tanz

  18. Isotopic Equilibration Between Sulfide and Organic Matter: Implications for Records of Sedimentary δ34S.

    NASA Astrophysics Data System (ADS)

    Raven, M. R.; Sessions, A. L.; Adkins, J. F.; Fischer, W. W.

    2015-12-01

    Records of the sulfur-isotopic composition of sedimentary pyrite have been used to constrain the evolutionary timing of major metabolic pathways, the size of the marine sulfate reservoir, and the redox balance of the planet. It remains a major challenge, however, to explain the enormous range of pyrite δ34S values in the literature and their typical ~10‰ offset relative to sedimentary organic S. We investigate the development of pyrite and organic S records in Santa Barbara Basin, which has suboxic bottom water and high (≥4 wt%) organic matter burial. Concentration and δ34S profiles of major sulfur species (sulfate, sulfide, elemental S, proto-kerogen, pyrite, and extractable organic matter) suggest the occurrence of S-isotope exchange between porewater sulfide and organic S, so we conducted laboratory experiments to test organic S exchangeability with 34S-labelled sulfide-polysulfide solutions. We found that both extractable and proto-kerogen organic matter incorporated significant amounts of label within days, supporting the feasibility of equilibration between sulfide and organic matter in the environment. Unlike organic S, pyrite δ34S values in Santa Barbara Basin sediments are up to 30‰ lower than those for porewater sulfide. We hypothesize that this strongly 34S-depleted pyrite reflects the immediate products of bacterial sulfate reduction at organic-rich structures like microbial biofilms or aggregates and suggest that this δ34S difference between porewater sulfide and pyrite may be a more common than previously recognized. Pyrite δ34S values are not necessarily reflective of porewater sulfide δ34S, suggesting that this common assumption should be revisited. Sedimentary pyrite and organic S are potentially powerful and complementary archives of environmental information. To meaningfully interpret these records, it is essential that we take into account the complex processes affecting sedimentary pyrite and organic sulfur δ34S in modern sediments.

  19. {alpha}-cluster states in {sup 38}Ar observed via the {sup 34}S({sup 7}Li,t{alpha}){sup 34}S reaction

    SciTech Connect

    Fukada, M.; Ohmura, M.; Harima, F.; Ogino, K.; Takimoto, K.; Ohkubo, S.

    2005-06-01

    To study the {alpha}-cluster states in the {sup 38}Ar nucleus, angular correlation functions between t and {alpha} in the {sup 34}S({sup 7}Li, t{alpha}){sup 38}Ar reaction have been measured. Seven states at 10.2, 10.8, 11.4, 12.2, 12.7, 14.3, and 15.0 MeV were newly observed.

  20. In situ sulfur isotopes (δ(34)S and δ(33)S) analyses in sulfides and elemental sulfur using high sensitivity cones combined with the addition of nitrogen by laser ablation MC-ICP-MS.

    PubMed

    Fu, Jiali; Hu, Zhaochu; Zhang, Wen; Yang, Lu; Liu, Yongsheng; Li, Ming; Zong, Keqing; Gao, Shan; Hu, Shenghong

    2016-03-10

    The sulfur isotope is an important geochemical tracer in diverse fields of geosciences. In this study, the effects of three different cone combinations with the addition of N2 on the performance of in situ S isotope analyses were investigated in detail. The signal intensities of S isotopes were improved by a factor of 2.3 and 3.6 using the X skimmer cone combined with the standard sample cone or the Jet sample cone, respectively, compared with the standard arrangement (H skimmer cone combined with the standard sample cone). This signal enhancement is important for the improvement of the precision and accuracy of in situ S isotope analysis at high spatial resolution. Different cone combinations have a significant effect on the mass bias and mass bias stability for S isotopes. Poor precisions of S isotope ratios were obtained using the Jet and X cones combination at their corresponding optimum makeup gas flow when using Ar plasma only. The addition of 4-8 ml min(-1) nitrogen to the central gas flow in laser ablation MC-ICP-MS was found to significantly enlarge the mass bias stability zone at their corresponding optimum makeup gas flow in these three different cone combinations. The polyatomic interferences of OO, SH, OOH were also significantly reduced, and the interference free plateaus of sulfur isotopes became broader and flatter in the nitrogen mode (N2 = 4 ml min(-1)). However, the signal intensity of S was not increased by the addition of nitrogen in this study. The laser fluence and ablation mode had significant effects on sulfur isotope fractionation during the analysis of sulfides and elemental sulfur by laser ablation MC-ICP-MS. The matrix effect among different sulfides and elemental sulfur was observed, but could be significantly reduced by line scan ablation in preference to single spot ablation under the optimized fluence. It is recommended that the d90 values of the particles in pressed powder pellets for accurate and precise S isotope analysis should be less than 10 μm. Under the selected optimized analytical conditions, excellent agreements between the determined values and the reference values were achieved for the IAEA-S series standard reference materials and a set of six well-characterized, isotopic homogeneous sulfide standards (PPP-1, MoS2, MASS-1, P-GBW07267, P-GBW07268, P-GBW07270), validating the capability of the developed method for providing high-quality in situ S isotope data in sulfides and elemental sulfur.

  1. THz and Ft-Ir Study of 18-O Isotopologues of Sulfur Dioxide: 32S16O18O and 32S18O_2

    NASA Astrophysics Data System (ADS)

    Margulès, L.; Motiyenko, R. A.; Demaison, J.; Perrin, Agnes; Kwabia Tchana, F.; Manceron, Laurent

    2016-06-01

    Sulfur dioxide is a molecule that have a great interest in different domains: for atmospheric and planetology chemistry, it is also ubiquitous and abundant in interstellar medium. If the 16O species were extensively studied, this is not the case of the 18O isotopologues. The aim of this study is first to complete the rotational spectra of the ground state with these new measurements up to 1.5 THz, previous measurements are up to 1050 GHz for the 32S16O18O species, and 145 GHz concerning the 32S18O_2 species. The second part is making a global fit of the rotational and vibrational transitions for the excited vibrational states. For the v_2 band, we will complete the recent I.R. analysis. About the triad (v_1, 2v_2, v_3): 32S18O_2 species was studied, but not the 32S16O18O one. and 145 GHz concerning the 32S18O_2 species. The second part is making a global fit of the rotational and vibrational transitions for the excited vibrational states. For the v_2 band, we will complete the recent I.R. analysis. About the triad (v_1, 2v_2, v_3): 32S18O_2 species was studied, but not the 32S16O18O one. The FT-IR spectra were recorded on the AILES Beamline at Synchrotron SOLEIL using the Synchrotron light source, coupled to the Bruker IFS125HR Fourier transform spectrometer. The THz spectra were obtained from 150 to 1500 GHz using the Lille's solid state spectrometer. The analysis is in progress, the latest results will be presented. Support from the French Laboratoire d'Excellence CaPPA (Chemical and Physical Properties of the Atmosphere) through contract ANR-10-LABX-0005 of the Programme d'Investissements d'Avenir is acknowledged Belov, S. P.; et al., 1998, J. Mol. Spectrosc. 191, 17 Lindermayer, J.; et al., 1985, J. Mol. Spectrosc. 110, 357 Gueye, F.; et al. Mol. Phys. in press Ulenikov, O. N.; et al., 2015, JQSRT 166, 13 Brubach, J.; et al., 2010, AIP Conf. Proc. 1214, 81 Zakharenko, O.; et al., 2015, J. Mol. Spectrosc. 317, 41

  2. ``Background'' δ34S values of Kupferschiefer sulphides in Poland: pyrite-marcasite nodules

    NASA Astrophysics Data System (ADS)

    Jowett, E. C.; Roth, T.; Rydzewski, A.; Oszczepalski, S.

    1991-04-01

    Regional “background” δ 34S values of pyrite-(marcasite) nodules throughout the Zechstein basin in Poland have been measured to help estimate the proportion of externally derived sulphur in the Kupferschiefer Cu-Ag ores. The δ 34S values of the 17 FeS2 nodules measured range widely, from -25.2 to -51.9%., similar to the previously published -28 to -43%. range in disseminated pyrite in the Kupferschiefer. The wide variation cannot be attributed to pyrite versus marcasite mineralogy, amount of contained chalcopyrite or sphalerite, carbonate versus shale host rock, early versus late formation, percent of included calcite, or to size, shape, or texture. There is also no relation with proximity to the centres of copper mineralization in southwestern Poland where sulphides are typically isotopically heavier. The δ 34S values do, however, vary directly with percent of host-rock fragments included in the nodules. Repeat samples that were washed with acid or hot water show the same wide variation, indicating that contamination by sulphate sulphur in the host rock is not a factor. Neither is organic sulphur because of its small volume. Instead, the sulphur composition may be fundamentally controlled by the formation mechanism of the nodule, whereby 34S-rich sulphide is preferentially concentrated, possibly replacing anhydrite lenses. Alternatively, a network of host rock inclusions might act as a more accessible conduit for later, 34S-rich fluids to infiltrate the nodule and add to earlier, 34S-poor pyrite. In the ore deposits, higher δ 34S values of ore nodules suggest less indigenous sulphur in limestone than shale lithologies. An isotopic temperature of 61 °C from a chalcopyrite-galena pair agrees with other estimates of <105°C. Higher values in ore nodules/veinlets than in adjacent disseminations, and the calculated δ 34Spy value from a pyrite-bornite mixture support the idea that metal-bearing 34S-rich fluids penetrated the Kupfer-schiefer through a network

  3. VizieR Online Data Catalog: Interstellar S isotopes (Chin+, 1996)

    NASA Astrophysics Data System (ADS)

    Chin, Y.-N.; Henkel, C.; Whiteoak, J. B.; Langer, N.; Churchwell, E. B.

    1995-09-01

    A 12C32S, 13C32S, 12 has been made to study interstellar 32S/34S and 34S/33S ratios from the galactic disk. The four CS isotopomers were detected in 20 star forming regions with galactocentric distances between 3 and 9kpc. From a comparison of line velocities, the C33S J=2-1 rest frequency is ~250kHz below the value given in the Lovas (1992) catalog. Taking 12C/13C ratios from Wilson & Rood (1994) and assuming equal 12C32S and 13C32S excitation temperatures and beam filling factors, 12C32S opacities are in the range 3 to 15; average 32S/34S and 34S/33S isotope ratios are 24.4+/-5.0 and 6.27+/-1.01, respectively. While no systematic variation in the 34S/33S isotope ratio is found, the 32S/34S ratio increases with galactocentric distance when accounting for the 12C/13C gradient of the galactic disk. A fit to the unweighted data yields 32S/34S=3.3+/-0.5(DGC/kpc)+4.1+/-3.1 with a correlation coefficient of 0.84. Since the interstellar sulfur (S) isotopes are synthesized by oxygen burning in massive stars, consequences for nucleosynthesis and models of chemical evolution are briefly discussed. (1 data file).

  4. Translation of thyroglobulin 33S messenger RNA as a means of determining thyroglobulin quaternary structure.

    PubMed

    Vassart, G; Refetoff, S; Brocas, H; Dinsart, C; Dumont, J E

    1975-10-01

    Thyroglobulin is a 19S protein of approximately 660,000 daltons and unknown quaternary structure. We have previously shown that a 33S mRNA purified from mammalian thyroids promoted synthesis in the Xenopus oocyte of a peptide immunologically related to thyroglobulin. Chemical identity to the native protein is now presented by means of a tryptic peptide analysis. Moreover, the 33S mRNA is shown to contain all the information required for the synthesis of a complete 19S thyroglobulin molecule. Gel filtration in Sepharose under denaturing conditions indicates that the reduced polypeptide encoded by the 33S mRNA is larger than 210,000 daltons. A model of a dimeric thyroglobulin with about 300,000 dalton subunits is presented.

  5. Sulphur tracer experiments in laboratory animals using 34S-labelled yeast.

    PubMed

    Martínez-Sierra, J Giner; Moreno Sanz, F; Herrero Espílez, P; Marchante Gayón, J M; Rodríguez Fernández, J; García Alonso, J I

    2013-03-01

    We have evaluated the use of (34)S-labelled yeast to perform sulphur metabolic tracer experiments in laboratory animals. The proof of principle work included the selection of the culture conditions for the preparation of sulphur labelled yeast, the study of the suitability of this labelled yeast as sulphur source for tracer studies using in vitro gastrointestinal digestion and the administration of the (34)S-labelled yeast to laboratory animals to follow the fate and distribution of (34)S in the organism. For in vitro gastrointestinal digestion, the combination of sodium dodecyl sulphate-polyacrylamide gel electrophoresis and high-performance liquid chromatography and inductively coupled plasma mass spectrometry (HPLC-ICP-MS) showed that labelled methionine, cysteine and other low molecular weight sulphur-containing biomolecules were the major components in the digested extracts of the labelled yeast. Next, in vivo kinetic experiments were performed in healthy Wistar rats after the oral administration of (34)S-labelled yeast. The isotopic composition of total sulphur in tissues, urine and faeces was measured by double-focusing inductively coupled plasma mass spectrometry after microwave digestion. It was observed that measurable isotopic enrichments were detected in all samples. Finally, initial investigations on sulphur isotopic composition of serum and urine samples by HPLC-ICP-MS have been carried out. For serum samples, no conclusive data were obtained. Interestingly, chromatographic analysis of urine samples showed differential isotope enrichment for several sulphur-containing biomolecules.

  6. Evaporation residue corss sections for {sup 32}S + {sup 184}W

    SciTech Connect

    Back, B.B.; Blumenthal, D.J.; Davids, C.N.

    1995-08-01

    We recently measured evaporation residue cross sections for the {sup 32}S + {sup 184}W system over a range of beam energies using the Argonne Fragment Mass Analyzer (FMA). Absolute cross sections were obtained on the basis of the recent determination of the transmission probability through the FMA of heavy, slow-moving reaction products. The measurements were carried out using {sup 32}S-beams from the ATLAS superconducting linac at Argonne. Beam energies of 165, 174, 185, 195, 205, 215, 225, 236, 246, and 257 MeV were used. The sliding-seal target chamber is used to allow for measurements at finite angles.

  7. Highly accurate potential energy surface, dipole moment surface, rovibrational energy levels, and infrared line list for {sup 32}S{sup 16}O{sub 2} up to 8000 cm{sup −1}

    SciTech Connect

    Huang, Xinchuan E-mail: Timothy.J.Lee@nasa.gov; Schwenke, David W.; Lee, Timothy J. E-mail: Timothy.J.Lee@nasa.gov

    2014-03-21

    A purely ab initio potential energy surface (PES) was refined with selected {sup 32}S{sup 16}O{sub 2} HITRAN data. Compared to HITRAN, the root-mean-squares error (σ{sub RMS}) for all J = 0–80 rovibrational energy levels computed on the refined PES (denoted Ames-1) is 0.013 cm{sup −1}. Combined with a CCSD(T)/aug-cc-pV(Q+d)Z dipole moment surface (DMS), an infrared (IR) line list (denoted Ames-296K) has been computed at 296 K and covers up to 8000 cm{sup −1}. Compared to the HITRAN and CDMS databases, the intensity agreement for most vibrational bands is better than 85%–90%. Our predictions for {sup 34}S{sup 16}O{sub 2} band origins, higher energy {sup 32}S{sup 16}O{sub 2} band origins and missing {sup 32}S{sup 16}O{sub 2} IR bands have been verified by most recent experiments and available HITRAN data. We conclude that the Ames-1 PES is able to predict {sup 32/34}S{sup 16}O{sub 2} band origins below 5500 cm{sup −1} with 0.01–0.03 cm{sup −1} uncertainties, and the Ames-296K line list provides continuous, reliable and accurate IR simulations. The K{sub a}-dependence of both line position and line intensity errors is discussed. The line list will greatly facilitate SO{sub 2} IR spectral experimental analysis, as well as elimination of SO{sub 2} lines in high-resolution astronomical observations.

  8. Charged particle spectra in {sup 32}S + {sup 32}S interactions at 200 GeV/nucleon from CCD-imaged nuclear collisions in a streamer chamber

    SciTech Connect

    Teitelbaum, L.P.

    1992-04-01

    We have measured the transverse momentum spectra 1/p{sub T} dN/dp{sub T} and rapidity distributions dN/dy of negatively charged hadrons and protons for central {sup 32}S + {sup 32}S interactions at 200 GeV/nucleon incident energy. The negative hadron dN/dy distribution is too broad to be accounted for by thermal models which demand isotropic particle emission. It is compatible with models which emphasize longitudinal dynamics, by either a particle production mechanism, as in the Lund fragmentation model, or by introducing one-dimensional hydrodynamic expansion, as in the Landau model. The proton dN/dy distribution, although showing no evidence for a peak in the target fragmentation region, exhibits limited nuclear stopping power. We estimate the mean rapidity shift of participant target protons to be {Delta}y {approximately} 1.5, greater than observed for pp collisions, less than measured in central pA collisions, and much less than would be observed for a single equilibrated fireball at midrapidity. Both the negative hadron and proton dN/dy distributions can be fit by a symmetric Landau two-fireball model. Although the spectrum possesses a two-component structure, a comparison to pp data at comparable center-of-mass energy shows no evidence for enhanced production at low p{sub T}. The two-component structure can be explained by a thermal and chemical equilibrium model which takes into account the kinematics of resonance decay. Using an expression motivated by longitudinal expansion we find the same temperature for both the protons and negative hadrons at freezeout, T{sub f} {approximately} 170 MeV. We conclude that the charged particle spectra of negative hadrons and protons can be accommodated in a simple collision picture of limited nuclear stopping, evolution through a state of thermal equilibrium, followed by longitudinal hydrodynamic expansion until freezeout.

  9. Charged particle spectra in [sup 32]S + [sup 32]S interactions at 200 GeV/nucleon from CCD-imaged nuclear collisions in a streamer chamber

    SciTech Connect

    Teitelbaum, L.P.

    1992-04-01

    We have measured the transverse momentum spectra 1/p[sub T] dN/dp[sub T] and rapidity distributions dN/dy of negatively charged hadrons and protons for central [sup 32]S + [sup 32]S interactions at 200 GeV/nucleon incident energy. The negative hadron dN/dy distribution is too broad to be accounted for by thermal models which demand isotropic particle emission. It is compatible with models which emphasize longitudinal dynamics, by either a particle production mechanism, as in the Lund fragmentation model, or by introducing one-dimensional hydrodynamic expansion, as in the Landau model. The proton dN/dy distribution, although showing no evidence for a peak in the target fragmentation region, exhibits limited nuclear stopping power. We estimate the mean rapidity shift of participant target protons to be [Delta]y [approximately] 1.5, greater than observed for pp collisions, less than measured in central pA collisions, and much less than would be observed for a single equilibrated fireball at midrapidity. Both the negative hadron and proton dN/dy distributions can be fit by a symmetric Landau two-fireball model. Although the spectrum possesses a two-component structure, a comparison to pp data at comparable center-of-mass energy shows no evidence for enhanced production at low p[sub T]. The two-component structure can be explained by a thermal and chemical equilibrium model which takes into account the kinematics of resonance decay. Using an expression motivated by longitudinal expansion we find the same temperature for both the protons and negative hadrons at freezeout, T[sub f] [approximately] 170 MeV. We conclude that the charged particle spectra of negative hadrons and protons can be accommodated in a simple collision picture of limited nuclear stopping, evolution through a state of thermal equilibrium, followed by longitudinal hydrodynamic expansion until freezeout.

  10. delta(34)S-value measurements in food origin assignments and sulfur isotope fractionations in plants and animals.

    PubMed

    Tanz, Nicole; Schmidt, Hanns-Ludwig

    2010-03-10

    The delta(34)S values of biological material, especially food commodities, serve as indicators for origin assignments. However, in the metabolism of higher plants sulfur isotope fractionations must be expected. As a matter of fact, the delta(34)S values of the sulfate- and organic-S, respectively, of Brassicaceae and Allium species vegetables showed differences between 3 and 6 per thousand, and differences in glucosinolates were between 0 and 14 per thousand. delta(34)S-value differences of total-S between individual tissues of the same plant were approximately 3 per thousand. It is believed that these relatively small and variable fractionations are due to the partition of individual S-metabolism steps to different plant compartments, where they may occur independently and quantitatively. The delta(34)S values of herbivore muscle meat and milk relative to the diet and between an animal and its child had trophic shifts of approximately 1.5 per thousand. (34)S enrichments of up to 4 per thousand were observed for hair, hooves, and horn, an isotope fractionation of -5 per thousand between the diet sulfate and cartilage. Therefore, the reported agreements between delta(34)S value of biomass and primary S sources are true for only bulk material and not for individual compounds or tissues.

  11. Tracking selenium behaviour in chalk aquifer (northern France): Sr and 34S-sulphates isotopes constraints.

    NASA Astrophysics Data System (ADS)

    Cary, Lise; Benabderraziq, Hind; Elkhattabi, Jamal; Parmentier, Marc; Gourcy, Laurence; Négrel, Philippe

    2014-05-01

    Groundwaters in parts of the Paris Basin (France) are facing increasing selenium (Se) contents that can exceed the drinking water limit of 10 μg/L according to the European Framework Directive in the field of water policy (2000/60/EC). To better understand the groundwater origins and the selenium dynamics, the water chemistry of the Chalk aquifer supplying drinkable water to Lille city was studied. This area is submitted to quantitative and qualitative pressure from industrial, urban and agriculture origins. An integrated study was settled to determine the water sources and dynamics of elements, with a focus on Se. After a large chemical characterisation of the groundwater chemistry in the four field wells, a monthly monitoring was held in four wells and in the Deûle channel. Chemical analysis of major and trace elements, stable isotopes (δ18O, δ2H), strontium isotopes, and δ34S and δ18O of sulphates were realised. The chemical composition of solids sampled at various depths at vicinity of the four wells was also analysed. The specific geochemical signature of groundwater as revealed by Sr isotopes, in addition to element concentrations ratios like Mg/Sr and Se/Sr, highlighted mixture of three main groundwaters bodies: (1) the upstream groundwaters in the recharge area with the most radiogenic 87Sr/86Sr isotopic signature; (2) the confined groundwaters with high Sr concentrations due to water-rock interactions and the lowest 87Sr/86Sr isotopic signature close to the one of the chalk in Paris and London basins; (3) the Se-rich formations of Tertiary and Quaternary. The contents of Se, mainly present as SeV I (and locally as SeIV ), displayed spatial and temporal disparities that can be explained by geological and hydrogeological conditions. Se-rich clayed sediments originating from the dismantling of Se-rich tertiary formations (i.e. Ypresian) overlay the chalk formation and can be found in saturated conditions depending of the water table level. Oxidation of

  12. Detangling the Web of Sulfur Metabolisms in Santa Barbara Basin with High-Resolution δ34S and Genomic Profiles

    NASA Astrophysics Data System (ADS)

    Raven, M. R.; Adkins, J. F.; Sessions, A. L.; Dawson, K.; Connon, S. A.; Orphan, V. J.

    2014-12-01

    Sulfur metabolisms are major drivers of organic matter remineralization and microbial growth in marine sediments. Sulfur-isotope systematics are particularly powerful for interrogating metabolic processes in these systems due to the large sulfur-isotope fractionations associated with bacterial sulfate reduction (BSR) and some other metabolic reactions. Recent analytical advancements have made it possible to measure δ34S values of very small samples (>50 nmol), including aqueous sulfate and sulfide as well as pyrite, elemental sulfur, and multiple fractions of sedimentary organic matter. We have generated comprehensive 2.5 cm-resolution depth profiles of these sulfur pools over a 2-m core from Santa Barbara Basin, a sub-oxic environment off the California coast. We find that the porewater sulfide δ34S values appear to be strongly influenced by anaerobic sulfide oxidation and sulfur disproportionation in addition to BSR. These sulfur-isotope signals can be tracked over the course of several thousand years of sediment diagenesis, moving from the oxic-anoxic transition at the sediment-water interface to the sulfate-methane transition zone in deeper sediments. Shifts in δ34S relationships among sulfur pools correlate with changes in microbial community composition as shown in TAG genomic data, which supports the existence of the metabolisms indicated by δ34S profiles. Our results suggest that the existence and activity of multiple microbial communities and coexisting sulfur metabolisms have the potential to be recorded in sedimentary δ34S records.

  13. The fusion-fission process in the reaction 34S +186W near the interaction barrier

    NASA Astrophysics Data System (ADS)

    Harca, I. M.; Dmitriev, S.; Itkis, J.; Kozulin, E. M.; Knyazheva, G.; Loktev, T.; Novikov, K.; Azaiez, F.; Gottardo, A.; Matea, I.; Verney, D.; Chubarian, G.; Hanappe, F.; Piot, J.; Schmitt, C.; Trzaska, W. H.; Vardaci, E.

    2015-02-01

    The reaction 34S +186W at Elab=160 MeV was investigated with the aim of diving into the features of the fusion-fission process. Gamma rays in coincidence with binary reaction fragments were measured using the high efficiency gamma-ray spectrometer ORGAM at the TANDEM Accelerator facility of I.P.N., Orsay, and the time-of-flight spectrometer for fission fragments (FF) registration CORSET of the Flerov Laboratory of Nuclear Reactions (FLNR), Dubna. The coupling of the ORGAM and CORSET setups offers the unique opportunity of extracting details for characterizing the fusion-fission process and gives information regarding production of neutron-rich heavy nuclei. The FF-γ coincidence method is of better use then the γ - γ coincidence method when dealing with low statistic measurements and also offers the opportunity to precisely correct the Dopler shift for in-flight emitted gamma rays. Evidence of symmetric and asymmetric fission modes were observed in the mass and TKE distributions, occurring due to shell effects in the fragments. Coincident measurements allow for discrimination between the gamma rays by accepting a specific range within the mass distribution of the reaction products. Details regarding the experimental setup, methods of processing the acquisitioned data and preliminary results are presented.

  14. Challenging fission dynamics around the barrier: The case of 34S + 186W

    NASA Astrophysics Data System (ADS)

    Kozulin, E. M.; Vardaci, E.; Harca, I. M.; Schmitt, C.; Itkis, I.; Knyazheva, G.; Novikov, K.; Bogachev, A.; Dmitriev, S.; Loktev, T.; Azaiez, F.; Matea, I.; Verney, D.; Gottardo, A.; Dorvaux, O.; Piot, J.; Chubarian, G.; Trzaska, W. H.; Hanappe, F.; Borcea, C.; Calinescu, S.; Petrone, C.

    2016-09-01

    The current status of fission dynamics studies in heavy-ion collisions around the Coulomb barrier is illustrated with the 34S + 186W reaction. The fission-fragment mass and total kinetic energy were measured at the ALTO facility at IPN Orsay, France, with a dedicated set-up using the ( v, E) approach. The measurement reveals the presence of an asymmetric fission component on top of a predominantly symmetric distribution. The asymmetric structure, pointed out for the first time, is discussed along with results of previous experiments studying the same reaction. While these analyses suggested the contribution from either quasi-fission or pre-equilibrium fission, we offer an alternative interpretation, in terms of shell-driven compound-nucleus fission. The present measurement demonstrates the critical influence of resolution when addressing puzzling cases, situated at the crossroads of the various channels opened in a heavy-ion collision. Current status in the field clearly calls for innovative measurements involving manifold correlations and new observables. The outcome of the attempt done in this work in this direction, based on the coincident measurement of prompt γ-rays is reported, and encouraging perspectives are discussed.

  15. Sedimentary pyrite δ34S differs from porewater sulfide in Santa Barbara Basin: Proposed role of organic sulfur

    NASA Astrophysics Data System (ADS)

    Raven, Morgan Reed; Sessions, Alex L.; Fischer, Woodward W.; Adkins, Jess F.

    2016-08-01

    Santa Barbara Basin sediments host a complex network of abiotic and metabolic chemical reactions that knit together the carbon, sulfur, and iron cycles. From a 2.1-m sediment core collected in the center of the basin, we present high-resolution profiles of the concentrations and isotopic compositions of all the major species in this system: sulfate, sulfide (∑H2S), elemental sulfur (S0), pyrite, extractable organic sulfur (OS), proto-kerogen S, total organic and dissolved inorganic carbon, and total and reducible iron. Below 10 cm depth, the core is characterized by low apparent sulfate reduction rates (<0.01 mM/yr) except near the sulfate-methane transition zone. Surprisingly, pyrite forming in shallow sediments is ∼30‰ more 34S-depleted than coexisting ∑H2S in porewater. S0 has the same strongly 34S-depleted composition as pyrite where it forms near the sediment-water interface, though not at depth. This pattern is not easily explained by conventional hypotheses in which sedimentary pyrite derives from abiotic reactions with porewater ∑H2S or from the products of S0 disproportionation. Instead, we propose that pyrite formation in this environment occurs within sulfate reducing microbial aggregates or biofilms, where it reflects the isotopic composition of the immediate products of bacterial sulfate reduction. Porewater ∑H2S in Santa Barbara Basin may be more 34S-enriched than pyrite due to equilibration with relatively 34S-enriched OS. The difference between OS and pyrite δ34S values would then reflect the balance between microbial sulfide formation and the abundance of exchangeable OS. Both OS and pyrite δ34S records thus have the potential to provide valuable information about biogeochemical cycles and redox structure in sedimentary paleoenvironments.

  16. Symmetric splitting for the system 32S+238U at energies near and below the barrier

    NASA Astrophysics Data System (ADS)

    Freifelder, R.; Braun-Munzinger, P.; Deyoung, P.; Schicker, R.; Sen, S.; Stachel, J.

    1987-06-01

    The total capture cross section for the system 32S+238U has been measured at energies from 0.93 to 1.08 times the s-wave interaction barrier by detecting coincident fission fragments following full momentum transfer reactions. The subbarrier cross section cannot be reproduced by a one-dimensional barrier penetration model. Using a quantum mechanical coupled channels model, good agreement is obtained. The measured angular distributions of fission fragments were compared to the predictions of saddle and scission point transition state theory. Saddle point transition state model calculations fail to reproduce the data, while scission point transition state calculations are in agreement with their qualitative trend. Evidence for nonequilibrium processes is presented.

  17. Measurement of the 33S(n,α) cross-section at n_TOF(CERN): Applications to BNCT

    PubMed Central

    Sabaté-Gilarte, Marta; Praena, Javier; Porras, Ignacio; Quesada, José Manuel; Mastinu, Pierfrancesco

    2016-01-01

    Aim The main purpose of this work is to present a new (n,α) cross-section measurement for a stable isotope of sulfur, 33S, in order to solve existing discrepancies. Background 33S has been studied as a cooperating target for Boron Neutron Capture Therapy (BNCT) because of its large (n,α) cross-section in the epithermal neutron energy range, the most suitable one for BNCT. Although the most important evaluated databases, such as ENDF, do not show any resonances in the cross-section, experimental measurements which provided data from 10 keV to 1 MeV showed that the lowest-lying and strongest resonance of 33S(n,α) cross-section occurs at 13.5 keV. Nevertheless, the set of resonance parameters that describe such resonance shows important discrepancies (more than a factor of 2) between them. Materials and methods A new measurement of the 33S(n,α)30Si reaction cross-section was proposed to the ISOLDE and Neutron Time-of-Flight Experiments Committee of CERN. It was performed at n_TOF(CERN) in 2012 using MicroMegas detectors. Results In this work, we will present a brief overview of the experiment as well as preliminary results of the data analysis in the neutron energy range from thermal to 100 keV. These results will be taken into account to calculate the kerma-fluence factors corresponding to 33S in addition to 10B and those of a standard four-component ICRU tissue. Conclusions MCNP simulations of the deposited dose, including our experimental data, shows an important kerma rate enhancement at the surface of the tissue, mainly due to the presence of 33S. PMID:26933393

  18. Significant human impact on the flux and δ(34)S of sulfate from the largest river in North America.

    PubMed

    Killingsworth, Bryan A; Bao, Huiming

    2015-04-21

    Riverine dissolved sulfate (SO4(2-)) flux and sulfur stable isotope composition (δ(34)S) yield information on the sources and processes affecting sulfur cycling on different spatial and temporal scales. However, because pristine preindustrial natural baselines of riverine SO4(2-) flux and δ(34)S cannot be directly measured, anthropogenic impact remains largely unconstrained. Here we quantify natural and anthropogenic SO4(2-) flux and δ(34)S for North America's largest river, the Mississippi, by means of an exhaustive source compilation and multiyear monitoring. Our data and analysis show that, since before industrialization to the present, Mississippi River SO4(2-) has increased in flux from 7.0 to 27.8 Tg SO4(2-) yr(-1), and in mean δ(34)S from -5.0‰, within 95% confidence limits of -14.8‰ to 4.1‰ (assuming normal distribution for mixing model input parameters), to -2.7 ± 1.6‰, reflecting an impressive footprint of bedrocks particular to this river basin and human activities. Our first-order modern Mississippi River sulfate partition is 25 ± 6% natural and 75% ± 6% anthropogenic sources. Furthermore, anthropogenic coal usage is implicated as the dominant source of modern Mississippi River sulfate, with an estimated 47 ± 5% and 13% of total Mississippi River sulfate due to coal mining and burning, respectively.

  19. Coupling of [33S]sulphur to molybdenum(V) in different reduced forms of xanthine oxidase.

    PubMed Central

    Malthouse, J P; George, G N; Lowe, D J; Bray, R C

    1981-01-01

    Different reduced forms of xanthine oxidase, labelled specifically in the cyanide-labile site with 33S, were prepared and examined by electron paramagnetic resonance. Coupling of this isotope to molybdenum(V) was quantified with the help of computer simulations and found to differ markedly from one reduced form to another. The xanthine Very Rapid signal shows strong, highly anisotropic, coupling with A(33S)av. 1.27 mT. For this signal, axes of the g- and A(33S)-tensors are rotated relative to one another. One axis of the A-tensor is in the plane of gxx ang gyy, but rotated by 40 degrees relative to the gxx axis, whereas the direction of weakest coupling to sulphur deviates by 10 degrees from the gzz axis. In contrast with this signal, only rather weaker coupling was observed in different types of Rapid signal [A(33S)av. 0.3--0.4 mT], and in the Inhibited signal coupling was weaker still [A(33S)av. 0.1--0.2 mT]. Clearly, there must be substantial differences in the structures of the molybdenum centre in the different signal-giving species, with the sulphur atom perhaps in an equatorial type of ligand position in the Very Rapid species but in a more axial one in the other species. Structures are discussed in relation to the mechanism of action of the enzyme and the nature of the proton-accepting group that participates in turnover. PMID:6280672

  20. Vibrational studies of {sup 13}C- and {sup 34}S-labelled bis(ethylenedithio)tetrathiafulvalene (ET) donor molecule

    SciTech Connect

    Ferraro, J.R.; Kini, A.M.; Williams, J.M.; Stout, P.

    1994-06-01

    FT-IR and FT-Raman studies of {sup 13}C- and {sup 34}S-labelled bis(ethylenedithio)-tetrathiafulvalene (BEDT-TTF or ET) electron-donor molecules were made and the results presented herein. Assignments for fundamental vibrations in ET were verified. Spectral data confirms that ET has no center-of-symmetry, and that the data can be reconciled by a D-type point group with only slight interactions occurring between the 4 molecules per unit cell.

  1. Open system sulphate reduction in a diagenetic environment - Isotopic analysis of barite (δ34S and δ18O) and pyrite (δ34S) from the Tom and Jason Late Devonian Zn-Pb-Ba deposits, Selwyn Basin, Canada

    NASA Astrophysics Data System (ADS)

    Magnall, J. M.; Gleeson, S. A.; Stern, R. A.; Newton, R. J.; Poulton, S. W.; Paradis, S.

    2016-05-01

    Highly positive δ34S values in sulphide minerals are a common feature of shale hosted massive sulphide deposits (SHMS). Often this is attributed to near quantitative consumption of seawater sulphate, and for Paleozoic strata of the Selwyn Basin (Canada), this is thought to occur during bacterial sulphate reduction (BSR) in a restricted, euxinic water column. In this study, we focus on drill-core samples of sulphide and barite mineralisation from two Late Devonian SHMS deposits (Tom and Jason, Macmillan Pass, Selwyn Basin), to evaluate this euxinic basin model. The paragenetic relationship between barite, pyrite and hydrothermal base metal sulphides has been determined using transmitted and reflected light microscopy, and backscatter electron imaging. This petrographic framework provides the context for in-situ isotopic microanalysis (secondary ion mass spectrometry; SIMS) of barite and pyrite. These data are supplemented by analyses of δ34S values for bulk rock pyrite (n = 37) from drill-core samples of un-mineralised (barren), siliceous mudstone, to provide a means by which to evaluate the mass balance of sulphur in the host rock. Three generations of barite have been identified, all of which pre-date hydrothermal input. Isotopically, the three generations of barite have overlapping distributions of δ34S and δ18O values (+22.5‰ to +33.0‰ and +16.4‰ to +18.3‰, respectively) and are consistent with an origin from modified Late Devonian seawater. Radiolarian tests, enriched in barium, are abundant within the siliceous mudstones, providing evidence that primary barium enrichment was associated with biologic activity. We therefore propose that barite formed following remobilisation of productivity-derived barium within the sediment, and precipitated within diagenetic pore fluids close to the sediment water interface. Two generations of pyrite are texturally associated with barite: framboidal pyrite (py-I), which has negative δ34S values (-23‰ to -28

  2. Signal of unusual large fluctuations in 32S-Em interactions at SPS energies

    NASA Astrophysics Data System (ADS)

    Rasool, Mir Hashim; Ahmad, Shafiq; Ahmad, M. Ayaz

    2015-08-01

    An investigation on the presence of large dynamical fluctuations was carried out in the pseudorapidity phase space ( η-space) of relativistic charged particles produced in 32S-Em interactions at 200 AGeV/c by the method of scaled factorial moments, F q , in terms of the new scaled variable X( η) suggested by Bialas and Gazdzicki. The Nuclear emulsion technique was employed to collect the experimental data. We compared our experimental results with those obtained from simulated events by using Monte Carlo Code FRITIOF. The variation of ln F q with ln M in pseudorapidity ( η) phase space revealed a power law behavior. The values of the slopes, α q , determined from the analyses of the F q moments are discussed. The generalized fractal dimensions, D q , determined from the above method are calculated and found to decrease with the order of the moments, q, indicating multifractality in multiparticle production. Also, the anomalous fractal dimension d q obtained was found to increase linearly with the order of moments, q suggesting a self-similar cascade mechanism. In order to check for the presence of the statistical fluctuations, we generated uncorrelated Monte Carlo events (MC-RAND) randomly in -space based on the assumption of independent emission of particles and compared the results with the experimental and FRITIOF data. The experimental data on intermittency were found to exhibit a remarkable proximity to the analogous data obtained from the FRITIOF code. However, the uncorrelated Monte Carlo events exhibited no such dependence on M, which indicates the absence of a statistical contribution in the experimental data. The flat behavior in the Monte Carlo events is expected for an independent emission of particles.

  3. Study of the 30P({alpha},p){sup 33}S reaction using a gas-filled magnetic spectrograph

    SciTech Connect

    Figueira, J. M.; Deibel, C. M.; Fernandez Niello, J. O.; Greene, J.; Jiang, C. L.; Lee, H. Y.; Pardo, R. C.; Rehm, K. E.; Ugalde, C.; Zinkann, G.; Marley, S. T.; Patel, N.; Paul, M.

    2010-08-04

    We have developed a technique using a gas-filled magnetic spectrograph which enables us to study ({alpha},p) transfer reactions of astrophysical interest in inverse kinematics and by means of the time-inverse reactions. We present preliminary experimental results of the reaction {sup 30}P({alpha},p){sup 33}S which confirm that the technique permits the study of these kinds of transfer reactions.

  4. Thyroglobulin messenger RNA: translation of a 33-S mRNA into a peptide immunologically related to thyroglobulin.

    PubMed

    Vassart, G; Brocas, H; Lecocq, R; Dumont, J E

    1975-06-16

    Poly(UC)--Sepharose chromatography of the RNA extracted from a thyroid fraction sedimenting between 800 X g and 27000 X g allows the purification of two RNA fractions amounting each to 1% of the applied material. The first one is loosely bound to the column from which it is eluted at 25 degrees C. It is mainly composed of 16-S and 12-S RNA comprising no poly(A) sequences. This could correspond to mitochondrial rRNA. The second one, which is eluted at 50 degrees C, is poly(A)-rich and represents 33-S and 17--18-S RNA species. The 33-S RNA resists heating at 80 degrees C, suggesting that it is composed of one polynucleotide chain. When injected into Xenopus oocytes, the 33-S RNA specifically promotes the synthesis of a peptide with an apparent molecular weight of 185000 and an apparent sedimentation coefficient of 10-S. This peptide is immunologically related to thyroglobulin and could represent its main precursor. Under the conditions tested it does not polymerize spontaneously into 19-S thyroglobulin, suggesting that assembly of the molecule could require specific, post-translational alterations of the precursor and/or the presence of additional lighter subunits.

  5. The catalytic incineration of (CH3)2S and its mixture with CH(3)SH over a Pt/Al(2)O(3) catalyst.

    PubMed

    Chu, H; Lee, W T; Horng, K H; Tseng, T K

    2001-03-19

    Catalytic incineration is one of the cost-effective technologies to solve the troublesome volatile organic compounds (VOCs). However, some sulfur containing VOCs, such as dimethyl sulfide, may deactivate the Pt catalyst that is commonly used in the catalytic incineration process. This paper provides information on the poisoning effect of (CH3)2S. The catalytic incineration of (CH3)2S, typically emitted from the petrochemical industry, over a Pt/Al(2)O(3) fixed bed catalytic reactor was studied. The effects of operating parameters including inlet temperature, space velocity, (CH3)2S concentration, O2 concentration and catalyst size were characterized. Catalytic incineration on a mixture of (CH3)2S with CH(3)SH was also tested. The results show that the conversions of (CH3)2S increase as the inlet temperature increases and the space velocity decreases. The higher the (CH3)2S concentration is, the lower its conversion is. The O2 concentration has a positive effect on the conversion of (CH3)2S. (CH3)2S has a poisoning effect on the Pt/Al(2)O(3) catalyst, especially at lower temperatures. The conversion of (CH3)2S is significantly suppressed by the existence of CH(3)SH.

  6. Modeling and measuring intracellular fluxes of secreted recombinant protein in Pichia pastoris with a novel 34S labeling procedure

    PubMed Central

    2011-01-01

    Background The budding yeast Pichia pastoris is widely used for protein production. To determine the best suitable strategy for strain improvement, especially for high secretion, quantitative data of intracellular fluxes of recombinant protein are very important. Especially the balance between intracellular protein formation, degradation and secretion defines the major bottleneck of the production system. Because these parameters are different for unlimited growth (shake flask) and carbon-limited growth (bioreactor) conditions, they should be determined under "production like" conditions. Thus labeling procedures must be compatible with minimal production media and the usage of bioreactors. The inorganic and non-radioactive 34S labeled sodium sulfate meets both demands. Results We used a novel labeling method with the stable sulfur isotope 34S, administered as sodium sulfate, which is performed during chemostat culivations. The intra- and extracellular sulfur 32 to 34 ratios of purified recombinant protein, the antibody fragment Fab3H6, are measured by HPLC-ICP-MS. The kinetic model described here is necessary to calculate the kinetic parameters from sulfur ratios of consecutive samples as well as for sensitivity analysis. From the total amount of protein produced intracellularly (143.1 μg g-1 h-1 protein per yeast dry mass and time) about 58% are degraded within the cell, 35% are secreted to the exterior and 7% are inherited to the daughter cells. Conclusions A novel 34S labeling procedure that enables in vivo quantification of intracellular fluxes of recombinant protein under "production like" conditions is described. Subsequent sensitivity analysis of the fluxes by using MATLAB, indicate the most promising approaches for strain improvement towards increased secretion. PMID:21703020

  7. 33S hyperfine interactions in H2S and SO2 and revision of the sulfur nuclear magnetic shielding scale

    NASA Astrophysics Data System (ADS)

    Helgaker, Trygve; Gauss, Jürgen; Cazzoli, Gabriele; Puzzarini, Cristina

    2013-12-01

    Using the Lamb-dip technique, the hyperfine structure in the rotational spectra of H233S and 33SO2 has been resolved and the corresponding parameters—that is, the sulfur quadrupole-coupling and spin-rotation tensors—were determined. The experimental parameters are in good agreement with results from high-level coupled-cluster calculations, provided that up to quadruple excitations are considered in the cluster operator, sufficiently large basis sets are used, and vibrational corrections are accounted for. The 33S spin-rotation tensor for H2S has been used to establish a new sulfur nuclear magnetic shielding scale, combining the paramagnetic part of the shielding as obtained from the spin-rotation tensor with a calculated value for the diamagnetic part as well as computed vibrational and temperature corrections. The value of 716(5) ppm obtained in this way for the sulfur shielding of H2S is in good agreement with results from high-accuracy quantum-chemical calculations but leads to a shielding scale that is about 28 ppm lower than the one suggested previously in the literature, based on the 33S spin-rotation constant of OCS.

  8. 16O + 16O molecular structures of positive- and negative-parity superdeformed bands in 34S

    NASA Astrophysics Data System (ADS)

    Taniguchi, Yasutaka

    2016-05-01

    The structures of excited states in 34S are investigated using the antisymmetrized molecular dynamics and generator coordinate method(GCM). The GCM basis wave functions are calculated via energy variation with a constraint on the quadrupole deformation parameter β. By applying the GCM after parity and angular momentum projections, the coexistence of two positive- and one negative-parity super de formed(SD) bands are predicted, and low-lying states and other deformed bands are obtained. The SD bands have structures of 16O + 16O + two valence neutrons in molecular orbitals around the two 16O cores in a cluster picture. The configurations of the two valence neutrons are δ2 and π2 for the positive-parity SD bands and π1δ1 for the negative parity SD band.

  9. The stable isotopic composition of a phosphorite deposit: δ13C, δ34S, and δ18O

    USGS Publications Warehouse

    Piper, D.Z.; Kolodny, Y.

    1987-01-01

    The stable isotopes of carbon and sulfur in a major marine sedimentary phosphate deposit from the northwestern United States (the Phosphoria Formation of Permian age) characterize the chemical properties of the depositional environment. The δ34S and δ13C analyses suggest deposition under conditions of variable redox from a solution the acidity of which was controlled by reaction with carbonate rocks and exchange with seawater. The δ18O concentration of apetite indicates phosphatization in a shallow sea, during three glacial and intervening interglacial stages. These data tend to corroborate the interpretation of field studies by others, that the apatite formed on a continental shelf in an area of intense oceanic upwelling during several episodes of sea level change. 

  10. Vibrational-rotational spectra of 13CS and global multi-isotopologue analysis

    NASA Astrophysics Data System (ADS)

    Uehara, Hiromichi; Horiai, Koui; Sakamoto, Yukihiro

    2015-07-01

    In total, 626 vibrational-rotational spectral lines of the Δv = 1 transitions of 13C32S up to band v = 5-4 have been measured with a Fourier-transform spectrometer at resolution 0.010 cm-1. To calibrate accurately the spectral lines, a separate observation of the vibrational-rotational bands of 12C32S was made with simultaneous recording of the N2O spectrum in absorption, to serve as wavenumber standards, with dual sample cells at resolution 0.008 cm-1. The spectral wavenumbers of 12C32S in turn become calibration standards. All present vibrational-rotational spectra of 13C32S and 12C32S, the reported vibrational-rotational spectra of 12C32S, 12C33S, 12C34S, and 13C32S, and the reported rotational spectra of 12C32S, 12C33S, 12C34S, 12C36S, 13C32S, 13C33S and 13C34S were subjected to a global multi-isotopologue analysis, which reduced them to molecular parameters in a single set. The wavenumbers of 3974 spectral lines, in total, comprising data of seven isotopologues were fitted with 22 isotopically invariant, traditional molecular parameters in a single set. As the normalized standard deviation is 1.38, the obtained fit is satisfactory. To facilitate the calculation of spectral wavenumbers, the values of the Dunham coefficients of 42 Yij for each of 12C32S, 12C33S, 12C34S, 12C36S, 13C32S, 13C33S, 13C34S, 13C36S, 14C32S, 14C33S, 14C34S and 14C36S, of which the spectra of the latter five isotopologues are not yet reported, were back-calculated with uncertainties using the evaluated 22 molecular parameters. The physical significance of the conventional treatments of the adiabatic and nonadiabatic corrections for Δ01C and Δ01S is discussed.

  11. Reaction mechanisms in {sup 24}Mg+{sup 12}C and {sup 32}S+{sup 24}Mg

    SciTech Connect

    Beck, C.; Sanchez i Zafra, A.; Papka, P.; Thummerer, S.; Azaiez, F.; Courtin, S.; Curien, D.; Dorvaux, O.; Lebhertz, D.; Nourreddine, A.; Rousseau, M.; Oertzen, W. von; Gebauer, B.; Kokalova, Tz.; Wheldon, C.; De Angelis, G.; Gadea, A.; Lenzi, S.; Napoli, D. R.; Szilner, S.

    2009-03-04

    The occurrence of 'exotic' shapes in light N = Z{alpha}-like nuclei is investigated for {sup 24}Mg+{sup 12}C and {sup 32}S+{sup 24}Mg. Various approaches of superdeformed and hyperdeformed bands associated with quasimolecular resonant structures with low spin are presented. For both reactions, exclusive data were collected with the Binary Reaction Spectrometer in coincidence with EUROBALL IV installed at the VIVITRON Tandem facility of Strasbourg. Specific structures with large deformation were selectively populated in binary reactions and their associated {gamma}-decays studied. The analysis of the binary and ternary reaction channels is discussed.

  12. The fusion-fission process in the reaction {sup 34}S+{sup 186}W near the interaction barrier

    SciTech Connect

    Harca, I. M.; Dmitriev, S.; Itkis, J.; Kozulin, E. M.; Knyazheva, G.; Loktev, T.; Novikov, K.; Azaiez, F.; Gottardo, A.; Matea, I.; Verney, D.; Hanappe, F.; Piot, J.; Schmitt, C.; Vardaci, E.

    2015-02-24

    The reaction {sup 34}S+{sup 186}W at E{sub lab}=160 MeV was investigated with the aim of diving into the features of the fusion-fission process. Gamma rays in coincidence with binary reaction fragments were measured using the high efficiency gamma-ray spectrometer ORGAM at the TANDEM Accelerator facility of I.P.N., Orsay, and the time-of-flight spectrometer for fission fragments (FF) registration CORSET of the Flerov Laboratory of Nuclear Reactions (FLNR), Dubna. The coupling of the ORGAM and CORSET setups offers the unique opportunity of extracting details for characterizing the fusion-fission process and gives information regarding production of neutron-rich heavy nuclei. The FF–γ coincidence method is of better use then the γ – γ coincidence method when dealing with low statistic measurements and also offers the opportunity to precisely correct the Dopler shift for in-flight emitted gamma rays. Evidence of symmetric and asymmetric fission modes were observed in the mass and TKE distributions, occurring due to shell effects in the fragments. Coincident measurements allow for discrimination between the gamma rays by accepting a specific range within the mass distribution of the reaction products. Details regarding the experimental setup, methods of processing the acquisitioned data and preliminary results are presented.

  13. The Rotational Spectrum of H_2S: the H_2^{33}S Isotopologue and the Sub-Doppler Resolution in the THz Regime

    NASA Astrophysics Data System (ADS)

    Cazzoli, Gabriele; Puzzarini, Cristina

    2013-06-01

    Measurements of the rotational spectrum of H_2^{33}S, detected in natural abundance, were performed in the 200 GHz - 1.072 THz frequency range. The Lamb-dip technique was employed to exploit sub-doppler resolution and thus to resolve the hyperfine structure of the rotational lines. The retrieved transition frequency values allowed us to revise the ^{33}S spin-rotation tensor as well as to improve the ^{33}S quadrupole-coupling and centrifugal-distortion constants. Furthermore, the rotational spectrum of the main isotopopologue was investigated in the THz frequency regime. The Lamb-dip technique was employed as well in order to obtain sub-doppler resolution in this frequency region and thus to provide transition frequency values at 1 THz with an accuracy of 1 kHz.

  14. Direct demonstration of the presence of coordinated sulfate in the reaction pathway of Arabidopsis thaliana sulfite oxidase using 33S labeling and ESEEM spectroscopy

    PubMed Central

    Astashkin, Andrei V.; Johnson-Winters, Kayunta; Klein, Eric L.; Byrne, Robert S.; Hille, Russ; Raitsimring, Arnold M.; Enemark, John H.

    2008-01-01

    Sulfite oxidase from Arabidopsis thaliana has been reduced at pH = 6 with sulfite labeled with 33S (nuclear spin I = 3/2), followed by reoxidation by ferricyanide to generate the Mo(V) state of the active center. To obtain information about the hyperfine interaction (hfi) of 33S with Mo(V), continuous wave EPR and electron spin echo envelope modulation (ESEEM) experiments have been performed. The interpretation of the EPR and ESEEM spectra was facilitated by a theoretical analysis of the nuclear transition frequencies expected for the situation of the nuclear quadrupole interaction being much stronger than the Zeeman and hyperfine interactions. The isotropic hfi constant of 33S determined in these experiments was about 3 MHz, which demonstrates the presence of coordinated sulfate in the sulfite-reduced low-pH form of the plant enzyme. PMID:17983221

  15. Seasonal and event variations in δ34S values of stream sulfate in a Vermont forested catchment: Implications for sulfur sources and cycling

    USGS Publications Warehouse

    Shanley, James B.; Mayer, Bernhard; Mitchell, Myron J.; Bailey, Scott W.

    2008-01-01

    Stable sulfur (S) isotope ratios can be used to identify the sources of sulfate contributing to streamwater. We collected weekly and high-flow stream samples for S isotopic analysis of sulfate through the entire water year 2003 plus the snowmelt period of 2004. The study area was the 41-ha forested W-9 catchment at Sleepers River Research Watershed, Vermont, a site known to produce sulfate from weathering of sulfide minerals in the bedrock. The δ34S values of streamwater sulfate followed an annual sinusoidal pattern ranging from about 6.5‰ in early spring to about 10‰ in early fall. During high-flow events, δ34S values typically decreased by 1 to 3‰ from the prevailing seasonal value. The isotopic evidence suggests that stream sulfate concentrations are controlled by: (1) an overall dominance of bedrock-derived sulfate (δ34S ~ 6–14‰); (2) contributions of pedogenic sulfate (δ34S ~ 5–6‰) during snowmelt and storms with progressively diminishing contributions during base flow recession; and (3) minor effects of dissimilatory bacterial sulfate reduction and subsequent reoxidation of sulfides. Bedrock should not be overlooked as a source of S in catchment sulfate budgets.

  16. 19F single-quantum and 19F-33S heteronuclear multiple-quantum coherence NMR of SF6 in thermotropic nematogens and in the gas phase.

    PubMed

    Tervonen, Henri; Saunavaara, Jani; Ingman, L Petri; Jokisaari, Jukka

    2006-08-24

    (19)F single-quantum (SQC) and (19)F-(33)S heteronuclear multiple-quantum coherence (HMQC) NMR spectroscopy of sulfur hexafluoride (SF(6)) dissolved in thermotropic liquid crystals (TLCs) were used to investigate the properties of TLCs. On one hand, environmental effects on the NMR parameters of SF(6), (19)F nuclear shielding, (19)F-(33)S spin-spin coupling, secondary isotope effects of sulfur on (19)F shielding, and the self-diffusion coefficient in the direction of the external magnetic field were studied as well. The temperature dependence of the (19)F shielding of SF(6) in TLCs was modeled with a function that takes into account the properties of both TLC and SF(6). It appears that the TLC environment deforms the electronic system of SF(6) so that the (19)F shielding tensor becomes slightly anisotropic, with the anisotropy being from -0.5 to -1.4 ppm, depending upon the TLC solvent. On the contrary, no sign of residual dipolar coupling between (19)F and (33)S was found, meaning that the so-called deformational effects, which arise from the interaction between vibrational and reorientational motions of the molecule, on the geometry of the molecule are insignificant. Diffusion activation energies, E(a), were determined from the temperature dependence of the self-diffusion coefficients. In each TLC, E(a) increases when moving from an isotropic phase to a nematic phase. The spin-spin coupling constant, J((19)F,(33)S), increases by ca. 10 Hz when moving from the gas phase to TLC solutions. The secondary isotope shifts of (19)F shielding are practically independent of TLC solvent and temperature. For the first time, (19)F-(33)S heteronuclear multiple-quantum NMR spectra were recorded for SF(6) in the gas phase and in a liquid-crystalline solution.

  17. A re-evaluation of /sup 32/S(n,p) cross sections from threshold to 5 MeV

    SciTech Connect

    Fu, C.Y.

    1989-01-01

    Two evaluations of the /sup 32/S(n,p) reaction cross sections, currently being used for the Nagasaki and Hiroshima dosimetry studies, yielded results that differ significantly. These two evaluations were reviewed and both were found to be quite old and without benefit of modern theoretical guidance and recent experimental data, hence inadequate in view of its relative importance for the present application. The necessity for a re-evaluation is further enhanced by the fact that: the present data search has uncovered a relatively high-quality data set that was not known previously, a generalized Bayes-theorem code is now available for averaging the various data sets with uncertainties and generating uncertainties for the results, effects on data combination of differing energy resolution in the various measurements can now be accounted for, and the ENDF/B-VI standards for /sup 238/U(n,f) cross sections have become available for renormalizing two of the available data sets. The re-evaluation is performed to 5 MeV, the upper energy limit for the present purpose. 8 refs., 2 figs.

  18. Tracking photosynthetic sulfide oxidation in a meromictic lake using sulfate δ34S and δ18O

    NASA Astrophysics Data System (ADS)

    Gilhooly, W. P.; Reinhard, C.; Lyons, T. W.; Glass, J. B.

    2012-12-01

    Phototrophic sulfur bacteria oxidize sulfide and fix carbon dioxide in the presence of sunlight without producing oxygen. Environmental conditions in the Paleo- and Mesoproterozoic, when atmospheric oxygen concentrations were at low levels and portions of the oceans were anoxic and sulfidic (euxinic), were conducive to widespread carbon fixation by anoxygenic photosynthesis. This pathway may have helped sustain euxinic conditions in the Proterozoic water column. With limited organic biomarker and geochemical evidence for widespread production of anoxygenic phototrophs, however, additional proxies are needed to fingerprint paleoecological and biogeochemical signals associated with photic zone euxinia. Paired δ34S and δ18O from ancient sulfates (gypsum, barite, or CAS) may offer an added constraint on the history and ecological dominance of photosynthetic S-oxidation. Sulfate-oxygen can fractionate during sulfate reduction, but the extent of isotopic enrichment is controlled either by kinetic isotope effects imparted during intracellular enzymatic steps or equilibrium oxygen exchange with ambient water. An improved understanding of these processes can be gained from modern natural environments. Mahoney Lake is a density-stratified lake located within the White Lake Basin of British Columbia. The euxinic water column supports a dense plate of purple sulfur bacteria (Amoebobacter purpureus) that thrives where free sulfide intercepts the photic zone at ~7 m water depth. We analyzed the isotopic composition of sulfate (δ34SSO4 and δ18OSO4), sulfide (δ34SH2S), and water (δ18OH2O) to track the potentially coupled processes of dissimilatory sulfate reduction and phototrophic sulfide oxidation within this meromictic lake. Large isotopic offsets observed between sulfate and sulfide within the monimolimnion (δ34SSO4-H2S = 51‰) and within pore waters along the oxic margin (δ34SSO4-H2S >50‰) are consistent with sulfate reduction in both the sediments and the anoxic

  19. Direct measurement of several resonance strengths and energies in 34S(α , γ) 38 Ar within the T = 2 . 2 GK Gamow window with DRAGON

    NASA Astrophysics Data System (ADS)

    Connolly, D.; O'Malley, P.; Akers, C.; Chen, A. A.; Christian, G.; Davids, B.; Erikson, L. E.; Fallis, J.; Fulton, B. R.; Greife, U.; Hager, Ulrike; Hutcheon, D. A.; Ilyushkin, S.; Laird, A. M.; Mahl, A.; Ruiz, C.

    2015-10-01

    Radiative α capture on 34S can impact nucleosynthesis in several astrophysical environments, including oxygen burning, explosive oxygen burning (Type II supernovae), and Type Ia supernovae. However, there exist discrepancies in the literature for the resonance strengths of two strong resonances within the Gamow window for oxygen burning temperatures (E0 +/- Δ / 2 = 3183 +/- 897 keV at T = 2 . 2 GK). Previous measurements suffered from systematic uncertainties inherent in the experimental technique. Furthermore, there are several states in 38Ar in the energy range of interest for which no 34S + α resonance strength/energy measurements have been performed. This measurement was performed in inverse kinematics at the DRAGON recoil separator at TRIUMF in BC, Canada. DRAGON's experimental technique allows direct measurement of quantities such as stopping power and resonance energy, alleviating the need for external inputs and reducing uncertainty. This talk will discuss DRAGON's experimental technique, analysis methods and results.

  20. Evidence for an impact-induced biosphere from the δ34S signature of sulphides in the Rochechouart impact structure, France

    NASA Astrophysics Data System (ADS)

    Simpson, S. L.; Boyce, A. J.; Lambert, P.; Lindgren, P.; Lee, M. R.

    2017-02-01

    The highly eroded 23 km diameter Rochechouart impact structure, France, has extensive evidence for post-impact hydrothermal alteration and sulphide mineralisation. The sulphides can be divided into four types on the basis of their mineralogy and host rock. They range from pyrites and chalcopyrite in the underlying coherent crystalline basement to pyrites hosted in the impactites. Sulphur isotopic results show that δ34S values vary over a wide range, from -35.8‰ to +0.4‰. The highest values, δ34S -3.7‰ to +0.4‰, are recorded in the coherent basement, and likely represent a primary terrestrial sulphur reservoir. Sulphides with the lowest values, δ34S -35.8‰ to -5.2‰, are hosted within locally brecciated and displaced parautochthonous and autochthonous impactites. Intermediate δ34S values of -10.7‰ to -1.2‰ are recorded in the semi-continuous monomict lithic breccia unit, differing between carbonate-hosted sulphides and intraclastic and clastic matrix-hosted sulphides. Such variable isotope values are consistent with a biological origin, via bacterial sulphate reduction, for sulphides in the parautochthonous and autochthonous units; these minerals formed in the shallow subsurface and are probably related to the post impact hydrothermal system. The source of the sulphate is likely to have been seawater, penecontemporaneous to the impact, as inferred from the marginal marine paleogeography of the structure. In other eroded impact craters that show evidence for impact-induced hydrothermal circulation, indirect evidence for life may be sought isotopically within late-stage (≤120 °C) secondary sulphides and within the shocked and brecciated basement immediately beneath the transient crater floor.

  1. First analysis of the rotationally-resolved ν2 and 2ν2-ν2 bands of sulfur dioxide, 33S16O2

    NASA Astrophysics Data System (ADS)

    Blake, T. A.; Flaud, J.-M.; Lafferty, W. J.

    2017-03-01

    A Fourier transform spectrum of sulfur dioxide 33S16O2 has been recorded in the 18.3 μm spectral region at a resolution of 0.002 cm-1 using a Bruker IFS 125HR spectrometer leading to the observation of the ν2 and 2ν2-ν2 vibrational bands of the 33S16O2 molecule. The corresponding upper state ro-vibrational levels were fit using Watson-type Hamiltonians. In this way it was possible to reproduce the upper state ro-vibrational levels to within the experimental uncertainty; i.e., ∼0.20 × 10-3 cm-1. Very accurate rotational and centrifugal distortion constants were derived from the fit together with the following band centers: ν0 (ν2) = 515.659089(50) cm-1, ν0 (2ν2) = 1030.697723(20) cm-1.

  2. First analysis of the rotationally-resolved ν2 and 2ν2-ν2 bands of sulfur dioxide, 33S16O2

    DOE PAGES

    Blake, T. A.; Flaud, J. -M.; Lafferty, W. J.

    2017-01-03

    A Fourier transform spectrum of sulfur dioxide 33S16O2 has been recorded in the 18.3 μm spectral region at a resolution of 0.002 cm$-$1 using a Bruker IFS 125HR spectrometer leading to the observation of the ν2 and 2ν2-ν2 vibrational bands of the 33S16O2 molecule. The corresponding upper state ro-vibrational levels were fit using Watson-type Hamiltonians. In this way it was possible to reproduce the upper state ro-vibrational levels to within the experimental uncertainty; i.e., ~ 0.20 × 10$-$3 cm$-$1. Finally, very accurate rotational and centrifugal distortion constants were derived from the fit together with the following band centers: ν0 (ν2)more » = 515.659089(50) cm$-$1, ν0 (2ν2) = 1030.697723(20) cm$-$1.« less

  3. {sup 33}S hyperfine interactions in H{sub 2}S and SO{sub 2} and revision of the sulfur nuclear magnetic shielding scale

    SciTech Connect

    Helgaker, Trygve; Gauss, Jürgen; Cazzoli, Gabriele Puzzarini, Cristina

    2013-12-28

    Using the Lamb-dip technique, the hyperfine structure in the rotational spectra of H{sub 2}{sup 33}S and {sup 33}SO{sub 2} has been resolved and the corresponding parameters—that is, the sulfur quadrupole-coupling and spin–rotation tensors—were determined. The experimental parameters are in good agreement with results from high-level coupled-cluster calculations, provided that up to quadruple excitations are considered in the cluster operator, sufficiently large basis sets are used, and vibrational corrections are accounted for. The {sup 33}S spin-rotation tensor for H{sub 2}S has been used to establish a new sulfur nuclear magnetic shielding scale, combining the paramagnetic part of the shielding as obtained from the spin–rotation tensor with a calculated value for the diamagnetic part as well as computed vibrational and temperature corrections. The value of 716(5) ppm obtained in this way for the sulfur shielding of H{sub 2}S is in good agreement with results from high-accuracy quantum-chemical calculations but leads to a shielding scale that is about 28 ppm lower than the one suggested previously in the literature, based on the {sup 33}S spin-rotation constant of OCS.

  4. Differentiating atmospheric and mineral sources of sulfur during snowmelt using δ 34S, 35S activity, and δ 18O of sulfate and water as tracers

    NASA Astrophysics Data System (ADS)

    Shanley, J. B.; Mayer, B.; Mitchell, M. J.; Michel, R. L.; Bailey, S.; Kendall, C.

    2003-12-01

    The biogeochemical cycling of sulfur was studied during the 2000 snowmelt at Sleepers River Research Watershed in northeastern Vermont, USA using a combination of isotopic, chemical, and hydrometric measurements. The snowpack and 10 streams of varying size and land use were sampled for sulfate concentrations and isotopic analyses of 35S, δ 34S, and δ 18O of sulfate. Values of δ 18O of water were measured at one of the streams. Apportionment of atmospheric and mineral S sources based on δ 34S was possible at 7 of the 10 streams. Weathering of S-containing minerals was a major contributor to sulfate flux in streamwater, but atmospheric contributions exceeded 50% in several of the streams at peak snowmelt and averaged 41% overall. In contrast, δ 18Osulfate values of streamwater remained significantly lower than those of atmospheric sulfate throughout the melt period, indicating that atmospheric sulfate undergoes microbial redox reactions in the soil that replace the oxygen of atmospheric sulfate with isotopically lighter oxygen from soil water. Streamwater 35S activities were low relative to those of the snowpack; the youngest 35S-ages of the atmospheric S component in each of the 7 streams ranged from 184 to 320 days. Atmospheric S contributions to streamwater, as determined by δ 34S values, co-varied both with 35S activity and new water contributions as determined by δ 18Owater. However, the δ 18Osulfate and 35S ages clearly show that this new water carries very little of the atmospheric sulfate entering with the current snowmelt to the stream. Most incoming atmospheric sulfate first cycles through the organic soil S pool and ultimately reaches the stream as pedogenic sulfate.

  5. Organic Matter Sulfurization in the Cariaco Water Column Revealed by High-Sensitivity and Compound-Specific d34S Analyses.

    NASA Astrophysics Data System (ADS)

    Raven, M. R.; Sessions, A. L.; Adkins, J. F.; Thunell, R.

    2015-12-01

    Organic matter burial in marine sediments is a major process in the global carbon cycle, and enhanced organic matter burial is often associated with periods of global climatic and ecological change. Still, we have only a limited understanding of the processes that drive enhanced OM burial during oxygen-deficient conditions. Abiotic OM sulfurization has the potential to enhance the preservation of OM, but for this process to be significant it must compete with heterotrophic remineralization, most of which occurs before sinking particles reach the sea floor. We investigate the sources of sulfur to sinking particles in a modern marine basin using samples from the CARIACO fixed sediment trap time-series, applying recently developed methods for d34S analysis of small (≥20 nmol) sulfur pools and individual volatile organosulfur compounds. Relative to expectations for planktonic biomass, we find that sinking particles are both sulfur-rich and 34S-depleted. Higher apparent fluxes of 34S-depleted organic sulfur are associated with high OM export from the surface ocean, low terrestrial inputs, and high concentrations of both elemental S and the dominant non-polar organosulfur compound, C20 thiophene. We conclude that OM sulfurization is occurring in particles sinking through the Cariaco water column on timescales of days or less. Depending on the frequency of high OM export events, we estimate that this rapid sulfurization delivers roughly half of the total organic S present at 5 cm depth in underlying sediments. Accordingly, many OM-rich deposits in the geologic record may represent the products of water column sulfurization. This process provides a strong mechanistic feedback between oxygen deficiency and OM preservation.

  6. A compilation of information on the {sup 31}P(p,{alpha}){sup 28}Si reaction and properties of excited levels in the compound nucleus {sup 32}S

    SciTech Connect

    Miller, R.E.; Smith, D.L.

    1997-11-01

    This report documents a survey of the literature, and provides a compilation of data contained therein, for the {sup 31}P(p,{alpha}){sup 28}Si reaction. Attention is paid here to resonance states in the compound-nuclear system {sup 32}S formed by {sup 31}P + p, with emphasis on the alpha-particle decay channels, {sup 28}Si + {alpha} which populate specific levels in {sup 28}Si. The energy region near the proton separation energy for {sup 32}S is especially important in this context for applications in nuclear astrophysics. Properties of the excited states in {sup 28}Si are also considered. Summaries of all the located references are provided and numerical data contained in them are compiled in EXFOR format where applicable.

  7. Sub-barrier one- and two-neutron pickup measurements in {sup 32}S+{sup 93}Nb, {sup 98,100}Mo reactions at 180{degrees}

    SciTech Connect

    Roberts, R.B.; Gazes, S.B.; Mason, J.E.

    1993-04-01

    Excitation functions for sub-barrier one- and two-neutron pickup reactions were measured for E{sub lab}{le}106 MeV in {sup 32}S+{sup 93}Nb, {sup 98,100}Mo systems by detecting target-like recoils at 0{degrees} using a recoil mass spectrometer. Measured differential cross sections are compared to those predicted by the DWBA code PTOLEMY. The slopes of transfer probability versus distance of closest approach, are in good agreement with the slopes obtained from binding energies, indicating the absence of a {open_quotes}slope anomaly.{close_quotes} Angle-integrated transfer cross sections derived from measured 180{degrees} yields correlate with fusion enhancements in previously measured fusion yields for the {sup 32}S+{sup 98,100}Mo systems.

  8. Inelastic scattering of 65 MeV protons from /sup 12/C, /sup 24/Mg, /sup 28/Si, and /sup 32/S

    SciTech Connect

    Kato, S.; Okada, K.; Kondo, M.; Hosono, K.; Saito, T.; Matsuoka, N.; Hatanaka, K.; Noro, T.; Nagamachi, S.; Shimizu, H.; Ogino, K.; Kadota, Y.; Matsuki, S.; Wakai, M.

    1985-05-01

    Measurements of angular distributions of the cross sections and analyzing powers for the elastic and inelastic scatterings of 65 MeV polarized protons from /sup 12/C, /sup 24/Mg, /sup 28/Si, and /sup 32/S are reported. Coupled channels analyses of the scattering data are presented assuming the 0/sub 1//sup +/, 2/sub 1//sup +/, and 4/sub 1//sup +/ states to be members of the ground band, the 0/sub 2//sup +/ state to begin the

  9. Intermediate mass fragment emission in 32S + 51V, 109Ag, and 238U collisions at E = 31.6 MeV A

    NASA Astrophysics Data System (ADS)

    Machner, H.; Nolte, M.; Palarczyk, M.; Kutsarova, T.

    2015-11-01

    Intermediate mass fragment emission for reactions of 32S + 51V, 109Ag, and 238U has been studied. Double differential cross sections were analysed in terms of the generalised moving source model yielding charge distributions. Isotope ratios show strong fragment mass dependencies. The data were successfully reproduced by the coalescence model as well as by statistical multifragmentation model calculations. Quantum molecular dynamics model calculations were not so successful.

  10. Role of Barrier Modification and Inelastic Surface Excitations in Sub-Barrier Fusion of 16 32 S + 40 94 Zr Reaction

    NASA Astrophysics Data System (ADS)

    Gautam, Manjeet Singh; Rajni; Sharma, Manoj K.

    2016-04-01

    The fusion dynamics of 16 32 S + 40 94 Zr reaction at near and sub-barrier energies is investigated within the context of different theoretical approaches. The various theoretical models like one-dimensional Wong formula, ℓ-summed extended Wong formula, the energy-dependent Woods-Saxon potential model (EDWSP model), and coupled channel formulation have been used to address the impacts of nuclear structure degrees of freedom of the colliding pairs. The roles of different Skyrme forces along with Wong formalism are also tested in the analysis of the sub-barrier fusion dynamics of the 16 32 S + 40 94 Zr reaction. The influence of the low-lying surface vibrational states of the collision partners is investigated within the framework of coupled channel calculations performed by the code CCFULL. In the present work, it has been observed that the EDWSP model introduces barrier modification effects somewhat similar to those of the coupled channel approach, as well as those of using different Skyrme forces and hence it reasonably addresses the observed fusion data of 16 32 S + 40 94 Zr reaction in the close vicinity of the Coulomb barrier.

  11. The first data on mass-independent fractionation of sulfur isotopes in sulfides from rocks of the eastern part of the Fennoscandian Shield

    NASA Astrophysics Data System (ADS)

    Ignat'ev, A. V.; Khanchuk, A. I.; Vysotskii, S. V.; Velivetskaya, T. A.; Levitskii, V. I.; Terekhov, E. N.

    2016-08-01

    The first data on the multi-isotope composition of sulfur (32S, 33S, 34S) in samples from the Fennoscandian Shield were obtained by the laser local method. An anomalous concentration of the stable isotope 33S was registered in some samples. Δ33S ranges from-0.45 to +0.24‰, which indicates the mass-independent fractionation of S isotopes and provides evidence for the processes of primarily sedimentary accumulation of sulfides in the Archean oxygen-free atmosphere.

  12. The kinetics of catalytic incineration of C2H5SH and (CH3)2S2 over a Pt/Al2O3 catalyst.

    PubMed

    Chu, H; Lee, W T; Chiou, Y Y; Tseng, T K

    2001-05-01

    Catalytic incineration is one of the cost-effective technologies to solve the troublesome VOCs. However, some sulfur containing VOCs, such as ethyl mercaptan and dimethyl disulfide, may deactivate the Pt catalyst that is commonly used in the catalytic incineration process. The catalytic incineration of these compounds over a Pt/Al2O3 catalyst was carried out in a bench scale catalytic incinerator. Three kinetic models, such as power-rate law, Mars and Van Krevelen model, and Langmuir-Hinshelwood model were used to analyze the results. A differential reactor design was used for best fit of kinetic models in this study. The results show that the Langmuir-Hinshelwood model is feasible to describe the catalytic incineration of both C2H5SH and (CH3)2S2. This suggests that the chemical adsorption of O2 molecule is important in the process of catalytic incineration of C2H5SH and (CH3)2S2.

  13. The Fauna Of Two New Discovered Hydrothermal Fields At 5°S And 9°33'S On The Mid-Atlantic-Ridge

    NASA Astrophysics Data System (ADS)

    Stecher, J. E.

    2005-12-01

    Before April 2005 there was a zoogeographical puzzle to solve: Are there any hydrothermal vent communities south of the equator the Atlantic Ocean, and if so, what will be their characteristics? Are they similar with those of the northern Atlantic Ocean or will they differ? Before the cruise 169 of the British "Charles Darwin" research vessel started, no vent site was discovered on the southern Atlantic Ridge. Using an autonomous underwater vehicle from WHOI, the first hydrothermal active vent site was found at 5°S in April 2005. With the support by British and American colleagues(Chris German and Tim Shank) the scientific crew of Meteor cruise M64/1 sampled this site at 5° first with the ROV "Quest 4000" from Marum, University Bremen. But far in excess of this success one more vent site was discovered and investigated by the Meteor cruise M64/1: the Lilliput Field at 9°33S on the Mid-Atlantic-Ridge. Our first results indicate that the identified taxa of the hydrothermal fields at 5°S and 9°33S resemble the northern Logatchev community (Gebruk et al. 2000) in most elements. Remarkable is the missing of following typical hydrothermal taxa: Decapods of the families Alvinocaridae, like Chorocaris, and Galatheidae, echinoderms like Ophiuridae and Ventfishes of the family Zoarcidae. Obviously the Romanch Fracture Zone act only partly as a physical barrier between vent fauna assemblages of the North and South Atlantic Oceans (see Shank 2004). Gebruk, A.V., Chevaldonne, P., Shank, T., Lutz, R.A. & Vrijenhoek, R.C. (2000): Deep-sea hydrothermal vent communities of the Logatchev area (14°45'N, Mid-Atlantic Ridge): diverse biotopes and high biomass. J. Mar. Biol. Assoc. U. K. 80: 383-393. Shank, T. (2004): The evolutionary puzzle of seafloor life. - Oceanus Magazine Vol. 42, No.2 http://oceanusmag.whoi.edu/v42n2/shank.html.

  14. Chemical weathering and the role of sulfuric and nitric acids in carbonate weathering: Isotopes (13C, 15N, 34S, and 18O) and chemical constraints

    NASA Astrophysics Data System (ADS)

    Li, Cai; Ji, Hongbing

    2016-05-01

    Multiple isotopes (13C-DIC, 34S and 18O-SO42-, 15N and 18O-NO3-) and water chemistry were used to evaluate weathering rates and associated CO2 consumption by carbonic acid and strong acids (H2SO4 and HNO3) in a typical karst watershed (Wujiang River, Southwest China). The dual sulfate isotopes indicate that sulfate is mainly derived from sulfide oxidation in coal stratum and sulfide-containing minerals, and dual nitrate isotopes indicate that nitrate is mainly derived from soil N and nitrification. The correlation between isotopic compositions and water chemistry suggests that sulfuric and nitric acids, in addition to carbonic acid, are involved in carbonate weathering. The silicate and carbonate weathering rates are 7.2 t km-2 yr-1 and 76 t km-2 yr-1, respectively. In comparison with carbonate weathering rates (43 t km-2 yr-1) by carbonic acid alone, the subsequent increase in rates indicates significant enhancement of weathering when combined with sulfuric and nitric acids. Therefore, the role of sulfuric and nitric acids in the rock weathering should be considered in the global carbon cycle.

  15. The effect of acid rain and altitude on concentration, δ34S, and δ18O of sulfate in the water from Sudety Mountains, Poland

    USGS Publications Warehouse

    Szynkiewicz, Anna; Modelska, Magdalena; Jedrysek, Mariusz Orion; Mastalerz, Maria

    2008-01-01

    Sulfate content, δ34S(SO42−), δ18O(SO42−), and δ18O(H2O) values revealed a remarkable dependence on the altitude. The calculated altitude effects for five season averages of these parameters were − 1.00 mg/l/100 m, − 0.18‰/100 m, − 0.27‰/100 m, and − 0.17‰/100 m, respectively. This dependence on the altitude resulted mainly from the mixing of sulfates of different origins such as anthropogenic sulfate, sulfate produced in the soil within the weathered zone of the massif, and that one from the tree canopy. The oxygen isotope mass balance indicates that, in the study area, about one third of the sulfate delivered to the surface and groundwater by modern precipitation comes from anthropogenic pollution. Further interaction of meteoric water within the weathered rocks causes a continuous decrease of δ18O(SO42−) values resulting from biological transformation of the sulfate due to plant vegetation and decomposition of organic matter.

  16. Investigation of Shell Effects in the Fusion-Fission Process in the Reaction 34S + 186W Near the Interaction Barrier

    NASA Astrophysics Data System (ADS)

    Harca, I. M.; Kozulin, E. M.; Bogachev, A.; Dmitriev, S. N.; Itkis, J.; Knyazheva, G.; Loktev, T.; Novikov, K.; Vardaci, E.; Azaiez, F.; Gottardo, A.; Matea, I.; Verney, D.; Chubarian, G.; Hanappe, F.; Piot, J.; Schmitt, C.; Trzaska, W. H.

    2015-06-01

    The reaction 34S + 186W at Elab = 160 MeV was investigated with the aim of diving into the features of the fusion-fission process. Gamma rays coincident with binary reaction fragments were measured using the high efficiency gamma-ray spectrometer ORGAM at the TANDEM Accelerator facility of I.P.N., Orsay, and the time-of-flight spectrometer for fission fragments registration CORSET of the Flerov Laboratory of Nuclear Reactions (FLNR), Dubna. Evidence of symmetric and asymmetric fission modes were observed in the mass and TKE distributions, occurring due to shell effects in the fragments. The coupling of the ORGAM and CORSET setups enables the FF-γ coincident measurement which offers the opportunity to extract the isotopic distribution of the fragments of different masses formed in the aforementioned reaction and to find the exact neutron multiplicity, the average spin and average angular momenta. Details regarding the experimental setup, methods of processing the acquisitioned data and preliminary results are presented.

  17. Elemental formula annotation of polar and lipophilic metabolites using (13) C, (15) N and (34) S isotope labelling, in combination with high-resolution mass spectrometry.

    PubMed

    Giavalisco, Patrick; Li, Yan; Matthes, Annemarie; Eckhardt, Aenne; Hubberten, Hans-Michael; Hesse, Holger; Segu, Shruthi; Hummel, Jan; Köhl, Karin; Willmitzer, Lothar

    2011-10-01

    The unbiased and comprehensive analysis of metabolites in any organism presents a major challenge if proper peak annotation and unambiguous assignment of the biological origin of the peaks are required. Here we provide a comprehensive multi-isotope labelling-based strategy using fully labelled (13) C, (15) N and (34) S plant tissues, in combination with a fractionated metabolite extraction protocol. The extraction procedure allows for the simultaneous extraction of polar, semi-polar and hydrophobic metabolites, as well as for the extraction of proteins and starch. After labelling and extraction, the metabolites and lipids were analysed using a high-resolution mass spectrometer providing accurate MS and all-ion fragmentation data, providing an unambiguous readout for every detectable isotope-labelled peak. The isotope labelling assisted peak annotation process employed can be applied in either an automated database-dependent or a database-independent analysis of the plant polar metabolome and lipidome. As a proof of concept, the developed methods and technologies were applied and validated using Arabidopsis thaliana leaf and root extracts. Along with a large repository of assigned elemental compositions, which is provided, we show, using selected examples, the accuracy and reliability of the developed workflow.

  18. Tracking natal dispersal in a coastal population of a migratory songbird using feather stable isotope (δ2H, δ34S) tracers.

    PubMed

    Haché, Samuel; Hobson, Keith A; Bayne, Erin M; Van Wilgenburg, Steven L; Villard, Marc-André

    2014-01-01

    Adult birds tend to show high fidelity to their breeding territory or disperse over relatively short distances. Gene flow among avian populations is thus expected to occur primarily through natal dispersal. Although natal dispersal is a critical demographic process reflecting the area over which population dynamics take place, low recapture rates of birds breeding for the first time have limited our ability to reliably estimate dispersal rates and distances. Stable isotope approaches can elucidate origins of unmarked birds and so we generated year- and age-specific δ2H and δ34S feather isoscapes (ca. 180 000 km2) of coastal-breeding Ovenbirds (Seiurus aurocapilla) and used bivariate probability density functions to assign the likely natal areas of 35 males recruited as first-year breeders into a population located in northwestern New Brunswick, Canada. Most individuals (80-94% depending on the magnitude of an age correction factor used; i.e. 28-33 out of 35) were classified as residents (i.e. fledged within our study area) and estimated minimum dispersal distances of immigrants were between 40 and 240 km. Even when considering maximum dispersal distances, the likely origin of most first-year breeders was<200 km from our study area. Our method identified recruitment into our population from large geographic areas with relatively few samples whereas previous mark-recapture based methods have required orders of magnitude more individuals to describe dispersal at such geographic scales. Natal dispersal movements revealed here suggest the spatial scale over which many population processes are taking place and we suggest that conservation plans aiming to maintain populations of Ovenbirds and ecologically-similar species should consider management units within 100 or at most 200 km of target breeding populations.

  19. Rare earth element and stable sulphur (δ 34S) isotope study of baryte-copper mineralization in Gulani area, Upper Benue Trough, NE Nigeria

    NASA Astrophysics Data System (ADS)

    El-Nafaty, Jalo Muhammad

    2015-06-01

    The geology of Gulani area comprises of inliers of diorite and granites of the Older Granite suite of the Pan-African (600 ± 150 Ma) age within Cretaceous sediments of the Bima, Yolde and Pindiga Formations and the Tertiary/Quaternary basalts of the Biu Plateau. Epigenetic baryte-copper mineralization occurs as baryte veins within the Bima and Yolde sandstones and fracture-filling malachite in Pan-African granites. Unaltered (distal), hydrothermally altered (proximal) granites and sandstones and vein materials (mineral separates of baryte and chalcopyrite/malachite mineralized rocks) were analysed for rare earth elements (REE) and stable sulphur isotopes. The REE patterns of the unaltered rocks (both granites and sandstones) indicate background values before mineralization, depicted by enriched LREE, depleted HREE and weak negative Eu anomalies typical of Pan-African (calc-alkaline) granites and sandstones derived from them. On the other hand, the hydrothermally altered and mineralized rocks and mineral separates show a distinct baryte and copper mineralization sub-systems characterized by similar high LREE and corresponding low HREE abundances. However, the negative Eu anomalies of the copper sub-system hosted by granites are typical of Pan-African (calc-alkaline) granites. The sandstone host rocks of the baryte sub-system are marked by positive Eu anomalies interpreted as reflecting the injection and subsequent deposition of the baryte-bearing hydrothermal solutions under oxidizing conditions. The baryte mineral separates show δ (34S) isotope range of 12.3-13.1‰ (CDT) indicating sulphur from sedimentary formation sources. This ruled out magmatic source of the sulphur from the nearby Tertiary/Quaternary volcanic rocks of the Biu Plateau as well as ocean water. However, the stable sulphur isotopic determination of the sulphides (chalcopyrite/malachite mineral separates and mineralized rocks) did not yield peaks and therefore no inferences drawn in this regard.

  20. Nuclear orientation in the reaction {sup 34}S+{sup 238}U and synthesis of the new isotope {sup 268}Hs

    SciTech Connect

    Nishio, K.; Ikezoe, H.; Mitsuoka, S.; Nagame, Y.; Nishinaka, I.; Hofmann, S.; Hessberger, F. P.; Ackermann, D.; Duellmann, Ch. E.; Heinz, S.; Heredia, J. A.; Khuyagbaatar, J.; Kindler, B.; Kojouharov, I.; Lommel, B.; Mann, R.; Schaedel, M.; Antalic, S.; Saro, S.; Aritomo, Y.

    2010-08-15

    The synthesis of isotopes of the element hassium was studied using the reaction {sup 34}S+{sup 238}U{yields}{sup 272}Hs{sup *}. At a kinetic energy of 163.0 MeV in the center-of-mass system we observed one {alpha}-decay chain starting at the isotope {sup 267}Hs. The cross section was 1.8{sub -1.5}{sup +4.2} pb. At 152.0 MeV one decay of the new isotope {sup 268}Hs was observed. It decays with a half-life of 0.38{sub -0.17}{sup +1.8} s by 9479{+-}16 keV {alpha}-particle emission. Spontaneous fission of the daughter nucleus {sup 264}Sg was confirmed. The measured cross section was 0.54{sub -0.45}{sup +1.3} pb. In-beam measurements of fission-fragment mass distributions were performed to obtain information on the fusion probability at various orientations of the deformed target nucleus. The distributions changed from symmetry to asymmetry when the beam energy was changed from above-barrier to sub-barrier values, indicating orientation effects on fusion and/or quasifission. It was found that the distribution of symmetric mass fragments originates not only from fusion-fission, but has a strong component from quasifission. The result was supported by a calculation based on a dynamical description using the Langevin equation, in which the mass distributions for fusion-fission and quasifission fragments were separately determined.

  1. Tracking Natal Dispersal in a Coastal Population of a Migratory Songbird Using Feather Stable Isotope (δ2H, δ34S) Tracers

    PubMed Central

    Haché, Samuel; Hobson, Keith A.; Bayne, Erin M.; Van Wilgenburg, Steven L.; Villard, Marc-André

    2014-01-01

    Adult birds tend to show high fidelity to their breeding territory or disperse over relatively short distances. Gene flow among avian populations is thus expected to occur primarily through natal dispersal. Although natal dispersal is a critical demographic process reflecting the area over which population dynamics take place, low recapture rates of birds breeding for the first time have limited our ability to reliably estimate dispersal rates and distances. Stable isotope approaches can elucidate origins of unmarked birds and so we generated year- and age-specific δ2H and δ34S feather isoscapes (ca. 180 000 km2) of coastal-breeding Ovenbirds (Seiurus aurocapilla) and used bivariate probability density functions to assign the likely natal areas of 35 males recruited as first-year breeders into a population located in northwestern New Brunswick, Canada. Most individuals (80–94% depending on the magnitude of an age correction factor used; i.e. 28–33 out of 35) were classified as residents (i.e. fledged within our study area) and estimated minimum dispersal distances of immigrants were between 40 and 240 km. Even when considering maximum dispersal distances, the likely origin of most first-year breeders was<200 km from our study area. Our method identified recruitment into our population from large geographic areas with relatively few samples whereas previous mark-recapture based methods have required orders of magnitude more individuals to describe dispersal at such geographic scales. Natal dispersal movements revealed here suggest the spatial scale over which many population processes are taking place and we suggest that conservation plans aiming to maintain populations of Ovenbirds and ecologically-similar species should consider management units within 100 or at most 200 km of target breeding populations. PMID:24740314

  2. Paired δ34S data from carbonate-associated sulfate and chromium-reducible sulfur across the traditional Lower-Middle Cambrian boundary of W-Gondwana

    NASA Astrophysics Data System (ADS)

    Wotte, Thomas; Strauss, Harald; Fugmann, Artur; Garbe-Schönberg, Dieter

    2012-05-01

    In this study, we present the first high-resolution data from coupled δ34S analyses of carbonate-associated sulfate (CAS) and chromium-reducible sulfur (CRS) from three Lower-Middle Cambrian sections in western Gondwana. CAS and CRS were extracted and analyzed from marine dolostone, limestone, and nodular limestone from Spanish and French successions. In parallel, carbonate samples were also analyzed for δ13Ccarb, δ18Ocarb, and major/trace element concentrations (Ca, Fe, Mg, Mn, Sr). δ34SCAS values vary between 17.6‰ and 33.2‰, with a maximum CAS concentration of ca. 900 ppm. δ34SCRS data show a similar broad range between -5.1‰ and 29.7‰, with maximal CRS contents up to ca. 3700 ppm. Notably, there is little stratigraphic variation in the δ34SCAS data in each of the sections confounding inter-basinal chemostratigraphic correlations. Nonetheless, the absolute differences in δ34SCAS between sections as well as variations in CAS and CRS concentrations are attributed to paleoenvironmental differences between proximal and distal parts of the carbonate ramp, as well as effects of subaerial exposure and riverine input. Thus, the generated δ34SCAS data deliver not only valuable paleoecological and paleoenvironmental information, they also illustrate a heterogeneity in the seawater sulfate sulfur isotopic composition of the western Gondwanan ocean. Consequently, the lack of correlation between our Gondwanan δ34SCAS data and time equivalent sections of Laurentia and Siberia is probably not only caused by the absence of an internationally accepted biostratigraphic correlation, but rather supports the view that sulfate was non-conservative anion in seawater during the Cambrian Period.

  3. Stable Isotope (δ13C, δ15N, δ34S) Analysis and Satellite Telemetry Depict the Complexity of Gray Wolf (Canis lupus) Diets in Southwest Alaska

    NASA Astrophysics Data System (ADS)

    Stanek, A.; Watts, D. E.; Cohn, B. R.; Spencer, P.; Mangipane, B.; Welker, J. M.

    2010-12-01

    Throughout Alaska, gray wolves (Canis lupus) are a top predator of large ungulates. While they primarily rely on ungulates such as moose (Alces alces) and caribou (Rangifer tarandus) as food, they are opportunistic and use alternative resources. The variation and supplemental protein sources in wolf diet has not been studied extensively on live animals currently using the landscape. With large seasonal influxes of Pacific salmon (Oncorhynchus sp.) into Alaska, terrestrial carnivore use of marine species is of particular interest. Using stable isotope (δ13C, δ15N, δ34S) analysis of wolf guard hair and blood, this study aims to determine the proportion of marine derived nutrients (MDN) in the diet of wolf packs within and surrounding Lake Clark National Park and Preserve and Alaska Peninsula and Becharof National Wildlife Refuges in Southwest Alaska. Satellite telemetry from the animals sampled facilitates quantification of landscape use patterns in correspondence with isotopic traits. Wolf pack territories within and surrounding the Lake Clark region appear to vary in spatial extent and in availability of MDN, such as salmon. Initial analysis shows that two packs with smaller home ranges, centrally located around areas with greater salmon availability, have enriched δ15N values compared to packs that have larger home ranges not centralized around salmon spawning waters. This pattern of isotopic enrichment is found in red blood cells, blood serum and hair, representing diets over different time scales. The enrichment in both blood and hair indicates a sustained use of MDN over the previous six to nine months. In the Lake Clark region, simple mixing model estimates suggest that up to 30% of wolf pack diets may be from marine sources. In contrast, packs with larger home ranges and less access to salmon have stable isotope values representative of a terrestrial diet.

  4. Protein Distribution and d34S Variation Within Microbially Formed Metal-Sulfide Colloids Provide Clues to the Mechanism and Kinetics of Extracellular Biomineralization

    NASA Astrophysics Data System (ADS)

    Moreau, J. W.; Weber, P. K.; Martin, M. C.; Webb, R. I.; Hutcheon, I. D.; Banfield, J. F.

    2005-12-01

    Micron-scale spheroidal aggregates of 1-5 nanometer-diameter sphalerite and wurtzite particles form as the result of the activity of sulfate-reducing bacteria (Labrenz et al. 2000, Moreau et al. 2004). Because these particles can also sequester contaminant metal(loid)s such as Pb2+, Cd2+, As3+ and Hg2+, the process provides a model for the study of phenomena that occur during in situ environmental bioremediation. Our analyses have focused on biofilms growing on decaying wood in neutralized acid-mine drainage in subsurface regions of the flooded Piquette Mine near Tennyson, WI. The system experiences nearly constant annual temperatures of 8°C. Spectroscopic and electron diffraction methods revealed that the biogenic sulfides are virtually homogenous in composition (nearly pure ZnS), but contain both (cubic) sphalerite and metastable (hexagonal) wurtzite that reflect size-dependent phase stabilities. In order to explore the kinetics of sulfate reduction and metal sequestration, and to identify forces driving particle aggregation (thus, limiting their mobility in the subsurface), we have isotopically and biochemically characterized ultramicrotomed ZnS aggregates in situ using secondary ion mass spectrometry (nanoSIMS) and synchrotron Fourier transform infra-red spectroscopy (SR-FTIR). Initial nanoSIMS results showed that the spheroidal ZnS aggregates contain fine-scale variations in δ34S and significant organic nitrogen concentrations. SR-FTIR data support the presence of amide I and II absorption features indicative of the presence of polypeptides localized within aggregates. Efforts to isolate and identify candidate proteins are currently under way. We propose that isotopic heterogeneities may reflect open-system variations in the composition of local source sulfate (including via biologically-mediated reoxidation of biogenic sulfide), and/or variation in bacterial sulfate reduction rate over the growth cycle(s) of sulfate-reducers. Furthermore, we suggest that

  5. Biogeochemical Indicators in High- and Low-Arctic Marine and Terrestrial Avian Community Changes: Comparative Isotopic (13C, 15N, and 34S) Studies in Alaska and Greenland

    NASA Astrophysics Data System (ADS)

    Causey, D.; Bargmann, N. A.; Burnham, K. K.; Burnham, J. L.; Padula, V. M.; Johnson, J. A.; Welker, J. M.

    2011-12-01

    Understanding the complex dynamics of environmental change in northern latitudes is of paramount importance today, given documented rapid shifts in sea ice, plant phenology, temperatures, deglaciation, and habitat fidelity. This knowledge is particularly critical for Arctic avian communities, which are integral components by which biological teleconnections are maintained between the mid and northern latitudes. Furthermore, Arctic birds are fundamental to Native subsistence lifestyles and a focus for conservation activities. Avian communities of marine and terrestrial Arctic environments represent a broad spectrum of trophic levels, from herbivores (eg., geese Chen spp.), planktivores (eg., auklets Aethia spp.), and insectivores (eg., passerines: Wheatears Oenanthe spp., Longspurs Calcarius spp.), to predators of marine invertebrates (eg., eiders Somateria spp.), nearshore and offshore fish (eg., cormorants Phalacrocorax spp, puffins Fratercula spp.), even other bird species (eg., gulls Larus spp., falcons Peregrinus spp.). This diversity of trophic interconnections is an integral factor in the dynamics of Arctic ecosystem ecology, and they are key indicators for the strength and trajectories of change. We are especially interested in their feeding ecology, using stable isotope-diet relations to examine historical diets and to predict future feeding ecology by this range of species. Since 2009, we have been studying the foodweb ecology using stable isotopes (δ13C, δ15N, δ34S) of contemporaneous coastal and marine bird communities in High Arctic (Northwest Greenland) and Low Arctic (western Aleutian Islands, AK). We are quantifying the isotopic values of blood, organ tissues, and feathers, and have carried out comparisons between native and lipid-extracted samples. Although geographically distant, these communities comprise similar taxonomic and ecological congeners, including several species common to both (eg., Common Eider, Black-legged Kittiwake, Northern

  6. Processes affecting δ34S and δ18O values of dissolved sulfate in alluvium along the Canadian River, central Oklahoma, USA

    USGS Publications Warehouse

    Tuttle, Michele L.W.; Breit, George N.; Cozzarelli, Isabelle M.

    2009-01-01

    The δ34S and δ18O values for dissolved sulfate in groundwater are commonly used in aquifer studies to identify sulfate reservoirs and describe biogeochemical processes. The utility of these data, however, often is compromised by mixing of sulfate sources within reservoirs and isotope fractionation during sulfur redox cycling. Our study shows that, after all potential sulfate sources are identified and isotopically characterized, the δ34SSO4 and δ18OSO4 values differentiate processes such as sulfate-source mixing, sulfide oxidation, barite dissolution, and organosulfur decomposition. During bacterial reduction of sulfate, the values reflect kinetic sulfur isotope fractionation and exchange of oxygen isotopes between sulfate and water. Detailed analysis of the chemistry (Cl and SO4 concentrations) and isotopic composition (δ2HH2Oand δ18OH2O) of groundwater in an alluvial aquifer in Central Oklahoma, USA allowed the identification of five distinct end members that supply water to the aquifer (regional groundwater flowing into the study area, river water, leachate from a closed landfill that operated within the site, rain, and surface runoff). The δ34SSO4 and δ18OSO4 values in each end member differentiated three sources of sulfate: sulfate dissolved from Early to Late Permian rocks within the drainage basin (δ34SSO4 = 8–12‰ and δ18OSO4 = 10‰), iron sulfides oxidized by molecular oxygen during low water-table levels (δ34SSO4 = − 16‰ and δ18OSO4 = 10‰), and organosulfur compounds (predominately ester sulfates) from decomposition of vegetation on the surface and from landfill trash buried in the alluvium (δ34SSO4 = 8‰ and δ18OSO4 = 6‰). During bacterial reduction of these sulfate sources, similar isotope fractionation processes are recorded in the parallel trends of increasing δ34SSO4 and δ18OSO4 values. When extensive reduction occurs, the kinetic sulfur isotope fractionation (estimated by εH2S–SO4 = − 23

  7. Sulfur isotope homogeneity of lunar mare basalts

    NASA Astrophysics Data System (ADS)

    Wing, Boswell A.; Farquhar, James

    2015-12-01

    We present a new set of high precision measurements of relative 33S/32S, 34S/32S, and 36S/32S values in lunar mare basalts. The measurements are referenced to the Vienna-Canyon Diablo Troilite (V-CDT) scale, on which the international reference material, IAEA-S-1, is characterized by δ33S = -0.061‰, δ34S ≡ -0.3‰ and δ36S = -1.27‰. The present dataset confirms that lunar mare basalts are characterized by a remarkable degree of sulfur isotopic homogeneity, with most new and published SF6-based sulfur isotope measurements consistent with a single mass-dependent mean isotopic composition of δ34S = 0.58 ± 0.05‰, Δ33S = 0.008 ± 0.006‰, and Δ36S = 0.2 ± 0.2‰, relative to V-CDT, where the uncertainties are quoted as 99% confidence intervals on the mean. This homogeneity allows identification of a single sample (12022, 281) with an apparent 33S enrichment, possibly reflecting cosmic-ray-induced spallation reactions. It also reveals that some mare basalts have slightly lower δ34S values than the population mean, which is consistent with sulfur loss from a reduced basaltic melt prior to eruption at the lunar surface. Both the sulfur isotope homogeneity of the lunar mare basalts and the predicted sensitivity of sulfur isotopes to vaporization-driven fractionation suggest that less than ≈1-10% of lunar sulfur was lost after a potential moon-forming impact event.

  8. Application of 34S analysis for elucidating terrestrial, marine and freshwater ecosystems: Evidence of animal movement/husbandry practices in an early Viking community around Lake Mývatn, Iceland

    NASA Astrophysics Data System (ADS)

    Sayle, Kerry L.; Cook, Gordon T.; Ascough, Philippa L.; Hastie, Helen R.; Einarsson, Árni; McGovern, Thomas H.; Hicks, Megan T.; Edwald, Ágústa; Friðriksson, Adolf

    2013-11-01

    Carbon and nitrogen stable isotope ratios (δ13C and δ15N) have been used widely in archaeology to investigate palaeodiet. Sulphur stable isotope ratios (δ34S) have shown great promise in this regard but the potential of this technique within archaeological science has yet to be fully explored. Here we report δ34S, δ13C and δ15N values for 129 samples of animal bone collagen from Skútustaðir, an early Viking age (landnám) settlement in north-east Iceland. This dataset represents the most comprehensive study to date of its kind on archaeological material and the results show a clear offset in δ34S values between animals deriving their dietary resources from terrestrial (mean = +5.6 ± 2.8‰), freshwater (mean = -2.7 ± 1.4‰) or marine (mean = +15.9 ± 1.5‰) reservoirs (with the three food groups being significantly different at 2σ). This offset allows reconstruction of the dietary history of domesticated herbivores and demonstrates differences in husbandry practices and animal movement/trade, which would be otherwise impossible using only δ13C and δ15N values. For example, several terrestrial herbivores displayed enriched bone collagen δ34S values compared to the geology of the Lake Mývatn region, indicating they may have been affected by sea-spray whilst being pastured closer to the coast, before being traded inland. Additionally, the combination of heavy δ15N values coupled with light δ34S values within pig bone collagen suggests that these omnivores were consuming freshwater fish as a significant portion of their diet. Arctic foxes were also found to be consuming large quantities of freshwater resources and radiocarbon dating of both the pigs and foxes confirmed previous studies showing that a large freshwater radiocarbon (14C) reservoir effect exists within the lake. Overall, these stable isotope and 14C data have important implications for obtaining a fuller reconstruction of the diets of the early Viking settlers in Iceland, and may allow

  9. The overexpression of the SAPB of Bacillus pumilus CBS and mutated sapB-L31I/T33S/N99Y alkaline proteases in Bacillus subtilis DB430: new attractive properties for the mutant enzyme.

    PubMed

    Jaouadi, Nadia Zaraî; Jaouadi, Bassem; Aghajari, Nushin; Bejar, Samir

    2012-02-01

    The sapB gene encoding for Bacillus pumilus CBS protease (SAPB) and the triple mutated sapB-L31I/T33S/N99Y gene were cloned and overexpressed in the protease-deficient Bacillus subtilis DB430 using an Escherichia coli-Bacillus shuttle vector pBSMuL2. The 34,625.13 and 34,675.11-Da enzymes were purified from the culture supernatant of B. subtilis expressing the wild-type and mutated genes, respectively. The purified proteases showed the same N-terminal sequences and biochemical properties of those expressed in E. coli. Further investigations demonstrated that, compared to wild-type and other proteases, SAPB-L31I/T33S/N99Y had the highest catalytic efficiency and the best degree of hydrolysis. The mutant enzyme was also noted to exhibit a number of newly explored properties that are highly valued in the marketplace, namely considerable stability to detergents, higher resistance towards organic solvents, and potent dehairing ability. Overall, the findings indicated that SAPB-L31I/T33S/N99Y is a promising candidate for future use in a wide range of industrial and commercial applications.

  10. Insights into the unusual barrierless reaction between two closed shell molecules, (CH3)2S + F2, and its H2S + F2 analogue: role of recoupled pair bonding.

    PubMed

    Leiding, Jeff; Woon, David E; Dunning, Thom H

    2012-05-31

    Early flowtube studies showed that (CH(3))(2)S (DMS) reacted very rapidly with F(2); hydrogen sulfide (H(2)S), however, did not. Recent crossed molecular beam studies found no barrier to the reaction between DMS and F(2) to form CH(2)S(F)CH(3) + HF. At higher collision energies, a second product channel yielding (CH(3))(2)S-F + F was identified. Both reaction channels proceed through an intermediate with an unusual (CH(3))(2)S-F-F bond structure. Curiously, these experimental studies have found no evidence of direct F(2) addition to DMS, resulting in (CH(3))(2)SF(2), despite the fact that the isomer in which both fluorines occupy axial positions is the lowest energy product. We have characterized both reactions, H(2)S + F(2) and DMS + F(2), with high-level ab initio and generalized valence bond calculations. We found that recoupled pair bonding accounts for the structure and stability of the intermediates present in both reactions. Further, all sulfur products possess recoupled pair bonds with CH(2)S(F)CH(3) having an unusual recoupled pair bond dyad involving π bonding. In addition to explaining why DMS reacts readily with F(2) while H(2)S does not, we have studied the pathways for direct F(2) addition to both sulfide species and found that (for (CH(3))(2)S + F(2)) the CH(2)S(F)CH(3) + HF channel dominates the potential energy surface, effectively blocking access to F(2) addition. In the H(2)S + F(2) system, the energy of the transition state for formation of H(2)SF(2) lies very close to the H(2)SF + F asymptote, making the potential pathway a roaming atom mechanism.

  11. Human-Induced Long-Term Shifts in Gull Diet from Marine to Terrestrial Sources in North America's Coastal Pacific: More Evidence from More Isotopes (δ2H, δ34S).

    PubMed

    Hobson, Keith A; Blight, Louise K; Arcese, Peter

    2015-09-15

    Measurements of naturally occurring stable isotopes in tissues of seabirds and their prey are a powerful tool for investigating long-term changes in marine foodwebs. Recent isotopic (δ(15)N, δ(13)C) evidence from feathers of Glaucous-winged Gulls (Larus glaucescens) has shown that over the last 150 years, this species shifted from a midtrophic marine diet to one including lower trophic marine prey and/or more terrestrial or freshwater foods. However, long-term isotopic patterns of δ(15)N and δ(13)C cannot distinguish between the relative importance of lower trophic-level marine foods and terrestrial sources. We examined 48 feather stable-hydrogen (δ(2)H) and -sulfur (δ(34)S) isotope values from this same 150-year feather set and found additional isotopic evidence supporting the hypothesis that gulls shifted to terrestrial and/or freshwater prey. Mean feather δ(2)H and δ(34)S values (± SD) declined from the earliest period (1860-1915; n = 12) from -2.5 ± 21.4 ‰ and 18.9 ± 2.7 ‰, respectively, to -35.5 ± 15.5 ‰ and 14.8 ± 2.4 ‰, respectively, for the period 1980-2009 (n = 12). We estimated a shift of ∼ 30% increase in dependence on terrestrial/freshwater sources. These results are consistent with the hypothesis that gulls increased terrestrial food inputs in response to declining forage fish availability.

  12. Influence of different organic fertilizers on quality parameters and the delta(15)N, delta(13)C, delta(2)H, delta(34)S, and delta(18)O values of orange fruit (Citrus sinensis L. Osbeck).

    PubMed

    Rapisarda, Paolo; Camin, Federica; Fabroni, Simona; Perini, Matteo; Torrisi, Biagio; Intrigliolo, Francesco

    2010-03-24

    To investigate the influence of different types of fertilizers on quality parameters, N-containing compounds, and the delta(15)N, delta(13)C, delta(2)H, delta (34)S, and delta(18)O values of citrus fruit, a study was performed on the orange fruit cv. 'Valencia late' (Citrus sinensis L. Osbeck), which was harvested in four plots (three organic and one conventional) located on the same farm. The results demonstrated that different types of organic fertilizers containing the same amount of nitrogen did not effect important changes in orange fruit quality parameters. The levels of total N and N-containing compounds such as synephrine in fruit juice were not statistically different among the different treatments. The delta(15)N values of orange fruit grown under fertilizer derived from animal origin as well as from vegetable compost were statistically higher than those grown with mineral fertilizer. Therefore, delta(15)N values can be used as an indicator of citrus fertilization management (organic or conventional), because even when applied organic fertilizers are of different origins, the natural abundance of (15)N in organic citrus fruit remains higher than in conventional ones. These treatments also did not effect differences in the delta(13)C, delta(2)H, delta(34)S, and delta(18)O values of fruit.

  13. Defining fish community structure in Lake Winnipeg using stable isotopes (δ(13)C, δ(15)N, δ(34)S): implications for monitoring ecological responses and trophodynamics of mercury & other trace elements.

    PubMed

    Ofukany, Amy F A; Wassenaar, Leonard I; Bond, Alexander L; Hobson, Keith A

    2014-11-01

    The ecological integrity of freshwater lakes is influenced by atmospheric and riverine deposition of contaminants, shoreline development, eutrophication, and the introduction of non-native species. Changes to the trophic structure of Lake Winnipeg, Canada, and consequently, the concentrations of contaminants and trace elements measured in tissues of native fishes, are likely attributed to agricultural runoff from the 977,800 km(2) watershed and the arrival of non-native zooplankters and fishes. We measured δ(13)C, δ(15)N, and δ(34)S along with concentrations of 15 trace elements in 17 native fishes from the north and south basins of Lake Winnipeg in 2009 and 2010. After adjusting for differences in isotopic baseline values between the two basins, fishes in the south basin had consistently higher δ(13)C and δ(34)S, and lower δ(15)N. We found little evidence of biomagnification of trace elements at the community level, but walleye (Sander vitreus) and freshwater drum (Aplodinotus grunniens) had higher mercury and selenium concentrations with increased trophic position, coincident with increased piscivory. There was evidence of growth dilution of cobalt, copper, manganese, molybdenum, thallium, and vanadium, and bioaccumulation of mercury, which could be explained by increases in algal (and consequently, lake and fish) productivity. We conclude that the north and south basins of Lake Winnipeg represent very different communities with different trophic structures and trace element concentrations.

  14. Sulphur isotopes and the search for life: strategies for identifying sulphur metabolisms in the rock record and beyond.

    PubMed

    Johnston, D T; Farquhar, J; Habicht, K S; Canfield, D E

    2008-12-01

    The search for life can only be as successful as our understanding of the tools we use to search for it. Here we present new sulphur isotope data (32S, 33S, 34S, 36S) from a variety of modern marine environments and use these observations, along with previously published work, to contribute to this search. Specifically, we use these new data to gain a sense of life's influences on the sulphur isotope record and to distinguish these biologically influenced signatures from their non-biological counterparts. This treatment extends sulphur isotope analyses beyond traditional (34S/32S) measures and employs trace isotope relationships (33S/32S, 36S/32S), as the inclusion of these isotopes provides unique information about biology and its role in the sulphur cycle through time. In the current study we compare and contrast isotope effects produced by sulphur-utilizing microorganisms (experimental), modern and ancient sedimentary records (observational) and non-biological reactions (theoretical). With our collective search for life now extending to neighbouring planets, we present this study as a first step towards more fully understanding the capability of the sulphur isotope system as a viable tool for life detection, both on Earth and beyond.

  15. Multiple S-isotopic evidence for episodic shoaling of anoxic water during Late Permian mass extinction.

    PubMed

    Shen, Yanan; Farquhar, James; Zhang, Hua; Masterson, Andrew; Zhang, Tonggang; Wing, Boswell A

    2011-02-22

    Global fossil data show that profound biodiversity loss preceded the final catastrophe that killed nearly 90% marine species on a global scale at the end of the Permian. Many hypotheses have been proposed to explain this extinction and yet still remain greatly debated. Here, we report analyses of all four sulphur isotopes ((32)S, (33)S, (34)S and (36)S) for pyrites in sedimentary rocks from the Meishan section in South China. We observe a sulphur isotope signal (negative δ(34)S with negative Δ(33)S) that may have resulted from limitation of sulphate supply, which may be linked to a near shutdown of bioturbation during shoaling of anoxic water. These results indicate that episodic shoaling of anoxic water may have contributed to the profound biodiversity crisis before the final catastrophe. Our data suggest a prolonged deterioration of oceanic environments during the Late Permian mass extinction.

  16. Multiple S-isotopic evidence for episodic shoaling of anoxic water during Late Permian mass extinction

    PubMed Central

    Shen, Yanan; Farquhar, James; Zhang, Hua; Masterson, Andrew; Zhang, Tonggang; Wing, Boswell A.

    2011-01-01

    Global fossil data show that profound biodiversity loss preceded the final catastrophe that killed nearly 90% marine species on a global scale at the end of the Permian. Many hypotheses have been proposed to explain this extinction and yet still remain greatly debated. Here, we report analyses of all four sulphur isotopes (32S, 33S, 34S and 36S) for pyrites in sedimentary rocks from the Meishan section in South China. We observe a sulphur isotope signal (negative δ34S with negative Δ33S) that may have resulted from limitation of sulphate supply, which may be linked to a near shutdown of bioturbation during shoaling of anoxic water. These results indicate that episodic shoaling of anoxic water may have contributed to the profound biodiversity crisis before the final catastrophe. Our data suggest a prolonged deterioration of oceanic environments during the Late Permian mass extinction. PMID:21343928

  17. Solvothermal synthesis of a new 3-D mixed-metal sulfide framework, (H1.33tren)[In2.67Sb1.33S8]·tren

    NASA Astrophysics Data System (ADS)

    Lampkin, John D.; Powell, Anthony V.; Chippindale, Ann M.

    2016-11-01

    A new indium(III) antimony(V) sulfide, (H1.33tren)[In2.67Sb1.33S8]·tren, has been prepared solvothermally at 433 K. The compound crystallises in the tetragonal space group I-42d (lattice parameters, a=12.6248(5) and c=19.4387(18) Å at 150 K) and contains adamantane-like T2 supertetrahedral units comprised of corner-sharing InS45- and SbS43- tetrahedra. The adamantane-like units are then linked through sulfur vertices to generate an open, 3-D framework structure containing large pores in which neutral, protonated tren (tris(2-aminoethylene)amine) molecules reside. The presence of the organic components was confirmed by solid-state 13C NMR (10 kHz), combustion and thermogravimetric analysis. The band gap, obtained from UV-vis diffuse reflectance measurements, is 2.7(2) eV. Stirring with either water or alkali-metal salt solution leads to removal of the neutral tren molecules and an 9% reduction in unit-cell volume on formation of (H1.33tren)[In2.67Sb1.33S8]·(H2O)4.

  18. The Effect of Parasite Infection on Stable Isotope Turnover Rates of δ15N, δ13C and δ34S in Multiple Tissues of Eurasian Perch Perca fluviatilis

    PubMed Central

    Yohannes, Elizabeth; Grimm, Claudia; Rothhaupt, Karl-Otto; Behrmann-Godel, Jasminca

    2017-01-01

    Stable isotope analysis of commercially and ecologically important fish can improve understanding of life-history and trophic ecology. However, accurate interpretation of stable isotope values requires knowledge of tissue-specific isotopic turnover that will help to describe differences in the isotopic composition of tissues and diet. We performed a diet-switch experiment using captive-reared parasite-free Eurasian perch (Perca fluviatilis) and wild caught specimens of the same species, infected with the pike tapeworm Triaenophorus nodulosus living in host liver tissue. We hypothesize that metabolic processes related to infection status play a major role in isotopic turnover and examined the influence of parasite infection on isotopic turn-over rate of carbon (δ13C), nitrogen (δ15N) and sulphur (δ34S) in liver, blood and muscle. The δ15N and δ13C turnovers were fastest in liver tissues, followed by blood and muscle. In infected fish, liver and blood δ15N and δ13C turnover rates were similar. However, in infected fish, liver and blood δ13C turnover was faster than that of δ15N. Moreover, in infected subjects, liver δ15N and δ13C turnover rates were three to five times faster than in livers of uninfected subjects (isotopic half-life of ca.3-4 days compared to 16 and 10 days, respectively). Blood δ34S turnover rate were about twice faster in non-infected individuals implying that parasite infection could retard the turnover rate of δ34S and sulphur containing amino acids. Slower turnover rate of essential amino acid could probably decrease individual immune function. These indicate potential hidden costs of chronic and persistent infections that may have accumulated adverse effects and might eventually impair life-history fitness. For the first time, we were able to shift the isotope values of parasites encapsulated in the liver by changing the dietary source of the host. We also report variability in isotopic turnover rates between tissues, elements and

  19. The Effect of Parasite Infection on Stable Isotope Turnover Rates of δ15N, δ13C and δ34S in Multiple Tissues of Eurasian Perch Perca fluviatilis.

    PubMed

    Yohannes, Elizabeth; Grimm, Claudia; Rothhaupt, Karl-Otto; Behrmann-Godel, Jasminca

    2017-01-01

    Stable isotope analysis of commercially and ecologically important fish can improve understanding of life-history and trophic ecology. However, accurate interpretation of stable isotope values requires knowledge of tissue-specific isotopic turnover that will help to describe differences in the isotopic composition of tissues and diet. We performed a diet-switch experiment using captive-reared parasite-free Eurasian perch (Perca fluviatilis) and wild caught specimens of the same species, infected with the pike tapeworm Triaenophorus nodulosus living in host liver tissue. We hypothesize that metabolic processes related to infection status play a major role in isotopic turnover and examined the influence of parasite infection on isotopic turn-over rate of carbon (δ13C), nitrogen (δ15N) and sulphur (δ34S) in liver, blood and muscle. The δ15N and δ13C turnovers were fastest in liver tissues, followed by blood and muscle. In infected fish, liver and blood δ15N and δ13C turnover rates were similar. However, in infected fish, liver and blood δ13C turnover was faster than that of δ15N. Moreover, in infected subjects, liver δ15N and δ13C turnover rates were three to five times faster than in livers of uninfected subjects (isotopic half-life of ca.3-4 days compared to 16 and 10 days, respectively). Blood δ34S turnover rate were about twice faster in non-infected individuals implying that parasite infection could retard the turnover rate of δ34S and sulphur containing amino acids. Slower turnover rate of essential amino acid could probably decrease individual immune function. These indicate potential hidden costs of chronic and persistent infections that may have accumulated adverse effects and might eventually impair life-history fitness. For the first time, we were able to shift the isotope values of parasites encapsulated in the liver by changing the dietary source of the host. We also report variability in isotopic turnover rates between tissues, elements and

  20. The promoter effect and a rate expression of the catalytic incineration of (CH3)2S2 over an improved CuO-MoO3/gamma-Al2O3 catalyst.

    PubMed

    Wang, Ching-Huei; Lin, Shiow-Shyung; Liou, Shen-Ben; Weng, Hung-Shan

    2002-10-01

    The CuO-MoO3/gamma-Al2O3 catalyst, confirmed previously as having good activity in the catalytic incineration of (CH3)2S2, was employed as the principal catalyst in this study. With the aim of improving catalyst activity and resistance to deactivation by sulfur compounds, a promoter was added either before adding the precursors of Cu and Mo or together with Cu and Mo onto the gamma-Al2O3. Promoters included transition metals and elements from groups IA-VIIA in the chemical periodic table. Experimental results reveal Cr2O3 as the most effective promoter, with an optimal composition of 5 wt.% Cu, 6 wt.% Mo and 4 wt.% Cr (designated as Cu(5)-Mo(6)-Cr(4)/gamma-Al2O3). Knowing that higher acidity can improve activity, we further investigated the effect of acid treatment on the performance of the Cu(5)-Mo(6)-Cr(4)/gamma-Al2O3 catalyst. Experimental results indicate the H2SO4-treated catalyst (Cu(5)-Mo(6)-Cr(4)/sulfated-gamma-Al2O3) has a better activity and durability. A study for finding an appropriate rate expression for the catalytic incineration of (CH3)2S2 by Cu(5)-Mo(6)-Cr(4)/sulfated-gamma-Al2O3 was carried out in a differential reactor. The results show that the Mars-Van Krevelen model is applicable to this destructive oxidation reaction. Results additionally reveal that competitive adsorption of CH4 reduces conversion of (CH3)2S2.

  1. S-33 constraints on the seawater sulfate contribution in modern seafloor hydrothermal vent sulfides

    USGS Publications Warehouse

    Ono, Shuhei; Shanks, Wayne C.; Rouxel, O.J.; Rumble, D.

    2007-01-01

    Sulfide sulfur in mid-oceanic ridge hydrothermal vents is derived from leaching of basaltic-sulfide and seawater-derived sulfate that is reduced during high temperature water rock interaction. Conventional sulfur isotope studies, however, are inconclusive about the mass-balance between the two sources because 34S/32S ratios of vent fluid H2S and chimney sulfide minerals may reflect not only the mixing ratio but also isotope exchange between sulfate and sulfide. Here, we show that high-precision analysis of S-33 can provide a unique constraint because isotope mixing and isotope exchange result in different ??33S (?????33S-0.515 ??34S) values of up to 0.04??? even if ??34S values are identical. Detection of such small ??33S differences is technically feasible by using the SF6 dual-inlet mass-spectrometry protocol that has been improved to achieve a precision as good as 0.006??? (2??). Sulfide minerals (marcasite, pyrite, chalcopyrite, and sphalerite) and vent H2S collected from four active seafloor hydrothermal vent sites, East Pacific Rise (EPR) 9-10??N, 13??N, and 21??S and Mid-Atlantic Ridge (MAR) 37??N yield ??33S values ranging from -0.002 to 0.033 and ??34S from -0.5??? to 5.3???. The combined ??34S and ??33S systematics reveal that 73 to 89% of vent sulfides are derived from leaching from basaltic sulfide and only 11 to 27% from seawater-derived sulfate. Pyrite from EPR 13??N and marcasite from MAR 37??N are in isotope disequilibrium not only in ??34S but also in ??33S with respect to associated sphalerite and chalcopyrite, suggesting non-equilibrium sulfur isotope exchange between seawater sulfate and sulfide during pyrite precipitation. Seafloor hydrothermal vent sulfides are characterized by low ??33S values compared with biogenic sulfides, suggesting little or no contribution of sulfide from microbial sulfate reduction into hydrothermal sulfides at sediment-free mid-oceanic ridge systems. We conclude that 33S is an effective new tracer for interplay among

  2. Multiple sulfur isotope evidence for massive oceanic sulfate depletion in the aftermath of Snowball Earth

    NASA Astrophysics Data System (ADS)

    Sansjofre, Pierre; Cartigny, Pierre; Trindade, Ricardo I. F.; Nogueira, Afonso C. R.; Agrinier, Pierre; Ader, Magali

    2016-07-01

    The terminal Neoproterozoic Era (850-542 Ma) is characterized by the most pronounced positive sulfur isotope (34S/32S) excursions in Earth's history, with strong variability and maximum values averaging δ34S~+38‰. These excursions have been mostly interpreted in the framework of steady-state models, in which ocean sulfate concentrations do not fluctuate (that is, sulfate input equals sulfate output). Such models imply a large pyrite burial increase together with a dramatic fluctuation in the isotope composition of marine sulfate inputs, and/or a change in microbial sulfur metabolisms. Here, using multiple sulfur isotopes (33S/32S, 34S/32S and 36S/32S ratios) of carbonate-associated sulfate, we demonstrate that the steady-state assumption does not hold in the aftermath of the Marinoan Snowball Earth glaciation. The data attest instead to the most impressive event of oceanic sulfate drawdown in Earth's history, driven by an increased pyrite burial, which may have contributed to the Neoproterozoic oxygenation of the oceans and atmosphere.

  3. Applying Statement 34's Capital Asset Requirements.

    ERIC Educational Resources Information Center

    Finden, Randal

    2001-01-01

    Discusses common issues and offers recommendations related to revisions in Governmental Accounting Standards Board Statement 34 wherein the financial reporting of the general fixed-assets account group is eliminated and instead a school district's general capital assets are reported and depreciated on the new statement of net assets and statement…

  4. Tissue S/N ratios and stable isotopes (delta(34)S and delta(15)N) of epilithic mosses (Haplocladium microphyllum) for showing air pollution in urban cities in Southern China.

    PubMed

    Xiao, Hua-Yun; Tang, Cong-Guo; Xiao, Hong-Wei; Wang, Yan-Li; Liu, Xue-Yan; Liu, Cong-Qiang

    2010-05-01

    In urban cities in Southern China, the tissue S/N ratios of epilithic mosses (Haplocladium microphyllum), varied widely from 0.11 to 0.19, are strongly related to some atmospheric chemical parameters (e.g. rainwater SO(4)(2-)/NH(4)(+) ratios, each people SO(2) emission). If tissue S/N ratios in the healthy moss species tend to maintain a constant ratio of 0.15 in unpolluted area, our study cities can be divided into two classes: class I (S/N > 0.15, S excess) and class II (S/N < 0.15, N excess), possibly indicative of stronger industrial activity and higher density of population, respectively. Mosses in all these cities obtained S and N from rainwater at a similar ratio. Sulphur and N isotope ratios in mosses are found significantly linearly correlated with local coal delta(34)S and NH(4)(+)-N wet deposition, respectively, indicating that local coal and animal NH(3) are the major atmospheric S and N sources.

  5. Active microbial sulfur disproportionation in the Mesoproterozoic.

    PubMed

    Johnston, David T; Wing, Boswell A; Farquhar, James; Kaufman, Alan J; Strauss, Harald; Lyons, Timothy W; Kah, Linda C; Canfield, Donald E

    2005-12-02

    The environmental expression of sulfur compound disproportionation has been placed between 640 and 1050 million years ago (Ma) and linked to increases in atmospheric oxygen. These arguments have their basis in temporal changes in the magnitude of 34S/32S fractionations between sulfate and sulfide. Here, we present a Proterozoic seawater sulfate isotope record that includes the less abundant sulfur isotope 33S. These measurements imply that sulfur compound disproportionation was an active part of the sulfur cycle by 1300 Ma and that progressive Earth surface oxygenation may have characterized the Mesoproterozoic.

  6. Report for Full-Scale Mulch Wall Treatment of Chlorinated Hydrocarbon-Impacted Groundwater

    DTIC Science & Technology

    2006-05-31

    MW-33S MW-34S MW-31S MW-32S B301-MP5S ND B301- MP6S 1.2 SB9 SB7 SB3 SB5 SB2 HP4 SB1 HP1 A’ A MW-30S MW-27S 4/13/04 FULL-SCALE MULCH WALL Site B... MP6S 1.2 SB9 SB7 SB3 SB5 SB2 HP4 SB1 HP1 A’ A MW-30S MW-27S INSET MAP N Inset Scale (ft) 500 10000 Groundwater Flow 4 in steel gas main 24 in CMP

  7. Sulphur tales from the early Archean world

    NASA Astrophysics Data System (ADS)

    Montinaro, A.; Strauss, H.

    2016-07-01

    Sedimentary and magmatic rocks and their distinct sulphur isotopic signatures indicate the sources and processes of sulphur cycling, in particular through the analysis of all four stable sulphur isotopes (32S, 33S, 34S and 36S). Research over the past 15 years has substantially advanced our understanding of sulphur cycling on the early Earth, most notably through the discovery of mass-independently fractionated sulphur isotopic signatures. A strong atmospheric influence on the early Archean global sulphur cycle is apparent, much in contrast to the modern world. Diverse microbially driven sulphur cycling is clearly discernible, but its importance for Earth surface environments remains to be quantified.

  8. High resolution study of the rotational structure of doubly excited vibrational states of 32S16O18O: The first analysis of the 2ν1, ν1 +ν3 , and 2ν3 bands

    NASA Astrophysics Data System (ADS)

    Ulenikov, O. N.; Bekhtereva, E. S.; Gromova, O. V.; Zamotaeva, V. A.; Kuznetsov, S. I.; Sydow, C.; Bauerecker, S.

    2017-03-01

    The high resolution infrared spectra of the 32S16O18O molecule were recorded with a Bruker IFS 120 HR Fourier transform interferometer for the first time in the region of 1800-2800 cm-1 where the bands 2ν1, ν1 +ν3 , and 2ν3 are located. About 3970, 2960 and 3450 transitions were assigned in the experimental spectra with the maximum values of quantum numbers Jmax. /Kamax. equal to 59/20, 68/25, and 43/18 to the bands 2ν1, ν1 +ν3 , and 2ν3, respectively. The subsequent weighted fit of experimentally assigned transitions was made with the Hamiltonian model which takes into account the resonance interactions between the studied vibrational states. As the result, a set of 39 fitted parameters was obtained which reproduces the initial 3213 ro-vibrational energy values obtained from the assigned transitions with the drms = 2.4 ×10-4cm-1 .

  9. Combined S-33 and O-18 Isotope Tracing of Intracellular Sulfur Metabolism during Microbial Sulfate Reduction

    NASA Astrophysics Data System (ADS)

    Antler, Gilad; Bosak, Tanja; Ono, Shuhei; Sivan, Orit; Turchyn, Alexandra V.

    2014-05-01

    Microbial sulfate reduction is a key player in the global carbon cycle, oxidizing nearly 50% of organic matter in marine sediments. The biochemical pathway of microbial sulfate reduction fractionates sulfur and oxygen isotopes and these fractionations can be used to reconstruct S cycling in sediments. Sulfur isotope fractionation during microbial sulfate reduction, which partitions lighter sulfur (32S) into sulfide and heavier sulfur (33S and 34S) into the residual sulfate, can be as high as 72o for 34S/32S. The availability and type of organic substrate control the magnitude of sulfur isotope fractionation by influencing the fluxes of and the transfer of electrons to different S species. The partitioning of oxygen in sulfate during microbial sulfate reduction appears to be strongly influenced by the oxygen isotopic composition of water in which the bacteria grow, but its magnitude also seems to correlate with the magnitude of 34S/32S isotope fractionation. In addition, the fractionation of 33S/32S is thought to reflect the reversibility of some intercellular fluxes. We wanted to investigate whether the 18O/16O, 34S/32S and 33S/32S isotope fractionations in sulfate are controlled by the same intracellular processes and conditions. This was done by investigating the combined sulfur and oxygen isotope partitioning by a marine Desulfovibrio sp. grown in pure culture on different organic substrates and in water with different isotopic composition of oxygen. The isotope fractionations of oxygen and sulfur correlated with the cell specific sulfate reduction rates (csSRR), where slower rates yielded higher sulfur fractionation (as high as 60) and higher oxygen isotope fractionation. The trends in 33S/32S and 34S/32S with the changing csSRR was similar to the trends in 18O/16O with the csSRR, suggesting that the same intercellular pathways controlled both oxygen and sulfur isotope signatures during microbial sulfate reduction. The use of water with different isotopic

  10. Multiple sulfur isotope evidence for massive oceanic sulfate depletion in the aftermath of Snowball Earth

    PubMed Central

    Sansjofre, Pierre; Cartigny, Pierre; Trindade, Ricardo I. F.; Nogueira, Afonso C. R.; Agrinier, Pierre; Ader, Magali

    2016-01-01

    The terminal Neoproterozoic Era (850–542 Ma) is characterized by the most pronounced positive sulfur isotope (34S/32S) excursions in Earth's history, with strong variability and maximum values averaging δ34S∼+38‰. These excursions have been mostly interpreted in the framework of steady-state models, in which ocean sulfate concentrations do not fluctuate (that is, sulfate input equals sulfate output). Such models imply a large pyrite burial increase together with a dramatic fluctuation in the isotope composition of marine sulfate inputs, and/or a change in microbial sulfur metabolisms. Here, using multiple sulfur isotopes (33S/32S, 34S/32S and 36S/32S ratios) of carbonate-associated sulfate, we demonstrate that the steady-state assumption does not hold in the aftermath of the Marinoan Snowball Earth glaciation. The data attest instead to the most impressive event of oceanic sulfate drawdown in Earth's history, driven by an increased pyrite burial, which may have contributed to the Neoproterozoic oxygenation of the oceans and atmosphere. PMID:27447895

  11. Multiple sulfur isotope evidence for massive oceanic sulfate depletion in the aftermath of Snowball Earth.

    PubMed

    Sansjofre, Pierre; Cartigny, Pierre; Trindade, Ricardo I F; Nogueira, Afonso C R; Agrinier, Pierre; Ader, Magali

    2016-07-22

    The terminal Neoproterozoic Era (850-542 Ma) is characterized by the most pronounced positive sulfur isotope ((34)S/(32)S) excursions in Earth's history, with strong variability and maximum values averaging δ(34)S∼+38‰. These excursions have been mostly interpreted in the framework of steady-state models, in which ocean sulfate concentrations do not fluctuate (that is, sulfate input equals sulfate output). Such models imply a large pyrite burial increase together with a dramatic fluctuation in the isotope composition of marine sulfate inputs, and/or a change in microbial sulfur metabolisms. Here, using multiple sulfur isotopes ((33)S/(32)S, (34)S/(32)S and (36)S/(32)S ratios) of carbonate-associated sulfate, we demonstrate that the steady-state assumption does not hold in the aftermath of the Marinoan Snowball Earth glaciation. The data attest instead to the most impressive event of oceanic sulfate drawdown in Earth's history, driven by an increased pyrite burial, which may have contributed to the Neoproterozoic oxygenation of the oceans and atmosphere.

  12. Dynamical cluster-decay model for hot and rotating light-mass nuclear systems applied to the low-energy {sup 32}S+{sup 24}Mg{yields}{sup 56}Ni{sup *} reaction

    SciTech Connect

    Gupta, Raj K.; Kumar, Rajesh; Singh, Dalip; Balasubramaniam, M.; Beck, C.

    2005-01-01

    The dynamical cluster-decay model (DCM) is developed further for the decay of hot and rotating compound nuclei (China) formed in light heavy-ion reactions. The model is worked out in terms of only one parameter, namely the neck-length parameter, which is related to the total kinetic energy TKE(T) or effective Q value Q{sub eff}(T) at temperature T of the hot CN and is defined in terms of the CN binding energy and ground-state binding energies of the emitted fragments. The emission of both the light particles (LP), with A{<=}4,Z{<=}2, as well as the complex intermediate mass fragments (IMF), with 42, is considered as the dynamical collective mass motion of preformed clusters through the barrier. Within the same dynamical model treatment, the LPs are shown to have different characteristics compared to those of the IMFs. The systematic variations of the LP emission cross section {sigma}{sub LP} and IMF emission cross section {sigma}{sub IMF} calculated from the present DCM match exactly the statistical fission model predictions. A nonstatistical dynamical description is developed for the first time for emission of light particles from hot and rotating CN. The model is applied to the decay of {sup 56}Ni* formed in the {sup 32}S+{sup 24}Mg reaction at two incident energies E{sub c.m.}=51.6 and 60.5 MeV. Both the IMFs and average TKE{sup lowbar} spectra are found to compare resonably well with the experimental data, favoring asymmetric mass distributions. The LPs' emission cross section is shown to depend strongly on the type of emitted particles and their multiplicities.

  13. The reversed-flow gas chromatography technique as a tool for the study of the evaporation retardation of SO2 and (CH3)2S from water by soluble surfactants.

    PubMed

    Sevastos, D; Kotsalos, E; Koliadima, A

    2017-02-01

    In the present work the evaporation retardation of SO2 and (CH3)2S (=DMS) from water by soluble surfactants was studied by the Reversed-Flow Gas Chromatography (R.F.G.C.) technique. Using suitable mathematical analysis, rate coefficients, kc, for the transfer of SO2 and DMS from pure or artificial sea water to the atmospheric environment were determined in the presence or the absence of surfactants. The efficiency of the three surfactants used (CTAB, TRITON X-100 and SDS) to retard the evaporation rate of SO2 and DMS from water was estimated by the decrease of the kc values in the presence of the three surfactants, compared to those in the absence of surfactants. The more efficient surfactant for the retardation evaporation of SO2 from both the pure and the artificial sea water was found to be the cationic CTAB surfactant, as the maximum decreases of the kc values were found to be 4.61×10(-3)cms(-1) (number of films, n=1) and 3.07×10(-3)cms(-1) (n=3), respectively. On the other hand, more efficient surfactant for the retardation evaporation of DMS from pure water was found to be the non-ionic TRITON X-100, in which the decrease of the kc value was estimated to be 18.20×10(-3)cms(-1) (n=3) and from artificial sea water the cationic CTAB surfactant in which the decrease of the kc value was found to be 8.24×10(-3)cms(-1) (n=3). Finally, the precision of the R.F.G.C. method in studying the retardation effect of various surfactants in the transfer of SO2 and DMS from the water body to the atmosphere is estimated (mean value 96.69%), and the experimental values of kc are compared with those given in the literature.

  14. Synthesis and evaluation of 2-18F-fluoro-5-iodo-3-[2-(S)-3,4-dehydropyrrolinylmethoxy]pyridine (18F-Niofene) as a potential imaging agent for nicotinic α4β2 receptors

    PubMed Central

    Kuruvilla, Sharon A; Hillmer, Ansel T; Wooten, Dustin W; Patel, Ashna; Christian, Bradley T; Mukherjee, Jogeshwar

    2014-01-01

    Nicotinic α4β2 acetylcholine receptors (nAChRs) have been implicated in various pathophysiologies including neurodegenerative diseases. Currently, 2-18F-A85380 (2-FA) and 5-123I-A85380 (5-IA) are used separately in human PET and SPECT studies respectively and require >4-6 hours of scanning. We have developed 2-fluoro-5-iodo-3-[2-(S)-3-dehydropyrrolinylmethoxy]pyridine (niofene) as a potential PET/SPECT imaging agent for nAChRs with an aim to have rapid binding kinetics similar to that of 18F-nifene used in PET studies. Niofene exhibited a 10-fold better in vitro binding affinity in rat brain than that of nicotine. The relative binding of niofene was similar to that of niodene and twice as better as that of nifene. In vitro autoradiography in rat brain slices alongside niodene indicated selective binding of niofene to regions consistent with α4β2 receptor distribution. Niofene, 10 nM, displaced >70% of 3H-cytisine bound to α4β2 receptors in rat brain slices. Radiolabeling of 18F-niofene was achieved in 10-15% radiochemical yield in high specific activities >2 Ci/μmol and showed rapid in vivo kinetics similar to that of 18F-nifene and 18F-nifrolene. In vivo PET in rats showed rapid uptake in the brain and selective localization in receptor regions such as the thalamus (TH). Pseudoequilibrium with 18F-niofene was achieved in 30-40 minutes, which is similar to that of 18F-nifene. Further evaluation of 18F-niofene as a potential PET imaging agent is underway. Future studies will be conducted to radiolabel niofene with iodine-123 for use in SPECT imaging. PMID:24982821

  15. Large S-33 Anomalies in Late Archean Carbonacous Shales

    NASA Astrophysics Data System (ADS)

    Ono, S.; Rumble, D.; Pavlov, A.; Kharecha, P.; Kasting, J. F.

    2002-12-01

    Multi-sulfur isotope ratios (34S/33S/32S) were determined on sulfides extracted from two late Archean carbonaceous shale units, the Mt. McRae shale (~2.5 Ga) and the Jeerinah formation (~2.7 Ga), from the Hamersley Basin, Western Australia by using the CO2-laser fluorination line at the Geophisical Laboratory. We have measured the largest Δ33S anomaly yet reported for a terrestrial sample on sulfides from 22 m core section of the Mt McRae shale. The large positive Δ33S, up to +6.9 ‰ , is found in the lower part of the core section; the Δ33S shifts to negative upward in the section to as low as -1.9 ‰ . The age of the Mt. McRae shale is bracketed by 2470 and 2561 Ma. Therefore, the observed isotopic shift represents the maximum duration of 91 million years, but most likely less than 30 million years by assuming a constant sedimentation rate for the Mt. McRae shale that has average thickness of 60 m in the area. Sulfide sulfur from the Jeerinah formation also yield large Δ33S anomalies ranging from -0.1 to +4.4 ‰ . Our model fundamentally follows the one proposing a strong atmospheric influence in the Archean sulfur cycle by Farquhar et al. (2000). Our new data show the large and systematic variation between Δ33S and δ34S. This allows us to further speculate the isotopic compositions of Archean sulfur reservoirs and the manner in which the atmospheric signature was transferred to sediments. Our data are consistent with the late Archean seawater sulfate reservoir that has a negative Δ33S of ~ -2 ‰ . Thus, pyrite formed via microbial sulfate reduction shows variable δ34S and negative Δ33S. The large positive Δ33S of + 6.9 ‰ is likely to be a signature of deposition of sulfur aerosol, probably elemental sulfur. Our sulfur isotope data is best explained by mixing of those two components. Atmospheric deposition of elemental sulfur requires an anoxic atmosphere, and subsequent burial and preservation of the signature into pelagic sediments would have

  16. Chemical dynamics of the "St. Lawrence" riverine system: δD H 2O, δ 18O H 2O, δ 13C DIC, δ 34S sulfate, and dissolved 87Sr/ 86Sr

    NASA Astrophysics Data System (ADS)

    Yang, Chao; Telmer, Kevin; Veizer, Ján

    1996-03-01

    Chemical and stable isotope analyses of the St. Clair, Detroit, Niagara, and St. Lawrence rivers ("St. Lawrence" system) and their tributaries show that the chemical and isotopic compositions of the waters are strongly controlled by the geology of their drainage basins. Tributaries draining the Canadian Shield have very low TDS, HCO 3-, SO 42-, Ca 2+, Mg 2+, NO 3-, Sr 2+, higher Si and Fe total, and high 87Sr/ 86Sr ratios (0.710-0.713). The Grand and Thames rivers that drain Paleozoic limestones, dolostones, and evaporites are characterized by opposite attributes. The "St. Lawrence" and the tributaries draining the Canadian Appalachians fall between these two endmembers. The St. Clair, Detroit, and Niagara rivers do not show any pronounced seasonal variations in major component chemistry due to buffering by the Great Lakes. In contrast, pronounced seasonal variations characterize the lower St. Lawrence mainly because of significant tributary inputs into the overall water budget. The δD and δ18O in the "St. Lawrence" range from -60.9 to -44.5‰ and from -8.5 to -6.1‰ SMOW, respectively, much heavier than the comparative values measured for the tributaries (-92.8 to -58.3‰ and -13.1 to -8.5‰). This is a consequence of evaporative loss that, over the residence time of water of 10 2 years, equals about 7% of the water volume in the Great Lakes. The strontium and sulfur isotopic values for the "St. Lawrence" system are relatively uniform, with measured values from 0.70927 to 0.71112 for 87Sr/ 86Sr and from 4.3 to 5.6‰ for sulfate δ34S. Their seasonal variations are also minor. The strontium and sulfur fluxes of the St. Lawrence river are calculated to be 7.84 × 10 8 and 1.09 × 10 11 mol/a, respectively. The relative contributions of the Great Lakes, tributaries, and other sources to these fluxes are 73:16:11% for strontium and 64:13:23% for sulfur. Isotopic composition of dissolved inorganic carbon ( δ13C DIC) in the "St. Lawrence" system ranges from -4

  17. Atmospheric record in the Hadean Eon from multiple sulfur isotope measurements in Nuvvuagittuq Greenstone Belt (Nunavik, Quebec)

    PubMed Central

    Thomassot, Emilie; O’Neil, Jonathan; Francis, Don; Cartigny, Pierre; Wing, Boswell A.

    2015-01-01

    Mass-independent fractionation of sulfur isotopes (S-MIF) results from photochemical reactions involving short-wavelength UV light. The presence of these anomalies in Archean sediments [(4–2.5 billion years ago, (Ga)] implies that the early atmosphere was free of the appropriate UV absorbers, of which ozone is the most important in the modern atmosphere. Consequently, S-MIF is considered some of the strongest evidence for the lack of free atmospheric oxygen before 2.4 Ga. Although temporal variations in the S-MIF record are thought to depend on changes in the abundances of gas and aerosol species, our limited understanding of photochemical mechanisms complicates interpretation of the S-MIF record in terms of atmospheric composition. Multiple sulfur isotope compositions (δ33S, δ34S, and δ36S) of the >3.8 billion-year-old Nuvvuagittuq Greenstone Belt (Ungava peninsula) have been investigated to track the early origins of S-MIF. Anomalous S-isotope compositions (Δ33S up to +2.2‰) confirm a sedimentary origin of sulfide-bearing banded iron and silica-rich formations. Sharp isotopic transitions across sedimentary/igneous lithological boundaries indicate that primary surficial S-isotope compositions have been preserved despite a complicated metamorphic history. Furthermore, Nuvvuagittuq metasediments recorded coupled variations in 33S/32S, 34S/32S, and 36S/32S that are statistically indistinguishable from those identified several times later in the Archean. The recurrence of the same S-isotope pattern at both ends of the Archean Eon is unexpected, given the complex atmospheric, geological, and biological pathways involved in producing and preserving this fractionation. It implies that, within 0.8 billion years of Earth’s formation, a common mechanism for S-MIF production was established in the atmosphere. PMID:25561552

  18. Atmospheric record in the Hadean Eon from multiple sulfur isotope measurements in Nuvvuagittuq Greenstone Belt (Nunavik, Quebec).

    PubMed

    Thomassot, Emilie; O'Neil, Jonathan; Francis, Don; Cartigny, Pierre; Wing, Boswell A

    2015-01-20

    Mass-independent fractionation of sulfur isotopes (S-MIF) results from photochemical reactions involving short-wavelength UV light. The presence of these anomalies in Archean sediments [(4-2.5 billion years ago, (Ga)] implies that the early atmosphere was free of the appropriate UV absorbers, of which ozone is the most important in the modern atmosphere. Consequently, S-MIF is considered some of the strongest evidence for the lack of free atmospheric oxygen before 2.4 Ga. Although temporal variations in the S-MIF record are thought to depend on changes in the abundances of gas and aerosol species, our limited understanding of photochemical mechanisms complicates interpretation of the S-MIF record in terms of atmospheric composition. Multiple sulfur isotope compositions (δ(33)S, δ(34)S, and δ(36)S) of the >3.8 billion-year-old Nuvvuagittuq Greenstone Belt (Ungava peninsula) have been investigated to track the early origins of S-MIF. Anomalous S-isotope compositions (Δ(33)S up to +2.2‰) confirm a sedimentary origin of sulfide-bearing banded iron and silica-rich formations. Sharp isotopic transitions across sedimentary/igneous lithological boundaries indicate that primary surficial S-isotope compositions have been preserved despite a complicated metamorphic history. Furthermore, Nuvvuagittuq metasediments recorded coupled variations in (33)S/(32)S, (34)S/(32)S, and (36)S/(32)S that are statistically indistinguishable from those identified several times later in the Archean. The recurrence of the same S-isotope pattern at both ends of the Archean Eon is unexpected, given the complex atmospheric, geological, and biological pathways involved in producing and preserving this fractionation. It implies that, within 0.8 billion years of Earth's formation, a common mechanism for S-MIF production was established in the atmosphere.

  19. Mantle Sulfur Cycle: A Case for Non-Steady State ?

    NASA Astrophysics Data System (ADS)

    Cartigny, Pierre; Labidi, Jabrane

    2016-04-01

    Data published over the last 5 years show that the early inference that mantle is isotopically homogeneous is no more valid. Instead, new generation data on lavas range over a significant 34S/32S variability of up to 5‰ with δ 34S values often correlated to Sr- and Nd-isotope compositions. This new set of data also reveals the Earth's mantle to have a sub-chondritic 34S/32S ratio, by about ˜ 1‰. We will present at the conference our published and unpublished data on samples characterizing the different mantle components (i.e. EM1, EM2, HIMU and LOMU). All illustrate 34S-enrichments compared to MORB with Δ 33S and Δ 36S values indistinguishable from CDT or chondrites at the 0.03‰ level. These data are consistent with the recycling of subducted components carrying sulfur with Δ 33S and Δ 36S-values close to zero. Archean rocks commonly display Δ 33S and Δ 36S values deviating from zero by 1 to 10 ‰. The lack of variations for Δ 33S and Δ 36S values in present day lava argue against the sampling of any subducted protolith of Archean age in their mantle source. Instead, our data are consistent with the occurrence of Proterozoic subducted sulfur in the source of the EM1, EM2, LOMU and HIMU endmember at the St-Helena island. This is in agreement with the age of those components early derived through the use of the Pb isotope systematic. Currently, the negative δ 34S-values of the depleted mantle seem to be associated with mostly positive values of enriched components. This would be inconsistent with the concept a steady state of sulfur. Assuming that the overall observations of recycled sulfur are not biased, the origin of such a non-steady state remains unclear. It could be related to the relatively compatible behavior of sulfur during partial melting, as the residue of present-day melting can be shown to always contain significant amounts of sulfide (50{%} of what is observed in a fertile source). This typical behavior likely prevents an efficient

  20. Triple isotope composition of sulfur from nanomoles of dissolved sulfate on the MC-ICPMS Neptune (Invited)

    NASA Astrophysics Data System (ADS)

    Paris, G.; Sessions, A. L.; Subhas, A. V.; Adkins, J. F.

    2013-12-01

    Over the last decade, the increasing use of Inductively-Coupled plasma mass spectrometer (ICPMS) for measuring the isotopic composition of sulfur helped decreasing significantly the detection limit for analyzing dissolved sulfate, with no loss of precision. Because of intereferences on mass 33 and 36, only the two major isotopes were analyzed. Here, we present a new method to measure precise and accurate 34S /32S and 33S /32S ratios from sulfate in solution. Understanding past and modern sulfur cycle is crucial on many points of view and exploring the isotopic composition of sulfur from Carbonate Associated Sulfate (CAS) during geological times or sulfate from seawater or porewaters provide essential information. For carbonates, existing methods focus on samples rather rich in CAS (>100 ppm) or samples available in important amounts (> 1g). Samples with either very low sulfate concentration (Archean carbonates or continental waters, for instance) and/or samples with limited available amounts (such as foraminifera) require a new analytical method. Isotopic composition of many trace components are successfully measured on MC-ICPMS (MultiCollector ICPMS). The ThermoScientific magnetic sector ICPMS Neptune has already been used successfully for bulk and in-situ δ34S evaluation of sulfate and sulfide minerals [1] and organic compounds [2]. Isotopic composition measurement on the Neptune requires however removal of the complex matrix of the samples so that samples are analyzed as sodium sulfate diluted in 5% HNO3. Sulfate is purified using the AG1X8 anionic resin to remove cations. Because sulfate is not volatile at low temperatures, we use a desolvating membrane (Aridus, Cetac) in order to decrease the various oxygen and S-H interferences on the sulfur peaks. Working at High Resolution (M/ΔM=10000), 32S-H interferences can be resolved and the 33S signal can be measured on an interference-free narrow shoulder. This method allows 34S /32S and 33S /32S ratios measurement

  1. In-situ Measurements of Sedimentary Graphites and Sulfides in Early Archean (>3.7 Ga) Banded Iron-Formations from West Greenland: Biological and Atmospheric Influences

    NASA Astrophysics Data System (ADS)

    Mojzsis, S. J.

    2001-05-01

    Stable isotopes of carbon [13C, 12C] and sulfur [32S, 33S, 34S and 36S] are used as tracers for igneous, hydrothermal and biological processes on Earth. Carbon and sulfur are abundant in marine systems and they have been utilized as biomarkers in ancient sediments. Kinetic isotope fractionations between inorganic and bioorganic carbon and sulfur during metabolic cycling results in a marked enrichment of the light isotope in the biological component by several percent. Graphitic inclusions from early Archean banded iron-formations are isotopically light [range δ 13CVPDB = -20 to -50‰ ]; these results are consistent with a biological origin. Bacterial sulfate reduction has been linked to the range of over 150‰ in δ 34S from sulfate and sulfide in the rock record. Mass-dependent sulfur isotope fractionations, commonly expressed as δ 34SCDT values for sulfur-containing minerals, exhibit a small range centered at ~0‰ for terrestrial igneous [0+/-5‰ ] and hydrothermal [0+/-10‰ ] systems. Atmospheric chemical reactions on the low pO2 early Earth are implicated in non-mass-dependent sulfur isotope anomalies [expressed as: Δ 33S33S-0.520δ 34S] reported from whole-rock analyses of sulfur-containing phases in Precambrian sediments. Only atmospheric processes in planetary environments, and nucleosynthetic, spallation or ion-molecule reactions in the stellar or near-stellar environment, appear capable of producing non-mass-dependent isotope fractionations. To explore how sulfur signatures are preserved in early Archean BIFs new techniques have been developed to obtain precise 32S, 33S and 34S measurements in situ of sulfide grains from sedimentary rocks ranging in age from early Archean [ ~3.83 Ga] to Proterozoic [ ~1.8 Ga]. High-precision simultaneous measurements of multiple sulfur isotopes enable Δ 33S to be evaluated at the sub-grain scale [<30 μm ]. These results may then be compared with previous carbon isotope measurements from the same rocks. How

  2. Identification of sources and formation processes of atmospheric sulfate by sulfur isotope and scanning electron microscope measurements

    NASA Astrophysics Data System (ADS)

    Guo, Zhaobing; Li, Zhanqing; Farquhar, James; Kaufman, Alan J.; Wu, Nanping; Li, Can; Dickerson, Russell R.; Wang, Pucai

    2010-04-01

    Atmospheric sulfate aerosols have a cooling effect on the Earth's surface and can change cloud microphysics and precipitation. China has heavy loading of sulfate, but their sources and formation processes remain uncertain. In this study we characterize possible sources and formation processes of atmospheric sulfate by analyzing sulfur isotope abundances (32S, 33S, 34S, and 36S) and by detailed X-ray diffraction and scanning electron microscope (SEM) imaging of aerosol samples acquired at a rural site in northern China from March to August 2005. The comparison of SEM images from coal fly ash and the atmospheric aerosols suggests that direct emission from coal combustion is a substantial source of primary atmospheric sulfate in the form of CaSO4. Airborne gypsum (CaSO4·2H2O) is usually attributed to eolian dust or atmospheric reactions with H2SO4. SEM imaging also reveals mineral particles with soot aggregates adhered to the surface where they could decrease the single scattering albedo of these aerosols. In summer months, heterogeneous oxidation of SO2, derived from coal combustion, appears to be the dominant source of atmospheric sulfate. Our analyses of aerosol sulfate show a seasonal variation in Δ33S33S describes either a 33S excess or depletion relative to that predicted from consideration of classical mass-dependent isotope effects). Similar sulfur isotope variations have been observed in other atmospheric samples and in (homogenous) gas-phase reactions. On the basis of atmospheric sounding and satellite data as well as a possible relationship between Δ33S and Convective Available Potential Energy (CAPE) during the sampling period, we attribute the sulfur isotope anomalies (Δ33S and Δ36S) in Xianghe aerosol sulfates to another atmospheric source (upper troposphere or lower stratosphere).

  3. Rare Isotope Insights into Supereruptions: Rare Sulfur and Triple Oxygen Isotope Geochemistry of Stratospheric Sulfate Aerosols Absorbed on Volcanic Ash Particles

    NASA Astrophysics Data System (ADS)

    Bindeman, I. N.; Eiler, J.; Wing, B.; Farquhar, J.

    2006-12-01

    We present analyses of stable isotopic ratios of 17O/16O, 18O/16O, 34S/32S, and 33S/32S, 36S/32S of sulfate leached from volcanic ash of a series of well-known volcanic eruptions. This list covers much of the diversity of sizes and the character of volcanic eruptions. Particular emphasis is paid to the Lava Creek Tuff of Yellowstone and we present wide geographic sample coverage for this unit. This global dataset spans a significant range in δ34S, δ18O, and Δ17O of sulfate (29, 30 and 3.3 permil respectively) with oxygen isotopes recording mass-independent fractionation and sulfur isotopes exhibiting mass-dependent behavior. These ranges are defined by the isotopic compositions of products of large caldera forming eruptions. Proximal ignimbrites and coarse ash typically do not contain sulfate. The presence of sulfate with Δ17O > 0.2 permil is characteristic of small distal ash particles, suggesting that sulfate aerosols were scavenged after they underwent atmospheric photochemical reactions. Additionally, sediments that embed ash layers either do not contain sulfate or contain minor sulfate with Δ17O near 0 permil, suggesting that the observed sulfate in ash is of volcanic origin. Mass-dependent sulfur isotopic compositions suggest that sulfate-forming reactions did not involve photolysis of SO2, unlike the situation inferred for some pre-2.3 Ga sulfates or hypothesized to occur during the formation of sulfate associated with plinian eruptions that pierce the ozone layer. However, sulfate in the products of caldera-forming eruptions display a large δ34S range and fractionation relationships that do not follow equilibrium slopes of 0.515 and 1.90 for 33S/32S vs. 34S/32S and 36S/32S vs. 34S/32S, respectively. This implies that the sulfur isotopic characteristics of these sulfates were not set by a single stage, high-temperature equilibrium process in the volcanic plum. The data presented here are consistent with a single stage kinetic fractionation of sulfur

  4. High-precision sulfur isotope composition of enstatite meteorites and implications of the formation and evolution of their parent bodies

    NASA Astrophysics Data System (ADS)

    Defouilloy, C.; Cartigny, P.; Assayag, N.; Moynier, F.; Barrat, J.-A.

    2016-01-01

    In order to better understand the formation and evolution of their parent bodies, the three isotope ratios of sulfur were analyzed in 33 enstatite meteorites (24 enstatite chondrites and 9 aubrites). The results show that on average all enstatite chondrite groups are enriched in the lightest isotopes compared to other chondrite groups, with means of δ34S of -0.28 ± 0.22‰ for EH3/4, -0.16 ± 0.16‰ for EH5, -0.32 ± 0.15‰ for EL3, -0.67 ± 0.16‰ for EL6 and -0.64 ± 0.00‰ for EL7 (all 1σ). Aubrites show a larger isotope variability in their composition, with a δ34S varying from -1.350‰ to +0.154‰. Contrary to previously published results, our data show a distinct composition for EL6 compared to other enstatite chondrites. This could be related to an impact-induced loss of isotopically heavy oldhamite (δ34S = by 3.62 ± 3.02‰ (1σ)) on the EL parent body. Although the bulk sulfur in both enstatite meteorites and aubrites does not show any significant Δ33S and Δ36S, the oldhamite fraction shows clear evidence of mass independent fractionation on the 36S/32S ratio (in 3 out of 9 analyzes, Δ36S up to +2.2‰), a signal that is not correlated to any 33S/32S anomaly (in 1 out of 9 analyzes, Δ33S down to -0.085‰). Though a nebular or photochemical origin cannot be ruled out, the most plausible mechanism to produce such isolated non-mass dependent 36S/32S anomalies would be a contribution of FeCl2 containing excesses of 36S due to the decay of 36Cl to the leached oldhamite fraction. Even though the sulfur isotopic composition measured in enstatite meteorites is distinct from the Bulk Silicate Earth (BSE), the isotopically lightest samples of EL6, EL7 and aubrites are approaching the isotopic composition of the BSE and enstatite meteorites remain the meteorites with the sulfur isotopic composition the closest to the terrestrial one.

  5. Word Frequency Analysis. MOS: 33S. Skill Levels 1 & 2.

    DTIC Science & Technology

    1981-05-01

    82171 14 PF 14 F, 1 1; -1 IF~) P. 1" !4 nr,r3A.npS 14 op7 rIV I NG 1’ ’I SI STAIfE 14’ I’’I(’’T’IP q3 ’l.1, ym’P’F . 13 411110 17 T1 1 II tq 11 ’v’ 11 1

  6. Sulfur isotopic analysis of carbonyl sulfide and its application for biogeochemical cycles

    NASA Astrophysics Data System (ADS)

    Hattori, Shohei; Kamezaki, Kazuki; Ogawa, Takahiro; Toyoda, Sakae; Katayama, Yoko; Yoshida, Naohiro

    2016-04-01

    Carbonyl sulfide (OCS or COS) is the most abundant gas containing sulfur in the atmosphere, with an average mixing ratio of 500 p.p.t.v. in the troposphere. OCS is suggested as a sulfur source of the stratospheric sulfate aerosols (SSA) which plays an important role in Earth's radiation budget and ozone depletion. Therefore, OCS budget should be validated for prediction of climate change, but the global OCS budget is imbalance. Recently we developed a promising new analytical method for measuring the stable sulfur isotopic compositions of OCS using nanomole level samples: the direct isotopic analytical technique of on-line gas chromatography-isotope ratio mass spectrometry (GC-IRMS) using fragmentation ions S+ (Hattori et al., 2015). The first measurement of the δ34S value for atmospheric OCS coupled with isotopic fractionation for OCS sink reactions in the stratosphere (Hattori et al., 2011; Schmidt et al., 2012; Hattori et al., 2012) explains the reported δ34S value for background stratospheric sulfate, suggesting that OCS is a potentially important source for background (nonepisodic or nonvolcanic) stratospheric sulfate aerosols. This new method measuring δ34S values of OCS can be used to investigate OCS sources and sinks in the troposphere to better understand its cycle. It is known that some microorganisms in soil can degrade OCS, but the mechanism and the contribution to the OCS in the air are still uncertain. In order to determine sulfur isotopic enrichment factor of OCS during degradation via microorganisms, incubation experiments were conducted using strains belonging to the genera Mycobacterium, Williamsia and Cupriavidus, isolated from natural soil environments (Kato et al., 2008). As a result, sulfur isotope ratios of OCS were increased during degradation of OCS, indicating that reaction for OC32S is faster than that for OC33S and OC34S. OCS degradation via microorganisms is not mass-independent fractionation (MIF) process, suggesting that this

  7. Multi-isotope biogeochemistry of sulfur in the water column and surface sediments of the Baltic Sea

    NASA Astrophysics Data System (ADS)

    Böttcher, M. E.; Kamyshny, A.; Dellwig, O.; Farquhar, J.

    2012-04-01

    The anoxic deeps of the modern Baltic Sea with the temporal development of a pelagic redoxcline offer the opportunity to study the fundamental processes in the sulfur cycle of natural dynamic euxinic systems. In the low-temperature sulfur cycle multi-sulfur isotope discrimination has been found to be of particular value for the evaluation of fundamental biogeochemical processes and has, therefore, reached a lot of attention within the past decade. We analyzed the concentrations and stable sulfur isotope (S-32, S-33, S-34, S-36) compositions of dissolved sulfide and sulfate, as well as elemental sulfur in the water column, and of sulfate, acid-volatile sulfide (FeS + HS-) and CrII-reducible sulfur (essentially pyrite) in surface sediments of several stations in the Landsort Deep (LD) and the Gotland Basin (GB). Samples were recovered during several research cruises to the Baltic Sea. Water column samples were obtained via the IOW pump-CTD system or a conventional CTD-rosette system; short sediment cores were retrieved with a multi coring device. Special focus was set on the zone at and below the pelagic redoxcline. Stable isotope results are compared to previous measurements of the traditional sulfur isotopes (S-32, S-34), and findings from other euxinic systems. The direct correlation between salinity and dissolved sulfate and the low concentrations of dissolved sulfide (below 40 µM in the LD and 130 µM in the GB) indicate that now significant net pelagic sulfate reduction took place. Most of the sulfide originates from microbial processes in the surface sediments and further diffusion into the water column. The magnitude of overall 34S/32S discrimination between dissolved sulfate and sulfide in the anoxic water column was 49±1 (LD) and 46±2 (GB) per mil, with only small vertical variations and significantly smaller than in the modern Black Sea. This partitioning is within the range of published results found in experiments with pure cultures of sulfate

  8. Sulfur Isotope Effects of Dissimilatory Sulfite Reductase

    PubMed Central

    Leavitt, William D.; Bradley, Alexander S.; Santos, André A.; Pereira, Inês A. C.; Johnston, David T.

    2015-01-01

    The precise interpretation of environmental sulfur isotope records requires a quantitative understanding of the biochemical controls on sulfur isotope fractionation by the principle isotope-fractionating process within the S cycle, microbial sulfate reduction (MSR). Here we provide the only direct observation of the major (34S/32S) and minor (33S/32S, 36S/32S) sulfur isotope fractionations imparted by a central enzyme in the energy metabolism of sulfate reducers, dissimilatory sulfite reductase (DsrAB). Results from in vitro sulfite reduction experiments allow us to calculate the in vitro DsrAB isotope effect in 34S/32S (hereafter, 34εDsrAB) to be 15.3 ± 2‰, 2σ. The accompanying minor isotope effect in 33S, described as 33λDsrAB, is calculated to be 0.5150 ± 0.0012, 2σ. These observations facilitate a rigorous evaluation of the isotopic fractionation associated with the dissimilatory MSR pathway, as well as of the environmental variables that govern the overall magnitude of fractionation by natural communities of sulfate reducers. The isotope effect induced by DsrAB upon sulfite reduction is a factor of 0.3–0.6 times prior indirect estimates, which have ranged from 25 to 53‰ in 34εDsrAB. The minor isotope fractionation observed from DsrAB is consistent with a kinetic or equilibrium effect. Our in vitro constraints on the magnitude of 34εDsrAB is similar to the median value of experimental observations compiled from all known published work, where 34εr−p = 16.1‰ (r–p indicates reactant vs. product, n = 648). This value closely matches those of MSR operating at high sulfate reduction rates in both laboratory chemostat experiments (34εSO4−H2S =  17.3 ± 1.5‰, 2σ) and in modern marine sediments (34εSO4−H2S =  17.3 ± 3.8‰). Targeting the direct isotopic consequences of a specific enzymatic processes is a fundamental step toward a biochemical foundation for reinterpreting the biogeochemical and geobiological sulfur isotope records in

  9. Sulfur Isotope Effects of Dissimilatory Sulfite Reductase.

    PubMed

    Leavitt, William D; Bradley, Alexander S; Santos, André A; Pereira, Inês A C; Johnston, David T

    2015-01-01

    The precise interpretation of environmental sulfur isotope records requires a quantitative understanding of the biochemical controls on sulfur isotope fractionation by the principle isotope-fractionating process within the S cycle, microbial sulfate reduction (MSR). Here we provide the only direct observation of the major ((34)S/(32)S) and minor ((33)S/(32)S, (36)S/(32)S) sulfur isotope fractionations imparted by a central enzyme in the energy metabolism of sulfate reducers, dissimilatory sulfite reductase (DsrAB). Results from in vitro sulfite reduction experiments allow us to calculate the in vitro DsrAB isotope effect in (34)S/(32)S (hereafter, [Formula: see text]) to be 15.3 ± 2‰, 2σ. The accompanying minor isotope effect in (33)S, described as [Formula: see text], is calculated to be 0.5150 ± 0.0012, 2σ. These observations facilitate a rigorous evaluation of the isotopic fractionation associated with the dissimilatory MSR pathway, as well as of the environmental variables that govern the overall magnitude of fractionation by natural communities of sulfate reducers. The isotope effect induced by DsrAB upon sulfite reduction is a factor of 0.3-0.6 times prior indirect estimates, which have ranged from 25 to 53‰ in (34)εDsrAB. The minor isotope fractionation observed from DsrAB is consistent with a kinetic or equilibrium effect. Our in vitro constraints on the magnitude of [Formula: see text] is similar to the median value of experimental observations compiled from all known published work, where (34)ε r-p = 16.1‰ (r-p indicates reactant vs. product, n = 648). This value closely matches those of MSR operating at high sulfate reduction rates in both laboratory chemostat experiments ([Formula: see text] 17.3 ± 1.5‰, 2σ) and in modern marine sediments ([Formula: see text] 17.3 ± 3.8‰). Targeting the direct isotopic consequences of a specific enzymatic processes is a fundamental step toward a biochemical foundation for reinterpreting the

  10. Assay of S for Quantitation of PEG and TNF Ligated Au Nanoparticles using ID-HR-MC-ICP-MS

    NASA Astrophysics Data System (ADS)

    Mann, J. L.; Vocke, R. D.; Newman, J. D.; Kelly, W. R.

    2009-12-01

    measurements in high-resolution (HR) mode to resolve these interferences reduces the overall signal intensity. To further reduce the effects of the interferences and limit the signal attentuation resulting from running in HR mode, an Aridus II desolvator was used to introduce the sample as a dry aerosol. The signal intensities obtained on the most abundant isotope mass 32 are typically 6 x 10-11 A per ug S/g solution. A small sulfur hydride, however, remains 3 x 10-14 A at mass 33S. By using a 33S enriched spike for isotope dilution, the overall effect of the hydride on mass 33 is significantly reduced (<0.2 %). The samples and standards were spiked in both a 1:1 and 2:1 ratio 32S:33S and the 32S/34S ratio was used as the internal normalization ratio for mass bias determination. Using an iterative procedure, the mass bias and measured 32S/33S ratios were successively corrected until the values converged. This calculation removes the spike contribution to the sample to obtain the mass bias corrected 33S/32S. The corrected 33S/32S ratios were then used in the isotope dilution calculation for S quantitation. Preliminary results on pure sulfur solutions and PEG solutions at a concentration of approximately 1 ppm S (≈ 38 nM PEG/g), show comparable results with rsd’s in the 0.5 to 1% range.

  11. Sulfur and Oxygen Isotopic Analysis of a Cosmic Symplectite from a Comet Wild 2 Stardust Terminal Particle

    NASA Technical Reports Server (NTRS)

    Nguyen, A. N.; Berger, E. L.; Nakamura-Messenger, K.; Messenger, S.

    2015-01-01

    Introduction: Analyses of comet 81P/Wild 2 samples re-turned from the Stardust mission have uncovered surprising simi-larities to meteoritic material, including the identification of inner solar system grains [1-3]. The TEM characterization of terminal particle (TP) 4 from Stardust track #147 revealed an assemblage consisting of symplectically intergrown pentlandite and nanocrys-talline maghemite coexisting with high-Ca pyroxene [4]. Mineral-ogically similar cosmic symplectites (COS) containing pentlandite and magnetite in the primitive Acfer 094 meteorite are highly de-pleted in 16O (?17O, ?18O 180 per mille) [5-7]. This isotopic signature is proposed to record alteration with primordial solar nebula water. Conversely, the normal O isotopic composition of the Stardust COS indicates alteration by a different aqueous reservoir, perhaps on the comet [8]. In this study, we analyzed the Wild 2 COS for S isotopes to further constrain its origin. Experimental: Thin sections of TP4 (12 ?m) were produced and their mineralogy was thoroughly characterized by TEM. Two of the sections were analyzed for O isotopes by isotopic imaging in the JSC NanoSIMS 50L. The sample in one of the slices was completely consumed. The remaining material in the adjacent slice was analyzed simultaneously for 16O, 32S, 33S, 34S, and 56Fe16O in electron multipliers using a Cs+ primary ion beam. Quasi-simulta-neous arrival (QSA) can have a significant effect on S isotopic ra-tios when using electron multipliers, resulting in undercounting of 32S [9]. Canyon Diablo troilite (CDT) was measured numerous times to deduce a correction factor for QSA and ensure measure-ment reproducibility. Isotopic ratios are reported relative to CDT. Results and Discussion: The Wild 2 COS is enriched in the heavy S isotopes relative to CDT (?33S = 6.5 +/- 1.6 per mille; ?34S = 5.1 +/- 0.7 per mille; 1?). The degree of 33S enrichment indicates mass-inde-pendent fractionation (MIF) with ?33S = 3.9 +/- 1.7 per mille. MIF of

  12. Multiple sulfur isotope records at the end-Guadalupian (Permian) at Chaotian, China: Implications for a role of bioturbation in the Phanerozoic sulfur cycle

    NASA Astrophysics Data System (ADS)

    Saitoh, Masafumi; Ueno, Yuichiro; Matsu'ura, Fumihiro; Kawamura, Tetsuya; Isozaki, Yukio; Yao, Jianxin; Ji, Zhansheng; Yoshida, Naohiro

    2017-03-01

    A recent study on quadruple sulfur isotopes (32S, 33S, 34S, and 36S) of sedimentary pyrite suggested that the end-Guadalupian extinction was caused by shoaling of the sulfidic deep-water. This scenario is based on the assumption that sulfur isotopic compositions of pyrite from hosting sediments were controlled by benthos activities, thus by the redox conditions of the sedimentary environments. Nonetheless, the relationship between the sulfur isotope records and redox conditions, reconstructed from litho- and bio-facies, are poorly known. In order to examine the effect of bioturbation in sediments, quadruple sulfur isotopic compositions of sedimentary pyrite from the end-Guadalupian succession in Chaotian, South China, were analyzed. Black mudstones of deep-water facies immediately below the extinction horizon have consistently high Δ33S values of ca. +0.079‰, clearly suggesting a sulfate reduction in the anoxic water column. Our new data are consistent with the emergence of a sulfidic deep-water mass prior to the end-Guadalupian extinction; the upwelling of the toxic deep-water may have contributed to the extinction. In contrast, shallow-marine bioclastic limestones with burrows deposited under oxic conditions have negative Δ33S values. This anomalous isotopic signal indicates the mixing of two distinct types of pyrite; one generated during the sulfate reduction in an open system and the other in a closed system. We interpret that bioturbation supplied sulfate in the sediments and promoted sulfate reduction and in-situ sulfide precipitation within the sediments. The negative Δ33S values of oxic sediments in Chaotian are inconsistent with the previous model and demonstrate that the sedimentary sulfur cycle associated with bioturbation was more complicated than previously thought. Our study also implies that, more generally, the role of bioturbation in increasing seawater sulfate concentration in the Phanerozoic may have been overestimated in the previous

  13. Line Intensities of Isotopic Carbonyl Sulfide (ocs) at 2.5 Micrometer

    NASA Astrophysics Data System (ADS)

    Toth, Robert A.; Sung, Keeyoon; Brown, Linda R.; Crawford, Timothy J.

    2009-06-01

    We have measured line intensities of ^{16}O^{12}C^{32}S, ^{16}O^{13}C^{32}S, ^{16}O^{12}C^{33}S, ^{16}O^{12}C^{34}S, and ^{18}O^{12}C^{32}S in the 2.5 μm region for the first time to support planetary studies of the Venus atmosphere. Laboratory absorption spectra of OCS were recorded at 0.0033 cm^{-1} resolution at room temperature using a Bruker IFS 125-HR Fourier transform spectrometer at the Jet Propulsion Laboratory. Normal samples of OCS were used in this study, and sample impurities and isotopic abundances were determined from mass spectrum analysis. Optical densities sufficient to observe isotopic bands and weaker hot bands were achieved by using a multi-pass White cell and single pass gas cells in various path lengths, which were validated by analyzing near-IR CO_2 spectra. We present line intensities for almost 30 bands of the OCS isotopes excluding ground state bands of ^{16}O^{12}C^{32}S, which we have reported recently. We have Herman-Wallis factors determined for the individual bands. In some cases, it has been observed that band intensities normalized to 100% isotopic species show a significant deviation from that of the primary isotopic species (up to by 12.5%). No earlier measurements have been reported for these bands. Measurement precision and accuracies will be discussed. Research described in this paper was performed at the Jet Propulsion Laboratory, California Institute of Technology, under contracts and cooperative agreements with the National Aeronautics and Space Administration. We thank Drs. Stojan Madzunkov, John A. MacAskill, and Murray R. Darrach from the Atomic and Molecular Collision Group at Jet Propulsion Laboratory for recording mass spectrum of the OCS sample used in this work.

  14. Theoretical estimation of equilibrium sulfur isotope fractionations among aqueous sulfite species: Implications for isotope models of microbial sulfate reduction

    NASA Astrophysics Data System (ADS)

    Eldridge, D. L.; Farquhar, J.; Guo, W.

    2015-12-01

    Sulfite (sensu lato), an intermediate in a variety sulfur redox processes, plays a particularly important role in microbial sulfate reduction. It exists intracellularly as multiple species between sets of enzymatic reactions that transform sulfate to sulfide, with the exact speciation depending on pH, T, and ionic strength. However, the complex speciation of sulfite is ignored in current isotope partitioning models of microbial sulfate reduction and simplified solely to the pyramidal SO32- (sulfite sensu stricto), due to a lack of appropriate constraints. We theoretically estimated the equilibrium sulfur isotope fractionations (33S/32S, 34S/32S, 36S/32S) among all documented sulfite species in aqueous solution, including sulfite (SO32-), bisulfite isomers and dimers ((HS)O3-, (HO)SO2-, S2O52-), and SO2(aq), through first principles quantum mechanical calculations. The calculations were performed at B3LYP/6-31+G(d,p) level using cluster models with 30-40 water molecules surrounding the solute. Our calculated equilibrium fractionation factors compare well to the available experimental constraints and suggest that the minor and often-ignored tetrahedral (HS)O3- isomer of bisulfite strongly influences isotope partitioning behavior in the sulfite system under most environmentally relevant conditions, particularly fractionation magnitudes and unusual temperature dependence. For example, we predict that sulfur isotope fractionation between sulfite and bulk bisulfite in solution should have an apparent inverse temperature dependence due to the influence of (HS)O3- and its increased stability at higher temperatures. Our findings highlight the need to appropriately account for speciation/isomerization of sulfur species in sulfur isotope studies. We will also present similar calculation results of other aqueous sulfur compounds (e.g., H2S/HS-, SO42-, S2O32-, S3O62-, and poorly documented SO22- species), and discuss the implication of our results for microbial sulfate

  15. Multiple sulfur isotope composition of oxidized Samoan melts and the implications of a sulfur isotope 'mantle array' in chemical geodynamics

    NASA Astrophysics Data System (ADS)

    Labidi, J.; Cartigny, P.; Jackson, M. G.

    2015-05-01

    To better address how subducted protoliths drive the Earth's mantle sulfur isotope heterogeneity, we report new data for sulfur (S) and copper (Cu) abundances, S speciation and multiple S isotopic compositions (32S, 33S, 34S, 36S) in 15 fresh submarine basaltic glasses from the Samoan archipelago, which defines the enriched-mantle-2 (EM2) endmember. Bulk S abundances vary between 835 and 2279 ppm. About 17 ± 11% of sulfur is oxidized (S6+) but displays no consistent trend with bulk S abundance or any other geochemical tracer. The S isotope composition of both dissolved sulfide and sulfate yield homogeneous Δ33S and Δ36S values, within error of Canyon Diablo Troilite (CDT). In contrast, δ34S values are variable, ranging between +0.11 and +2.79‰ (±0.12‰ 1σ) for reduced sulfur, whereas oxidized sulfur values vary between +4.19 and +9.71‰ (±0.80‰, 1σ). Importantly, δ34S of the reduced S pool correlates with the 87Sr/86Sr ratios of the glasses, in a manner similar to that previously reported for South-Atlantic MORB, extending the trend to δ34S values up to + 2.79 ± 0.04 ‰, the highest value reported for undegassed oceanic basalts. As for EM-1 basalts from the South Atlantic ridge, the linear δ34S-87Sr/86Sr trend requires the EM-2 endmember to be relatively S-rich, and only sediments can account for these isotopic characteristics. While many authors argue that both the EM-1 and EM-2 mantle components record subduction of various protoliths (e.g. upper or lower continental crust, lithospheric mantle versus intra-metasomatized mantle, or others), it is proposed here that they primarily reflect sediment recycling. Their distinct Pb isotope variation can be accounted for by varying the proportion of S-poor recycled oceanic crust in the source of mantle plumes.

  16. Placing an upper limit on cryptic marine sulphur cycling.

    PubMed

    Johnston, D T; Gill, B C; Masterson, A; Beirne, E; Casciotti, K L; Knapp, A N; Berelson, W

    2014-09-25

    A quantitative understanding of sources and sinks of fixed nitrogen in low-oxygen waters is required to explain the role of oxygen-minimum zones (OMZs) in controlling the fixed nitrogen inventory of the global ocean. Apparent imbalances in geochemical nitrogen budgets have spurred numerous studies to measure the contributions of heterotrophic and autotrophic N2-producing metabolisms (denitrification and anaerobic ammonia oxidation, respectively). Recently, 'cryptic' sulphur cycling was proposed as a partial solution to the fundamental biogeochemical problem of closing marine fixed-nitrogen budgets in intensely oxygen-deficient regions. The degree to which the cryptic sulphur cycle can fuel a loss of fixed nitrogen in the modern ocean requires the quantification of sulphur recycling in OMZ settings. Here we provide a new constraint for OMZ sulphate reduction based on isotopic profiles of oxygen ((18)O/(16)O) and sulphur ((33)S/(32)S, (34)S/(32)S) in seawater sulphate through oxygenated open-ocean and OMZ-bearing water columns. When coupled with observations and models of sulphate isotope dynamics and data-constrained model estimates of OMZ water-mass residence time, we find that previous estimates for sulphur-driven remineralization and loss of fixed nitrogen from the oceans are near the upper limit for what is possible given in situ sulphate isotope data.

  17. SQUID-SIMS is a useful approach to uncover primary signals in the Archean sulfur cycle.

    PubMed

    Fischer, Woodward W; Fike, David A; Johnson, Jena E; Raub, Timothy D; Guan, Yunbin; Kirschvink, Joseph L; Eiler, John M

    2014-04-15

    Many aspects of Earth's early sulfur cycle, from the origin of mass-anomalous fractionations to the degree of biological participation, remain poorly understood--in part due to complications from postdepositional diagenetic and metamorphic processes. Using a combination of scanning high-resolution magnetic superconducting quantum interference device (SQUID) microscopy and secondary ion mass spectrometry (SIMS) of sulfur isotopes ((32)S, (33)S, and (34)S), we examined drill core samples from slope and basinal environments adjacent to a major Late Archean (∼2.6-2.5 Ga) marine carbonate platform from South Africa. Coupled with petrography, these techniques can untangle the complex history of mineralization in samples containing diverse sulfur-bearing phases. We focused on pyrite nodules, precipitated in shallow sediments. These textures record systematic spatial differences in both mass-dependent and mass-anomalous sulfur-isotopic composition over length scales of even a few hundred microns. Petrography and magnetic imaging demonstrate that mass-anomalous fractionations were acquired before burial and compaction, but also show evidence of postdepositional alteration 500 million y after deposition. Using magnetic imaging to screen for primary phases, we observed large spatial gradients in Δ(33)S (>4‰) in nodules, pointing to substantial environmental heterogeneity and dynamic mixing of sulfur pools on geologically rapid timescales. In other nodules, large systematic radial δ(34)S gradients (>20‰) were observed, from low values near their centers increasing to high values near their rims. These fractionations support hypotheses that microbial sulfate reduction was an important metabolism in organic-rich Archean environments--even in an Archean ocean basin dominated by iron chemistry.

  18. SQUID–SIMS is a useful approach to uncover primary signals in the Archean sulfur cycle

    PubMed Central

    Fischer, Woodward W.; Fike, David A.; Johnson, Jena E.; Raub, Timothy D.; Guan, Yunbin; Kirschvink, Joseph L.; Eiler, John M.

    2014-01-01

    Many aspects of Earth’s early sulfur cycle, from the origin of mass-anomalous fractionations to the degree of biological participation, remain poorly understood—in part due to complications from postdepositional diagenetic and metamorphic processes. Using a combination of scanning high-resolution magnetic superconducting quantum interference device (SQUID) microscopy and secondary ion mass spectrometry (SIMS) of sulfur isotopes (32S, 33S, and 34S), we examined drill core samples from slope and basinal environments adjacent to a major Late Archean (∼2.6–2.5 Ga) marine carbonate platform from South Africa. Coupled with petrography, these techniques can untangle the complex history of mineralization in samples containing diverse sulfur-bearing phases. We focused on pyrite nodules, precipitated in shallow sediments. These textures record systematic spatial differences in both mass-dependent and mass-anomalous sulfur-isotopic composition over length scales of even a few hundred microns. Petrography and magnetic imaging demonstrate that mass-anomalous fractionations were acquired before burial and compaction, but also show evidence of postdepositional alteration 500 million y after deposition. Using magnetic imaging to screen for primary phases, we observed large spatial gradients in Δ33S (>4‰) in nodules, pointing to substantial environmental heterogeneity and dynamic mixing of sulfur pools on geologically rapid timescales. In other nodules, large systematic radial δ34S gradients (>20‰) were observed, from low values near their centers increasing to high values near their rims. These fractionations support hypotheses that microbial sulfate reduction was an important metabolism in organic-rich Archean environments—even in an Archean ocean basin dominated by iron chemistry. PMID:24706767

  19. Hydrogen Sulfide Sequestration and Storage in Geothermal System: New Mitigation Strategy to Reduce H2S from the Atmosphere and Detect its Mineralization with Multiple Sulfur Isotopic Systematics

    NASA Astrophysics Data System (ADS)

    Marieni, C.; Stefansson, A.; Gudbrandsson, S.; Gunnarsson, I.; Aradottir, E. S.; Gunnarsson Robin, J.; Ono, S.

    2015-12-01

    Hydrogen sulfide (H2S) is one of the major components in geothermal fluids and is commonly emitted into the atmosphere from geothermal power plants causing potential environmental problems. Among several mitigation methods proposed to reduce the H2S emissions, is H2S sequestration into geothermal systems. Reykjavík Energy is undertaking a pilot project at Hellisheidi geothermal system (SW Iceland) called Sulfix project where H2S is being injected into the geothermal reservoir for permanent sequestration into pyrite. The SulFix project started its operation in June 2014: the soluble geothermal gases are dissolved in geothermal waste water, and injected at 8 bars into the high temperature reservoir (>200˚C) at 750 m below the wellhead. The reactions involving sulfur in the geothermal reservoir may be traced using sulfur fluid chemistry and multiple sulfur isotope systematics (32S, 33S, 34S and 36S), including mixing between the reservoir geothermal fluid and the injection fluid, sulfide mineralization and oxidation of sulfide to sulfate. In this study we investigated the multiple sulfur isotope systematics upon sulfide mineralization under geothermal conditions. High temperature flow through experiments were carried out in basaltic glass at 200-250°C and ~5 mmol/kg H2S to study the fluid-rock interaction. The results indicate that the sulfide mineralization occurs rapidly under geothermal conditions, highlighting the leaching rate of iron from the basaltic glass as the mineralization rate determining factor. Moreover, the formation of sulfide may be traced using the δ34S33S relationship in the fluids and pyrite formation - for example to determine if non-reactive mixing between the injection fluids and reservoir fluids occurs at Hellisheidi. The experimental results have been further supported by geochemical modeling involving multiple sulfur isotope fractionation between aqueous sulfide species and rocks upon basalt dissolution and secondary pyrite formation.

  20. Multiple sulfur isotopes fractionations associated with abiotic sulfur transformations in Yellowstone National Park geothermal springs

    PubMed Central

    2014-01-01

    Background The paper presents a quantification of main (hydrogen sulfide and sulfate), as well as of intermediate sulfur species (zero-valent sulfur (ZVS), thiosulfate, sulfite, thiocyanate) in the Yellowstone National Park (YNP) hydrothermal springs and pools. We combined these measurements with the measurements of quadruple sulfur isotope composition of sulfate, hydrogen sulfide and zero-valent sulfur. The main goal of this research is to understand multiple sulfur isotope fractionation in the system, which is dominated by complex, mostly abiotic, sulfur cycling. Results Water samples from six springs and pools in the Yellowstone National Park were characterized by pH, chloride to sulfate ratios, sulfide and intermediate sulfur species concentrations. Concentrations of sulfate in pools indicate either oxidation of sulfide by mixing of deep parent water with shallow oxic water, or surface oxidation of sulfide with atmospheric oxygen. Thiosulfate concentrations are low (<6 μmol L-1) in the pools with low pH due to fast disproportionation of thiosulfate. In the pools with higher pH, the concentration of thiosulfate varies, depending on different geochemical pathways of thiosulfate formation. The δ34S values of sulfate in four systems were close to those calculated using a mixing line of the model based on dilution and boiling of a deep hot parent water body. In two pools δ34S values of sulfate varied significantly from the values calculated from this model. Sulfur isotope fractionation between ZVS and hydrogen sulfide was close to zero at pH < 4. At higher pH zero-valent sulfur is slightly heavier than hydrogen sulfide due to equilibration in the rhombic sulfur–polysulfide – hydrogen sulfide system. Triple sulfur isotope (32S, 33S, 34S) fractionation patterns in waters of hydrothermal pools are more consistent with redox processes involving intermediate sulfur species than with bacterial sulfate reduction. Small but resolved differences in ∆33S among

  1. Non-chondritic sulphur isotope composition of the terrestrial mantle.

    PubMed

    Labidi, J; Cartigny, P; Moreira, M

    2013-09-12

    Core-mantle differentiation is the largest event experienced by a growing planet during its early history. Terrestrial core segregation imprinted the residual mantle composition by scavenging siderophile (iron-loving) elements such as tungsten, cobalt and sulphur. Cosmochemical constraints suggest that about 97% of Earth's sulphur should at present reside in the core, which implies that the residual silicate mantle should exhibit fractionated (34)S/(32)S ratios according to the relevant metal-silicate partition coefficients, together with fractionated siderophile element abundances. However, Earth's mantle has long been thought to be both homogeneous and chondritic for (34)S/(32)S, similar to Canyon Diablo troilite, as it is for most siderophile elements. This belief was consistent with a mantle sulphur budget dominated by late-accreted chondritic components. Here we show that the mantle, as sampled by mid-ocean ridge basalts from the south Atlantic ridge, displays heterogeneous (34)S/(32)S ratios, directly correlated to the strontium and neodymium isotope ratios (87)Sr/(86)Sr and (143)Nd/(144)Nd. These isotope trends are compatible with binary mixing between a low-(34)S/(32)S ambient mantle and a high-(34)S/(32)S recycled component that we infer to be subducted sediments. The depleted end-member is characterized by a significantly negative δ(34)S of -1.28 ± 0.33‰ that cannot reach a chondritic value even when surface sulphur (from continents, altered oceanic crust, sediments and oceans) is added. Such a non-chondritic (34)S/(32)S ratio for the silicate Earth could be accounted for by a core-mantle differentiation record in which the core has a (34)S/(32)S ratio slightly higher than that of chondrites (δ(34)S = +0.07‰). Despite evidence for late-veneer addition of siderophile elements (and therefore sulphur) after core formation, our results imply that the mantle sulphur budget retains fingerprints of core-mantle differentiation.

  2. SO2 photolysis as a source for sulfur mass-independent isotope signatures in stratospheric aerosols

    NASA Astrophysics Data System (ADS)

    Whitehill, A. R.; Jiang, B.; Guo, H.; Ono, S.

    2014-09-01

    Signatures of sulfur isotope mass-independent fractionation (S-MIF) have been observed in stratospheric sulfate aerosols deposited in polar ice. The S-MIF signatures are associated with stratospheric photochemistry following stratospheric volcanic eruptions, but the exact mechanism responsible for the production and preservation of these signatures is debated. In order to identify the origin and the mechanism of preservation for these signatures, a series of laboratory photochemical experiments were carried out to investigate the effect of temperature and added O2 on S-MIF produced by the two absorption band systems of SO2 photolysis in the 190 to 220 nm region and photoexcitation in the 250 to 350 nm region. The SO2 photolysis (SO2 + hν → SO + O) experiments showed S-MIF signals with large 34S / 32S fractionation, which increases with decreasing temperature. The overall S-MIF pattern observed for photolysis experiments, including high 34S / 32S fractionations, positive mass-independent anomalies in 33S, and negative anomalies in 36S, is consistent with a major contribution from optical isotopologue screening effects and measurements for stratospheric sulfate aerosols. SO2 photoexicitation produced products with positive MIF anomalies in both 33S and 36S that is different from stratospheric aerosols. SO2 photolysis in the presence of O2 produced SO3 with S-MIF signals, suggesting the transfer of the MIF signals of SO to SO3 by the SO + O2 + M → SO3 + M reaction. This is supported with energy calculations of stationary points on the SO3 potential energy surfaces, which indicate that this reaction occurs slowly on a single adiabatic surface, but that it can occur more rapidly through intersystem crossing. The results from our experiments constrain the termolecular reaction rate to between 1.0 × 10-37 cm6 molecule-2 s-1 and 1.0 × 10-36 cm6 molecule-2 s-1. This rate can explain the preservation of mass independent isotope signatures in stratospheric sulfate

  3. Spatially resolved Fe- and S-isotope composition of sedimentary pyrite

    NASA Astrophysics Data System (ADS)

    Rouxel, O.; Bekker, A.; Germain, Y.; Ponzevera, E.

    2012-04-01

    Past studies of iron and sulfur isotope records of sedimentary sulfides over geological time have placed important constraints on the biogeochemical cycle of sulfur and iron and the evolution of ocean chemistry. Since biogeochemical cycles of Fe and S are closely coupled in marine systems, Fe-limitation and S-limitation for pyrite formation in black shales should leave an imprint on the isotopic record of both elements. We developed a technique for accurate and spatially-resolved measurement of 34S/32S, 33S/32S, 56Fe/54Fe, and 57Fe/54Fe isotope ratios in sedimentary pyrite using a combination of solution and laser ablation analysis. Fe- and S-isotope ratios were measured by high-resolution MC-ICP-MS (ThermoElectron Neptune), enabling us to resolve major isobaric interferences on S isotopes and Fe isotopes from O2+, ArN+, and ArO+. A CETAC LSX 213 nm laser was used as the ablation source with He as the sample carrier gas. Fe- and S-isotope ratios were calibrated against several pyrite standards using the conventional "sample-standard bracketing technique". Instrumental mass bias of Fe and S isotopes were also corrected through an internal normalization technique using respectively Ni and Mg of known isotope composition. The long-term reproducibility of S- and Fe-isotope compositions was typically better than 0.2 per mil. We investigated the fine scale variations of d56Fe, d34S and d33S values of diagenetic pyrite nodules in several Devonian, Paleoproterozoic and Archean black shales in order to (1) explore biosignature potential of co-variations of Fe- and S-isotopes at the grain-size scale; (2) assess potential diagenetic effects on Fe-isotope fractionation during sulfide formation; and (3) assess potential mixing between isotopically distinct Fe- and S-pools using multiple S isotope data. Those results will be presented together with bulk stratigraphic S- and Fe-isotopic variations and Fe speciation data in order to establish an Fe isotope mass balance in black

  4. Experiments on δ34S mixing between organic and inorganic sulfur species during thermal maturation

    USGS Publications Warehouse

    Amrani, Alon; Said-Ahamed, Ward; Lewan, Michael D.; Aizenshtat, Zeev

    2006-01-01

    Reduced sulfur species were studied to constrain isotopic exchange-mixing with synthetic polysulfide cross-linked macromolecules (PCLM), model sulfur containing molecules and natural sulfur-rich kerogen, asphalt and oil of the Dead Sea area. PCLM represents protokerogens that are rich in sulfur and thermally unstable. Mixing rates of PCLM with HS-(aq) (added as (NH4)2S(aq)) at low to moderate temperatures (50–200 °C) are rapid. Elemental sulfur and H2S(gas) fully mix isotopes with PCLM during pyrolysis conditions at 200 °C. During these reactions significant structural changes of the PCLM occur to form polysulfide dimers, thiolanes and thiophenes. As pyrolysis temperatures or reaction times increase, the PCLM thermal products are transformed to more aromatic sulfur compounds. Isotopic mixing rates increase with increasing pyrolysis temperature and time. Polysulfide bonds (S–S) in the PCLM are responsible for most of these structural and isotopic changes because of their low stability. Conversely, sulfur isotope mixing does not occur between dibenzothiophene (aromatic S) or hexadecanthiol (C–SH) and HS-(aq) at 200 °C after 48 h. This shows that rates of sulfur isotope mixing are strongly dependent on the functionality of the sulfur in the organic matter. The order of isotopic mixing rates for organic matter is kerogen > asphalt > oil, which is inverse to their sulfur thermal stability. Asphalt and oil with more refractory sulfur show significantly lower isotopes mixing rates than the kerogen with more labile sulfur. Based on the findings of the present study we suggest that sulfur isotopes mixing can occur from early diagenesis into catagenesis and result in isotopic homogenization of the inorganic and organic reduced sulfur pools.

  5. Multiple sulfur isotope fractionation and mass transfer processes during pyrite precipitation and recrystallization: An experimental study at 300 and 350 °C

    NASA Astrophysics Data System (ADS)

    Syverson, Drew D.; Ono, Shuhei; Shanks, Wayne C.; Seyfried, William E.

    2015-09-01

    Equilibrium multiple sulfur isotope fractionation factors (33S/32S and 34S/32S) between aqueous SO4, H2S, and coexisting pyrite under hydrothermal conditions were determined experimentally at 300-350 °C and 500 bars. Two different experimental techniques were used to determine the fractionation factors and the rate of S isotope exchange between pyrite and constituent aqueous species, H2S and SO4; (1) closed system gold capsule pyrite-H2S exchange experiments and (2) complimentary time-series experiments at 300 and 350 °C, 500 bars using flexible gold cell hydrothermal equipment, which allowed monitoring the multiple S isotope composition of dissolved S species during pyrite precipitation and subsequent recrystallization. The three isotope technique was applied to the multiple S isotope data to demonstrate equilibrium S isotope fractionation between pyrite and H2S. Results at 350 °C indicate ln34αPyrite/H2S = -1.9‰ and ln33αPyrite/H2S = -1.0‰. The ln34αPyrite/H2S is not only different in magnitude but also in sign from the commonly used value of 1‰ from Ohmoto and Rye (1979). This experimental study also demonstrated initial S isotope disequilibrium amongst the aqueous S-species and pyrite during rapid precipitation, despite aqueous speciation indicating pyrite saturation at all stages. Textural, crystallographic, and S isotope interpretations suggest that pyrite formed by means of the FeS pathway. The initial S isotope disequilibrium between formed pyrite and dissolved S-species was effectively erased and approached isotopic equilibrium upon recrystallization during the course of 4297 h. Interpretation of seafloor hydrothermal vent sulfides using the revised equilibrium 34S/32S fractionation between pyrite and H2S suggests that pyrite is close to S isotope equilibrium with vent H2S, contrary to previous conclusions. The experimental data reported here broaden the range of pyrite formation mechanisms at seafloor hydrothermal vents, in that mineral

  6. Theoretical estimates of equilibrium sulfur isotope effects in aqueous sulfur systems: Highlighting the role of isomers in the sulfite and sulfoxylate systems

    NASA Astrophysics Data System (ADS)

    Eldridge, D. L.; Guo, W.; Farquhar, J.

    2016-12-01

    We present theoretical calculations for all three isotope ratios of sulfur (33S/32S, 34S/32S, 36S/32S) at the B3LYP/6-31+G(d,p) level of theory for aqueous sulfur compounds modeled in 30-40H2O clusters spanning the range of sulfur oxidation state (Sn, n = -2 to +6) for estimating equilibrium fractionation factors in aqueous systems. Computed 34β values based on major isotope (34S/32S) reduced partition function ratios (RPFRs) scale to a first order with sulfur oxidation state and coordination, where 34β generally increase with higher oxidation state and increasing coordination of the sulfur atom. Exponents defining mass dependent relationships based on β values (x/34κ = ln(xβ)/ln(34β), x = 33 or 36) conform to tight ranges over a wide range of temperature for all aqueous compounds (33/34κ ≈ 0.5148-0.5159, 36/34κ ≈ 1.89-1.90 from T ⩾ 0 °C). The exponents converge near a singular value for all compounds at the high temperature limit (33/34κT→∞ = 0.51587 ± 0.00003 and 36/34κT→∞ = 1.8905 ± 0.0002; 1 s.d. of all computed compounds), and typically follow trends based on oxidation state and coordination similar to those seen in 34β values at lower temperatures. Theoretical equilibrium fractionation factors computed from these β-values are compared to experimental constraints for HSO3-T(aq)/SO2(g, aq), SO2(aq)/SO2(g), H2S(aq)/H2S(g), H2S(aq)/HS-(aq), SO42-(aq)/H2ST(aq), S2O32-(aq) (intramolecular), and S2O32-(aq)/H2ST(aq), and generally agree within a reasonable estimation of uncertainties. We make predictions of fractionation factors where other constraints are unavailable. Isotope partitioning of the isomers of protonated compounds in the sulfite and sulfoxylate systems depend strongly on whether protons are bound to either sulfur or oxygen atoms. The magnitude of the HSO3-T/SO32- major isotope (34S/32S) fractionation factor is predicted to increase with temperature from 0 to 70 °C due to the combined effects of the large magnitude (HS)O3

  7. Multiple Sulfur Isotopes and Sulfur/Selenium Ratios as Tracers for the Subsurface Biosphere in Altered Oceanic Basalts in the Western Pacific

    NASA Astrophysics Data System (ADS)

    Rouxel, O. J.; Ono, S.; Alt, J.; Rumble, D.

    2006-05-01

    Alteration of oceanic crust by seawater is one of the most important processes controlling the global fluxes of elements and microbes likely play a significant role in this process. However, the study of the extent and nature of an active biosphere in the oceanic basement is currently limited due to technical difficulties involved in identifying indigenous microbes. Here, we report S isotope compositions of secondary sulfides in ~170 Ma altered basalt from ODP Site 801 in the western Pacific to assess the potential presence of microbial sulfate reduction within the basaltic oceanic crust. In-situ ion microprobe and bulk rock S isotope analyses show large variations of δ34S values ranging from -45‰ to 1‰. Low δ34S values are consistent with the coupled effects of bacterial reduction of seawater sulfate and disproportionation of S-intermediate species as observed in sedimentary environments. These low and variable δ34S values, together with bulk rock S concentrations ranging from 0.02% up to 1.28% are consistent with a net addition of reduced sulfur in some sections of the crust and constitute clear evidence for microbial activity in basaltic ocean crust. Preliminary results of high-precision multiple-sulfur isotope analyses (33S/32S, and 36S/32S) show at least two generations of secondary pyrite in altered basalt. One is mass- dependent with seawater sulfate, consistent with microbial sulfate reduction under low metabolic rate. Another set of data are consistent with either mixing of these sulfate-derived sulfides with basaltic primary sulfide or with partial oxidation-reprecipitation origin. Since Se substitutes for S in sulfides, S/Se ratios coupled to S isotopes provide further constraints on the source of S (whether remobilization of basaltic sulfide or seawater sulfate). Bacterial sulfate reduction is expected to produce a negative relationship between δ34S and S/Se composition of altered basalt since the S/Se ratio of seawater (~1.6x107) differs

  8. Ames 32S16O18O line list for high-resolution experimental IR analysis

    NASA Astrophysics Data System (ADS)

    Huang, Xinchuan; Schwenke, David W.; Lee, Timothy J.

    2016-12-01

    By comparing to the most recent experimental data and spectra of the SO2 628 ν1/ν3 bands (see Ulenikov et al., JQSRT 168 (2016) 29-39), this study illustrates the reliability and accuracy of the Ames-296K SO2 line list, which is accurate enough to facilitate such high-resolution spectroscopic analysis. The SO2 628 IR line list is computed on a recently improved potential energy surface (PES) refinement, denoted Ames-Pre2, and the published purely ab initio CCSD(T)/aug-cc-pV(Q+d)Z dipole moment surface. Progress has been made in both energy level convergence and rovibrational quantum number assignments agreeing with laboratory analysis models. The accuracy of the computed 628 energy levels and line list is similar to what has been achieved and reported for SO2 626 and 646, i.e. 0.01-0.03 cm-1 for bands up to 5500 cm-1. During the comparison, we found some discrepancies in addition to overall good agreements. The three-IR-list based feature-by-feature analysis in a 0.25 cm-1 spectral window clearly demonstrates the power of the current Ames line lists with new assignments, correction of some errors, and intensity contributions from varied sources including other isotopologues. We are inclined to attribute part of detected discrepancies to an incomplete experimental analysis and missing intensity in the model. With complete line position, intensity, and rovibrational quantum numbers determined at 296 K, spectroscopic analysis is significantly facilitated especially for a spectral range exhibiting such an unusually high density of lines. The computed 628 rovibrational levels and line list are accurate enough to provide alternatives for the missing bands or suspicious assignments, as well as helpful to identify these isotopologues in various celestial environments. The next step will be to revisit the SO2 828 and 646 spectral analyses.

  9. Fourier Transform Microwave Spectrum of CO{_2} -(CH{_3}){_2} S

    NASA Astrophysics Data System (ADS)

    Kawashima, Yoshiyuki; Moritani, Takayuki; Hirota, Eizi

    2012-06-01

    In spite of the fact that the oxygen and sulfur atoms belong to the same group in the periodic table, oxygen-containing molecules and their corresponding sulfur analogues often exhibit characteristic differences in their chemical and physical properties. We have been interested in these differences and have investigated, in a systematic way using Fourier transform microwave (FTMW) spectroscopy combined with ab initio molecular orbital calculations, complexes consisting of dimethyl ether (DME)/dimethyl sulfide (DMS) and ethylene oxide (EO)/ ethylene sulfide (ES), each being attached to either one of rare gas atoms (Rg), CO, N{_2}, or CO{_2}. Among others the CO{_2}-DMS complex should be mentioned, which, in sharp contrast with its counterpart: CO{_2}-DME behaves anomalously, presumably because of low-frequency internal motions, and we have decided to explore it in detail by a FTMW spectrometer. We have generated the CO{_2}-DMS complex by supersonic expansion of a CO{_2} and DMS mixture diluted with Ar, and have scanned the frequency region from 5 to 24 GHz to record the rotational spectra of the complex. We have found it difficult to fit the observed transition frequencies to the ordinary rotational Hamiltonian, but have succeeded to assign 75 transitions by sum rules among the observed transition frequencies. We are suspecting the anomalous behavior of the complex to be caused by a low-frequency torsion of the moieties. In the case of the CO{_2}-DME, the internal rotations of the two methyl groups of the DME were shown to be locked to the CO{_2} by hydrogen bonding, whereas, for the CO{_2}-DMS, we have observed internal-rotation splittings of the two methyl groups of the DMS, indicating the structure of the CO{_2}-DMS complex being considerably different from that of the CO{_2}-DME. We will report the structure at the potential minima and the internal motion of the CO{_2}-DMS, in comparison with the results predicted by quantum chemical calculations. Y. Kawashima, A. Sato, Y. Orita, and E. Hirota J. Phys. Chem. A 116, 1224 2012. J. J. Newby, R. A. Peebles, and S. A. Peebles J. Phys. Chem. A 108, 11234 2004.

  10. Multiple sulfur isotopes and the evolution of Earth's surface sulfur cycle

    NASA Astrophysics Data System (ADS)

    Johnston, David T.

    2011-05-01

    The distribution of sulfur isotopes in geological materials reveals information about Earth history and biogeochemical processes. Research during the last several decades has used sulfur isotope geochemistry as a tool to better understand microbial processes ( Harrison and Thode, 1958; Kaplan, 1975; Monster et al., 1979; Peck, 1959, 1962; Rees, 1973) and sediment diagenesis ( Berner, 1969, 1982; Canfield et al., 1993b). Earth historians also realized this potential, as there exists a rich record of environmental change within the sedimentary records ( Canfield and Teske, 1996; Claypool et al., 1980; Goodwin et al., 1976; Habicht et al., 2002; Kah et al., 2004; Monster et al., 1979; Shen et al., 2001; Strauss, 1993; Thode and Goodwin, 1983). These applications have championed the use of the two most abundant sulfur isotopes [ 32S and 34S], and provide a rich introduction to what the sulfur isotope record has to offer [see ( Canfield, 2004; Canfield and Raiswell, 1999)]. Within the last decade, this information has been supplemented by new data derived from the less abundant isotopes [ 33S and 36S]. The measurement of all four stable sulfur isotopes - multiple sulfur isotope geochemistry - has expanded our understanding of biological evolution and activity, atmospheric chemistry and transport, crustal recycling, and many more fields related to Earth surface processes [see ( Farquhar and Wing, 2003)]. Here, I present a review of recent works in multiple sulfur isotope geochemistry with a focus on results that inform our understanding of biogeochemical processes and Earth surface evolution.

  11. Thermal-neutron capture for A=36-44

    SciTech Connect

    Chunmei, Z.; Firestone, R.B.

    2003-01-01

    The prompt gamma-ray data of thermal- neutron captures fornuclear mass number A=26-35 had been evaluated and published in "ATOMICDATA AND NUCLEAR DATA TABLES, 26, 511 (1981)". Since that time the manyexperimental data of the thermal-neutron captures have been measured andpublished. The update of the evaluated prompt gamma-ray data is verynecessary for use in PGAA of high-resolution analytical prompt gamma-rayspectroscopy. Besides, the evaluation is also very needed in theEvaluated Nuclear Structure Data File, ENSDF, because there are no promptgamma-ray data in ENSDF. The levels, prompt gamma-rays and decay schemesof thermal-neutron captures fornuclides (26Mg, 27Al, 28Si, 29Si, 30Si,31P, 32S, 33S, 34S, and 35Cl) with nuclear mass number A=26-35 have beenevaluated on the basis of all experimental data. The normalizationfactors, from which absolute prompt gamma-ray intensity can be obtained,and necessary comments are given in the text. The ENSDF format has beenadopted in this evaluation. The physical check (intensity balance andenergy balance) of evaluated thermal-neutron capture data has been done.The evaluated data have been put into Evaluated Nuclear Structure DataFile, ENSDF. This evaluation may be considered as an update of the promptgamma-ray from thermal-neutron capture data tables as published in"ATOMIC DATA AND NUCLEAR DATA TABLES, 26, 511 (1981)".

  12. Vibronic origin of sulfur mass-independent isotope effect in photoexcitation of SO2 and the implications to the early earth’s atmosphere

    PubMed Central

    Whitehill, Andrew R.; Xie, Changjian; Hu, Xixi; Xie, Daiqian; Guo, Hua; Ono, Shuhei

    2013-01-01

    Signatures of mass-independent isotope fractionation (MIF) are found in the oxygen (16O,17O,18O) and sulfur (32S, 33S, 34S, 36S) isotope systems and serve as important tracers of past and present atmospheric processes. These unique isotope signatures signify the breakdown of the traditional theory of isotope fractionation, but the physical chemistry of these isotope effects remains poorly understood. We report the production of large sulfur isotope MIF, with Δ33S up to 78‰ and Δ36S up to 110‰, from the broadband excitation of SO2 in the 250–350-nm absorption region. Acetylene is used to selectively trap the triplet-state SO2 (3B1), which results from intersystem crossing from the excited singlet (1A2/1B1) states. The observed MIF signature differs considerably from that predicted by isotopologue-specific absorption cross-sections of SO2 and is insensitive to the wavelength region of excitation (above or below 300 nm), suggesting that the MIF originates not from the initial excitation of SO2 to the singlet states but from an isotope selective spin–orbit interaction between the singlet (1A2/1B1) and triplet (3B1) manifolds. Calculations based on high-level potential energy surfaces of the multiple excited states show a considerable lifetime anomaly for 33SO2 and 36SO2 for the low vibrational levels of the 1A2 state. These results demonstrate that the isotope selectivity of accidental near-resonance interactions between states is of critical importance in understanding the origin of MIF in photochemical systems. PMID:23836655

  13. Vibronic origin of sulfur mass-independent isotope effect in photoexcitation of SO2 and the implications to the early earth's atmosphere.

    PubMed

    Whitehill, Andrew R; Xie, Changjian; Hu, Xixi; Xie, Daiqian; Guo, Hua; Ono, Shuhei

    2013-10-29

    Signatures of mass-independent isotope fractionation (MIF) are found in the oxygen ((16)O,(17)O,(18)O) and sulfur ((32)S, (33)S, (34)S, (36)S) isotope systems and serve as important tracers of past and present atmospheric processes. These unique isotope signatures signify the breakdown of the traditional theory of isotope fractionation, but the physical chemistry of these isotope effects remains poorly understood. We report the production of large sulfur isotope MIF, with Δ(33)S up to 78‰ and Δ(36)S up to 110‰, from the broadband excitation of SO2 in the 250-350-nm absorption region. Acetylene is used to selectively trap the triplet-state SO2 ( (3)B1), which results from intersystem crossing from the excited singlet ( (1)A2/ (1)B1) states. The observed MIF signature differs considerably from that predicted by isotopologue-specific absorption cross-sections of SO2 and is insensitive to the wavelength region of excitation (above or below 300 nm), suggesting that the MIF originates not from the initial excitation of SO2 to the singlet states but from an isotope selective spin-orbit interaction between the singlet ( (1)A2/ (1)B1) and triplet ( (3)B1) manifolds. Calculations based on high-level potential energy surfaces of the multiple excited states show a considerable lifetime anomaly for (33)SO2 and (36)SO2 for the low vibrational levels of the (1)A2 state. These results demonstrate that the isotope selectivity of accidental near-resonance interactions between states is of critical importance in understanding the origin of MIF in photochemical systems.

  14. High-Precision Stable Isotope Analyses with the NanoSIMS 50L (Invited)

    NASA Astrophysics Data System (ADS)

    Hauri, E. H.; Wang, J.; Papineau, D.; Hillion, F.

    2009-12-01

    The in situ measurement of isotope ratios at high precision has always been a goal of secondary ion mass spectrometery (SIMS). The NanoSIMS 50L is a third-generation ion microprobe developed by Cameca and modified in collaboration with the Carnegie Institution of Washington. This instrument encorporates a number of design and functional improvements over the stock NS50, including precise stepper motor control over all slits, apertures and stage movements, a larger magnet, and a modified multicollector (6 moveable and 1 fixed) capable of holding both Faraday cups and miniature multi-dynode electron multipliers. The instrument is capable of attaining a minimum beam diameter of <50 nanometers with Cs and <200 nanometers with oxygen, a factor of 5-10 improvement over the IMS6F/7F/1280 generation of instruments. The CIW instrument is also the first NanoSIMS to be fitted with multiple Faradays and associated high-precision electrometers. Most tests to date have been performed on conductive Fe-bearing sulfides mouted in indium and polished with near-zero relief. With Cs, a routine primary beam diameter of 100 nm is obtained with 1-2pA of current, sufficient to yield 1MHz of 32S from pyrite at >6000 MRP. A 2.5 nA Cs beam with a diameter of 700 nm yields 90 pA of 32S from pyrite at >6000 MRP, sufficient to analyze 32S-33S-34S on Faraday cups and 36S in EM @ >10,000 cps. Specification tests immediately after installation in 2005 demonstrated a reproducibility of <0.3‰ (1σ) in 10 analyses within a single sputter crater on Balmat pyrite, and this was subsequently improved to 0.15‰ (1σ) in 2006. Further tests showed that reproducibility on separate craters of a single grain, and separate craters in separate Balmat pyrite grains located in different holes of the sample holder, were improved to better than 0.2‰ (1σ) through careful attention to reproducibility of sample height (Z-axis control) and centering of the secondary ion beam in the entrance slit of the mass

  15. Sulfur and oxygen isotope study of sulfate reduction in experiments with natural populations from Fællestrand, Denmark

    NASA Astrophysics Data System (ADS)

    Farquhar, James; Canfield, Don E.; Masterson, Andrew; Bao, Huiming; Johnston, David

    2008-06-01

    This study investigates the sulfur and oxygen isotope fractionations of dissimilatory sulfate reduction and works to reconcile the relationships between the oxygen and sulfur isotopic and elemental systems. We report results of experiments with natural populations of sulfate-reducing bacteria using sediment and seawater from a marine lagoon at Fællestrand on the northern shore of the island of Fyn, Denmark. The experiments yielded relatively large magnitude sulfur isotope fractionations for dissimilatory sulfate reduction (up to approximately 45‰ for 34S/32S) with higher δ18O accompanying higher δ34S, similar to that observed in previous studies. The seawater used in the experiments was spiked by addition of 17O-labeled water and the 17O content of residual sulfate was found to depend on the fraction of sulfate reduced in the experiments. The 17O data provides evidence for recycling of sulfur from metabolic intermediates and for an 18O/16O fractionation of ∼25-30‰ for dissimilatory sulfate reduction. The close correlation between the 17O data and the sulfur isotope data suggests that isotopic exchange between cell water and external water (reactor water) was rapid under experimental conditions. The molar ratio of oxygen exchange to sulfate reduction was found to be about 2.5. This value is slightly lower than observed in studies of natural ecosystems [e.g., Wortmann U. G., Chernyavsky B., Bernasconi S. M., Brunner B., Böttcher M. E. and Swart P. K. (2007) Oxygen isotope biogeochemistry of pore water sulfate in the deep biosphere: dominance of isotope exchange reactions with ambient water during microbial sulfate reduction (ODP Site 1130). Geochim. Cosmochim. Acta71, 4221-4232]. Using recent models of sulfur isotope fractionations we find that our combined sulfur and oxygen isotopic data places constraints on the proportion of sulfate recycled to the medium (78-96%), the proportion of sulfur intermediate sulfite that was recycled by way of APS to sulfate

  16. Microbial sulfate reduction within the Iheya North subseafloor hydrothermal system constrained by quadruple sulfur isotopes

    NASA Astrophysics Data System (ADS)

    Aoyama, Shinnosuke; Nishizawa, Manabu; Takai, Ken; Ueno, Yuichiro

    2014-07-01

    Subseafloor hydrothermal systems may host spatially extended and numerically abundant microbial communities sustained by sulfate reduction as one of the important terminal electron accepting metabolisms. In order to estimate microbial sulfate reduction in a subseafloor hydrothermal regime, we analyzed sulfur isotopes (S32/S33/S34/S36) of pore-water sulfate and mineralized sulfide in the upper 100 m of sedimentary sequences at the Iheya North hydrothermal field in the Okinawa Trough recovered in Integrated Ocean Drilling Program Expedition 331 (IODP Exp 331). On the basis of the pore water chemistry and temperature profiles, the subseafloor environment is divided into three hydrogeologic units. In the topmost Unit-1, relatively fresh seawater is recharged, and the bottommost Unit-3 is characterized by predominance of endmember-like high-temperature hydrothermal fluid (>300 °C) underlying the impermeable cap rock layers. Intermediate Unit-2 is subject to mixing between the hydrothermal fluid and seawater. The δ34S values of sulfate in the Unit-2 mixing zone were found to be more 34S-enriched than the values expected from simple mixing model of seawater sulfate in the Unit-1 with the hydrothermal fluid in the Unit-3. The observed SSO434-enrichment and sulfate concentration [SO2-4]-depletion suggest sulfate reduction is taking place below the seafloor. Based on our model calculation, the isotope discrimination (ε34) is estimated to be -21‰. This large isotope discrimination together with slight Δ33S‧ enrichment and Δ36S‧ depletion reveals that sulfate reduction is caused by microbial processes but not by thermochemical processes. In addition, our numerical simulation points out that sulfate may be reduced prior to presently undergoing mixing with high-temperature fluid, probably within the seawater recharge zone. Despite the abundant input of hydrothermal H2S, mineralized sulfide below 10 m seafloor (mbsf) shows characteristic sulfur isotopic signatures that

  17. Multiple sulfur and carbon isotope composition of the Mesoarchean Manjeri and Cheshire Formations (Belingwe Greenstone Belt, Zimbabwe): a window on the sulfur and carbon Mesoarchean biogeochemistry

    NASA Astrophysics Data System (ADS)

    Thomazo, C.; Strauss, H.; Grassineau, N.; Nisbet, E. G.

    2010-12-01

    In order to bring further insights into the biogeochemical conditions prevailing during the dampendown Mesoarchean Mass Independant Fractionation of Sulfur (MIF-S) attributed to changes in atmospheric and/or oceanic geochemistry, we report the results of a detailed carbon (12C, 13C) and multiple sulfur (32S, 33S, 34S) isotopic study through the ~2.7 Ga Manjeri and ~2.65 Ga Cheshire Formations (Belingwe Greenstone Belt, Zimbabwe). The studied rocks consist of low-grade metamorphic (sub-greenschist facies) black shales, laminated limestones, and stromatolites. In the Manjeri Fm. the stromatolites are a minor part of the succession, which mostly show organic rich black shales associated with sulfide-rich layers. In contrast, the Cheshire Fm. shows well preserved stromatolites and black shales. Organic δ13C values of the Manjeri Formation show a wide range of δ13Corg between -16.2 and -35.4‰ (average of -30.3 ± 6.0‰), while the Cheshire formation show a narrow range of isotopic composition of -41.3 ± 3.5‰. TOC (wt. %) vary from 0.06 to 3.31 (average of 1.28) and from 0.02 to 1.05 (average of 0.18) for the Manjeri and Cheshire Fm., respectively. The remarkable difference of carbon isotope signatures between these two formations argue for the occurrence of different biomass likely reflecting different metabolic pathways, including photosynthesis, methanogenesis and methanotrophy. The Manjeri Fm. δ34S values of sedimentary sulfides (Acid Volatile Sulfur and Chromium Reducible Sulfur) vary between -15.15 and 2.37‰ (average -1.71 ± 4.76‰) and show very small and mostly negative MIF-S varying from -0.58 to 0.87‰ (average 0.02 ± 0.43‰). The Cheshire Fm. is isotopically distinct with δ34S values ranging from -2.11 to 2.39‰ (average 0.25 ± 1.08‰) and show near zero but consistently positive Δ33S anomalies between 0.14 and 1.17 ‰ (average 0.56 ± 0.29‰). Sulfides S contents (wt. %) vary from 0.06 to 3.31 (average of 1.28) and from 0.02 to 1

  18. Negligible sulfur isotope fractionation during partial melting: Evidence from Garrett transform fault basalts, implications for the late-veneer and the hadean matte

    NASA Astrophysics Data System (ADS)

    Labidi, J.; Cartigny, P.

    2016-10-01

    We report the quadruple sulfur isotope compositions, sulfur contents and speciation major and trace elements (including copper and chlorine abundances) of eleven basalts collected in the Garrett transform fault. We combine these data to discuss the absence of S isotopic fractionation along both partial melting and low-pressure fractional crystallization. The variations of K2O/TiO2 and La/SmN-ratios (respectively between 0.017 and 0.067, and between 0.31 and 0.59) suggest a range of depletion in Garrett lavas that includes ultra depleted samples (K2O/TiO2 < 0.03). The remarkable level of incompatible element depletion is consistent with re-melting of a depleted source. Contrasting with incompatible element depletion, all samples display similar S and Cu abundance (at a given major-element composition) to mid-ocean ridge basalts (MORB). This indicates that Garrett Intra Transform Lavas (ITL) are sulfide saturated as MORB are. Copper content for Garrett parental melts (MgO >8%) are ∼80 ppm, indistinguishable from MORBs. This requires their mantle sources, variably depleted in incompatible element, to host residual sulfide buffering the Cu content of all erupted melts. We calculate a minimum S content for the source of ultra-depleted Garrett lavas of 100 ± 40ppmS, i.e. roughly a factor of 2 below the MORB mantle source. After exclusion of a single sample with Cl/K ratio >0.1 that likely experienced hydrothermal sulfide assimilation, Garrett ITLs display homogeneous δ34 S, Δ33 S and Δ36 S values with averages of - 0.68 ± 0.08 ‰, + 0.010 ± 0.005 ‰ and - 0.04 ± 0.04 ‰, respectively (all 1σ, n = 10). The δ34 S values display no relationship with either K2O/TiO2 variations or extent sulfide fractionation. From these observations, we derive a 34S/32S fractionation factor between exsolved sulfides and sulfide dissolved in silicate melts of 1.0000 ± 0.0003. The S isotopic fractionation during partial melting can thus be considered as negligible, and both

  19. Mass Independent Fractionation of Sulphur Isotopes in Precambrian Sedimentary Rocks: Indicator for Changes in Atmospheric Composition and the Operation of the Global Sulphur Cycle

    NASA Astrophysics Data System (ADS)

    Peters, M.; Farquhar, J.; Strauss, H.

    2005-12-01

    Large mass independent fractionation (MIF) of sulphur isotopes in sedimentary rocks older than 2.3 Ga and the absence of this isotopic anomaly in younger rocks seem to be the consequence of a change in Earth's atmospheric composition from essentially oxygen-free or to oxygen-rich conditions. MIF is produced by photochemical reactions of volcanogenic sulphur dioxide with UV radiation in the absence of an ozone shield. The products of such processes are elemental sulphur with positive and sulphate with negative Δ33S values. Here we present isotope data (32S, 33S, 34S) for sedimentary pyrites from Archaean and Palaeoproterozoic rocks of the Kaapvaal Craton (South Africa), the Pilbara Craton (Australia) and the Greenland Shield (Isua Supercrustal Belt). Their ages range from 3.85 to 2.47 Ga. Large positive Δ33S values up to +9.13 ‰ in several Archaean units from the Kapvaal and Pilbara Cratons are attributed to low atmospheric oxygen at that time. Interestingly, very low Δ33S values between -0.28 and +0.57 ‰ appear to characterize the Witwatersrand succession of South Africa (3.0 Ga). This rather small MIF signature was previously detected in rocks of the same age in Western Australia (OHMOTO et al., 2005). The signature is interpreted as a global signal, which could be the consequence of a shielding effect induced by one or more atmospheric components. The most probable chemical compounds for this process are methane and carbon dioxide. Rocks of the Kameeldoorns Fm. (2.71 Ga), Kaapvaal Craton, display also low values between -0.46 and +0.33 ‰, which are consistent with the small (absent) MIF signal in rocks of the Hardey Fm. (2.76 Ga) of Western Australia (OHMOTO et al., 2005). Very low carbon isotope values between -51 and -40 ‰ in late Archaean kerogens (2.6 - 2.8 Ga) indicate a high concentration of methane in the atmosphere (PAVLOV et al., 2001). This high methane level could produce an organic haze, which absorbed most of the UV radiation and prevented

  20. Sulfur isotope homogeneity of oceanic DMSP and DMS.

    PubMed

    Amrani, Alon; Said-Ahmad, Ward; Shaked, Yeala; Kiene, Ronald P

    2013-11-12

    Oceanic emissions of volatile dimethyl sulfide (DMS) represent the largest natural source of biogenic sulfur to the global atmosphere, where it mediates aerosol dynamics. To constrain the contribution of oceanic DMS to aerosols we established the sulfur isotope ratios ((34)S/(32)S ratio, δ(34)S) of DMS and its precursor, dimethylsulfoniopropionate (DMSP), in a range of marine environments. In view of the low oceanic concentrations of DMS/P, we applied a unique method for the analysis of δ(34)S at the picomole level in individual compounds. Surface water DMSP collected from six different ocean provinces revealed a remarkable consistency in δ(34)S values ranging between +18.9 and +20.3‰. Sulfur isotope composition of DMS analyzed in freshly collected seawater was similar to δ(34)S of DMSP, showing that the in situ fractionation between these species is small (<+1‰). Based on volatilization experiments, emission of DMS to the atmosphere results in a relatively small fractionation (-0.5 ± 0.2‰) compared with the seawater DMS pool. Because δ(34)S values of oceanic DMS closely reflect that of DMSP, we conclude that the homogenous δ(34)S of DMSP at the ocean surface represents the δ(34)S of DMS emitted to the atmosphere, within +1‰. The δ(34)S of oceanic DMS flux to the atmosphere is thus relatively constant and distinct from anthropogenic sources of atmospheric sulfate, thereby enabling estimation of the DMS contribution to aerosols.

  1. Stable sulfur isotope fractionation and discrimination between the sulfur atoms of thiosulfate during oxidation by Halothiobacillus neapolitanus.

    PubMed

    Kelly, Donovan P

    2008-05-01

    Growing cultures and nongrowing suspensions of Halothiobacillus neapolitanus selectively fractionated (32)S and (34)S during the oxidation of the sulfane- and sulfonate-sulfur atoms of thiosulfate. Sulfate was enriched in (32)S, with delta(34)S reaching -6.3 per thousand relative to the precursor sulfonate-sulfur of thiosulfate, which was progressively resynthesized from the thiosulfate-sulfane-sulfur during thiosulfate metabolism. Polythionates, principally trithionate, accumulated during thiosulfate oxidation and showed progressive increase in the relative (34)S content of their sulfonate groups, with delta(34)S values up to +20 per thousand, relative to the substrate sulfur. The origins of the sulfur in the sulfate and polythionate products of oxidation were tracked by the use thiosulfate labelled with (35)S in each of its sulfur atoms, enabling determination of the flow of the sulfur atoms into the oxidation products. The results confirm that highly significant fractionation of stable sulfur isotopes can be catalyzed by thiobacilli oxidizing thiosulfate, but that differences in the (34)S/(32)S ratios of the nonequivalent constituent sulfur atoms of the thiosulfate used as substrate mean that the oxidative fate of each atom needs separate determination. The data are very significant to the understanding of bacterial sulfur-compound oxidation and highly relevant to the origins of biogenic sulfate minerals.

  2. Isotope shift in the sulfur electron affinity: Observation and theory

    SciTech Connect

    Carette, Thomas; Scharf, Oliver; Godefroid, Michel; Froese Fischer, Charlotte

    2010-04-15

    The sulfur electron affinities {sup e}A(S) are measured by photodetachment microscopy for the two isotopes {sup 32}S and {sup 34}S (16 752.975 3(41) and 16 752.977 6(85) cm{sup -1}, respectively). The isotope shift in the electron affinity is found to be more probably positive, {sup e}A({sup 34}S)- {sup e}A({sup 32}S) =+0.0023(70) cm{sup -1}, but the uncertainty allows for the possibility that it may be either ''normal''[{sup e}A({sup 34}S) > {sup e}A({sup 32}S)] or ''anomalous''[{sup e}A({sup 34}S) < {sup e}A({sup 32}S)]. The isotope shift is estimated theoretically using elaborate correlation models, monitoring the electron affinity and the mass polarization term expectation value. The theoretical analysis predicts a very large specific mass shift (SMS) that counterbalances the normal mass shift (NMS) and produces an anomalous isotope shift {sup e}A({sup 34}S)- {sup e}A({sup 32}S) =-0.0053(24) cm{sup -1}, field shift corrections included. The total isotope shift can always be written as the sum of the NMS (here +0.0169 cm{sup -1}) and a residual isotope shift (RIS). Since the NMS has nearly no uncertainty, the comparison between experimental and theoretical RIS is more fair. With respective values of -0.0146(70) cm{sup -1} and -0.0222(24) cm{sup -1}, these residual isotope shifts are found to agree within the estimated uncertainties.

  3. Herschel Observations of EXtra-Ordinary Sources: H2S as a Probe of Dense Gas and Possibly Hidden Luminosity Toward the Orion KL Hot Core

    NASA Astrophysics Data System (ADS)

    Crockett, N. R.; Bergin, E. A.; Neill, J. L.; Black, J. H.; Blake, G. A.; Kleshcheva, M.

    2014-02-01

    We present Herschel/HIFI observations of the light hydride H2S obtained from the full spectral scan of the Orion Kleinmann-Low nebula (Orion KL) taken as part of the Herschel Observations of EXtra-Ordinary Sources GT (guaranteed time) key program. In total, we observe 52, 24, and 8 unblended or slightly blended features from H2 32S, H2 34S, and H2 33S, respectively. We only analyze emission from the so-called hot core, but emission from the plateau, extended ridge, and/or compact ridge are also detected. Rotation diagrams for ortho and para H2S follow straight lines given the uncertainties and yield T rot = 141 ± 12 K. This indicates H2S is in local thermodynamic equilibrium and is well characterized by a single kinetic temperature or an intense far-IR radiation field is redistributing the population to produce the observed trend. We argue the latter scenario is more probable and find that the most highly excited states (E up >~ 1000 K) are likely populated primarily by radiation pumping. We derive a column density, N tot(H2 32S) = 9.5 ± 1.9 × 1017 cm-2, gas kinetic temperature, T kin = 120+/- ^{13}_{10} K, and constrain the H2 volume density, n_H_2 >~ 9 × 10 7 cm-3, for the H2S emitting gas. These results point to an H2S origin in markedly dense, heavily embedded gas, possibly in close proximity to a hidden self-luminous source (or sources), which are conceivably responsible for Orion KL's high luminosity. We also derive an H2S ortho/para ratio of 1.7 ± 0.8 and set an upper limit for HDS/H2S of <4.9 × 10 -3. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

  4. A line confusion limited millimeter survey of Orion KL . I. Sulfur carbon chains

    NASA Astrophysics Data System (ADS)

    Tercero, B.; Cernicharo, J.; Pardo, J. R.; Goicoechea, J. R.

    2010-07-01

    We perform a sensitive (line confusion limited), single-side band spectral survey towards Orion KL with the IRAM 30 m telescope, covering the following frequency ranges: 80-115.5 GHz, 130-178 GHz, and 197-281 GHz. We detect more than 14 400 spectral features of which 10 040 have been identified up to date and attributed to 43 different molecules, including 148 isotopologues and lines from vibrationally excited states. In this paper, we focus on the study of OCS, HCS+, H2CS, CS, CCS, C3S, and their isotopologues. In addition, we map the OCS J = 18-17 line and complete complementary observations of several OCS lines at selected positions around Orion IRc2 (the position selected for the survey). We report the first detection of OCS ν2 = 1 and ν3 = 1 vibrationally excited states in space and the first detection of C3S in warm clouds. Most of CCS, and almost all C3S, line emission arises from the hot core indicating an enhancement of their abundances in warm and dense gas. Column densities and isotopic ratios have been calculated using a large velocity gradient (LVG) excitation and radiative transfer code (for the low density gas components) and a local thermal equilibrium (LTE) code (appropriate for the warm and dense hot core component), which takes into account the different cloud components known to exist towards Orion KL, the extended ridge, compact ridge, plateau, and hot core. The vibrational temperature derived from OCS ν2 = 1 and ν3 = 1 levels is ≃210 K, similar to the gas kinetic temperature in the hot core. These OCS high energy levels are probably pumped by absorption of IR dust photons. We derive an upper limit to the OC3S, H2CCS, HNCS, HOCS+, and NCS column densities. Finally, we discuss the D/H abundance ratio and infer the following isotopic abundances: 12C/13C = 45 ± 20, 32S/34S = 20 ± 6, 32S/33S = 75 ± 29, and 16O/18O = 250 ± 135. Appendices A and B are only available in electronic form at http://www.aanda.org

  5. Using multiple sulfur isotopes to link biological isotope fractionation in a sedimentary protolith to a magmatic Ni-sulfide deposit: Voisey's Bay Ni deposit, Labrador, Canada

    NASA Astrophysics Data System (ADS)

    Hiebert, R. S.; Bekker, A.; Wing, B. A.

    2012-12-01

    It is generally accepted that crustal contamination is required for the formation of significant magmatic Ni-Cu-PGE sulfide deposits. Either the addition of external S or SiO2 promote early sulfide saturation. The most direct indicator of S addition by this contaminant is S isotopes. However, the traditional use of δ34S values is inadequate in deposits where Archean sedimentary sulfides incorporated into these deposits might not have significantly different δ34S values from those of mantle S. Even in sediments that have variable δ34S values, δ34S signature can be reset to magmatic values by equilibrating large amounts of silicate magma with initial sulfide melt. However, sedimentary rocks contain isotope evidence of biological fractionation processes in the relationship between δ33S and δ34S values. We used multiple S isotope data to constrain the relationship between δ33S and δ34S values, identify biological S isotope fractionation in the metamorphosed sedimentary rocks of the Tasiuyak Gneiss, and compare this relationship to that in the Voisey's Bay magmatic Ni-deposit. The Voisey's Bay Ni-sulfide deposit, Labrador is hosted by a troctolitic conduit system. The Voisey's Bay intrusion is a part of the Nain plutonic suite and intruded at approximately 1.3 Ga along the boundary between the Proterozoic Tasiuyak Gneiss of the Churchill province and Archean gneisses of the Nain province. The general model suggests assimilation of a large amount of sulfidic Tasiuyak gneiss, leading to sulfur saturation prior to emplacement, even though the Tasiuyak gneiss does not have a high concentration of sulfur. High-temperature equilibrium relationships are not present in our measured δ33S and δ34S values from the Voisey's Bay deposit. Instead they indicate that a kinetic process is responsible for S isotope fractionations in the mineralization and troctolite, similar to that recorded by the Tasiuyak gneiss. The observed relationship between δ33S and δ34S values is

  6. Diffusive gradients in thin films measurement of sulfur stable isotope variations in labile soil sulfate.

    PubMed

    Hanousek, Ondrej; Santner, Jakob; Mason, Sean; Berger, Torsten W; Wenzel, Walter W; Prohaska, Thomas

    2016-11-01

    A diffusive gradient in thin films (DGT) technique, based on a strongly basic anion exchange resin (Amberlite IRA-400), was successfully tested for (34)S/(32)S analysis in labile soil sulfate. Separation of matrix elements (Na, K, and Ca) that potentially cause non-spectral interferences in (34)S/(32)S analysis by MC ICP-MS (multi-collector inductively coupled plasma-mass spectrometry) during sampling of sulfate was demonstrated. No isotopic fractionation caused by diffusion or elution of sulfate was observed below a resin gel disc loading of ≤79 μg S. Above this threshold, fractionation towards (34)S was observed. The method was applied to 11 different topsoils and one mineral soil profile (0-100 cm depth) and compared with soil sulfate extraction by water. The S amount and isotopic ratio in DGT-S and water-extractable sulfate correlated significantly (r (2) = 0.89 and r (2) = 0.74 for the 11 topsoils, respectively). The systematically lower (34)S/(32)S isotope ratios of the DGT-S were ascribed to mineralization of organic S.

  7. An update on the Thermal Gradient Induced Non -Mass-Dependent Isotope Fractionation

    NASA Astrophysics Data System (ADS)

    Sun, T.; Niles, P. B.; Bao, H.; Socki, R. A.

    2012-12-01

    Mass flow and compositional gradient (elemental and isotope separation) occur when fluid(s) or gas(es) in an enclosure is subjected to a thermal gradient, and the phenomenon is named thermal diffusion. Gas phase thermal diffusion has been experimentally and theoretically investigated for more than a century, although there has not been a satisfactory theory to date. Nevertheless, theories predict that when dealing with a multi-isotope system, such as O16-O17-O18, S32-S33-S34-S36, or Ne20-Ne21-Ne22, the mass difference is the only term in the thermal diffusion separation factors that distinguish one isotope pair from another. Thus a mass dependent relationship is expected. For O-bearing molecules the α17O/ α 18O is expected to be at 0.5 to 0.515, and for S-bearing molecules the α33S/ α 34S at 0.5 to 0.508, where α is isotope fractionation factor between cold and warm reservoirs. We recently reported that thermal diffusion generates non-mass dependent (NMD) isotope fractionation for low-pressure O2 and SF6 gases. The observed NMD phenomenon in the simple thermal-diffusion experiments demands quantitative validation and theoretical explanation. It was suggested that additional (not mass related) terms need to be theoretically considered in the order to account for the observations. In addition to the pressure and temperature dependency illustrated in our earlier report, the role of turbulence, batch gas effects, and whether it is only a transient, non-equilibrium effect have been examined in this study. We report here new results on low-pressure O2 gas thermal diffusion. (1) In a purely diffusive vertical two-bulb setting with colder reservoir at lower position, time course experiments showed that the NMD effect persists after the system reaches isotopic steady state between warmer and colder compartments, suggesting that the effect is not a transient one. (2) When the average temperature approaching condensation point for O2, the 17O switches to migrating

  8. First in-beam. gamma. -ray study of sup 67 As

    SciTech Connect

    Lang, T.F.; Moltz, D.M.; Reiff, J.E.; Batchelder, J.C.; Ognibene, T.J.; Cerny, J.; Robertson, J.D.; Beausang, C.W.; Deleplanque, M.A.; Diamond, R.M.; Stephens, F.S.

    1990-01-01

    Excited states of the neutron-deficient nucleus {sup 67}As were populated using the {sup 40}Ca({sup 32}S,{alpha}p){sup 67}As and the {sup 40}Ca({sup 33}S,{alpha}pn){sup 67}As reactions at bombarding energies between 95 and 110 MeV. We present a tentative level scheme for {sup 67}As, derived from {gamma}-{gamma} coincidence studies in conjunction with measurement of evaporated charged particles and neutrons.

  9. USE OF SLACK-WATER ENVIRONMENTS BY COHO SALMON JUVENILES IN A COASTAL OREGON STREAM AS INDICATED BY 34S STABLE ISOTOPE ANALYSIS

    EPA Science Inventory

    Stable isotopes of sulfur are rarely used in studies of elemental cycling, trophic position or use of marine-derived nutrients by salmonids. The main reason for this probably is the reluctance on the part of isotope labs to expose their instruments to SO2 (because of its corrosi...

  10. Exploring the in vitro formation of trimethylarsine sulfide from dimethylthioarsinic acid in anaerobic microflora of mouse cecum using HPLC-ICP-MS and HPLC-ESI-MS

    SciTech Connect

    Kubachka, Kevin M.; Kohan, Michael C.; Herbin-Davis, Karen; Creed, John T. Thomas, David J.

    2009-09-01

    Although metabolism of arsenicals to form methylated oxoarsenical species has been extensively studied, less is known about the formation of thiolated arsenical species that have recently been detected as urinary metabolites. Indeed, their presence suggests that the metabolism of ingested arsenic is more complex than previously thought. Recent reports have shown that thiolated arsenicals can be produced by the anaerobic microflora of the mouse cecum, suggesting that metabolism prior to systemic absorption may be a significant determinant of the pattern and extent of exposure to various arsenic-containing species. Here, we examined the metabolism of {sup 34}S labeled dimethylthioarsinic acid ({sup 34}S-DMTA{sup V}) by the anaerobic microflora of the mouse cecum using HPLC-ICP-MS and HPLC-ESI-MS/MS to monitor for the presence of various oxo- and thioarsenicals. The use of isotopically enriched {sup 34}S-DMTA{sup V} made it possible to differentiate among potential metabolic pathways for production of the trimethylarsine sulfide (TMAS{sup V}). Upon in vitro incubation in an assay containing anaerobic microflora of mouse cecum, {sup 34}S-DMTA{sup V} underwent several transformations. Labile {sup 34}S was exchanged with more abundant {sup 32}S to produce {sup 32}S-DMTA{sup V}, a thiol group was added to yield DMDTA{sup V}, and a methyl group was added to yield {sup 34}S-TMAS{sup V}. Because incubation of {sup 34}S-DMTA{sup V} resulted in the formation of {sup 34}S-TMAS{sup V}, the pathway for its formation must preserve the arsenic-sulfur bond. The alternative metabolic pathway postulated for formation of TMAS{sup V} from dimethylarsinic acid (DMA{sup V}) would proceed via a dimethylarsinous acid (DMA{sup III}) intermediate and would necessitate the loss of {sup 34}S label. Structural confirmation of the metabolic product was achieved using HPLC-ESI-MS/MS. The data presented support the direct methylation of DMTA{sup V} to TMAS{sup V}. Additionally, the detection of

  11. Contribution of isotopologue self-shielding to sulfur mass-independent fractionation during sulfur dioxide photolysis

    NASA Astrophysics Data System (ADS)

    Ono, S.; Whitehill, A. R.; Lyons, J. R.

    2013-03-01

    Signatures of sulfur mass-independent fractionation (S-MIF) are observed for sulfur minerals in Archean rocks, and for modern stratospheric sulfate aerosols (SSA) deposited in polar ice. Ultraviolet light photolysis of SO2 is thought to be the most likely source for these S-MIF signatures, although several hypotheses have been proposed for the underlying mechanism(s) of S-MIF production. Laboratory SO2 photolysis experiments are carried out with a flow-through photochemical reactor with a broadband (Xe arc lamp) light source at 0.1 to 5 mbar SO2 in 0.25 to 1 bar N2 bath gas, in order to test the effect of SO2 pressure on the production of S-MIF. Elemental sulfur products yield high δ34S values up to 140 ‰, with δ33S34S of 0.59 ± 0.04 and Δ36S/Δ33S ratios of -4.6 ± 1.3 with respect to initial SO2. The magnitude of the isotope effect strongly depends on SO2 partial pressure, with larger fractionations at higher SO2 pressures, but saturates at an SO2 column density of 1018 molecules cm-2. The observed pressure dependence and δ33S34S and Δ36S/Δ33S ratios are consistent with model calculations based on synthesized SO2 isotopologue cross sections, suggesting a significant contribution of isotopologue self-shielding to S-MIF for high SO2 pressure (>0.1 mbar) experiments. Results of dual-cell experiments further support this conclusion. The measured isotopic patterns, in particular the Δ36S/Δ33S relationships, closely match those measured for modern SSA from explosive volcanic eruptions. These isotope systematics could be used to trace the chemistry of SSA after large Plinian volcanic eruptions.

  12. Investigation of sulphur isotope variation due to different processes applied during uranium ore concentrate production.

    PubMed

    Krajkó, Judit; Varga, Zsolt; Wallenius, Maria; Mayer, Klaus; Konings, Rudy

    The applicability and limitations of sulphur isotope ratio as a nuclear forensic signature have been studied. The typically applied leaching methods in uranium mining processes were simulated for five uranium ore samples and the n((34)S)/n((32)S) ratios were measured. The sulphur isotope ratio variation during uranium ore concentrate (UOC) production was also followed using two real-life sample sets obtained from industrial UOC production facilities. Once the major source of sulphur is revealed, its appropriate application for origin assessment can be established. Our results confirm the previous assumption that process reagents have a significant effect on the n((34)S)/n((32)S) ratio, thus the sulphur isotope ratio is in most cases a process-related signature.

  13. [Fractionation of sulfur isotopes by phototrophic sulfur bacterium Ectothiorhodospira shaposhnikovii].

    PubMed

    Ivanov, M V; Gogotova, G I; Matrosov, A G; Ziakun, A M

    1976-01-01

    Two processes of sulphur isotope fractionation have been found in experiments with the sulphur purple bacterium Ectothiorhodospira shaposhnikovii. As a result, a light isotope, 32S, is concentrated in residual hydrogen sulphide, and a heavy isotope, 34S, in elementary suphur which is deposited outside the cell. The sulphate produced is lighter than elementary sulphur. Fractionation of sulphur isotopes is observed in natural conditions and is confined to places of mass growth of photosynthetic sulphur bacteria.

  14. Sulfur sources of sedimentary "buckshot" pyrite in the Auriferous Conglomerates of the Mesoarchean Witwatersrand and Ventersdorp Supergroups, Kaapvaal Craton, South Africa

    NASA Astrophysics Data System (ADS)

    Guy, B. M.; Ono, S.; Gutzmer, J.; Lin, Y.; Beukes, N. J.

    2014-08-01

    Large rounded pyrite grains (>1 mm), commonly referred to as "buckshot" pyrite grains, are a characteristic feature of the auriferous conglomerates (reefs) in the Witwatersrand and Ventersdorp supergroups, Kaapvaal Craton, South Africa. Detailed petrographic analyses of the reefs indicated that the vast majority of the buckshot pyrite grains are of reworked sedimentary origin, i.e., that the pyrite grains originally formed in the sedimentary environment during sedimentation and diagenesis. Forty-one of these reworked sedimentary pyrite grains from the Main, Vaal, Basal, Kalkoenkrans, Beatrix, and Ventersdorp Contact reefs were analyzed for their multiple sulfur isotope compositions (δ34S, Δ33S, and Δ36S) to determine the source of the pyrite sulfur. In addition, five epigenetic pyrite samples (pyrite formed after sedimentation and lithification) from the Middelvlei and the Ventersdorp Contact reefs were measured for comparison. The δ34S, Δ33S, and Δ36S values of all 41 reworked sedimentary pyrite grains indicate clear signatures of mass-dependent and mass-independent fractionation and range from -6.8 to +13.8 ‰, -1.7 to +1.7 ‰, and -3.9 to +0.9 ‰, respectively. In contrast, the five epigenetic pyrite samples display a very limited range of δ34S, Δ33S, and Δ36S values (+0.7 to +4.0 ‰, -0.3 to +0.0 ‰. and -0.3 to +0.1 ‰, respectively). Despite the clear signatures of mass-independent sulfur isotope fractionation, very few data points plot along the primary Archean photochemical array suggesting a weak photolytic control over the data set. Instead, other factors command a greater degree of influence such as pyrite paragenesis, the prevailing depositional environment, and non-photolytic sulfur sources. In relation to pyrite paragenesis, reworked syngenetic sedimentary pyrite grains (pyrite originally precipitated along the sediment-water interface) are characterized by negative δ34S and Δ33S values, suggesting open system conditions with respect

  15. Potential canopy influences on the isotopic composition of nitrogen and sulphur in atmospheric deposition.

    PubMed

    Heaton, T H E; Spiro, Baruch; Robertson, S Madeline C

    1997-02-01

    Isotopic studies of nitrogen and sulphur inputs to plant/soil systems commonly rely on limited published data for the (15)N/(14)N and (34)S/(32)S ratios of nitrate, ammonium and sulphate in rainfall. For systems with well-developed plant canopies, however, inputs of these ions from dry deposition or particulates may be more important than rainfall. The manner in which isotopic fractionation between ions and gases may lead to dry deposition and particulates having (15)N/(14)N or (34)S/(32)S ratios different from those of rainfall is considered. Data for rainfall and throughfall in coniferous plantations are then discussed, and suggest that: (1) in line with expectations, nitrate washed from the canopy has (15)N/(14)N ratios higher than those in rainfall; (2) the (15)N/(14)N ratios of ammonium washed from the canopy are variable, with high ratios being found for canopies of higher pH in conditions of elevated ambient ammonia gas concentrations; and (3) in accord with expectations and previous work, (34)S/(32)S ratios of sulphate washed from the canopy are not substantially different from those in rainfall. The study suggests that if atmospheric inputs are relevant to isotopic studies of the sources of nitrogen for canopied systems, then confident interpretation will require analysis of these inputs.

  16. Measurement of sulfur isotope compositions by tunable laser spectroscopy of SO2.

    PubMed

    Christensen, Lance E; Brunner, Benjamin; Truong, Kasey N; Mielke, Randall E; Webster, Christopher R; Coleman, Max

    2007-12-15

    Sulfur isotope measurements offer comprehensive information on the origin and history of natural materials. Tunable laser spectroscopy is a powerful analytical technique for isotope analysis that has proven itself readily adaptable for in situ terrestrial and planetary measurements. Measurements of delta(34)S in SO2 were made using tunable laser spectroscopy of combusted gas samples from six sulfur-bearing solids with delta(34)S ranging from -34 to +22 per thousand (also measured with mass spectrometry). Standard deviation between laser and mass spectrometer measurements was 3.7 per thousand for sample sizes of 200 +/- 75 nmol SO(2). Although SO(2)(g) decreased 9% over 15 min upon entrainment in the analysis cell from wall uptake, observed fractionation was insignificant (+0.2 +/- 0.6 per thousand). We also describe a strong, distinct (33)SO(2) rovibrational transition in the same spectral region, which may enable simultaneous delta(34)S and Delta(33)S measurements.

  17. Multiple sulphur and oxygen isotopes reveal microbial sulphur cycling in spring waters in the Lower Engadin, Switzerland.

    PubMed

    Strauss, Harald; Chmiel, Hannah; Christ, Andreas; Fugmann, Artur; Hanselmann, Kurt; Kappler, Andreas; Königer, Paul; Lutter, Andreas; Siedenberg, Katharina; Teichert, Barbara M A

    2016-01-01

    Highly mineralized springs in the Scuol-Tarasp area of the Lower Engadin and in the Albula Valley near Alvaneu, Switzerland, display distinct differences with respect to the source and fate of their dissolved sulphur species. High sulphate concentrations and positive sulphur (δ(34)S) and oxygen (δ(18)O) isotopic compositions argue for the subsurface dissolution of Mesozoic evaporitic sulphate. In contrast, low sulphate concentrations and less positive or even negative δ(34)S and δ(18)O values indicate a substantial contribution of sulphate sulphur from the oxidation of sulphides in the crystalline basement rocks or the Jurassic sedimentary cover rocks. Furthermore, multiple sulphur (δ(34)S, Δ(33)S) isotopes support the identification of microbial sulphate reduction and sulphide oxidation in the subsurface, the latter is also evident through the presence of thick aggregates of sulphide-oxidizing Thiothrix bacteria.

  18. Sulphur isotopes in animal hair track distance to sea.

    PubMed

    Zazzo, A; Monahan, F J; Moloney, A P; Green, S; Schmidt, O

    2011-09-15

    Stable sulphur isotope ratios ((34)S/(32)S) in animal tissues have been suggested as a tracer of coastal residency of terrestrial animals, but data are lacking that quantify the inland range of the sulphur coastal signal and the effects of seasonality. Here, we present δ(34)S measurements of sheep wool collected seasonally on eight farms across Ireland and wool samples collected opportunistically along the west and east coasts. We observed large (>10‰) δ(34)S differences across the island and we show that wool δ(34)S values were negatively correlated with distance to the west coast. We propose that this is due to the predominantly (south-)westerly airflow, possibly combined with the influence of anthropogenic sulphur deposited from the east. While essentially all the sulphur contained in west-coast wool is of marine origin, relatively high δ(34)S values were still measured >100 km inland, suggesting that marine sulphur can be carried over long distances. Seasonal variations are small at the individual level for sedentary grazing animals. We conclude that sulphur isotopes ratios measured in archival keratinous tissues can be used to describe regional δ(34)S isoscapes primarily defined by distance to coasts and thus provide a tool to detect short-term movements of domestic, feral and wild animals within such isoscapes.

  19. Stable sulfur isotope fractionation by the green bacterium Chlorobaculum parvum during photolithoautotrophic growth on sulfide.

    PubMed

    Kelly, Donovan P

    2008-01-01

    Growing cultures of the green obligate photolithotroph, Chlorobaculum parvum DSM 263T (formerly Chlorobium vibrioforme forma specialis thiosulfatophilum NCIB 8327), oxidized sulfide quantitatively to elemental sulfur, with no sulfate formation. In the early stages of growth and sulfide oxidation, the sulfur product became significantly enriched with 34S, with a maximum delta34S above +5 per thousand, while the residual sulfide was progressively depleted in 34S to delta34S values greater than -4 per thousand. As oxidation proceeded, the delta34S of the sulfur declined to approach that of the initial sulfide when most of the substrate sulfide had been converted to sulfur in this closed culture system. No significant formation of sulfate occurred, and the substrate sulfide and elemental sulfur product accounted for all the sulfur provided throughout oxidation. The mean isotope fractionation factors (epsilon) for sulfide and sulfur were equivalent at epsilon values of -2.4 per thousand and +2.4 per thousand respectively. The significance of the experimentally-observed fractionation to the 34S/32S ratios seen in natural sulfur-containing minerals is considered.

  20. Modeling the signature of sulfur mass-independent fractionation produced in the Archean atmosphere

    NASA Astrophysics Data System (ADS)

    Claire, Mark W.; Kasting, James F.; Domagal-Goldman, Shawn D.; Stüeken, Eva E.; Buick, Roger; Meadows, Victoria S.

    2014-09-01

    Minor sulfur isotope anomalies indicate the absence of O2 from the Archean atmosphere. A rich dataset showing large variations in magnitude and sign of Δ33S and Δ36S, preserved in both sulfates and sulfides, suggests that further constraints on Archean atmospheric chemistry are possible. We review previous quantitative constraints on atmospheric Δ33S production, and suggest that a new approach is needed. We added sulfur species containing 33S and 34S to a 1-D photochemical model and describe the numerical methodology needed to ensure accurate prediction of the magnitude and sign of Δ33S produced by and deposited from the Archean atmosphere. This methodology can test multiple MIF-S formation mechanisms subject to a variety of proposed atmospheric compositions, yielding Δ33S predictions that can be compared to the rock record. We systematically test SO2 isotopologue absorption effects in SO2 photolysis (Danielache et al., 2008), one of the primary proposed mechanisms for Δ33S formation. We find that differential absorption through the Danielache et al. (2008) cross sections is capable of altering predicted Δ33S as a function of multiple atmospheric variables, including trace O2 concentration, total sulfur flux, CO2 content, and the presence of hydrocarbons, but find a limited role for OCS and H2S. Under all realistic conditions, the Danielache et al. (2008) cross sections yield Δ33S predictions at odds with the geologic record, implying that additional pathways for sulfur MIF formation exist and/or the cross sections have significant errors. The methodology presented here will allow for quantitative constraints on the Archean atmosphere beyond the absence of O2, as soon as additional experimental measurements of MIF-S producing processes become available.

  1. Mass Dependency of Isotope Fractionation of Gases Under Thermal Gradient and Its Possible Implications for Planetary Atmosphere Escaping Process

    NASA Technical Reports Server (NTRS)

    Sun, Tao; Niles, Paul; Bao, Huiming; Socki, Richard

    2014-01-01

    Physical processes that unmix elements/isotopes of gas molecules involve phase changes, diffusion (chemical or thermal), effusion and gravitational settling. Some of those play significant roles for the evolution of chemical and isotopic compositions of gases in planetary bodies which lead to better understanding of surface paleoclimatic conditions, e.g. gas bubbles in Antarctic ice, and planetary evolution, e.g. the solar-wind erosion induced gas escaping from exosphere on terrestrial planets.. A mass dependent relationship is always expected for the kinetic isotope fractionations during these simple physical processes, according to the kinetic theory of gases by Chapman, Enskog and others [3-5]. For O-bearing (O16, -O17, -O18) molecules the alpha O-17/ alpha O-18 is expected at 0.5 to 0.515, and for S-bearing (S32,-S33. -S34, -S36) molecules, the alpha S-33/ alpha S-34 is expected at 0.5 to 0.508, where alpha is the isotope fractionation factor associated with unmixing processes. Thus, one isotope pair is generally proxied to yield all the information for the physical history of the gases. However, we recently] reported the violation of mass law for isotope fractionation among isotope pairs of multiple isotope system during gas diffusion or convection under thermal gradient (Thermal Gradient Induced Non-Mass Dependent effect, TGI-NMD). The mechanism(s) that is responsible to such striking observation remains unanswered. In our past studies, we investigated polyatomic molecules, O2 and SF6, and we suggested that nuclear spin effect could be responsible to the observed NMD effect in a way of changing diffusion coefficients of certain molecules, owing to the fact of negligible delta S-36 anomaly for SF6.. On the other hand, our results also showed that for both diffusion and convection under thermal gradient, this NMD effect is increased by lower gas pressure, bigger temperature gradient and lower average temperature, which indicate that the nuclear spin effect may

  2. Sulfide isotope ratios as a method for examining environmental conditions leading up to the Permian-Triassic extinction

    NASA Astrophysics Data System (ADS)

    Holmes, S. E.; Stebbins, A.; Fernandes, G.; Williams, J. C.; Hannigan, R.

    2013-12-01

    The Permian-Triassic (P-T) extinction that occurred 250 million years ago has an air of mystery surrounding it. One hypothesis for this event is widespread ocean anoxia. This study focuses on using sulfide isotope ratio values (δ34S) as a method for investigating changes in the sulfur cycle leading up to the P-T boundary. The sample site for this study, Lingti 2, was deposited in the Neo-Tethys ocean, now located in the Spiti Valley region of Himichal Pradesh, India. The section consists of Permian black shale (Gungri Formation) and was sampled along strike from the base of the P-T Boundary to the base of the exposed shale at this location. Sulfide was extracted from these shales using chromium reduction. A Costech 4010 Elemental Analyzer (EA) and Isotope Ratio Mass Spectrometer (IRMS) were used to measure the δ34S values in each sample. A chemostratigraphic profile of δ34S and the variations in isotopic composition was evaluated in the context of redox state at the time of sulfide formation. Based on the idea that, under anoxic conditions, bacterial sulfate reducers fractionate sulfur isotopes (reducing 32S preferentially over 34S) and therefore depleting the 32S (and enriching 34S) in the surrounding pore waters. Episodic shifts in δ34S were seen over time. These trends, coupled with degree of pyritization and iron speciation data, suggest periods of low sulfate with intervals euxinia prior to the P-T boundary. The low organic carbon content in these shales coupled with periodic "non-marine" S/C suggest that fluctuations in redox conditions combined with low organic matter content and reduced sulfate availability limited pyrite formation.

  3. Using Multiple Sulfur Isotope Signatures to Delineate Terrane Boundaries and Investigate Crustal Formation Mechanisms during the Paleoproterozoic

    NASA Astrophysics Data System (ADS)

    LaFlamme, C.; Fiorentini, M. L.; Johnson, S.; Occhipinti, S.; Wing, B. A.; Jeon, H.

    2015-12-01

    Proterozoic cratonic margins are structurally and magmatically complex areas of the Earth's crust, having undergone one or more orogenic cycles. Syn- to late-orogenic plutonic suites have a profound effect on the stabilization of cratonic margins by enabling the development of a refractory and buoyant subcontinental mantle and/or lower crust from which they were derived. In addition, these intrusive bodies act as isotopic tracers to the underlying lithospheric keel and its intricate and often obscured architecture. In situ multiple sulfur isotope systematics are a robust and powerful tool for fingerprinting spatially and temporally anomalous signatures found in the crust. When combined, δ34S and Δ33S have the potential to link source environment and age of a sulfur-bearing mineral. Here, we investigate the multiple sulfur isotopic signatures of two syn- to late-orogenic supersuites that form a large component of the Paleoproterozoic Capricorn Orogen of Western Australia: the ca. 1820-1775 Ma Moorarie Supersuite and the ca. 1680-1620 Ma Durlacher Supersuite. Results from secondary ion mass spectrometry demonstrate that the magmatic pyrite from the Moorarie Supersuite yields two differing signatures with δ34S and Δ33S equal to: 1) 3.1-4.8; ~0.00, and 2) 5.1-8.4; 0.1-0.24. This dichotomy is spatially associated with unexposed seismic blocks defined by Johnson et al., (2013).Multiple sulfur isotope systematics also lend insight into the poorly understood formation mechanisms and sources of syn- to late-orogenic plutonic suites. The Durlacher Supersuite does not preserve sample-to-sample variation (δ34S=5.0-8.3; Δ33S=0.0), indicating that it crystallized from a widespread and homogeneous source. This is in direct contrast to the systematic δ34S and Δ33S variation preserved in the Moorarie Supersuite, a feature that we attribute to smaller batch melting of localized and isotopically separate blocks. Lastly, the Durlacher Supersuite contains anomalous within

  4. Single cell visualization of sulfur cycling in intertidal microbial mats

    NASA Astrophysics Data System (ADS)

    Dawson, K.; Green, A.; Orphan, V. J.

    2014-12-01

    Chemoautrophic microbial mats form in shallow intertidal pools adjacent to sulfidic hydrothermal vents in San Pedro, CA. Sulfide is primarily geologically derived. However, microscopy revealed deltaproteobacteria closely associated with Beggiatoa -like filaments, indicating an additional biogenic sulfide source, derived from sulfate reduction or sulfur disproportionation. At small scales the intercellular interaction of sulfide producing and sulfide consuming bacteria may play a important role in biogeochemical sulfur cycling. We explored the intracellular transfer of biologically derived sulfide in this system with triple and quadruple stable isotope labeling experiments: 13C, 15N, 33S, and 34S. Silicon wafers colonized by microbial mats in situ, were then incubated with 34SO42- or 34SO42- and 33S0 as well as 13C-acetate and 15NH4+and analyzed by fluorescent in situ hybridization (FISH) coupled to nanometer-scale secondary ion mass spectrometry (NanoSIMS). We observed enrichment of 34S and 33S in both deltaproteobacteria and sulfide oxidizing gammaproteobacteria. Greater enrichment relative to killed controls occurred in deltaproteobacteria than the sulfide oxidizers during both sulfate reducing (Δ34Sdelta-killed = 240‰, Δ34Sgamma-killed = 40‰) and sulfur disproportionating incubations (Δ33Sdelta-killed = 1730‰, Δ33Sgamma-killed = 1050‰). These results provide a direct visualization of interspecies sulfur transfer and indicate that biogenic sulfide derived from either sulfate or intermediate oxidation state sulfur species plays a role in sulfur cycling in this system.

  5. Redox chemistry changes in the Panthalassic Ocean linked to the end-Permian mass extinction and delayed Early Triassic biotic recovery

    PubMed Central

    Zhang, Guijie; Zhang, Xiaolin; Hu, Dongping; Li, Dandan; Algeo, Thomas J.; Farquhar, James; Henderson, Charles M.; Qin, Liping; Shen, Megan; Shen, Danielle; Schoepfer, Shane D.; Chen, Kefan; Shen, Yanan

    2017-01-01

    The end-Permian mass extinction represents the most severe biotic crisis for the last 540 million years, and the marine ecosystem recovery from this extinction was protracted, spanning the entirety of the Early Triassic and possibly longer. Numerous studies from the low-latitude Paleotethys and high-latitude Boreal oceans have examined the possible link between ocean chemistry changes and the end-Permian mass extinction. However, redox chemistry changes in the Panthalassic Ocean, comprising ∼85–90% of the global ocean area, remain under debate. Here, we report multiple S-isotopic data of pyrite from Upper Permian–Lower Triassic deep-sea sediments of the Panthalassic Ocean, now present in outcrops of western Canada and Japan. We find a sulfur isotope signal of negative Δ33S with either positive δ34S or negative δ34S that implies mixing of sulfide sulfur with different δ34S before, during, and after the end-Permian mass extinction. The precise coincidence of the negative Δ33S anomaly with the extinction horizon in western Canada suggests that shoaling of H2S-rich waters may have driven the end-Permian mass extinction. Our data also imply episodic euxinia and oscillations between sulfidic and oxic conditions during the earliest Triassic, providing evidence of a causal link between incursion of sulfidic waters and the delayed recovery of the marine ecosystem. PMID:28167796

  6. Redox chemistry changes in the Panthalassic Ocean linked to the end-Permian mass extinction and delayed Early Triassic biotic recovery.

    PubMed

    Zhang, Guijie; Zhang, Xiaolin; Hu, Dongping; Li, Dandan; Algeo, Thomas J; Farquhar, James; Henderson, Charles M; Qin, Liping; Shen, Megan; Shen, Danielle; Schoepfer, Shane D; Chen, Kefan; Shen, Yanan

    2017-02-21

    The end-Permian mass extinction represents the most severe biotic crisis for the last 540 million years, and the marine ecosystem recovery from this extinction was protracted, spanning the entirety of the Early Triassic and possibly longer. Numerous studies from the low-latitude Paleotethys and high-latitude Boreal oceans have examined the possible link between ocean chemistry changes and the end-Permian mass extinction. However, redox chemistry changes in the Panthalassic Ocean, comprising ∼85-90% of the global ocean area, remain under debate. Here, we report multiple S-isotopic data of pyrite from Upper Permian-Lower Triassic deep-sea sediments of the Panthalassic Ocean, now present in outcrops of western Canada and Japan. We find a sulfur isotope signal of negative Δ(33)S with either positive δ(34)S or negative δ(34)S that implies mixing of sulfide sulfur with different δ(34)S before, during, and after the end-Permian mass extinction. The precise coincidence of the negative Δ(33)S anomaly with the extinction horizon in western Canada suggests that shoaling of H2S-rich waters may have driven the end-Permian mass extinction. Our data also imply episodic euxinia and oscillations between sulfidic and oxic conditions during the earliest Triassic, providing evidence of a causal link between incursion of sulfidic waters and the delayed recovery of the marine ecosystem.

  7. An Early Shelter for Life on Earth? S and O Isotope Evidence From the Nuvvuagittuq Greenstone Belt, Northeastern Superior Province, Canada

    NASA Astrophysics Data System (ADS)

    Thomassot, E.; O'Neil, J.; Francis, D.; Cartigny, P.; Rumble, D.; Wing, B.

    2009-05-01

    The Nuvvuagittuq Greenstone Belt (NGB,) is one of Earth's oldest Eoarchean volcano-sedimentary suites, and was emplaced prior to 3.75 Ga (Cates and Mojzsis, S.J. 2007), and likely as early as 4.28 Ga (O'Neil et al. 2008). As revealed by recent detailed mapping, the NGB geology is dominated by cummingtonite-bearing amphibolites (formerly called Faux-amphibolite, (O'Neil et al. 2008)) and a series of conformable gabbroic and ultra mafic sills. Minor horizons in the belt include banded iron formations (BIF) with cm-scale quartz-rich and magnetite-rich laminations, and a pyrite-bearing quartzite in gradational contact with the BIF. These rocks and may represent the oldest remains of the sedimentary record on Earth. We performed multiple O-isotope measurements of individual minerals (quartz, garnet, amphibole and magnetite) from three NGB lithologies (BIF, faux amphibolites and quartzite). In BIF samples, δ18O values cover a narrow range (from 1.36 per mil magnetite to 4.98 per mil with one outlier at 9.99 per mil), whereas silicate minerals in the faux reveal a more scattered range that is more depleted in light isotopes (7.77 per mil ≤ δ18O ≤ 13.38 per mil). One quartzite sample has also been analyzed and reveals the most 16O-depleted composition yet measured from the belt (δ18O = 15.44 per mil). The δ17O and δ18O values from these samples define a fractionation line for multiple oxygen isotopes with a slope of 0.528 ± 0.004 (MSWD = 0.47), statistically indistinguishable from the slope (0.524 +± 0.002) of the Archean Terrestrial Fractional Line (TFL) determined from other Archean rocks and minerals. These results show no evidence for the drastic O-isotope heterogeneity that would likely accompany the late heavy bombardment of the Earth-Moon system. We also performed multiple S-isotope ratio measurements (δ34S, Δ33S, Δ36S) in samples covering the entire lithological suite of the NGB. Samples from the quartzite and BIF display a narrow range of δ34S

  8. Recombination reactions as a possible mechanism of mass-independent fractionation of sulfur isotopes in the Archean atmosphere of Earth.

    PubMed

    Babikov, Dmitri

    2017-03-21

    A hierarchy of isotopically substituted recombination reactions is formulated for production of sulfur allotropes in the anoxic atmosphere of Archean Earth. The corresponding system of kinetics equations is solved analytically to obtain concise expressions for isotopic enrichments, with focus on mass-independent isotope effects due to symmetry, ignoring smaller mass-dependent effects. Proper inclusion of atom-exchange processes is shown to be important. This model predicts significant and equal depletions driven by reaction stoichiometry for all rare isotopes: (33)S, (34)S, and (36)S. Interestingly, the ratio of capital [Formula: see text] values obtained within this model for (33)S and (36)S is -1.16, very close to the mass-independent fractionation line of the Archean rock record. This model may finally offer a mechanistic explanation for the striking mass-independent fractionation of sulfur isotopes that took place in the Archean atmosphere of Earth.

  9. Identification of the. pi. g sub 9/2 band in sup 67 As

    SciTech Connect

    Lang, T.F.; Moltz, D.M.; Reiff, J.E.; Batchelder, J.C.; Cerny, J. Lawrence Berkeley Laboratory, Berkeley, CA ); Robertson, J.D. ); Beausang, C.W. )

    1990-10-01

    Charged-particle-{gamma}{gamma} and neutron-{gamma}{gamma} coincidences are employed to identify {gamma}-ray transitions in the {ital T}{sub {ital z}}=1/2 nucleus {sup 67}As, produced in the {sup 40}Ca({sup 32}S,{alpha}{ital p}){sup 67}As and {sup 40}Ca({sup 33}S,{alpha}{ital pn}){sup 67}As reactions at bombarding energies between 95 and 110 MeV. Gamma-ray angular distributions, {gamma}{gamma} coincidences, and {gamma}{gamma} angular correlations are used to deduce a level scheme for {sup 67}As up to 5.7 MeV.

  10. Sulfur isotope values in the sulfidic Frasassi cave system, central Italy: A case study of a chemolithotrophic S-based ecosystem

    NASA Astrophysics Data System (ADS)

    Zerkle, Aubrey L.; Jones, Daniel S.; Farquhar, James; Macalady, Jennifer L.

    2016-01-01

    Sulfide oxidation forms a critical step in the global sulfur cycle, although this process is notoriously difficult to constrain due to the multiple pathways and highly reactive intermediates involved. Multiple sulfur isotopes (δ34S and Δ33S) can provide a powerful tool for unravelling sulfur cycling processes in modern (and ancient) environments, although they have had limited application to systems with well-resolved oxidative S cycling. In this study, we report the major (δ34S) and minor (Δ33S) isotope values of sulfur compounds in streams and sediments from the sulfidic Frasassi cave system, Marche Region, Italy. These microaerophilic cave streams host prominent white biofilms dominated by chemolithotrophic organisms that oxidize sulfide to S0, allowing us to estimate S isotope fractionations associated with in situ sulfide oxidation and to evaluate any resulting isotope biosignatures. Our results demonstrate that chemolithotrophic sulfide oxidation produces 34S enrichments in the S0 products that are larger than those previously measured in laboratory experiments, with 34εS0-H2S of up to 8‰ calculated. These small reverse isotope effects are similar to those produced during phototrophic sulfide oxidation (⩽7‰), but distinct from the small normal isotope effects previously calculated for abiotic oxidation of sulfide with O2 (∼-5‰). An inverse correlation between the magnitude of 34εS0-H2S effects and sulfide availability, along with substantial differences in Δ33S, both support complex sulfide oxidation pathways and intracellular recycling of S intermediates by organisms inhabiting the biofilms. At the ecosystem level, we calculate fractionations of less than 40‰ between sulfide and sulfate in the water column and in the sediments. These fractionations are smaller than those typically calculated for systems dominated by sulfate reduction (>50‰), and contrast with the commonly held assumption that oxidative recycling of sulfide generally

  11. Multiple sulfur isotope systematics of Icelandic geothermal fluids and the source and reactions of sulfur in volcanic geothermal systems at divergent plate boundaries

    NASA Astrophysics Data System (ADS)

    Stefánsson, Andri; Keller, Nicole S.; Robin, Jóhann Gunnarsson; Ono, Shuhei

    2015-09-01

    Multiple sulfur isotope systematics of geothermal fluids at Krafla, Northeast Iceland, were studied in order to determine the source and reactions of sulfur in this system, as an example of a geothermal system hosted on a divergent plate boundary. Fluid temperatures ranged from 192 to 437 °C, and the fluids have low Cl concentration between ∼10 and ∼150 ppm, with liquid water and vapor being present in the reservoir. Dissolved sulfide (S-II) and sulfate (SVI) predominated in the water phase with trace concentrations of thiosulfate (S2O32-) whereas sulfide (S-II) was the only species observed in the vapor phase. The reconstructed sulfur isotope ratios of the reservoir fluids based on samples collected at surface from two-phase and vapor only well discharges indicated that δ34S and Δ33S of sulfide in the reservoir fluid ranged from -1.5 to +1.1‰ and -0.001 to -0.017‰, respectively, whereas δ34S and Δ33S of sulfate were significantly different and ranged from +3.4 to +13.4‰ and 0.000 to -0.036‰, respectively. Depressurization boiling upon fluid ascent coupled with progressive fluid-rock interaction and sulfide mineral (pyrite) formation results in the liquid phase becoming progressively isotopically lighter with respect to both δ34S and Δ33S. In contrast, H2S in the vapor phase and pyrite become isotopically heavier. The observed Δ33S and δ34S systematics for geothermal fluids at Krafla suggest that the source of sulfide in the reservoir fluids is the basaltic magma, either through degassing or upon dissolution of unaltered basalts. At high temperatures, insignificant SO4 was observed in the fluids but below ∼230 °C significant concentrations of SO4 were observed, the source inferred to be H2S oxidation. The two key factors controlling the multiple sulfur isotope systematics of geothermal fluids are: (1) the isotopic composition of the source material and (2) the isotope fractionation associated with aqueous and vapor speciation and how these

  12. Pleistocene sediment offloading and the global sulfur cycle

    NASA Astrophysics Data System (ADS)

    Markovic, S.; Paytan, A.; Wortmann, U. G.

    2015-05-01

    Quaternary sea level fluctuations have greatly affected the sediment budgets of the continental shelves. Previous studies suggested that this caused a considerable increase in the net loss of shelf sediments. Since sediment accumulation and erosion are closely tied to the formation and re-oxidation of pyrite, we use a high-resolution record of sulfur isotope ratios (34S / 32S) of marine sulfate to evaluate the implications of the so-called "shelf sediment offloading" on the global sulfur cycle. Modeling of our δ34S record suggests that erosion during sea level lowstands was only partly compensated by increased sedimentation during times of rising sea level and sea level highstands. Furthermore, our data suggests that shelf systems reached a new equilibrium state about 700 ka, which considerably slowed or terminated shelf sediment offloading.

  13. Pleistocene sediment offloading and the global sulfur cycle

    NASA Astrophysics Data System (ADS)

    Markovic, S.; Paytan, A.; Wortmann, U. G.

    2015-01-01

    Quaternary sea level fluctuations have greatly affected the sediment budgets of the continental shelves. Previous studies suggested that this caused a considerable increase in the net loss of shelf sediments. Since sediment accumulation and erosion are closely tied to the formation and re-oxidation of pyrite, we use a high resolution record of sulfur isotope ratios (34S / 32S) of marine sulfate to evaluate the implications of the so called "shelf sediment offloading" on the global sulfur cycle. Modeling of our δ34S record suggests that erosion during sea level lowstands was only partly compensated by increased sedimentation during times of rising sea level and sea level highstands. Furthermore, our data suggests that shelf systems reached a new equilibrium state about 700 kyr ago, which considerably slowed or terminated shelf sediment offloading.

  14. Using stable isotopes to monitor forms of sulfur during desulfurization processes: A quick screening method

    USGS Publications Warehouse

    Liu, Chao-Li; Hackley, Keith C.; Coleman, D.D.; Kruse, C.W.

    1987-01-01

    A method using stable isotope ratio analysis to monitor the reactivity of sulfur forms in coal during thermal and chemical desulfurization processes has been developed at the Illinois State Geological Survey. The method is based upon the fact that a significant difference exists in some coals between the 34S/32S ratios of the pyritic and organic sulfur. A screening method for determining the suitability of coal samples for use in isotope ratio analysis is described. Making these special coals available from coal sample programs would assist research groups in sorting out the complex sulfur chemistry which accompanies thermal and chemical processing of high sulfur coals. ?? 1987.

  15. Stable isotope ratio mass spectrometry of nanogram quantities of boron and sulfur

    NASA Astrophysics Data System (ADS)

    Wieser, Michael Eugene

    1998-09-01

    Instrumentation and analytical techniques were developed to measure isotope abundances from nanograms of sulfur and boron. Sulfur isotope compositions were determined employing continuous flow isotope ratio mass spectroscopy (CF-IRMS) procedures and AsS+ thermal ionization mass spectrometry techniques (AsS+-TIMS). Boron isotope abundances were determined by BO2/sp--TIMS. CF-IRMS measurements realized δ34S values from 10 μg sulfur with precisions of ±0.3/perthous. To extend sulfur isotope measurements to much smaller samples, a TIMS procedure was developed to measure 75As32S+ and 75As34S+ at masses 108 and 109 from 200 ng S on a Finnigan MAT 262 with an ion counter. This is possibly the smallest amount of sulfur which has been successfully analyzed isotopically. The internal precision of 32S/34S ratios measured by AsS+-TIMS was better than ±0.15 percent. δ34S-values calculated relative to the measured 32S/34S value of an IAEA AG2S standard (S-1) agreed with those determined by CF-IRMS to within ±3/perthous. The increasing sensitivity of S-isotope analyses permits hiterto impossible investigations e.g. sulfur in tree rings and ice cores. Boron isotope abundances were measured as BO2/sp- from 50 ng B using an older thermal ionization mass spectrometer which had been extensively upgraded including the addition of computer control electronics, sensitive ion current amplification and fiber optic data bus. The internal precisions of the measured 11B/10B ratios were ±0.15 percent and the precisions of δ11B values calculated relative to the accepted international standard (SRM-951) were ±3/perthous. Two applications of boron isotope abundance variations were initiated (1) ground waters of Northern Alberta and (2) coffee beans in different regions of the world. In the first it was demonstrated that boron isotopes could be used to trace boron released during steam injection of oil sands into the surrounding environment. Data from the second study suggest that boron

  16. Processes Affecting Tropospheric Ozone Inferred from Ozonesonde and Other Tracer Data from the R/V R H Brown Atlantic Cruise (37N-34S) in January-February 1999

    NASA Technical Reports Server (NTRS)

    Thompson, Anne M.; Doddridge, B. G.; Luke, W. T.; Johnson, J. E.; Witte, J. C.; Reynolds, R. M.; Johnson, B.; Oltmans, S. J.

    1999-01-01

    During the Aerosols-99 trans-Atlantic cruise from Norfolk, VA, to Cape Town, South Africa, 22 ozonesondes were launched from the NOAA R/V R H Brown between 17 Jan and 6 Feb 1999, with all sondes but one reaching 30 km. A composite of ozone profiles along the transect shows high free tropospheric ozone (up to 100 ppbv at 9 km) between 5N and 20S, a coherent feature straddling either side of the ITCZ. Latitudinal variations of tropospheric ozone are interpreted using correlative measurements of surface ozone, CO, water vapor, and aerosol optical thickness (column absorbance) measured from the ship. Elevated ozone in the lower troposphere results from photochemical reactions of precursors emitted by biomass burning north of the ITCZ. However, the greatest ozone mixing ratios are in the mid-troposphere south of the ITCZ, which gives evidence of interhemispheric transport. Column-integrated tropospheric ozone, 35 DU from 0-16 km, agrees with that derived from the TOMS satellite by the modified-residual method [Thompson and Hudson, 1999]. NCEP wind fields, ship-launched radiosondes and back trajectories are consistent with a picture of recirculating air parcels centered in the tropical Atlantic region which is identified with the maximum wave-one amplitude in total ozone seen in sondes and by satellite.

  17. Sulfur isotope composition of metasomatised mantle xenoliths from the Bultfontein kimberlite (Kimberley, South Africa): Contribution from subducted sediments and the effect of sulfide alteration on S isotope systematics

    NASA Astrophysics Data System (ADS)

    Giuliani, Andrea; Fiorentini, Marco L.; Martin, Laure A. J.; Farquhar, James; Phillips, David; Griffin, William L.; LaFlamme, Crystal

    2016-07-01

    Sulfur isotopes are a powerful geochemical tracer in high-temperature processes, but have rarely been applied to the study of mantle metasomatism. In addition, there are very limited S isotope data on sub-continental lithospheric mantle (SCLM) material. For cratonic regions, these data are restricted to sulfide inclusions in diamonds. To provide new constraints on the S isotope composition of the SCLM and on the source(s) of mantle metasomatic fluids beneath the diamondiferous Kimberley region (South Africa), we investigated the S isotope systematics of five metasomatised mantle xenoliths from the Bultfontein kimberlite. Pentlandite and chalcopyrite in these xenoliths were analysed by in situ secondary-ion mass spectrometry (SIMS), with bulk-rock material measured by gas source isotope ratio mass spectrometry techniques. Based on previous studies, the xenoliths experienced different types of metasomatism to one another at distinct times (∼180 and ∼90-80 Ma). Contained pentlandite grains show variable alteration to heazlewoodite (i.e. Ni sulfide) + magnetite. The in situ S isotope analyses of pentlandite exhibit a relatively restricted range between -5.9 and - 1.4 ‰δ34 S (compared to VCDT), with no statistically meaningful differences between samples. Chalcopyrite only occurs in one sample and shows δ34 S values between -5.4 and - 1.0 ‰. The bulk-rock Ssulfide isotope analyses vary between -3.4 and + 0.8 ‰δ34 S. Importantly, the only sample hosting dominantly fresh sulfides shows a bulk-rock δ34 S value consistent with the mean value for the sulfides, whereas the other samples exhibit higher bulk 34S/32S ratios. The differences between bulk-rock and average in situδ34 S values are directly correlated with the degree of sulfide alteration. This evidence indicates that the elevated 34S/32S ratios in the bulk samples are not due to the introduction of heavy S (commonly as sulfates) and are best explained by isotopic fractionation coupled with the removal

  18. Mass-dependent and Mass-independent Sulphur Isotope Fractionation Accompanying Thermal- and Photo-chemical Decomposition of Sulphur Bearing Organic Compounds

    NASA Astrophysics Data System (ADS)

    Oduro, Harry; Izon, Gareth; Ono, Shuhei

    2014-05-01

    The bimodal S-isotope record, specifically the transition from mass independent (MIF) to mass dependent fractionation (MDF), is perhaps the most widely cited line of evidence for an irreversible rise in atmospheric oxygen at ca. 2.4Ga. The production and preservation of S-MIF, manifested in both Δ33S and Δ36S, within the geological record are linked to atmospheric O2 via a number of arguments. However, to date, the only mechanism capable of generating S-MIF consistent with the Archaean sedimentary records involves gas-phase ultraviolet irradiation of SO21 photolysis. More recently, Δ33S S-MIF trends have been reported from en vitro thermochemical sulphate reduction (TSR) experiments, prompting authors to question the importance of S-MIF as a proxy for Earth oxidation2. Importantly, whilst emerging TSR experiments3,4 affirm the reported Δ33S trends2, these experiments fail to identify correlated S-MIF between Δ33S and Δ36S values3,4. Realization that S-MIF is confined to Δ33S during TSR, precludes TSR as a mechanism responsible for the origin of the Archaean S-MIF record but strongly suggests the effect originating from a magnetic isotope effect (MIE) associated with 33S nucleus3,4. Clearly, photochemical and thermochemical processes impart different Δ36S/Δ33S trends with significant variation in δ34S; however, a complete experimental elucidation of mechanisms responsible for the S-MIF and S-MIE signatures is lacking. Interestingly, a complete understanding of the S-isotope chemistry during thermal- and photo-chemical decomposition may reveal wavelength and thermal dependence archived in the sedimentary record. Here we extend the experimental database to explore the magnitude and sign of Δ36S/Δ33S and δ34S produced during both photo- and thermochemical processes. Here the organic sulphur compounds (OSC) utilized in these experiments carries diagnostic Δ36S/Δ33S patterns that differ from those reported from photolysis experiment SO2 and from the

  19. Exploring Archean seawater sulfate via triple S isotopes in carbonate associated sulfate.

    NASA Astrophysics Data System (ADS)

    Paris, G.; Fischer, W. W.; Sessions, A. L.; Adkins, J. F.

    2015-12-01

    Multiple sulfur isotope ratios in Archean sedimentary rocks provide powerful insights into the behavior of the ancient sulfur cycle, the redox state of fluid Earth, and the timing of the rise of atmospheric oxygen [1]. The Archean sulfur isotope record is marked by pronounced mass-independent fractionation (Δ33S≠0)—signatures widely interpreted as the result of SO2 photolysis from "short-wavelength" UV light resulting in a reduced phase carrying positive Δ33S values (ultimately recorded in pyrite) and an oxidized phase carrying negative Δ33S values carried by sulfate [2]. Support for this hypothesis rests on early laboratory experiments and observations of negative Δ33S from barite occurrences in mixed volcanic sedimentary strata in Mesoarchean greenstone terrains. Despite forming the framework for understanding Archean sulfur cycle processes, this hypothesis is still largely untested, notably due to the lack of sulfate minerals in Archean strata. Using a new MC-ICP-MS approach combined with petrography and X-ray spectroscopy we have generated a growing S isotope dataset from CAS extracted from Archean carbonates from a range of sedimentary successions, including: the 2.6 to 2.521 Ga Campbellrand-Malmani carbonate platform (Transvaal Supergroup, South Africa), 2.7 Ga Cheshire Formation (Zimbabwe), and 2.9 Ga Steep Rock Formation (Canada). Importantly, we observe positive δ34S and Δ33S values across a range of different lithologies and depositional environments. These results demonstrate that dissolved sulfate in seawater was characterized by positive Δ33S values—a result that receives additional support from recent laboratory and theoretical experiments [e.g. 4, 5]. [1] Farquhar et al., 2000, Science [2] Farquhar et al., 2001, Journal of Geophysical Research: Planets [3] Paris et al., 2014, Science. [4] Whitehill et al., 2013, Proceedings of the National Academy of Sciences. [5] Claire et al., 2014 Geochimica et Cosmochimica Acta

  20. Biosignatures in chimney structures and sediment from the Loki's Castle low-temperature hydrothermal vent field at the Arctic Mid-Ocean Ridge.

    PubMed

    Jaeschke, Andrea; Eickmann, Benjamin; Lang, Susan Q; Bernasconi, Stefano M; Strauss, Harald; Früh-Green, Gretchen L

    2014-05-01

    We investigated microbial life preserved in a hydrothermally inactive silica–barite chimney in comparison with an active barite chimney and sediment from the Loki's Castle low-temperature venting area at the Arctic Mid-Ocean Ridge (AMOR) using lipid biomarkers. Carbon and sulfur isotopes were used to constrain possible metabolic pathways. Multiple sulfur (dδ34S, Δ33S) isotopes on barite over a cross section of the extinct chimney range between 21.1 and 22.5 % in δ34S, and between 0.020 and 0.034 % in Δ33S, indicating direct precipitation from seawater. Biomarker distributions within two discrete zones of this silica–barite chimney indicate a considerable difference in abundance and diversity of microorganisms from the chimney exterior to the interior. Lipids in the active and inactive chimney barite and sediment were dominated by a range of 13C-depleted unsaturated and branched fatty acids with δ13C values between -39.7 and -26.7 %, indicating the presence of sulfur-oxidizing and sulfate-reducing bacteria. The majority of lipids (99.5 %) in the extinct chimney interior that experienced high temperatures were of archaeal origin. Unusual glycerol monoalkyl glycerol tetraethers (GMGT) with 0–4 rings were the dominant compounds suggesting the presence of mainly (hyper-) thermophilic archaea. Isoprenoid hydrocarbons with δ13C values as low as -46 % also indicated the presence of methanogens and possibly methanotrophs.

  1. Crystal structure of (+)-methyl (E)-3-[(2S,4S,5R)-2-amino-5-hy-droxy-meth-yl-2-tri-chloro-methyl-1,3-dioxolan-4-yl]-2-methyl-prop-2-enoate.

    PubMed

    Oishi, Takeshi; Yasushima, Daichi; Yuasa, Kihiro; Sato, Takaaki; Chida, Noritaka

    2016-03-01

    In the title compound, C10H14Cl3NO5, the five-membered dioxolane ring adopts an envelope conformation. The C atom at the flap, which is bonded to the hy-droxy-methyl substituent, deviates from the mean plane of other ring atoms by 0.357 (5) Å. There are two intra-molecular hydrogen bonds (O-H⋯N and N-H⋯O) between the hy-droxy and amino groups, so that O- and N-bound H atoms involved in these hydrogen bonds are each disordered with equal occupancies of 0.50. The methyl 2-methyl-prop-2-enoate substituent also shows a disordered structure over two sets of sites with refined occupancies of 0.482 (5) and 0.518 (5). In the crystal, mol-ecules are connected into a dimer by an O-H⋯O hydrogen bond. The dimers are further linked by N-H⋯O, C-H⋯N and C-H⋯O inter-actions, extending a sheet structure parallel to ([Formula: see text]01).

  2. Modeling novel isotopic proxies of the oxygenation of the earth's surface

    NASA Astrophysics Data System (ADS)

    Domagal-Goldman, Shawn D.

    Tracking the evolution of the oxidation state of the Earth's surface environment has increased understanding of the biological, atmospheric, oceanic, and geological evolution of the Earth, and may allow us to broaden the search for life on extrasolar planets. In this thesis, two relatively new proxies for the evolution of the Earth's surface oxidation state are examined. Both proxies use stable isotope measurements to identify a permanent oxidation of the surface that occurred between ˜2.4 and ˜1.8 billion years ago (Ga). Measurements of the stable isotopes of Fe (54Fe, 56Fe, and 57Fe) in sediments demonstrate an increase in maximum 56Fe/54Fe prior to ˜1.8 billion years ago (Ga) and an increase in the maximum and decrease in the minimum 56Fe/54Fe prior to ˜2.3 Ga. These data have been interpreted as being the result of stepwise changes to the oxidation state of the Earth's oceans. However, the measurement of Fe isotopes has also been proposed as a way to identify a history of life in a sample, as Fe isotopes have been shown to fractionate during metabolic processes and upon complexation with organic acids. In the first two chapters of the thesis, the fractionation associated with complexation of Fe with organic ligands is modeled. Equilibrium constants are predicted for equilibrium isotope exchange for redox and ligand exchange reactions. These predictions allow comparison of these two types of fractionation and place the two proposed uses of Fe isotopes in better theoretical context. Another novel tool for tracking the redox history of the Earth is the measurement of multiple S isotopes. In sediments younger than ˜2.3 Ga, the fractionation of the stable S isotopes (32S, 33 S, 34S, and 36S) follows specific trends that depend on the mass of the isotopes. This behavior is classified as mass-dependent fractionation, and is witnessed for almost all known kinetic, equilibrium, and biological fractionation processes. However, sediments older than ˜2.45 Ga do not

  3. Leishmaniasis Worldwide and Global Estimates of Its Incidence

    PubMed Central

    Vélez, Iván D.; Bern, Caryn; Herrero, Mercé; Desjeux, Philippe; Cano, Jorge; Jannin, Jean

    2012-01-01

    As part of a World Health Organization-led effort to update the empirical evidence base for the leishmaniases, national experts provided leishmaniasis case data for the last 5 years and information regarding treatment and control in their respective countries and a comprehensive literature review was conducted covering publications on leishmaniasis in 98 countries and three territories (see ‘Leishmaniasis Country Profiles Text S1, S2, S3, S4, S5, S6, S7, S8, S9, S10, S11, S12, S13, S14, S15, S16, S17, S18, S19, S20, S21, S22, S23, S24, S25, S26, S27, S28, S29, S30, S31, S32, S33, S34, S35, S36, S37, S38, S39, S40, S41, S42, S43, S44, S45, S46, S47, S48, S49, S50, S51, S52, S53, S54, S55, S56, S57, S58, S59, S60, S61, S62, S63, S64, S65, S66, S67, S68, S69, S70, S71, S72, S73, S74, S75, S76, S77, S78, S79, S80, S81, S82, S83, S84, S85, S86, S87, S88, S89, S90, S91, S92, S93, S94, S95, S96, S97, S98, S99, S100, S101’). Additional information was collated during meetings conducted at WHO regional level between 2007 and 2011. Two questionnaires regarding epidemiology and drug access were completed by experts and national program managers. Visceral and cutaneous leishmaniasis incidence ranges were estimated by country and epidemiological region based on reported incidence, underreporting rates if available, and the judgment of national and international experts. Based on these estimates, approximately 0.2 to 0.4 cases and 0.7 to 1.2 million VL and CL cases, respectively, occur each year. More than 90% of global VL cases occur in six countries: India, Bangladesh, Sudan, South Sudan, Ethiopia and Brazil. Cutaneous leishmaniasis is more widely distributed, with about one-third of cases occurring in each of three epidemiological regions, the Americas, the Mediterranean basin, and western Asia from the Middle East to Central Asia. The ten countries with the highest estimated case counts, Afghanistan, Algeria, Colombia, Brazil, Iran, Syria, Ethiopia, North Sudan, Costa

  4. Sulfur isotope mass-independent fractionation in impact deposits of the 3.2 billion-year-old Mapepe Formation, Barberton Greenstone Belt, South Africa

    NASA Astrophysics Data System (ADS)

    van Zuilen, M. A.; Philippot, P.; Whitehouse, M. J.; Lepland, A.

    2014-10-01

    Theoretical and experimental studies have shown that atmospheric SO2 isotopologue self-shielding effects in the 190-220 nm region of the solar spectrum are the likely cause for mass independent fractionation of sulfur isotopes (S-MIF). The main products of this photochemical reaction - SO3 and S0 - typically define a compositional array of ca. Δ33S34S = 0.06-0.14. This is at odds with the generally observed trend in Archean sulfides, which broadly defines an array of ca. Δ33S34S = 0.9. Various explanations have been proposed, including a diminution of δ34S caused by chemical and biogenic mass-dependent fractionation of sulfur isotopes (S-MDF), mixing with photolytic products produced during felsic volcanic events, or partial blocking of the low-wavelength part of the spectrum due to the presence of reduced atmospheric gases or an organic haze. Early in Earth history large meteorite impacts would have ejected dust and gas clouds into the atmosphere that shielded solar radiation and affected global climate. It is thus likely that at certain time intervals of high meteorite flux the atmosphere was significantly perturbed, having an effect on atmospheric photochemistry and possibly leaving anomalous sulfur isotopic signatures in the rock record. Here we describe the sulfur isotopic signatures in sulfides of spherule beds S2, S3 and S4 of the Barberton Greenstone Belt, South Africa. In particular, in spherule bed S3 - and to a lesser extent S4 - a trend of ca. Δ33S34S = 0.23 is observed that closely follows the expected trend for SO2-photolysis in the 190-220 nm spectral range. This suggests that an impact dust cloud (deposited as spherule beds), which sampled the higher region of the atmosphere, specifically incorporated products of SO2 photolysis in the 190-220 nm range, and blocked photochemical reactions at higher wavelengths (250-330 nm band). By implication, the generally observed Archean trend appears to be the result of mixing of different MIF

  5. Tracing sources of sulfur in the Florida everglades

    USGS Publications Warehouse

    Bates, A.L.; Orem, W.H.; Harvey, J.W.; Spiker, E. C.

    2002-01-01

    We examined concentrations and sulfur isotopic ratios (34S/32S, expressed as ??34S in parts per thousand [???] units) of sulfate in surface water, ground water, and rain water from sites throughout the northern Everglades to establish the sources of sulfur to the ecosystem. The geochemistry of sulfur is of particular interest in the Everglades because of its link, through processes mediated by sulfate -reducing bacteria, to the production of toxic methylmercury in this wetland ecosystem. Methylmercury, a neurotoxin that is bioaccumulated, has been found in high concentrations in freshwater fish from the Everglades, and poses a potential threat to fish-eating wildlife and to human health through fish consumption. Results show that surface water in large portions of the Everglades is heavily contaminated with sulfate, with the highest concentrations observed in canals and marsh areas receiving canal discharge. Spatial patterns in the range of concentrations and ??34S values of sulfate in surface water indicate that the major source of sulfate in sulfur-contaminated marshes is water from canals draining the Everglades Agricultural Area. Shallow ground water underlying the Everglades and rain water samples had much lower sulfate concentrations and ??34S values distinct from those found in surface water. The ??34S results implicate agricultural fertilizer as a major contributor to the sulfate contaminating the Everglades, but ground water under the Everglades Agricultural Area (EAA) may also be a contributing source. The contamination of the northern Everglades with sulfate from canal discharge may be a key factor in controlling the distribution and extent of methylmercury production in the Everglades.

  6. Multiple sulfur-isotope signatures in Archean sulfates and their implications for the chemistry and dynamics of the early atmosphere

    PubMed Central

    Muller, Élodie; Philippot, Pascal; Rollion-Bard, Claire; Cartigny, Pierre

    2016-01-01

    Sulfur isotopic anomalies (∆33S and ∆36S) have been used to trace the redox evolution of the Precambrian atmosphere and to document the photochemistry and transport properties of the modern atmosphere. Recently, it was shown that modern sulfate aerosols formed in an oxidizing atmosphere can display important isotopic anomalies, thus questioning the significance of Archean sulfate deposits. Here, we performed in situ 4S-isotope measurements of 3.2- and 3.5-billion-year (Ga)-old sulfates. This in situ approach allows us to investigate the diversity of Archean sulfate texture and mineralogy with unprecedented resolution and from then on to deconvolute the ocean and atmosphere Archean sulfur cycle. A striking feature of our data is a bimodal distribution of δ34S values at ∼+5‰ and +9‰, which is matched by modern sulfate aerosols. The peak at +5‰ represents barite of different ages and host-rock lithology showing a wide range of ∆33S between −1.77‰ and +0.24‰. These barites are interpreted as primary volcanic emissions formed by SO2 photochemical processes with variable contribution of carbonyl sulfide (OCS) shielding in an evolving volcanic plume. The δ34S peak at +9‰ is associated with non–33S-anomalous barites displaying negative ∆36S values, which are best interpreted as volcanic sulfate aerosols formed from OCS photolysis. Our findings confirm the occurrence of a volcanic photochemical pathway specific to the early reduced atmosphere but identify variability within the Archean sulfate isotope record that suggests persistence throughout Earth history of photochemical reactions characteristic of the present-day stratosphere. PMID:27330111

  7. Multiple sulfur-isotope signatures in Archean sulfates and their implications for the chemistry and dynamics of the early atmosphere

    NASA Astrophysics Data System (ADS)

    Muller, Élodie; Philippot, Pascal; Rollion-Bard, Claire; Cartigny, Pierre

    2016-07-01

    Sulfur isotopic anomalies (∆33S and ∆36S) have been used to trace the redox evolution of the Precambrian atmosphere and to document the photochemistry and transport properties of the modern atmosphere. Recently, it was shown that modern sulfate aerosols formed in an oxidizing atmosphere can display important isotopic anomalies, thus questioning the significance of Archean sulfate deposits. Here, we performed in situ 4S-isotope measurements of 3.2- and 3.5-billion-year (Ga)-old sulfates. This in situ approach allows us to investigate the diversity of Archean sulfate texture and mineralogy with unprecedented resolution and from then on to deconvolute the ocean and atmosphere Archean sulfur cycle. A striking feature of our data is a bimodal distribution of δ34S values at ˜+5‰ and +9‰, which is matched by modern sulfate aerosols. The peak at +5‰ represents barite of different ages and host-rock lithology showing a wide range of ∆33S between -1.77‰ and +0.24‰. These barites are interpreted as primary volcanic emissions formed by SO2 photochemical processes with variable contribution of carbonyl sulfide (OCS) shielding in an evolving volcanic plume. The δ34S peak at +9‰ is associated with non-33S-anomalous barites displaying negative ∆36S values, which are best interpreted as volcanic sulfate aerosols formed from OCS photolysis. Our findings confirm the occurrence of a volcanic photochemical pathway specific to the early reduced atmosphere but identify variability within the Archean sulfate isotope record that suggests persistence throughout Earth history of photochemical reactions characteristic of the present-day stratosphere.

  8. Correlation between multielement stable isotope ratio and geographical origin in Peretta cows' milk cheese.

    PubMed

    Manca, G; Franco, M A; Versini, G; Camin, F; Rossmann, A; Tola, A

    2006-03-01

    The aim of this study was to characterize the isotopic composition and protect "Peretta" cows' milk cheese, a typical product of Sardinia, against other cheeses of the same appearance sold under the same name, but made of raw materials from northern Europe. The study was concerned with 3 types of cheese: those produced in local dairies from milk from free-grazing or pasture-grazing cows in Sardinia (local dairy product), cheeses made on an industrial scale from milk produced by intensive farming in Sardinia (factory cheese), and cheeses made with raw materials imported from other countries (imported product). To distinguish the Sardinian cheeses from the imported product, the stable isotope ratios 13C/12C, 15N/14N, D/H, 34S/32S, and (18)O/(16)O were used. Determination of the isotopic data delta13C, delta15N, delta2H, and delta34S was performed in the casein fraction, whereas delta(18)O and delta13C were determined in the glycerol fraction. Measurements were performed by isotope ratio mass spectrometry. A comparison between mean values of the isotope ratios by statistical analysis (ANOVA and Tukey's test) showed that the greatest difference between the 3 types of cheese (local dairy, factory, and imported products) was in the 13C/12C, 34S/32S, and (18)O/(16)O isotope ratios. In the other parameters, either no differences (delta15N) or minimal differences (delta2H) were found. Evaluation of the data by multivariate statistical analysis (principal component analysis and hierarchical cluster analysis) revealed that the isotope characteristics of the factory products were similar to those of the cheeses produced from imported raw materials, whereas a difference was found between the local dairy-produced cheeses and the products in the other 2 categories.

  9. Sulfur Isotopic Compositions of Individual Aerosol Particles from Below and Within Stratocumulus Clouds over the Southeast Pacific Ocean During VOCALS

    NASA Astrophysics Data System (ADS)

    Bose, M.; Anderson, J. R.; Twohy, C. H.; Williams, P.

    2012-12-01

    The VAMOS Ocean-Cloud-Atmosphere-Land Study Regional Experiment (VOCALS-Rex) was a large multi-national field experiment that collected data and samples from a region of the southeast Pacific with the world's largest stratocumulus cloud systems. Samples examined here are residues of cloud droplets and ambient particles from below the clouds collected during flights of the NCAR C-130 off the coast of Chile. Selected samples were studied using scanning electron microscopy (SEM) and secondary ion mass spectrometry (SIMS) in order to contribute to the understanding of the source of non-sea-salt sulfate in this region. Particles in the size range from 0.2 to 1μm diameter on holey and lacey carbon were characterized by SEM combined with energy dispersive spectrometry (EDS), thus identifying sulfur-containing particles. Subsequently, sulfur ion imaging of identified sea salt, ammonium sulfate and sodium sulfate particles was done with the Cameca Ametek NanoSIMS 50L at Arizona State University. A <1pA Cs+ beam was rastered over 5×5μm2 or 10×10μm2 areas while secondary ions (12C-, 16O-, 32S-, 34S-, 35Cl-) and secondary electrons were collected simultaneously at high mass resolution (m/Δm>10000). Each measurement typically consists of 5 to 8 frames (~5.4 min/frame). NIST barium sulfate and ammonium sulfate particles were used as isotopic standards. Preliminary analyses on a small pool of VOCALS individual particles show a wide range in sulfur isotopic compositions (δ34S = -56 to +41‰). In addition, the in-cloud particles are enriched in 32S, while the ambient particles exhibit 34S excesses. Isotopic data on a large inventory of particles is being currently acquired, which will be presented at the meeting. Data will be used to investigate sulfur sources (marine vs. continental) and the processing of aerosols through sulfate formation.

  10. Stable sulfur isotopes identify habitat-specific foraging and mercury exposure in a highly mobile fish community.

    PubMed

    Carr, Meghan K; Jardine, Timothy D; Doig, Lorne E; Jones, Paul D; Bharadwaj, Lalita; Tendler, Brett; Chételat, John; Cott, Pete; Lindenschmidt, Karl-Erich

    2017-02-10

    Tracking the uptake and transfer of toxic chemicals, such as mercury (Hg), in aquatic systems is challenging when many top predators are highly mobile and may therefore be exposed to chemicals in areas other than their location of capture, confounding interpretation of bioaccumulation trends. Here we show how the application of a less commonly used ecological tracer, stable sulfur isotope ratios ((34)S/(32)S, or δ(34)S), in a large river-delta-lake complex in northern Canada allows differentiation of resident from migrant fishes, beyond what was possible with more conventional (13)C/(12)C and (15)N/(14)N measurements. Though all large fishes (n=105) were captured in the river, the majority (76%) had δ(34)S values that were indicative of the fish having been reared in the lake. These migrant fishes were connected to a food chain with greater Hg trophic magnification relative to the resident fish of the river and delta. Yet, despite a shallower overall trophic magnification slope, large river-resident fish had higher Hg concentrations owing to a greater biomagnification of Hg between small and large fishes. These findings reveal how S isotopes can trace fish feeding habitats in large freshwater systems and better account for fish movement in complex landscapes with differential exposure pathways and conditions.

  11. S and O Isotope Studies of Microbial S Cycling in the Deep Biosphere of Marine Sediments: Eastern Equatorial Pacific Ocean

    NASA Astrophysics Data System (ADS)

    Blake, R. E.; Bottcher, M. E.; Surkov, A. V.; Ferdelman, T. G.; Jorgensen, B. B.

    2004-12-01

    We have determined the oxygen (18O/16O) and sulfur (34S/32S) isotope ratios of porewater sulfate to depths of over 400 mbsf in sediments from open-ocean and upwelling sites in the Eastern Equatorial Pacific ocean. Sulfate δ 18O ranges from near-normal seawater values (9.5 permil) at organic-poor open-ocean sites, to approximately 30 permil at sites with higher organic matter content and higher associated microbial activity. Depth-correlative trends of δ 18O, δ 34S, alkalinity, methane, ammonium and the presence of sulfide, indicate significant oxidation of sedimentary organic matter by sulfate-reducing microbial populations as well as anaerobic oxidation of methane. δ 18O-SO4 values at low-activity sites reveal the presence of significant microbial sulfur-cycling activity despite relatively flat sulfate concentration and δ 34S profiles. This activity may include contributions from several processes including: enzyme-catalyzed equilibration between oxygen in sulfate and water superimposed upon microbial sulfate reduction, sulfide oxidation, and bacterial disproportionation of sulfur intermediates. Large isotope enrichment factors observed at low-activity sites (40-80 permil) likely reflect concurrent processes of: kinetic isotope fractionation, equilibrium fractionation between sulfate and water, and sulfide oxidation at low rates of sulfate reduction. Results of this study indicate that coupled measurements of S and O isotope ratios of porewater sulfate are a powerful tool for tracing microbial activity and sulfur cycling in marine sediments.

  12. Multiple sulfur and carbon isotope composition of sediments from the Belingwe Greenstone Belt (Zimbabwe): A biogenic methane regulation on mass independent fractionation of sulfur during the Neoarchean?

    NASA Astrophysics Data System (ADS)

    Thomazo, Christophe; Nisbet, Euan G.; Grassineau, Nathalie V.; Peters, Marc; Strauss, Harald

    2013-11-01

    To explore the linkage between mass-independent sulfur isotope fractionation (MIF-S) and δ13Corg excursions during the Neoarchean, as well as the contemporary redox state and biogeochemical cycling of carbon and sulfur, we report the results of a detailed carbon and multiple sulfur (δ34S, δ33S, δ36S) isotopic study of the ∼2.7 Ga Manjeri and ∼2.65 Ga Cheshire formations of the Ngezi Group (Belingwe Greenstone Belt, Zimbabwe). Multiple sulfur isotope data show non-zero Δ33S and Δ36S values for sediments older than 2.4 Ga (i.e. prior to the Great Oxidation Event, GOE), indicating MIF-S thought to be associated with low atmospheric oxygen concentration. However, in several 2.7-2.5 Ga Neoarchean localities, small-scale variations in MIF-S signal (magnitude) seem to correlate with negative excursion in δ13Corg, possibly reflecting a global connection between the relative reaction rate of different MIF-S source reaction and sulfur exit channels and the biogenic flux of methane into the atmosphere during periods of localized, microbiologically mediated, shallow surface-water oxygenation. The Manjeri Formation black shales studied here display a wide range of δ13Corg between -35.4‰ and -16.2‰ (average of -30.3 ± 6.0‰, 1σ), while the Cheshire Formation shales have δ13Corg between -47.7‰ and -35.1‰ (average -41.3 ± 3‰, 1σ). The δ34S values of sedimentary sulfides from Manjeri Formation vary between -15.15‰ and +2.37‰ (average -1.71 ± 4.76‰, 1σ), showing very small and mostly negative Δ33S values varying from -0.58‰ to 0.87‰ (average 0.02 ± 0.43‰, 1σ). Cheshire Formation black shale sulfide samples measured in this study have δ34S values ranging from -2.11‰ to 2.39‰ (average 0.25 ± 1.08‰, 1σ) and near zero and solely positive Δ33S anomalies between 0.14‰ and 1.17‰ (average 0.56 ± 0.29‰, 1σ). Moreover, Δ36S/Δ33S in the two formations are comparable with a slope of -1.38 (Manjeri Formation) and -1.67 (Cheshire

  13. Sulfur and Hydrogen Isotope Anomalies in Organic Compounds from the Murchison Meteorite

    NASA Astrophysics Data System (ADS)

    Cooper, G. W.; Thiemens, M. H.; Jackson, T.; Chang, S.

    1995-09-01

    Carbon, hydrogen and sulfur isotopic measurements have been made on individual members of a recently discovered class of organic sulfur compounds, alkyl sulfonates, in the Murchison meteorite. Cooper and Chang (1) reported the first carbon isotopic measurements of Murchison organic sulfonates, providing insight into potential synthetic mechanisms of these, and possibly other, organic species. Hydrogen isotopic measurements of the sulfonates now reveal deuterium excesses ranging from +660 to +2730 per mil. The deuterium enrichments indicate formation of the hydrocarbon portion of these compounds in a low temperature astrophysical environment consistent with that of dense molecular clouds. Measurement of the sulfur isotopes provide further constraints on the origin and mechanism of formation of these organic molecules. Recently, there has been growing documentation of sulfur isotopic anomalies in meteoritic material. Thiemens and Jackson (2) have shown that some bulk ureilites possess excess 33S and Thiemens et al. (3) have reported excess 33S in an oldhamite separate from Norton County. Rees and Thode (4) reported a large 33S excess in an Allende acid residue, however, attempts to verify this measurement have been unsuccessful, possibly due to the heterogeneous nature of the carrier phase. With the recognition that sulfur isotopes may reflect nebular chemistry, identification of potential carriers is of considerable interest. In the present study the three stable isotopes of sulfur were measured in methane sulfonate extracted from the Murchison meteorite. The isotopic composition was found to be delta 33S=2.48, delta 34S=2.49 and delta 36S = 6.76 per mil. Based upon analysis of more than 60 meteoritic, and numerous terrestrial samples, the mass fractionation lines are defined by 33Delta = delta 33S-0.50 delta 34S and 36Delta = delta 36S -1.97 delta 34S. From these relations a 33Delta = 1.24 per mil and 36Delta = 0.89 per mil is observed. These anomalies

  14. Carbon and Sulfur Isotopic Signatures of Ancient Life and Environment at the Microbial Scale: Neoarchean Shales and Carbonates

    NASA Technical Reports Server (NTRS)

    Williford, K. H.; Ushikubo, T.; Lepot, K.; Kitajima, K.; Hallmann, C.; Spicuzza, M. J.; Kozdon, R.; Eigenbrode, J. L.; Summons, R. E.; Valley, J. W.

    2015-01-01

    An approach to coordinated, spatially resolved, in situ carbon isotope analysis of organic matter and carbonate minerals, and sulfur three- and four-isotope analysis of pyrite with an unprecedented combination of spatial resolution, precision, and accuracy is described. Organic matter and pyrite from eleven rock samples of Neoarchean drill core express nearly the entire range of delta(sup 13)C, delta(sup 34)S, Delta(sup 33)S, and Delta(sup 36)S known from the geologic record, commonly in correlation with morphology, mineralogy, and elemental composition. A new analytical approach (including a set of organic calibration standards) to account for a strong correlation between H/C and instrumental bias in SIMS delta(sup 13)C measurement of organic matter is identified. Small (2-3 microns) organic domains in carbonate matrices are analyzed with sub-permil accuracy and precision. Separate 20- to 50-micron domains of kerogen in a single approx. 0.5 cu cm sample of the approx. 2.7 Ga Tumbiana Formation have delta(sup 13)C = -52.3 +/- 0.1per mille and -34.4 +/- 0.1per mille, likely preserving distinct signatures of methanotrophy and photoautotrophy. Pyrobitumen in the approx. 2.6 Ga Jeerinah Formation and the approx. 2.5 Ga Mount McRae Shale is systematically 13C-enriched relative to co-occurring kerogen, and associations with uraniferous mineral grains suggest radiolytic alteration. A large range in sulfur isotopic compositions (including higher Delta(sup 33)S and more extreme spatial gradients in Delta(sup 33)S and Delta(sup 36)S than any previously reported) are observed in correlation with morphology and associated mineralogy. Changing systematics of delta(sup 34)S, Delta(sup 33)S, and Delta(sup 36)S, previously investigated at the millimeter to centimeter scale using bulk analysis, are shown to occur at the micrometer scale of individual pyrite grains. These results support the emerging view that the dampened signature of mass-independent sulfur isotope fractionation

  15. Carbon and sulfur isotopic signatures of ancient life and environment at the microbial scale: Neoarchean shales and carbonates.

    PubMed

    Williford, K H; Ushikubo, T; Lepot, K; Kitajima, K; Hallmann, C; Spicuzza, M J; Kozdon, R; Eigenbrode, J L; Summons, R E; Valley, J W

    2016-03-01

    An approach to coordinated, spatially resolved, in situ carbon isotope analysis of organic matter and carbonate minerals, and sulfur three- and four-isotope analysis of pyrite with an unprecedented combination of spatial resolution, precision, and accuracy is described. Organic matter and pyrite from eleven rock samples of Neoarchean drill core express nearly the entire range of δ(13) C, δ(34) S, Δ(33) S, and Δ(36) S known from the geologic record, commonly in correlation with morphology, mineralogy, and elemental composition. A new analytical approach (including a set of organic calibration standards) to account for a strong correlation between H/C and instrumental bias in SIMS δ(13) C measurement of organic matter is identified. Small (2-3 μm) organic domains in carbonate matrices are analyzed with sub-permil accuracy and precision. Separate 20- to 50-μm domains of kerogen in a single ~0.5 cm(3) sample of the ~2.7 Ga Tumbiana Formation have δ(13) C = -52.3 ± 0.1‰ and -34.4 ± 0.1‰, likely preserving distinct signatures of methanotrophy and photoautotrophy. Pyrobitumen in the ~2.6 Ga Jeerinah Formation and the ~2.5 Ga Mount McRae Shale is systematically (13) C-enriched relative to co-occurring kerogen, and associations with uraniferous mineral grains suggest radiolytic alteration. A large range in sulfur isotopic compositions (including higher Δ(33) S and more extreme spatial gradients in Δ(33) S and Δ(36) S than any previously reported) are observed in correlation with morphology and associated mineralogy. Changing systematics of δ(34) S, Δ(33) S, and Δ(36) S, previously investigated at the millimeter to centimeter scale using bulk analysis, are shown to occur at the micrometer scale of individual pyrite grains. These results support the emerging view that the dampened signature of mass-independent sulfur isotope fractionation (S-MIF) associated with the Mesoarchean continued into the early Neoarchean, and that the connections

  16. Sulfur and Hydrogen Isotopic Evidence for Open-System Degassing during the Climactic and Pre-Climactic Eruptions of Mount Mazama, Crater Lake, Oregon

    NASA Astrophysics Data System (ADS)

    Mandeville, C. W.; Webster, J. D.; Tappen, C. M.; Taylor, B. E.; Timbal, A.; Sasaki, A.; Hauri, E. H.; Bacon, C. R.; Eschen, M. L.

    2001-05-01

    Assessing the source(s) of magmatic volatiles through isotopic characterization requires evaluation of modifications to initial isotopic composition during degassing. Sulfur, and hydrogen isotope compositions of whole rocks and matrix glasses were measured in climactic rhyodacitic to andesitic tephra and in pre-climactic rhyodacitic tephra to identify the likely source(s) of magmatic volatiles (H2O, S). Sulfur isotope analyses of climactic rhyodacitic whole-rock samples indicate δ 34S values ranging from +2.8‰ to +14.8‰ with corresponding matrix glass δ 34S values of +4.9‰ to +13.2‰ . Matrix glass δ 34S values are generally 1-2 % higher than whole-rock δ 34S values in corresponding samples. The whole-rock δ 34S is strongly controlled by the 34/32S ratio and sulfur concentration of the glass. Whole-rock and matrix glass δ 34S values generally tend to increase with stratigraphic height. Average sulfur concentration (by Kiba extraction) of climactic rhyodacitic matrix glasses is 71 ppm and compares well to 77 ppm (by ion chromatography). Electron microprobe analyses of plagioclase-hosted glass inclusions from rhyodacitic pumices have sulfur concentrations of 80 to 330 ppm, with the highest sulfur concentrations in inclusions with 4.8 - 5.2 wt. % H2O (by FTIR and ion probe, respectively). Lower sulfur concentrations in glass inclusions containing 4.0 wt. % water (by ion probe) are attributed to melt entrapment following pre-eruptive degassing. Negative correlation of δ 34S values with sulfur concentration indicates sulfur degassing of mostly SO2 from an oxidized magma with SO4 as the dominant sulfur species in the melt. SIMS δ 34S analyses of pyrrhotites in climactic rhyodacitic tephra range from -1.0‰ to +5.6‰ and from -1.0‰ to +4.0‰ in andesitic scoria. The initial δ 34S value of rhyodacitic magma was most likely near a mantle value of 0‰ . Elevated δ 34S values of +7‰ to +14‰ in degassed matrix glasses are best explained by open

  17. SO2 photolysis as a source for sulfur mass-independent isotope signatures in stratospehric aerosols

    NASA Astrophysics Data System (ADS)

    Whitehill, A. R.; Jiang, B.; Guo, H.; Ono, S.

    2015-02-01

    Signatures of sulfur isotope mass-independent fractionation (S-MIF) have been observed in stratospheric sulfate aerosols deposited in polar ice. The S-MIF signatures are thought to be associated with stratospheric photochemistry following stratospheric volcanic eruptions, but the exact mechanism responsible for the production and preservation of these signatures is debated. In order to identify the origin and the mechanism of preservation for these signatures, a series of laboratory photochemical experiments were carried out to investigate the effect of temperature and added O2 on the S-MIF produced by two absorption band systems of SO2: photolysis in the 190 to 220 nm region and photoexcitation in the 250 to 350 nm region. The SO2 photolysis (SO2 + hν → SO + O) experiments showed S-MIF signals with large 34S/34S fractionations, which increases with decreasing temperature. The overall S-MIF pattern observed for photolysis experiments, including high 34S/34S fractionations, positive mass-independent anomalies in 33S, and negative anomalies in 36S, is consistent with a major contribution from optical isotopologue screening effects and data for stratospheric sulfate aerosols. In contrast, SO2 photoexcitation produced products with positive S-MIF anomalies in both 33S and 36S, which is different from stratospheric sulfate aerosols. SO2 photolysis in the presence of O2 produced SO3 with S-MIF signals, suggesting the transfer of the S-MIF anomalies from SO to SO3 by the SO + O2 + M → SO3 + M reaction. This is supported with energy calculations of stationary points on the SO3 potential energy surfaces, which indicate that this reaction occurs slowly on a single adiabatic surface, but that it can occur more rapidly through intersystem crossing. Based on our experimental results, we estimate a termolecular rate constant on the order of 10-37 cm6 molecule-2 s-1. This rate can explain the preservation of mass independent isotope signatures in stratospheric sulfate

  18. Multimodal information Management: Evaluation of Auditory and Haptic Cues for NextGen Communication Displays

    NASA Technical Reports Server (NTRS)

    Begault, Durand R.; Bittner, Rachel M.; Anderson, Mark R.

    2012-01-01

    Auditory communication displays within the NextGen data link system may use multiple synthetic speech messages replacing traditional ATC and company communications. The design of an interface for selecting amongst multiple incoming messages can impact both performance (time to select, audit and release a message) and preference. Two design factors were evaluated: physical pressure-sensitive switches versus flat panel "virtual switches", and the presence or absence of auditory feedback from switch contact. Performance with stimuli using physical switches was 1.2 s faster than virtual switches (2.0 s vs. 3.2 s); auditory feedback provided a 0.54 s performance advantage (2.33 s vs. 2.87 s). There was no interaction between these variables. Preference data were highly correlated with performance.

  19. MX Siting Investigation. Geotechnical Evaluation. Verification Study - Lake Valley, Nevada. Volume II. Geotechnical Data.

    DTIC Science & Technology

    1981-07-31

    dolomite, chalk). J S3 Argillaceous Rocks - Composed of clay and silt-sized particles (e.g., siltstone, shale, claystone). S4 Evaporite Rocks...K 0FOPHONES 1 7 18 24 18ago fm (576 mp) .o ( smp ) ---- s z Z 00 - (2561 mpis) 100 w Wb a a I150 0 MIETERS 50 MX SITING INVESTIGATION SI I I I _j Ir...8217 ~ ’ SH4- 3oV N 8ii~ AO33 S 51~ S a- 8( 8 L 3d~i 3l0NV- mad&#34.s * -s~A LO C42 co o a (0 0 S4 Co 0 ’Ua. c 51 C S C 0 ! .0 0 E t’ t~~•o IoMCW IC ", C1> ti

  20. Proton Spectroscopic Factors Deduced from Helium-3 Global Phenomenological and Microscopic Optical Model Potentials

    NASA Astrophysics Data System (ADS)

    Jenny, Lee; Pang, Dan-Yang; Han, Yin-Lu; B. Tsang, M.

    2014-09-01

    Global phenomenological GDP08 and microscopic helium-3 optical model potentials have been recently derived. We evaluate these two potential sets by comparing the elastic scattering data of 25 MeV 3He on 16O, 18O, 19F, 23Na, 24Mg, 25Mg, 26Mg, 27Al, 28Si, 30Si, 31P, 32S, 34S, 35Cl, 37Cl, and 39K isotopes. Using the deuteron angular distributions calculated with the distorted wave Born approximation model, we extract the ground-state proton spectroscopic factors from (3He, d) reactions on the same set of nuclei. The extracted proton spectroscopic factors are compared with the large-basis shell-model calculations.

  1. Ultrahigh resolution metabolomics for S-containing metabolites.

    PubMed

    Nakabayashi, Ryo; Saito, Kazuki

    2017-02-01

    The advent of the genome-editing era greatly increases the opportunities for synthetic biology research that aims to enhance production of potentially useful bioactive metabolites in heterologous hosts. A wide variety of sulfur (S)-containing metabolites (S-metabolites) are known to possess bioactivities and health-promoting properties, but finding them and their chemical assignment using mass spectrometry-based metabolomics has been difficult. In this review, we highlight recent advances on the targeted metabolomic analysis of S-metabolites (S-omics) in plants using ultrahigh resolution mass spectrometry. The use of exact mass and signal intensity differences between (32)S-containing monoisotopic ions and counterpart (34)S isotopic ions exploits an entirely new method to characterize S-metabolites. Finally, we discuss the availability of S-omics for synthetic biology.

  2. Cometary Isotopic Measurements

    NASA Astrophysics Data System (ADS)

    Bockelée-Morvan, Dominique; Calmonte, Ursina; Charnley, Steven; Duprat, Jean; Engrand, Cécile; Gicquel, Adeline; Hässig, Myrtha; Jehin, Emmanuël; Kawakita, Hideyo; Marty, Bernard; Milam, Stefanie; Morse, Andrew; Rousselot, Philippe; Sheridan, Simon; Wirström, Eva

    2015-12-01

    Isotopic ratios in comets provide keys for the understanding of the origin of cometary material, and the physical and chemical conditions in the early Solar Nebula. We review here measurements acquired on the D/H, 14N/15N, 16O/18O, 12C/13C, and 32S/34S ratios in cometary grains and gases, and discuss their cosmogonic implications. The review includes analyses of potential cometary material available in collections on Earth, recent measurements achieved with the Herschel Space Observatory, large optical telescopes, and Rosetta, as well as recent results obtained from models of chemical-dynamical deuterium fractionation in the early solar nebula. Prospects for future measurements are presented.

  3. The Neoarchaean surficial sulphur cycle: An alternative hypothesis based on analogies with 20th-century atmospheric lead.

    PubMed

    Gallagher, M; Whitehouse, M J; Kamber, B S

    2017-05-01

    We revisit the S-isotope systematics of sedimentary pyrite in a shaly limestone from the ca. 2.52 Ga Gamohaan Formation, Upper Campbellrand Subgroup, Transvaal, South Africa. The analysed rock is interpreted to have been deposited in a water depth of ca. 50-100 m, in a restricted sub-basin on a drowning platform. A previous study discovered that the pyrites define a nonzero intercept δ(34) SV-CDT -Δ(33) S data array. The present study carried out further quadruple S-isotope analyses of pyrite, confirming and expanding the linear δ(34) SV-CDT -Δ(33) S array with an δ(34) S zero intercept at ∆(33) S ca. +5. This was previously interpreted to indicate mixing of unrelated S-sources in the sediment environment, involving a combination of recycled sulphur from sulphides that had originally formed by sulphate-reducing bacteria, along with elemental sulphur. Here, we advance an alternative explanation based on the recognition that the Archaean seawater sulphate concentration was likely very low, implying that the Archaean ocean could have been poorly mixed with respect to sulphur. Thus, modern oceanic sulphur systematics provide limited insight into the Archaean sulphur cycle. Instead, we propose that the 20th-century atmospheric lead event may be a useful analogue. Similar to industrial lead, the main oceanic input of Archaean sulphur was through atmospheric raindown, with individual giant point sources capable of temporally dominating atmospheric input. Local atmospheric S-isotope signals, of no global significance, could thus have been transmitted into the localised sediment record. Thus, the nonzero intercept δ(34) SV-CDT -Δ(33) S data array may alternatively represent a very localised S-isotope signature in the Neoarchaean surface environment. Fallout from local volcanic eruptions could imprint recycled MIF-S signals into pyrite of restricted depositional environments, thereby avoiding attenuation of the signal in the subdued, averaged global open ocean

  4. Sulfur Isotope Variation in Basaltic Melt Inclusions from Krakatau Revealed by a Newly Developed Secondary Ion Mass Spectrometry Technique for Silicate Glasses

    NASA Astrophysics Data System (ADS)

    Mandeville, C. W.; Shimizu, N.; Kelley, K. A.; Cheek, L.

    2008-12-01

    Sulfur is a ubiquitous element with variable valance states (S2-, S0, S4+, S6+) allowing for its participation in a wide variety of chemical and biogeochemical processes. However, its potential as an isotopic tracer in magmatic processes has not been fully developed and is crucial to understanding of sulfur recycling in subduction zones and between Earth's major reservoirs, mantle, lithosphere and coupled hydrosphere-atmosphere. Previous studies of silicate glasses and melt inclusions have been hampered by lack of an in situ isotopic measurement technique with spatial resolution of 10 to 100 microns. We have developed a new secondary ion mass spectrometry (SIMS) analytical technique for measurement of 34S/32S ratios in silicate glasses utilizing the IMS 1280 at Woods Hole Oceanographic Institution. A beam of 133Cs+ ions with 13 keV energy and current of 1-2 nA is focused onto a 10 micron spot and rastered over 30 × 30 microns. A Normal Incidence Electron Gun was used to compensate excess charge. The rastered beam is then centered to the optical axis of the machine, and a mechanical aperture is placed on the image plane to limit the area of analysis to the central 15 × 15 microns. The energy slit width was adjusted to 50 eV. A mass resolving power of 5500 was sufficient for eliminating mass interferences. A suite of synthetic and natural glasses with δ34SVCDT values spanning from - 5.6‰ to 18.5‰ with SiO2 from 44-72 weight % were measured. Magnitude of the instrumental mass fractionation (α) for 34S/32S ratios is 0.991 and is constant for all the glasses measured despite their compositions. Precision of individual measurements of 34S/32S ratios is 0.4 ‰, or better. Preliminary δ34S measurements of olivine-hosted basaltic melt inclusions in pre- 1883 basaltic scoria from Krakatau volcano Indonesia vary from -5.6 to 7.9‰ with sulfur concentrations from 490 to 2170 ppm, respectively. Host olivines are Fo77-80 and inclusions generally need minor to no post

  5. Stable light isotope biogeochemistry of hydrothermal systems.

    PubMed

    Des Marais, D J

    1996-01-01

    The stable isotopic composition of the elements O, H, S and C in minerals and other chemical species can indicate the existence, extent, conditions and the processes (including biological activity) of hydrothermal systems. Hydrothermal alteration of the 18O/16O and D/H values of minerals can be used to detect fossil systems and delineate their areal extent. Water-rock interactions create isotopic signatures which indicate fluid composition, temperature, water-rock ratios, etc. The 18O/16O values of silica and carbonate deposits tend to increase with declining temperature and thus help to map thermal gradients. Measurements of D/H values can help to decipher the origin(s) of hydrothermal fluids. The 34S/32S and 13C/12C values of fluids and minerals reflect the origin of the S and C as well as oxygen fugacities and key redox processes. For example, a wide range of 34S/32S values which are consistent with equilibration below 100 degrees C between sulfide and sulfate can be attributed to sulfur metabolizing bacteria. Depending on its magnitude, the difference in the 13C/12C value of CO2 and carbonates versus organic carbon might be attributed either to equilibrium at hydrothermal temperatures or, if the difference exceeds 1% (10/1000), to organic biosynthesis. Along the thermal gradients of thermal spring outflows, the 13C/12C value of carbonates and 13C-depleted microbial organic carbon increases, principally due to the outgassing of relatively 13C-depleted CO2.

  6. Hydrated sulfates on Mars's surface: water cycle and S isotope tracking

    NASA Astrophysics Data System (ADS)

    Caracas, R.; Bobocioiu, E.

    2014-12-01

    We study a range of hydrated sulfate minerals from first-principles calculations based on density-functional and density-functional perturbation theory. We report the results extensively on the WURM website (http://wurm.info, Caracas and Bobcioiu, 2011). We find that hydration has a more pronounced effect on the spectroscopic properties than cation replacement. The Raman spectra of all phases present clear SO4 features that are easily identifiable. We use this to show one can use the vibrational spectroscopic information as an identification tool in a remote environment, like the Martian surface. Based on the computed vibrational results we analyze the S isotope partitioning. We observe that in general hydration favors enrichment in the lighter S isotope 32S with respect to the heavier 34S, which is accumulated in the less hydrous structures. Thus we show for the first time that the signature of 34S/32S partitioning could be observed by in situ spectroscopy on the surface of Mars. Finally we compute hydration energies. For example, in the hydrated magnesium sulfate series we find that epsomite and meridianiite with, respectively 7 and 11 water molecules per MgSO4 unit are particularly stable with respect to other individual or combinations of hydration states (Bobocioiu and Caracas, 2014). This can be related to the diurnal cycle of hydration and dehydration and hence it can improve the modeling of the water circulation on Mars. References: E. Bobocioiu, R. Caracas (2014) Stability and spectroscopy of Mg sulfate minerals. Role of hydration on sulfur isotope partitioning. Amer. Mineral., 99, 1216-1220. R. Caracas, E. Bobocioiu (2011) The WURM project - a freely available web-based repository of computed physical data for minerals. Amer. Mineral. 96, 437-444.

  7. Triple sulfur isotope composition of Late Archean seawater sulfate

    NASA Astrophysics Data System (ADS)

    Paris, G.; Fischer, W. W.; Sessions, A. L.; Adkins, J. F.

    2013-12-01

    Multiple sulfur isotope ratios in Archean sedimentary rocks have provided powerful insights into the behavior of the ancient sulfur cycle, the redox state of fluid Earth, and the timing of the rise of atmospheric oxygen [1]. Most processes fractionate sulfur isotopes in proportion to their mass differences, but the Archean sulfur isotope record is marked by pronounced mass-independent fractionation (MIF, Δ33S≠0). The origin of these signatures has been traditionally interpreted as the result of photolysis of SO2 from short wavelength UV light, with positive Δ33S values recorded in pyrite and negative Δ33S values in sulfate-bearing phases [2]. This long-held hypothesis rests on observations of negative Δ33S from enigmatic barite occurrences from mixed volcanic sedimentary strata in Mesoarchean greenstone terrains. Despite forming the framework for understanding Archean sulfur cycle processes [3], it is largely untested [3]. It is largely untested. Consequently, the biggest challenge to our current understanding of the early sulfur cycle is a poor understanding of the isotopic composition of seawater sulfate. Sulfate evaporite minerals are absent from Archean strata and the sulfur isotope record is written entirely by measurements of pyrite. Carbonate associated sulfate (CAS) provides an important archive for assaying the isotopic composition of ancient seawater sulfate It has been exploited in many studies of Phanerozoic and Proterozoic sulfate but have been only marginally used thus far for Archean samples because of the extremely low concentration of CAS in limestones and dolomites from this era. We have developed a novel MC-ICP-MS approach to solve this problem [4]. This new method lowers the detection limit by up to three orders of magnitude for δ34S and Δ33S measurements, enabling to work on a few nmols of sulfate which represent only tens of mg of sample powders micromilled from specific carbonate textures. Two stratigraphic sections from the 2

  8. Determination of trace sulfur in biodiesel and diesel standard reference materials by isotope dilution sector field inductively coupled plasma mass spectrometry.

    PubMed

    Amais, Renata S; Long, Stephen E; Nóbrega, Joaquim A; Christopher, Steven J

    2014-01-02

    A method is described for quantification of sulfur at low concentrations on the order of mgkg(-1) in biodiesel and diesel fuels using isotope dilution and sector field inductively coupled plasma mass spectrometry (ID-SF-ICP-MS). Closed vessel microwave-assisted digestion was employed using a diluted nitric acid and hydrogen peroxide decomposition medium to reduce sample dilution volumes. Medium resolution mode was employed to eliminate isobaric interferences at (32)S and (34)S related to polyatomic phosphorus and oxygen species, and sulfur hydride species. The method outlined yielded respective limits of detection (LOD) and limits of quantification (LOQ) of 0.7 mg kg(-1) S and 2.5 mg kg(-1) S (in the sample). The LOD was constrained by instrument background counts at (32)S but was sufficient to facilitate value assignment of total S mass fraction in NIST SRM 2723b Sulfur in Diesel Fuel Oil at 9.06±0.13 mg kg(-1). No statistically significant difference at a 95% confidence level was observed between the measured and certified values for certified reference materials NIST SRM 2773 B100 Biodiesel (Animal-Based), CENAM DRM 272b and NIST SRM 2723a Sulfur in Diesel Fuel Oil, validating method accuracy.

  9. Changes in depth-transect redox conditions spanning the end-Permian mass extinction and their impact on the marine extinction: Evidence from biomarkers and sulfur isotopes

    NASA Astrophysics Data System (ADS)

    Kaiho, Kunio; Oba, Masahiro; Fukuda, Yoshihiko; Ito, Kosuke; Ariyoshi, Shun; Gorjan, Paul; Riu, Yuqing; Takahashi, Satoshi; Chen, Zhong-Qiang; Tong, Jinnan; Yamakita, Satoshi

    2012-08-01

    Changes in redox conditions during the Changhsingian to Griesbachian spanning the end-Permian mass extinction were recently reported based on analyses of organic molecules. We provide more precise organic-molecular data, that detail redox conditions spanning the end-Permian mass extinction at different palaeowater depths in the neritic Palaeotethys (estimated water depths: 10, 40, 100, and 200 m; Bulla, Huangzhishan, Meishan, and Chaohu sections, respectively) during this period. Here we propose that a change from occasional euxinia to anoxia in the shallow Palaeotethys occurred at the time of the mass extinction intercalated with oxic pulses. The second extinction at 0.7 myr after the main extinction was also caused by anoxia. New and published sulfur-isotope ratios (34S/32S) measured in carbonate-associated sulfate from the neritic Palaeotethys and in sulfide from pelagic central Panthalassa sediments show high values during the Changhsingian, consistent with the development of euxinia. The mass extinction coincided with a global fall in δ34S values, as well as a shift in δ13C values, indicating a global oxidation of H2S. This organic and isotopic geochemistry implies that accumulation of hydrogen sulfide in intermediate and deep waters followed by oxidation of hydrogen sulfide led to dissolved oxygen consumption, surface-water anoxia, and acidification, resulting in the end-Permian mass extinction in the seas.

  10. Isotope effects in the infrared spectra of OCS-He complexes and clusters.

    PubMed

    Abusara, Z; Borvayeh, L; Moazzen-Ahmadi, N; McKellar, A R W

    2006-10-14

    Infrared spectra of the OCS-He van der Waals complex and of OCS-He(N) clusters have been studied in the region of the OCS nu1 fundamental band using a tunable diode laser to probe a pulsed supersonic slit jet. For the complex, the spectrum of the normal isotope, 16O12C32S-4He, has been considerably extended and the 34S- and 13C-substituted forms have been recorded for the first time. The data could be analyzed satisfactorily using a conventional asymmetric rotor Hamiltonian with sextic centrifugal distortion terms. For the clusters, the 34S- and 13C-substituted forms have been observed and assigned for N = 2-7, including some transitions with higher J values than previously reported for the normal isotope, e.g., R5. The observed vibrational shifts, relative to the free OCS molecule, were very similar to those of the normal isotope, and most of the difference could be explained by simple scaling. These results constitute a subtle and precise probe of intermolecular forces and dynamical effects in a system which is of current interest for cluster studies.

  11. Evaluating the earliest traces of Archean sub-seafloor life by NanoSIMS

    NASA Astrophysics Data System (ADS)

    Mcloughlin, N.; Grosch, E. G.; Kilburn, M.; Wacey, D.

    2012-12-01

    The Paleoarchean sub-seafloor has been proposed as an environment for the emergence of life with titanite microtextures in pillow lavas argued to be the earliest traces of microbial micro-tunneling (Furnes et al. 2004). Here we use a nano-scale ion microprobe (NanoSIMS) to evaluate possible geochemical traces of life in 3.45 Ga pillow lavas of the Barberton Greenstone Belt, South Africa. We investigated both surface and drill core samples from the original "Biomarker" outcrop in the Hooggenoeg Fm. Pillow lava metavolcanic glass contain clusters of segmented microcrystalline titanite filaments, ~4μm across and <200μm in length. Their size, shape and distribution have been directly compared to those found in recent oceanic crust. Thus it has been argued that they are the mineralized remains of tunnels formed by microbes that etched volcanic glass in the Archean sub-seafloor (Furnes et al 2004; Banerjee et al. 2006). Elemental mapping by NanoSIMS was undertaken to investigate reports of enrichments in carbon (possibly also nitrogen) along the margins of the microtextures previously interpreted as decayed cellular remains. We mapped for 12C-, 26CN-, 32S- along with 16O-, 28Si-, 24Mg+,27Al+, 40Ca+, 48Ti+ and 56Fe+ in chlorite and quartz hosted examples. The 12C- or 26CN- linings were not found along the margins of the microtextures in neither the original, nor the drill core samples, despite NanoSIMS being a more sensitive and higher-spatial-resolution technique than earlier microprobe X-ray maps. The absence of organic linings in these samples excludes a key line of evidence previously used to support the biogenicity of the microtextures. Sulfur isotopes 32S and 34S were measured by NanoSIMS on two types of sulfide: i) small sulfides (1-15μm) intimately associated with the microtextures and; ii) larger sulfides (10-60μm) that cross-cut the microtextures and are disseminated near a quartz-carbonate vein. The sulfide inclusions in the microtextures have strongly

  12. Natural variations of copper and sulfur stable isotopes in blood of hepatocellular carcinoma patients.

    PubMed

    Balter, Vincent; Nogueira da Costa, Andre; Bondanese, Victor Paky; Jaouen, Klervia; Lamboux, Aline; Sangrajrang, Suleeporn; Vincent, Nicolas; Fourel, François; Télouk, Philippe; Gigou, Michelle; Lécuyer, Christophe; Srivatanakul, Petcharin; Bréchot, Christian; Albarède, Francis; Hainaut, Pierre

    2015-01-27

    The widespread hypoxic conditions of the tumor microenvironment can impair the metabolism of bioessential elements such as copper and sulfur, notably by changing their redox state and, as a consequence, their ability to bind specific molecules. Because competing redox state is known to drive isotopic fractionation, we have used here the stable isotope compositions of copper ((65)Cu/(63)Cu) and sulfur ((34)S/(32)S) in the blood of patients with hepatocellular carcinoma (HCC) as a tool to explore the cancer-driven copper and sulfur imbalances. We report that copper is (63)Cu-enriched by ∼0.4‰ and sulfur is (32)S-enriched by ∼1.5‰ in the blood of patients compared with that of control subjects. As expected, HCC patients have more copper in red blood cells and serum compared with control subjects. However, the isotopic signature of this blood extra copper burden is not in favor of a dietary origin but rather suggests a reallocation in the body of copper bound to cysteine-rich proteins such as metallothioneins. The magnitude of the sulfur isotope effect is similar in red blood cells and serum of HCC patients, implying that sulfur fractionation is systemic. The (32)S-enrichment of sulfur in the blood of HCC patients is compatible with the notion that sulfur partly originates from tumor-derived sulfides. The measurement of natural variations of stable isotope compositions, using techniques developed in the field of Earth sciences, can provide new means to detect and quantify cancer metabolic changes and provide insights into underlying mechanisms.

  13. Microwave spectra and gas phase structural parameters for N-hydroxypyridine-2(1H)-thione.

    PubMed

    Daly, Adam M; Mitchell, Erik G; Sanchez, Daniel A; Block, Eric; Kukolich, Stephen G

    2011-12-22

    The microwave spectrum for N-hydroxypyridine-2(1H)-thione (pyrithione) was measured in the frequency range 6-18 GHz, providing accurate rotational constants and nitrogen quadrupole coupling strengths for three isotopologues, C(5)H(4)(32)S(14)NOH, C(5)H(4)(32)S(14)NOD, and C(5)H(4)(34)S(14)NOH. Pyrithione was found to be in a higher concentration in the gas phase than the other tautomer, 2-mercaptopyridine-N-oxide (MPO). Microwave spectroscopy is best suited to determine which structure predominates in the gas phase. The measured rotational constants were used to accurately determine the coordinates of the substituted atoms and provided sufficient data to determine some of the important structural parameters for pyrithione, the only tautomer observed in the present work. The spectra were obtained using a pulsed-beam Fourier transform microwave spectrometer, with sufficient resolution to allow accurate measurements of the (14)N nuclear quadrupole hyperfine interactions. Ab initio calculations provided structural parameters and quadrupole coupling strengths that are in very good agreement with measured values. The experimental rotational constants for the parent compound are A = 3212.10(1), B = 1609.328(7), and C = 1072.208(6) MHz, yielding the inertial defect Δ(0) = -0.023 amu·Å(2) for the C(5)H(4)(32)S(14)NOH isotopologue. The observed near zero inertial defect clearly indicates a planar structure. The least-squares fit structural analysis yielded the experimental bond lengths R(O-H) = 0.93(2) Å, R(C-S) = 1.66(2) Å, and angle (N-O-H) = 105(4)° for the ground state structure.

  14. Natural variations of copper and sulfur stable isotopes in blood of hepatocellular carcinoma patients

    NASA Astrophysics Data System (ADS)

    Balter, Vincent; Nogueira da Costa, Andre; Paky Bondanese, Victor; Jaouen, Klervia; Lamboux, Aline; Sangrajrang, Suleeporn; Vincent, Nicolas; Fourel, François; Télouk, Philippe; Gigou, Michelle; Lécuyer, Christophe; Srivatanakul, Petcharin; Bréchot, Christian; Albarède, Francis; Hainaut, Pierre

    2015-01-01

    The widespread hypoxic conditions of the tumor microenvironment can impair the metabolism of bioessential elements such as copper and sulfur, notably by changing their redox state and, as a consequence, their ability to bind specific molecules. Because competing redox state is known to drive isotopic fractionation, we have used here the stable isotope compositions of copper (65Cu/63Cu) and sulfur (34S/32S) in the blood of patients with hepatocellular carcinoma (HCC) as a tool to explore the cancer-driven copper and sulfur imbalances. We report that copper is 63Cu-enriched by ∼0.4‰ and sulfur is 32S-enriched by ∼1.5‰ in the blood of patients compared with that of control subjects. As expected, HCC patients have more copper in red blood cells and serum compared with control subjects. However, the isotopic signature of this blood extra copper burden is not in favor of a dietary origin but rather suggests a reallocation in the body of copper bound to cysteine-rich proteins such as metallothioneins. The magnitude of the sulfur isotope effect is similar in red blood cells and serum of HCC patients, implying that sulfur fractionation is systemic. The 32S-enrichment of sulfur in the blood of HCC patients is compatible with the notion that sulfur partly originates from tumor-derived sulfides. The measurement of natural variations of stable isotope compositions, using techniques developed in the field of Earth sciences, can provide new means to detect and quantify cancer metabolic changes and provide insights into underlying mechanisms.

  15. Modified sulfur isotopic compositions of sulfides in the nakhlites and Chassigny

    SciTech Connect

    Greenwood, J.P.; Riciputi, L.R.; McSween, H.Y. Jr.; Taylor, L.A.

    2000-03-01

    Variable sulfur isotopic ratios of sulfide minerals in the nakhlites and Chassigny have been measured by ion microprobe. The ranges and means of {delta}{sup 34}S values of pyrrhotite and pyrite in nakhlites become more negative in the sequence Nakhla > Governador Valadares > Lafayette. This is also the sequence of increasing degrees of subsolidus re-equilibration, suggesting that {sup 32}S enrichment may be related to the subsolidus thermal history. A chalcopyrite vein cross cutting a pyrrhotite in Nakhla, coupled with chalcopyrite having slightly lighter {delta}{sup 34}S values, suggests that subsolidus fluids may have become isotopically lighter (with respect to sulfur) in Nakhla with time. Pyrite has replaced pyrrhotite in Lafayette, suggesting that {line_integral}O{sub 2} and/or {line_integral}S{sub 2} increased after pyrrhotite crystallization. A model involving subsolidus hydrothermal modification of igneous sulfide minerals (with {delta}{sup 34}S {approximately} 0{degree}) due to late-stage oxidation of fluids provides a reasonable explanation for the sulfur isotopic systematics of the nakhlites and Chassigny. Sulfur isotopic alteration is believed to have occurred during the waning stages of nakhlite magmatism, rather than during a much later low-temperature (<100 C) iddingsite formation event, based on the ineffectiveness of abiogenic sulfur isotopic fractionation below 200 C. Variable mixing of two isotopically different fluids also could have produced the observed fractionations, although an isotopically light reservoir of sulfur is problematic. Other possible mechanisms evaluated to explain the sulfur isotopic values of the sulfide minerals include martial mantle heterogeneity, possible influence of martial biological processes, and magmatic degassing of SO{sub 2}.

  16. Sulfur in submarine eruptions: Observations and preliminary data from West Mata, NE Lau Basin

    NASA Astrophysics Data System (ADS)

    Keller, N. S.; Rubin, K. H.; Clague, D. A.; Michael, P. J.; Resing, J. A.; Cooper, L. B.; Shaw, A. M.; Ono, S.; Tamura, Y.

    2009-12-01

    Sulfur in its various oxidation states is a major component of magmatic volatiles; its abundance and isotopic composition constrain degassing processes as well as sulfur sources, and have been used as a tool to study sulfur cycling at convergent plate margins. However, there are almost no sulfur isotope data on active submarine eruptions as such eruptions have only been witnessed in recent years. Little is known on the effect of water depth and eruptive processes on the isotopic composition of all sulfur-bearing phases, in particular on the relationship between δ33S and δ34S. Therefore, the active eruption observed at West Mata Volcano during a NOAA/NSF rapid response cruise to the NE Lau Basin in May 2009 provided a unique opportunity to study lavas, fluids and native sulfur from an ongoing submarine eruption. West Mata is situated about 40 km west of the northern termination of the Tonga Arc and its summit is at a water depth of 1193 m. Two main areas of active vents were discovered near the summit, named Hades and Prometheus. The observed eruptive processes consisted of pyroclastic activity and degassing at both vents; additionally, extrusion of tubular pillows was observed at Hades. The eruption plumes had a pronounced yellow color, due to the presence of large quantities of native sulfur globules. Five ROV Jason 2 dives on and around the summit area returned samples of pillows, sheet flows, spatter fragments, pyroclastic deposits, as well as gas and fluid samples. The pyroclastic deposits close to the vents contain numerous sulfur droplets, whereas sediment scoops taken further from the vents are free of native sulfur, suggesting that the droplets disintegrate and dissolve over time, so their presence may be a qualitative age indicator for the eruptive material. The sulfur globules are generally quasi perfect spheres up to 5 mm in diameter, mostly yellow, but sometimes pink, orange or grey. Several droplets were found to have elongated or twisted shapes

  17. Crystal structure of (+)-methyl (E)-3-[(2S,4S,5R)-2-amino-5-hy­droxy­meth­yl-2-tri­chloro­methyl-1,3-dioxolan-4-yl]-2-methyl­prop-2-enoate

    PubMed Central

    Oishi, Takeshi; Yasushima, Daichi; Yuasa, Kihiro; Sato, Takaaki; Chida, Noritaka

    2016-01-01

    In the title compound, C10H14Cl3NO5, the five-membered dioxolane ring adopts an envelope conformation. The C atom at the flap, which is bonded to the hy­droxy­methyl substituent, deviates from the mean plane of other ring atoms by 0.357 (5) Å. There are two intra­molecular hydrogen bonds (O—H⋯N and N—H⋯O) between the hy­droxy and amino groups, so that O- and N-bound H atoms involved in these hydrogen bonds are each disordered with equal occupancies of 0.50. The methyl 2-methyl­prop-2-enoate substituent also shows a disordered structure over two sets of sites with refined occupancies of 0.482 (5) and 0.518 (5). In the crystal, mol­ecules are connected into a dimer by an O—H⋯O hydrogen bond. The dimers are further linked by N—H⋯O, C—H⋯N and C—H⋯O inter­actions, extending a sheet structure parallel to (01). PMID:27006804

  18. Sulphur cycling in a Neoarchaean microbial mat.

    PubMed

    Meyer, N R; Zerkle, A L; Fike, D A

    2017-01-27

    Multiple sulphur (S) isotope ratios are powerful proxies to understand the complexity of S biogeochemical cycling through Deep Time. The disappearance of a sulphur mass-independent fractionation (S-MIF) signal in rocks <~2.4 Ga has been used to date a dramatic rise in atmospheric oxygen levels. However, intricacies of the S-cycle before the Great Oxidation Event remain poorly understood. For example, the isotope composition of coeval atmospherically derived sulphur species is still debated. Furthermore, variation in Archaean pyrite δ(34) S values has been widely attributed to microbial sulphate reduction (MSR). While petrographic evidence for Archaean early-diagenetic pyrite formation is common, textural evidence for the presence and distribution of MSR remains enigmatic. We combined detailed petrographic and in situ, high-resolution multiple S-isotope studies (δ(34) S and Δ(33) S) using secondary ion mass spectrometry (SIMS) to document the S-isotope signatures of exceptionally well-preserved, pyritised microbialites in shales from the ~2.65-Ga Lokammona Formation, Ghaap Group, South Africa. The presence of MSR in this Neoarchaean microbial mat is supported by typical biogenic textures including wavy crinkled laminae, and early-diagenetic pyrite containing <26‰ μm-scale variations in δ(34) S and Δ(33) S = -0.21 ± 0.65‰ (±1σ). These large variations in δ(34) S values suggest Rayleigh distillation of a limited sulphate pool during high rates of MSR. Furthermore, we identified a second, morphologically distinct pyrite phase that precipitated after lithification, with δ(34) S = 8.36 ± 1.16‰ and Δ(33) S = 5.54 ± 1.53‰ (±1σ). We propose that the S-MIF signature of this secondary pyrite does not reflect contemporaneous atmospheric processes at the time of deposition; instead, it formed by the influx of later-stage sulphur-bearing fluids containing an inherited atmospheric S-MIF signal and/or from magnetic isotope effects during

  19. Sulfur Isotopic Composition of Ocean Island Basalts: New insights into the composition of the primitive mantle and mantle recycling.

    NASA Astrophysics Data System (ADS)

    Dottin, J. W., III; Labidi, J.; Jackson, M. G.; Farquhar, J.

    2015-12-01

    Here, we report the S isotopic composition of bulk sulfide inclusions in olivine and pyroxene isolated from lavas originating from 11 oceanic hotspot volcanoes, including Hawaii, Samoa, Pitcairn, and Mangaia. We also report the S isotopic composition of a peridotite xenolith from a Hawaiian lava. We digested between 200 and 1500 mg of sample using an HF chemical extraction technique (Labidi et al., 2012) and analyzed for S isotopes on a Thermo-Finnigan MAT 235 IRMS. A total of 35 samples from 11 different islands were analyzed, but only 14 samples yielded sufficient S for analysis. S concentrations range between 22 and 555 ppm S (±10%) in magmatic olivines and pyroxenes from Mangaia. We extracted 47 ppm S from the Hawaiian xenolith. For Mangaia, δ34S values range between -4.90±0.20‰ and +0.42±0.20‰, and Δ33S values range between +0.001±0.008‰ and +0.044±0.008‰. Δ36S values range between -0.03±0.20‰ and +0.32±0.20‰ (all 1σ). We measured 20 ppm S in the Baffin Island olivine separate. We observe a δ34S value of -1.97±0.20‰ and a Δ33S value of +0.010±0.008‰ in this sample. This lava may tap into the most primitive mantle source, based on the primordial He isotopic composition of this locality. Therefore, our S isotopic data suggest a sub-chondritic δ34S value for the primitive mantle, in agreement with results from Labidi et al. (2014). Mangaia and Baffin phenocrysts are observed to host significant S amounts. However, samples from Pitcairn, Samoa, Hawaii, and others, all show S contents < 5 ppm S. This suggests negligible sulfide saturation for their host lavas. Lastly, we observe mass-dependent S isotope ratios for all Mangaia samples investigated here (n=8), inconsistent with the Cabral et al. (2013) report. However, we did not analyze the same samples from Mangaia. A lack of MIF in our sample suite may be attributed to: 1. Heterogeneities within the same hotspot and 2. Dilutions of the MIF signature when a single sulfide may contain

  20. Biogeochemistry of sulfur in the Vienna Woods: Study of sulfur stable isotope ratios by MC-ICP-MS as indicator of biogeochemical S cycling

    NASA Astrophysics Data System (ADS)

    Hanousek, Ondrej; Berger, Torsten W.; Prohaska, Thomas

    2014-05-01

    Sulfur entering forest ecosystems originates mainly from combustion of fossil fuels. This source of sulfur has been strongly (by more than 95 %) reduced in last decades and recently, higher sulfur output (in soil solution or stream water) than sulfur input (in rain water) in an ecosystem was registered in many monitored forest ecosystems. This unbalance may be caused by weathering of sulfur-bearing rocks, desorption of sulfur adsorbed in soil in the past or (re)mineralization of organic sulfur compounds. This 'negative' balance leads to mobilization of base cations along with SO42- and as such to an acidification of soils. As hypothesis, δ34S/32S depletion in stream water will be observed if a considerable proportion of atmospherically deposited sulfate is cycled through the organic S pool. Rain water and soil solutions samples were collected for this study at 3 sites (beech stands) in the Vienna Woods, Austria twice a month from May 2010 to April 2012. Due to the expected sulfate concentration gradient with respect to the distance from a tree, sampling was carried out at 5 intervals from a stem. The sulfur concentration in the samples was determined by ion chromatography. Sulfur isotope ratios (δ34S/32SV CDT) were analyzed by multicollector inductively coupled plasma mass spectrometry (MC-ICP-MS) in edge-resolution mode. The method was validated using IAEA-S-1 and IAEA-S-2 isotopic certified reference materials. The combined standard uncertainty of the measurement (uc = 0.10 %, k = 1) proves the suitability of the developed method. The concentration of sulfur in rain water showed expected behavior, with a seasonal maximum in winter months, in contrast to the corresponding δ34S/32SV CDT isotope ratios, where no or low seasonal trends were observed. The sulfur isotope ratios in soil solution samples show a dependence on the distance from a tree stem and the sampling depth with lower δ34S/32SV CDT ratios as compared to the precipitation. The measured isotopic

  1. Theoretical Investigations for Anomalous Fractionation of Sulfur Isotopes during a surface reaction

    NASA Astrophysics Data System (ADS)

    Otake, T.; Lasaga, A. C.; Watanabe, Y.; Ohmoto, H.

    2009-12-01

    While SO2 photolysis by UV radiation has been the most widely accepted process to cause Anomalous Isotope Fractionation (AIF: i.e., large deviation from the mass-dependent relationships) of sulfur in nature, recent experimental evidence demonstrated that thermochemical reduction of sulfate by simple amino acids also produce AIF (Watanabe et al., 2009). Their study provides an alternative process that may have caused AIF signatures in Archean sedimentary rocks: reactions between organic matter in sediments and sulfate-rich hydrothermal solutions. Our theoretical investigations (Lasaga et al. 2008) supported their study and suggested that a surface reaction is another mechanism that can cause AIF of sulfur. Applying squire adsorption-well and Morse potential models for adsorption of sulfur species on a solid surface, we showed that a combination of small chemisorption energies (<30 kJ/mole) with possible discontinuities in the number of bound energy levels for different sulfur isotopes may lead to AIF effects in heterogeneous reactions between a surface and sulfur-bearing species. We also performed ab initio calculations for SO2 adsorption onto a naphthalene molecule, which simulates a kerogen surface. The results indicate the possibility of producing large AIF effects (e.g., δ33S34S ≈ 1.08, δ36S/δ34S ≈ 0.84, Δ33S = 7.0 - 13.6‰, Δ36S = -13.0 - -25.2‰) by heterogeneous reactions between organic matter and sulfur-bearing solutions under hydrothermal conditions. The results also indicate that AIF signatures may increase with increasing temperature because the discontinuity occurs at high energy states. However, more recently, Balan et al. (2009) dismissed the surface reaction as a possible AIF mechanism. They recognized a significant overlap of wavefunctions between the last bound state and first unbound state for the systems where the boundary wall was arbitrarily set very close to the surface. The overlap led them to include the unbound state in the

  2. Sulfur mass-independent fractionation during photolysis and photoexcitation of SO2 and CS2 and implications to the source reactions for Archean sulfur isotope anomaly

    NASA Astrophysics Data System (ADS)

    Ono, S.; Whitehill, A. R.; Oduro, H. D.

    2012-12-01

    Signatures of sulfur mass-independent fractionations (S-MIF) in Archean sedimentary rocks provide critical constraints on the atmospheric oxygen level of an early atmosphere and documents fundamental difference in early sulfur biogeochemical cycle from that of today. Archcean sulfide and sulfate minerals often yield correlated relationships among δ34S, Δ33S and Δ36S values. Our goal is to use this S-MIF pattern to pinpoint the S-MIF source reaction(s), and to constrain early atmospheric conditions beyond the oxygen level. Such an effort may lead to a new hypothesis about the cause of the Great Oxidation Event at 2.4 Billion years ago. We will present new results of laboratory photochemical experiments that are designed to calibrate the pattern of S-MIF during the photochemistry of SO2 and CS2 as a function of UV spectrum regions, partial pressure of SO2 and CS2 (0.1 mbar and above) and total N2 pressure (0.25 to 1.0 bar). Both SO2 and CS2 exhibit high energy absorption band (190 to 220 nm) that leads to direct photolysis (SO2 → SO + O or CS2 → CS + S), and low energy band (>240 nm for SO2 and 280 nm for CS2) that excites molecules to low lying electronic states under dissociation thresholds. Broadband UV light sources (Xenon or Deuterium arc lamps) are used in combination with a series of bandpass (200±35 nm), longpass (250 or 280 nm) filters to isolate specific electronic transitions. Excited state SO2 is trapped by acetylene and excited state CS2 polymerizes in the reactor, and are collected for sulfur isotope ratio analysis. Although SO2 photolysis under 190 to 220 nm is thought to be the main Archean S-MIF source reaction, its S-MIF is characterized by high δ34S values (up to 140 ‰) and relatively low Δ36S/Δ33S values (-3.3 to -5.9) compared to Archean data (-0.9 to -1.5). Strong pSO2 dependence suggests S-MIF is primarily due to isotopologue self-shielding at least under our experimental conditions. In contrast, SO2 photoexciation under >250 nm

  3. Stable Isotope Phenotyping via Cluster Analysis of NanoSIMS Data As a Method for Characterizing Distinct Microbial Ecophysiologies and Sulfur-Cycling in the Environment

    PubMed Central

    Dawson, Katherine S.; Scheller, Silvan; Dillon, Jesse G.; Orphan, Victoria J.

    2016-01-01

    Stable isotope probing (SIP) is a valuable tool for gaining insights into ecophysiology and biogeochemical cycling of environmental microbial communities by tracking isotopically labeled compounds into cellular macromolecules as well as into byproducts of respiration. SIP, in conjunction with nanoscale secondary ion mass spectrometry (NanoSIMS), allows for the visualization of isotope incorporation at the single cell level. In this manner, both active cells within a diverse population as well as heterogeneity in metabolism within a homogeneous population can be observed. The ecophysiological implications of these single cell stable isotope measurements are often limited to the taxonomic resolution of paired fluorescence in situ hybridization (FISH) microscopy. Here we introduce a taxonomy-independent method using multi-isotope SIP and NanoSIMS for identifying and grouping phenotypically similar microbial cells by their chemical and isotopic fingerprint. This method was applied to SIP experiments in a sulfur-cycling biofilm collected from sulfidic intertidal vents amended with 13C-acetate, 15N-ammonium, and 33S-sulfate. Using a cluster analysis technique based on fuzzy c-means to group cells according to their isotope (13C/12C, 15N/14N, and 33S/32S) and elemental ratio (C/CN and S/CN) profiles, our analysis partitioned ~2200 cellular regions of interest (ROIs) into five distinct groups. These isotope phenotype groupings are reflective of the variation in labeled substrate uptake by cells in a multispecies metabolic network dominated by Gamma- and Deltaproteobacteria. Populations independently grouped by isotope phenotype were subsequently compared with paired FISH data, demonstrating a single coherent deltaproteobacterial cluster and multiple gammaproteobacterial groups, highlighting the distinct ecophysiologies of spatially-associated microbes within the sulfur-cycling biofilm from White Point Beach, CA. PMID:27303371

  4. Archaean microbial consortia of the 2.7-2.6 Ga Ngesi Gp. (Belingwe) sediments, Zimbabwe

    NASA Astrophysics Data System (ADS)

    Grassineau, N. V.; Nisbet, E. G.; Thomazo, C.

    2011-12-01

    Isotopic evidence from 2.7-2.65 Ga old sediments in the Belingwe belt, Zimbabwe, shows that a complex microbial community existed. Two major sequences have been studied, the 2.7 Ga Manjeri Fm. and, separated from it by thick komatiitic and basaltic lavas, the overlying 2.65 Ga Cheshire Fm. Both sedimentary formations contain a wide range of facies including stromatolites, silts and shales. In 2.7 Ga Manjeri stromatolites, δ13C(reduced) is around -23% in material with 1-2wt% reduced carbon content, ranging to -35%. δ13C in stromatolitic carbonate is around 0% and in carbonates from black shales δ13C(carbonate) is around -8%, indicating crystallisation in sediment after methanotrophy. In shallow-water shales δ13C(reduced) varies from -30 to -23%,, suggesting carbon capture by aerobic bacteria. A large sulphide population has δ34S from -20 to -12%, suggesting available sulphate. δ34S in sulphides show a 40% range in total , from -23.7% to +16.7%. Manjeri black shales show small and mostly negative MIF-S, with Δ33S varying from -0.6 to 0.9% (average around 0.0%). In deeper water samples, with proximal volcanism, carbon-sulphide sapropel-like deposits have δ13C(reduced) around -34%, and accompanying carbonate blebs have δ13C around -12 to -10%. In these samples, δ34S is markedly heavy, ranging from + 7 up to +14%. In the overlying ~2.65 Ga Cheshire Fm., carbonate in stromatolitic rocks has a narrow range in δ13C around +0.2 ±0.3%, while δ13C(reduced) within these samples is typically -28.8% ± 2.6%, consistent with capture of carbon by oxygenic photosynthesis. In associated Cheshire shales, δ13C(reduced) values range as light as -43.8% with the average at -40.0±3.0%, and some carbonate has δ13C -9 to -8%, implying methanogenesis and methanotrophy in the microbial consortia of the sedimentary column. δ34S values range from -2.1 to +2.4%. Δ33S anomalies are near zero but consistently positive between 0.1 and 1.2 % (average 0.7 ± 0.3%). A diverse

  5. Primary multiple sulfur isotopic compositions of pyrite in 2.7 Ga shales from the Joy Lake sequence (Superior Province) show felsic volcanic array-like signature

    NASA Astrophysics Data System (ADS)

    Li, Jianghanyang; Zhang, Zhe; Stern, Richard A.; Hannah, Judith L.; Stein, Holly J.; Yang, Gang; Li, Long

    2017-04-01

    Multiple sulfur isotopes provide a powerful tool to study photochemical and biological processes controlling the Archean sulfur cycle and infer related atmospheric and marine environments. However, our understanding of early Earth's environment remains limited by the availability of well-preserved geological samples, as most Archean sedimentary rocks have experienced some degree of metamorphic alteration. To evaluate sulfur isotopic behavior during post-depositional processes and elucidate the sulfur cycle at 2.7 Ga, we use high-resolution in situ analytical techniques (EPMA and SIMS) to determine elemental compositions and multiple sulfur isotopic compositions of large diagenetic pyrite nodules and fine-grained secondary pyrite disseminated in quartz veins (formed during a lower greenschist metamorphic event) in shales from the 2.7 Ga Joy Lake sequence in the southwest Superior Province. Results show that trace metals and sulfur in the secondary pyrite were derived from both metamorphic fluid and pre-existing diagenetic pyrite. Diagenetic pyrite nodules could have been partially dissolved by metamorphic fluid. But the surviving nodules show elemental and isotopic features different from those of the deduced metamorphic fluid endmember, suggesting the nodules were not geochemically altered by metamorphism, and thus preserve primary isotopic signatures acquired during diagenesis. The sulfur isotopic ratios of pyrite nodules show strong variations, with decreasing δ34S values and increasing Δ33S values from cores to rims. This negative Δ33S34S relationship is different from the commonly observed 'Archean reference line' defined by most Archean pyrite data, but similar to the 'felsic volcanic array'. Our observation provides a first possible case from 2.7 Ga, the age of peak crustal growth in the Archean, to support the hypothesis that photochemical pathways could be different under conditions of intense volcanic emission. This study also shows that high

  6. SO2 photoexcitation mechanism links mass-independent sulfur isotopic fractionation in cryospheric sulfate to climate impacting volcanism

    PubMed Central

    Hattori, Shohei; Schmidt, Johan A.; Johnson, Matthew S.; Danielache, Sebastian O.; Yamada, Akinori; Ueno, Yuichiro; Yoshida, Naohiro

    2013-01-01

    Natural climate variation, such as that caused by volcanoes, is the basis for identifying anthropogenic climate change. However, knowledge of the history of volcanic activity is inadequate, particularly concerning the explosivity of specific events. Some material is deposited in ice cores, but the concentration of glacial sulfate does not distinguish between tropospheric and stratospheric eruptions. Stable sulfur isotope abundances contain additional information, and recent studies show a correlation between volcanic plumes that reach the stratosphere and mass-independent anomalies in sulfur isotopes in glacial sulfate. We describe a mechanism, photoexcitation of SO2, that links the two, yielding a useful metric of the explosivity of historic volcanic events. A plume model of S(IV) to S(VI) conversion was constructed including photochemistry, entrainment of background air, and sulfate deposition. Isotopologue-specific photoexcitation rates were calculated based on the UV absorption cross-sections of 32SO2, 33SO2, 34SO2, and 36SO2 from 250 to 320 nm. The model shows that UV photoexcitation is enhanced with altitude, whereas mass-dependent oxidation, such as SO2 + OH, is suppressed by in situ plume chemistry, allowing the production and preservation of a mass-independent sulfur isotope anomaly in the sulfate product. The model accounts for the amplitude, phases, and time development of Δ33S34S and Δ36S/Δ33S found in glacial samples. We are able to identify the process controlling mass-independent sulfur isotope anomalies in the modern atmosphere. This mechanism is the basis of identifying the magnitude of historic volcanic events. PMID:23417298

  7. Geochemistry of pyrite from diamictites of the Hamersley Basin, Western Australia with implications for the GOE and Paleoproterozoic ice ages.

    NASA Astrophysics Data System (ADS)

    Swanner, Elizabeth; Cates, Nicole; Pecoits, Ernesto; Bekker, Andrey; Konhauser, Kurt O.; Mojzsis, Stephen J.

    2013-04-01

    Sediments of the ca. 2400 Ma Turee Creek Group of Western Australia span the oxygenation of Earth's surface resulting from the 'Great Oxidation Event' (GOE). Diamictite within the Boolgeeda Iron Formation from the Boundary Ridge section at Duck Creek Syncline have been correlated to the glaciogenic Meteorite Bore Member of the Turee Creek Group at Hardey Syncline (Martin, 1999). The Meteorite Bore Member is thought to be correlative and time-equivalent with the Paleoproterozoic glacial diamictites of North America. If diamictite units at Boundary Ridge represent worldwide Paleoproterozoic glaciations, they should record the disappearance of mass independently fractionated (MIF) sulfur. Triple S-isotope compositions for pyrites from the Boundary Ridge sections measured by in situ multi-collector ion microprobe yielded both mass-dependent and mass-independently fractionated (MIF) S isotope values (Δ33S values from -0.65 to 6.27). Trace element heterogeneities were found by measurements at multiple spatial scales within rounded pyrites in the Boundary Ridge section, signifying multiple generations of pyrite from sulfur processed in an anoxic atmosphere. S-isotope data from pyrite in the Boundary Ridge diamictites analyzed in this study and previous work (Williford et al., 2011) define multiple δ34S vs. δ33S arrays, linked to a source of detrital pyrite from the overlying Hamersley and Fortescue groups. Authigenic pyrite in an overlying shale unit from Boundary Ridge plot along the terrestrial fractionation line but retain positive MIF-S and detrital pyrite, results that are incompatible with a correlation to North American Paleoproterozoic glacially-influenced successions where the MIF-S signal permanently disappears. The diamictites at the Duck Creek Syncline are older than the Meteorite Bore Member because of their stratigraphic position within the Boolgeeda Iron Formation underlying the Turee Creek Group, which is separated from the Meteorite Bore Member by

  8. SO2 photoexcitation mechanism links mass-independent sulfur isotopic fractionation in cryospheric sulfate to climate impacting volcanism.

    PubMed

    Hattori, Shohei; Schmidt, Johan A; Johnson, Matthew S; Danielache, Sebastian O; Yamada, Akinori; Ueno, Yuichiro; Yoshida, Naohiro

    2013-10-29

    Natural climate variation, such as that caused by volcanoes, is the basis for identifying anthropogenic climate change. However, knowledge of the history of volcanic activity is inadequate, particularly concerning the explosivity of specific events. Some material is deposited in ice cores, but the concentration of glacial sulfate does not distinguish between tropospheric and stratospheric eruptions. Stable sulfur isotope abundances contain additional information, and recent studies show a correlation between volcanic plumes that reach the stratosphere and mass-independent anomalies in sulfur isotopes in glacial sulfate. We describe a mechanism, photoexcitation of SO2, that links the two, yielding a useful metric of the explosivity of historic volcanic events. A plume model of S(IV) to S(VI) conversion was constructed including photochemistry, entrainment of background air, and sulfate deposition. Isotopologue-specific photoexcitation rates were calculated based on the UV absorption cross-sections of (32)SO2, (33)SO2, (34)SO2, and (36)SO2 from 250 to 320 nm. The model shows that UV photoexcitation is enhanced with altitude, whereas mass-dependent oxidation, such as SO2 + OH, is suppressed by in situ plume chemistry, allowing the production and preservation of a mass-independent sulfur isotope anomaly in the sulfate product. The model accounts for the amplitude, phases, and time development of Δ(33)S/δ(34)S and Δ(36)S/Δ(33)S found in glacial samples. We are able to identify the process controlling mass-independent sulfur isotope anomalies in the modern atmosphere. This mechanism is the basis of identifying the magnitude of historic volcanic events.

  9. Variability of sulphur isotope ratios in pyrite and dissolved sulphate in granitoid fractures down to 1 km depth - Evidence for widespread activity of sulphur reducing bacteria

    NASA Astrophysics Data System (ADS)

    Drake, Henrik; Åström, Mats E.; Tullborg, Eva-Lena; Whitehouse, Martin; Fallick, Anthony E.

    2013-02-01

    higher δ34S values of the dissolved source SO42- caused by ongoing bacterial sulphate reduction in fractures with low-flow or stagnant waters. The measured groundwater had δ34SSO4 values of +9‰ to +37‰, with the highest values associated with low sulphate concentrations. These values are overall, and especially in the sulphate-poor waters down to -400 m, somewhat higher than the anticipated initial values, and can thus, like for the 34S-enriched pyrites, be explained by a Rayleigh distillation process driven by microbial sulphate reduction. An intriguing feature was that the δ34SSO4 values of the groundwater were in no case reaching up to the values required to produce biogenic pyrite with δ34S values of +40‰ to +91‰. To explain this feature, we suggest that groundwater in low-flow fractures with near-stagnant water (carrying sulphate and pyrite with high δ34S) is masked by high-flow parts of the fracture system carrying groundwater that often contains sulphate in abundance and considerably less fractionated with respect to 34S and 32S. In order to gain detailed knowledge of chemical processes and patterns in groundwater in fractured rock, fracture-mineral investigations are a powerful tool, as we have shown here for the sulphur system.

  10. A strategy for fast screening and identification of sulfur derivatives in medicinal Pueraria species based on the fine isotopic pattern filtering method using ultra-high-resolution mass spectrometry.

    PubMed

    Yang, Min; Zhou, Zhe; Guo, De-an

    2015-09-24

    Sulfurous compounds are commonly present in plants, fungi, and animals. Most of them were reported to possess various bioactivities. Isotopic pattern filter (IPF) is a powerful tool for screening compounds with distinct isotope pattern. Over the past decades, the IPF was used mainly to study Cl- and Br-containing compounds. To our knowledge, the algorithm was scarcely used to screen S-containing compounds, especially when combined with chromatography analyses, because the (34)S isotopic ion is drastically affected by (13)C2 and (18)O. Thus, we present a new method for a fine isotopic pattern filter (FIPF) based on the separated M + 2 ions ((12)C(x)(1)H(y)(16)O(z)(32)S(13)C2(18)O, (12)C(x+2)(1)H(y)(16)O(z+1)(34)S, tentatively named M + 2OC and M + 2S) with an ultra-high-resolution mass (100,000 FWHM @ 400 m/z) to screen sulfur derivatives in traditional Chinese medicines (TCM).This finer algorithm operates through convenient filters, including an accurate mass shift of M + 2OC and M + 2S from M and their relative intensity compared to M. The method was validated at various mass resolutions, mass accuracies, and screening thresholds of flexible elemental compositions. Using the established FIPF method, twelve S-derivatives were found in the popular medicinal used Pueraria species, and 9 of them were tentatively identified by high-resolution multiple stage mass spectrometry (HRMS(n)). The compounds were used to evaluate the sulfurous compounds' situation in commercially purchased Pueraria products. The strategy presented here provides a promising application of the IPF method in a new field.

  11. Stable isotope biogeochemistry of the sulfur cycle in modern marine sediments: I. Seasonal dynamics in a temperate intertidal sandy surface sediment.

    PubMed

    Böttcher, Michael; Hespenheide, Britta; Brumsack, Hans-Jürgen; Bosselmann, Katja

    2004-12-01

    A biogeochemical and stable isotope geochemical study was carried out in surface sediments of an organic-matter poor temperate intertidal sandy surface sediment (German Wadden Sea of the North Sea) to investigate the activity of sulfate-reducing bacteria and the dynamics of the vertical partitioning of sedimentary sulfur, iron, and manganese species in relation to the availability of total organic carbon (TOC) and mud contents. The contents and stable isotopic compositions ((34)S/(32)S) of total reduced inorganic sulfur species (TRIS) and dissolved sulfate were measured. Maximum oxygen penetration depths were estimated from the onset of a blackening of the sediments due to FeS accumulation and ranged from 5 to 10 mm below surface (mmbsf). A zone of relatively moderate relative organic-matter enrichment was found between 5 and 20 mmbsf leading to enhanced activities of sulfate-reducing bacteria with sulfate-reduction rates (SRR) up to 350 nmol cm(-3) d(-1). Below this zone, microbial SRR dropped significantly. Depth integrated SRR seem to depend not only on temperature but also on the availability of reactive organic matter. The sulfur-isotopic composition of TRIS was depleted in (34)S by 33-40 per thousand with respect to coexisting dissolved sulfate (constant at about +21 per thousand vs. Vienna-Canyon Diablo Troilite (V-CDT)). Since sulfate reduction is not limited by dissolved sulfate (open system), depth variations of the isotopic composition of TRIS reflect changes in overall isotope effect due to superimposed microbial and abiotic reactions. Most of the solid-phase iron and manganese was bonded to (non-reactive) heavy minerals. However, a layer of reactive Fe(III) and Mn(IV) oxi(hydroxi)des was found in the uppermost sediment section due to re-oxidation of dissolved Fe(II) and Mn(II) species at the sediment-water interface. Metal cycling below the surface is at least partially coupled to intense sulfur cycling.

  12. Isotope dilution ICP-MS with laser-assisted sample introduction for direct determination of sulfur in petroleum products.

    PubMed

    Boulyga, Sergei F; Heilmann, Jens; Heumann, Klaus G

    2005-08-01

    Inductively coupled plasma isotope dilution mass spectrometry (ICP-IDMS) with direct laser-assisted introduction of isotope-diluted samples into the plasma, using a laser ablation system with high ablation rates, was developed for accurate sulfur determinations in different petroleum products such as 'sulfur-free' premium gasoline, diesel fuel, and heating oil. Two certified gas oil reference materials were analyzed for method validation. Two different 34S-enriched spike compounds, namely, elementary sulfur dissolved in xylene and dibenzothiophene in hexane, were synthesized and tested for their usefulness in this isotope dilution technique. The isotope-diluted sample was adsorbed on a filter-paper-like material, which was fixed in a special holder for irradiation by the laser beam. Under these conditions no time-dependent spike/analyte fractionation was only observed for the dibenzothiophene spike during the laser ablation process, which means that the measured 34S/32S isotope ratio of the isotope-diluted sample remained constant-a necessary precondition for accurate results with the isotope dilution technique. A comparison of LA-ICP-IDMS results with the certified values of the gas oil reference materials and with results obtained from ICP-IDMS analyses with wet sample digestion demonstrated the accuracy of the new LA-ICP-IDMS method in the concentration range of 9.2 microg g(-1) ('sulfur-free' premium gasoline) to 10.4 mg g(-1) (gas oil reference material BCR 107). The detection limit for sulfur by LA-ICP-IDMS is 0.04 microg g(-1) and the analysis time is only about 10 min, which therefore also qualifies this method for accurate determinations of low sulfur contents in petroleum products on a routine level.

  13. The influence of pyrite grain size on the final oxygen isotope difference between sulphate and water in aerobic pyrite oxidation experiments.

    PubMed

    Heidel, Claudia; Tichomirowa, Marion; Junghans, Manuela

    2009-12-01

    Oxidation experiments with different pyrite grain sizes (63-100, 100-140, 140-180 microm) were carried out to investigate the oxygen and sulphur isotope composition of sulphate produced under aerobic acid conditions, which may help to understand oxidation mechanisms and to interpret data from natural sites. Long-term experiments with grain size 63-100 microm showed that constant delta (18)O(SO4) values were not achieved before 100 days. The final oxygen isotope difference between water and sulphate indicates that a small proportion of molecular oxygen is incorporated into sulphate even in the later course of the oxidation due to sulphite oxidation by molecular oxygen. However, most of the sulphate oxygen derives from water. Similar delta (18)O(SO4) values from experiments with grain sizes 63-100, 100-140, and 140-180 microm indicate similar oxidation mechanisms for all three grain sizes. These results differed from previous results of identical experiments with grain size<63 microm, where higher delta (18)O(SO4) values were obtained. We propose that the greater proportion of molecular oxygen in sulphate from oxidised fine-grained pyrite is caused by an intensified adsorption of molecular oxygen on sulphur sites of ultrafine pyrite particles. Hence, the formation of sulphate from the (initial) reaction on sulphur sites of pyrite and from sulphite oxidation should be more dominant if ultrafine material is present. The delta (34)S(SO4) values (2.0-2.7) obtained from experiments with the coarser grain sizes agreed with the delta (34)S value of pyrite (2.4), whereas sulphur isotopes of sulphate obtained from previous experiments with fine-grained pyrite showed an initial (32)S enrichment compared with pyrite. Due to the lack of delta (34)S(SO4) values from the beginning of the experiments with coarser grain sizes, it remains speculative that sulphur isotopes indicate at least initial differences in oxidation mechanisms between fine and coarser pyrite grain sizes.

  14. A new occurrence of ambient inclusion trails from the ~1900-million-year-old Gunflint Formation, Ontario: nanocharacterization and testing of potential formation mechanisms.

    PubMed

    Wacey, D; Saunders, M; Kong, C; Kilburn, M R

    2016-09-01

    Ambient inclusion trails (AITs) are tubular microstructures thought to form when a microscopic mineral crystal is propelled through a fine-grained rock matrix. Here, we report a new occurrence of AITs from a fossilized microbial mat within the 1878-Ma Gunflint Formation, at Current River, Ontario. The AITs are 1-15 μm in diameter, have pyrite as the propelled crystal, are infilled with chlorite and have been propelled through a microquartz (chert) or chlorite matrix. AITs most commonly originate at the boundary between pyrite- and chlorite-rich laminae and chert-filled fenestrae, with pyrite crystals propelled into the fenestrae. A subset of AITs originate within the fenestrae, rooted either within the chert or within patches of chlorite. Sulphur isotope data ((34) S/(32) S) obtained in situ from AIT pyrite have a δ(34) S of -8.5 to +8.0 ‰, indicating a maximum of ~30 ‰ fractionation from Palaeoproterozoic seawater sulphate (δ(34) S ≈ +20 ‰). Organic carbon is common both at the outer margins of the fenestrae and in patches of chlorite where most AITs originate, and can be found in smaller quantities further along some AITs towards the terminal pyrite grain. We infer that pyrite crystals now found within the AITs formed via the action of heterotrophic sulphate-reducing bacteria during early diagenesis within the microbial mat, as pore waters were becoming depleted in seawater sulphate. Gases derived from this process such as CO2 and H2 S were partially trapped within the microbial mat, helping produce birds-eye fenestrae, while rapid microquartz precipitation closed porosity. We propose that propulsion of the pyrite crystals to form AITs was driven by two complementary mechanisms during burial and low-grade metamorphism: firstly, thermal decomposition of residual organic material providing CO2 , and potentially CH4 , as propulsive gases, plus organic acids to locally dissolve the microquartz matrix; and secondly, reactions involving clay minerals that

  15. Observation of wavelength-sensitive mass-independent sulfur isotope effects during SO2 photolysis: Implications for the early atmosphere

    NASA Astrophysics Data System (ADS)

    Farquhar, James; Savarino, Joel; Airieau, Sabine; Thiemens, Mark H.

    2001-12-01

    Mass-independent isotopic signatures for δ33S, δ34S, and δ36S produced in the photolysis of sulfur dioxide exhibit a strong wavelength dependence. Photolysis experiments with three light sources (ArF excimer laser (193 nm), mercury resonance lamp (184.9 and 253.7 nm), and KrF excimer laser (248 nm) are presented. Products of sulfur dioxide photolysis undertaken with 193-nm radiation exhibit characteristics that are similar to sulfur multiple-isotope data for terrestrial sedimentary rock samples older than 2450 Ma (reported by Farquhar et al. [2000a]), while photolysis experiments undertaken with radiation at other wavelengths (longer than 220 nm and at 184.9 nm) exhibit different characteristics. The spectral window between 190 and 220 nm falls between the Schumann-Runge bands of oxygen and the Hartley bands of ozone, and its absorption is therefore more sensitive to changes in altitude and atmospheric oxygen content than neighboring wavelengths. These two observations are used to suggest a link between sulfur dioxide photolysis at 193 nm and sulfur isotope anomalies in Archean rocks. This hypothesis includes the suggestion that UV wavelengths shorter than 200 nm penetrated deep in the Earth's atmosphere during the Archean. Potential implications of this hypothesis for the chemistry, composition, and UV absorption of the atmosphere are explored. We also explore the implications of these observations for documentation of bacterial sulfur metabolisms early in Earth's history.

  16. Retinal circulation times in diabetes mellitus type 1.

    PubMed Central

    Bertram, B; Wolf, S; Fiehöfer, S; Schulte, K; Arend, O; Reim, M

    1991-01-01

    Video fluorescein angiography was performed in 124 patients between 18 and 65 years of age (mean 35.0, SD 12.3 years) with juvenile-onset, insulin-dependent diabetes mellitus (type 1). The arm-retina time (ART) and the retinal arteriovenous passage time (AVP) were measured by means of a picture analysis system to quantify the retinal microcirculation. Glucose metabolism was assessed by the blood level of haemoglobin A1c. The ART 11.5, SD 3.4 s) was similar to that in normal persons (11.2, SD 3.3 s), while the AVP was significantly longer in the diabetics (AVP = 2.35, SD 0.87 s) than in normal persons (AVP = 1.45, SD 0.40 s). The patients with severe diabetic retinopathy showed the most impressive change in AVP. The diabetics with good glycaemic control, that is, with glycosylated haemoglobin (HbA1c) less than or equal to 8.0 g/dl, had a shorter AVP than patients with bad glycaemic control (HbA1c greater than or equal to 9.5 g/dl). The group with a history of diabetes for less than five years showed circulation parameters similar to those of normal persons. The AVP in this group was significantly shorter than in groups with a history of diabetes for five or more years. PMID:1873263

  17. Sulfur Isotope Composition of Volcanic Sulfate in Polar Ice Cores (Invited)

    NASA Astrophysics Data System (ADS)

    Cole-Dai, J.; Savarino, J.; Thiemens, M. H.

    2013-12-01

    Explosive volcanic eruptions often emit copious amounts of sulfur gases into the atmosphere. Similar to that of anthropogenic aerosols, volcanic aerosols can influence climate by altering the atmosphere's radiative properties. Traces of sulfate aerosols from past explosive eruptions are preserved in the snow strata of polar ice sheets and can be retrieved with ice cores. We have been measuring sulfur isotope composition of volcanic sulfate in Antarctica and Greenland ice cores to investigate the kinetics of atmospheric oxidation chemistry and to determine the climatic impact of the eruptions. We have found that the chemical conversion process of volcanic sulfur dioxide into sulfuric acid and sulfate aerosols in the stratosphere proceeds through oxidation reaction pathways different from those for sulfur dioxide in the troposphere. Recent laboratory experiments and modeling efforts by other investigators support the hypothesis that short wavelength ultra-violet radiation above the stratospheric ozone layer plays a key role in the chemical conversion or oxidation and can cause mass independent fractionation (MIF) of sulfur isotopes (33S, 34S, 36S). The discovery of the sulfur MIF isotope signatures in the volcanic sulfate offers a unique and dependable way to distinguish the signals of large, stratospheric eruptions in the ice core volcanic records from those of eruptions with little or no climate impact. Identification of the climate-impacting eruptions helps to improve our understanding of the volcano-climate connection.

  18. Meteoritic Sulfur Isotopic Analysis

    NASA Technical Reports Server (NTRS)

    Thiemens, Mark H.

    1996-01-01

    Funds were requested to continue our program in meteoritic sulfur isotopic analysis. We have recently detected a potential nucleosynthetic sulfur isotopic anomaly. We will search for potential carriers. The documentation of bulk systematics and the possible relation to nebular chemistry and oxygen isotopes will be explored. Analytical techniques for delta(sup 33), delta(sup 34)S, delta(sup 36)S isotopic analysis were improved. Analysis of sub milligram samples is now possible. A possible relation between sulfur isotopes and oxygen was detected, with similar group systematics noted, particularly in the case of aubrites, ureilites and entstatite chondrites. A possible nucleosynthetic excess S-33 has been noted in bulk ureilites and an oldhamite separate from Norton County. High energy proton (approximately 1 GeV) bombardments of iron foils were done to experimentally determine S-33, S-36 spallogenic yields for quantitation of isotopic measurements in iron meteorites. Techniques for measurement of mineral separates were perfected and an analysis program initiated. The systematic behavior of bulk sulfur isotopes will continue to be explored.

  19. From snowball earth to the cambrian explosion: the interpretative potential of the isotope record

    NASA Astrophysics Data System (ADS)

    Shields, G.

    2003-04-01

    The interval in Earth history between 750 Ma and 530 Ma represents the erratic transition between the distinctly different "Earth systems" of the Proterozoic and the Phanerozoic. Geologists have developed several indirect methods to study this key interval but perhaps none with as much wanton enthusiasm as isotope geochemistry. Here I attempt a review of the isotope record across this key transition period, with special emphasis on the interpretative role that isotopes can play in understanding events such as the "Snowball Earth" glaciations and the "Cambrian Explosion". The marine isotope record reveals the Proterozoic-Phanerozoic transition to have been a unique period in Earth history with first-order features in all three of the major isotope proxies: 87Sr/86Sr, 34S/32S and 13C/12C ratios. Seawater 87Sr/86Sr, increased sharply between about 900 Ma and 500 Ma from 0.704 to 0.709, the largest rise ever. Although attributed to increasing rates of continental erosion, this remains only the most plausible explanation because few aspects of the rise have been satisfactorily linked to particular tectonic events. Much of the uncertainty surrounding the Proterozoic 87Sr/86Sr record is due to poor age dating and discrepancies in stratigraphic correlation schemes, which together with diagenetic alteration have led to the current inability to realise the potential of the 87Sr/86Sr record for global stratigraphic correlation. Carbon isotopes have played a key role in recent palaeoenvironmental interpretations of the Proterozoic-Phanerozoic transition, most of which have already been discarded or merely forgotten. Nevertheless, it is clear that the extraordinary δ13C values of the later Neoproterozoic (and the earliest Cambrian) demand extraordinary explanations, for which there is still much scope for future invention. Carbon isotopes may also play an important supporting role in correlation, however, the role that δ13C may play in global stratigraphic correlation has

  20. Sulfur-containing flavors: gas phase structures of dihydro-2-methyl-3-thiophenone.

    PubMed

    Mouhib, Halima; Van, Vinh; Stahl, Wolfgang

    2013-08-01

    Dihydro-2-methyl-3-thiophenone was investigated using a combination of quantum chemical calculations and molecular beam Fourier transform microwave spectroscopy. The substance is present in coffee, roasted peanuts, and whiskey. The microwave spectrum was recorded under molecular beam conditions in the frequency range from 9 to 14 GHz. We report on the two main conformers of dihydro-2-methyl-3-thiophenone, for which highly accurate rotational constants and centrifugal distortion constants were obtained. No splittings due to internal rotation of the methyl group could be observed in the microwave spectrum. This is in agreement with the theoretical predictions of the barrier heights, which have been determined to be more than 1000 cm(-1) at the MP2/6-311++G(d,p) level of theory. In addition to the most abundant (32)S-isotopologue of the main conformer, also the (34)S-isotopologue was assigned, which occurs with a natural abundance of about 4%. Using the experimental rotational constants, different quantum chemical calculations were validated for the two observed conformers. To complete the theoretical investigation of dihydro-2-methyl-3-thiophenone, different transition states were optimized to understand the intramolecular conversion between the two conformers at the MP2/6-311++G(d,p) level. The transition states were optimized using the Berny algorithm.

  1. (SO2)-S-34-O-16: High-resolution analysis of the (030),(101), (111), (002) and (201) vibrational states; determination of equilibrium rotational constants for sulfur dioxide and anharmonic vibrational constants

    SciTech Connect

    Lafferty, Walter; Flaud, Jean-marie; Ngom, El Hadji A.; Sams, Robert L.

    2009-01-02

    High resolution Fourier transform spectra of a sample of sulfur dioxide, enriched in 34S (95.3%). were completely analyzed leading to a large set of assigned lines. The experimental levels derived from this set of transitions were fit to within their experimental uncertainties using Watson-type Hamiltonians. Precise band centers, rotational and centrifugal distortion constants were determined. The following band centers in cm-1 were obtained: ν0(3ν2)=1538.720198(11), ν0(ν1+ν3)=2475.828004(29), ν0(ν1+ν2+ν3)=2982.118600(20), ν0(2ν3)=2679.800919(35), and ν0(2ν1+ν3)=3598.773915(38). The rotational constants obtained in this work have been fit together with the rotational constants of lower lying vibrational states [ W.J. Lafferty, J.-M. Flaud, R.L. Sams and EL Hadjiabib, in press] to obtain equilibrium constants as well as vibration-rotation constants. These equilibrium constants have been fit together with those of 32S16O2 [J.-M. Flaud and W.J. Lafferty, J. Mol. Spectrosc. 16 (1993) 396-402] leading to an improved equilibrium structure. Finally the observed band centers have been fit to obtain anharmonic rotational constants.

  2. Sulfuric acid speleogenesis of Carlsbad Cavern and its relationship to hydrocarbons, Delaware basin, New Mexico and Texas

    SciTech Connect

    Hill, C.A. )

    1990-11-01

    Sulfur-isotope data and pH-dependence of the mineral endellite support the hypothesis that Carlsbad Cavern and other caves in the Guadalupe Mountains were dissolved primarily by sulfuric acid rather than by carbonic acid. Floor gypsum deposits up to 10 m thick and native sulfur in the caves are significantly enriched in {sup 32}S; {delta}{sup 34}S values as low as {minus}25.8 {per thousand} (CDT) indicate that the cave sulfur and gypsum are the end products of microbial reactions associated with hydrocarbons. A model for a genetic connection between hydrocarbons in the basin and caves in the Guadalupe Mountains is proposed. As the Guadalupe Mountains were uplifted during the late Pliocene-Pleistocene, oil and gas moved updip in the basin. The gas reacted with sulfate anions derived from dissolution of the Castile anhydrite to form H{sub 2}S, CO{sub 2}, and castile limestone. The hydrogen sulfide rose into the Capitan reef along joints, forereef carbonate beds, or Bell Canyon siliciclastic beds and there reacted with oxygenated groundwater to form sulfuric acid and Carlsbad Cavern. A sulfuric-acid mode of dissolution may be responsible for large-scale porosity of some Delaware basin reservoirs and for oil-field karst reservoirs in other petroleum basins of the world. 8 figs.

  3. Production and reactions of triplet CS: Matrix infrared and ultraviolet spectra of C{sub 2}S{sub 2}

    SciTech Connect

    Bohn, R.B.; Hannachi, Y.; Andrews, L.

    1992-07-29

    Matrix infrared and visible-ultraviolet absorption spectroscopy and ab initio electronic structure calculations have been used to characterize the reaction products from a Tesla coil Ar/CS{sub 2} discharge. The discharge is an excellent source of CS, which reacts with other molecules to form the major C{sub 3}S{sub 2} product and the transient C{sub 2}S{sub 2} species. The spectra of discharged mixed isotopic samples Ar/{sup 12}CS{sub 2}/{sub 13}CS{sub 2} and Ar/C{sup 32}S{sub 2} exhibit triplet patterns in the CS antisymmetric stretching region, which unambiguously identifies the new C{sub 2}S{sub 2} molecule with two equivalent CS subgroups. The magnitudes of the {sup 12,13}C and {sup 32,34}S isotopic shifts further characterize the diatomic CS subgroup nature of C{sub 2}S{sub 2}. Another product contains two equivalent CS subgroups interacting with inequivalent S atom(s). The formation of C{sub 2}S{sub 2}({sup 3}{Sigma}) from the simple CS{sub 2} discharge requires triplet CS. Evidence was also obtained for other transient cumulene species. 32 refs., 8 figs., 7 tabs.

  4. Absolute line intensities for carbonyl sulfide from 827 to 2939 cm -1

    NASA Astrophysics Data System (ADS)

    Vander Auwera, J.; Fayt, A.

    2006-01-01

    Using a total of 18 unapodized high-resolution (MOPD=300 and 450 cm) Fourier transform absorption spectra of carbonyl sulfide ( P× ℓ=14.3-60,600 Pa×cm, T=296.0 K), we measured 1340 absolute line intensities in 8 bands (ν+ν21-ν21,2ν20,2ν,ν+2ν20,4ν20,ν,ν21+ν-ν21,ν+ν) of the main isotopologue, located between 827 and 2939 cm -1. In addition, we measured 307 absolute line intensities in the ν 3 fundamental band of 16O 12C 34S and 16O 13C 32S, observed near 2061.45 and 2009.23 cm -1, respectively. The observed Herman-Wallis dependences are in most cases reproduced by the global model of OCS [E. Rbaihi, A. Belafhal, J. Vander Auwera, S. Naïm, and A. Fayt, J. Mol. Spectrosc., 191:32-44, 1998]. The pressure self-broadening parameter was also measured up to J=83.

  5. Coastal submarine hydrothermal activity of Northern Baja California 2. Evolutionary history and isotope geochemistry

    SciTech Connect

    Vidal, V.M.V.; Vidal, F.V.; Isaacs, J.D.

    1981-10-10

    A geochemical model of the Punta Banda submarine hydrothermal system (PBSHS) and Ensenada quadrangle subaerial hot springs is developed using /sup 18/O//sup 16/O, D/H, /sup 34/S//sup 32/S, /sup 3/H, water and gas chemistry. The PBSHS water is a primary high temperature, acid, reducing fluid of old seawater origin which has been titrated by cold, alkaline groundwater of meteoric origin. The final exiting solutions represent a 1:1 mixture of the two primary mixing components. In contrast, the subaerial hot spring waters are of unmixed meteoric origin. The subaerial hot spring gas is predominantly atmospheric N/sub 2/, while the PBSHS contains large amounts of CH/sub 4/ and N/sub 2/ derived from trapped marine sediments of Cretaceous age, deltaS/sup 34/ values of sampled hydrothermal waters are similar to Cretaceous marine sulfate values and suggest that the waters contacted Cretaceous marine sedimentary strata. The presence of the Alisitos and Rosario marine sedimentary formations of Cretaceous age within the Ensenada-Punta Banda quadrangel renders support to the above hypothesis. The data also demonstrate the pyrite mineralization and deposition in submarine hydrothermal environments result from the complexing of ferrous iron with elemental sulfur and sulfide and that submarine hydrothermal activity acts as a major source of silica, Ca/sup 2 +/, and trace metals and as a major sink for seawater Mg/sup 2 +/ and SO/sub 4//sup 2 -/.

  6. Discovery of (1R,5S)-N-[3-amino-1-(cyclobutylmethyl)-2,3-dioxopropyl]- 3-[2(S)-[[[(1,1-dimethylethyl)amino]carbonyl]amino]-3,3-dimethyl-1-oxobutyl]- 6,6-dimethyl-3-azabicyclo[3.1.0]hexan-2(S)-carboxamide (SCH 503034), a selective, potent, orally bioavailable hepatitis C virus NS3 protease inhibitor: a potential therapeutic agent for the treatment of hepatitis C infection.

    PubMed

    Venkatraman, Srikanth; Bogen, Stéphane L; Arasappan, Ashok; Bennett, Frank; Chen, Kevin; Jao, Edwin; Liu, Yi-Tsung; Lovey, Raymond; Hendrata, Siska; Huang, Yuhua; Pan, Weidong; Parekh, Tejal; Pinto, Patrick; Popov, Veljko; Pike, Russel; Ruan, Sumei; Santhanam, Bama; Vibulbhan, Bancha; Wu, Wanli; Yang, Weiying; Kong, Jianshe; Liang, Xiang; Wong, Jesse; Liu, Rong; Butkiewicz, Nancy; Chase, Robert; Hart, Andrea; Agrawal, Sony; Ingravallo, Paul; Pichardo, John; Kong, Rong; Baroudy, Bahige; Malcolm, Bruce; Guo, Zhuyan; Prongay, Andrew; Madison, Vincent; Broske, Lisa; Cui, Xiaoming; Cheng, Kuo-Chi; Hsieh, Yunsheng; Brisson, Jean-Marc; Prelusky, Danial; Korfmacher, Walter; White, Ronald; Bogdanowich-Knipp, Susan; Pavlovsky, Anastasia; Bradley, Prudence; Saksena, Anil K; Ganguly, Ashit; Piwinski, John; Girijavallabhan, Viyyoor; Njoroge, F George

    2006-10-05

    Hepatitis C virus (HCV) infection is the major cause of chronic liver disease, leading to cirrhosis and hepatocellular carcinoma, which affects more than 170 million people worldwide. Currently the only therapeutic regimens are subcutaneous interferon-alpha or polyethylene glycol (PEG)-interferon-alpha alone or in combination with oral ribavirin. Although combination therapy is reasonably successful with the majority of genotypes, its efficacy against the predominant genotype (genotype 1) is moderate at best, with only about 40% of the patients showing sustained virological response. Herein, the SAR leading to the discovery of 70 (SCH 503034), a novel, potent, selective, orally bioavailable NS3 protease inhibitor that has been advanced to clinical trials in human beings for the treatment of hepatitis C viral infections is described. X-ray structure of inhibitor 70 complexed with the NS3 protease and biological data are also discussed.

  7. Discovery of (1R,5S)-N-[3-Amino-1-(cyclobutylmethyl)-2,3-dioxopropyl]- 3-[2(S)-[[[(1,1-dimethylethyl)amino]carbonyl]amino]-3,3-dimethyl-1-oxobutyl]- 6,6-dimethyl-3-azabicyclo[3.1.0]hexan-2(S)-carboxamide (SCH 503034), a Selective, Potent, Orally Bioavailable Hepatitis C Virus NS3 Protease Inhibitor: A Potential Therapeutic Agent for the Treatment of Hepatitis C Infection

    SciTech Connect

    Venkatraman, Srikanth; Bogen, Stephane L.; Arasappan, Ashok; Bennett, Frank; Chen, Kevin; Jao, Edwin; Liu, Yi-Tsung; Lovey, Raymond; Hendrata, Siska; Huang, Yuhua; Pan, Weidong; Parekh, Tejal; Pinto, Patrick; Popov, Veljko; Pike, Russel; Ruan, Sumei; Santhanam, Bama; Vibulbhan, Bancha; Wu, Wanli; Yang, Weiying; Kong, Jianshe; Liang, Xiang; Wong, Jesse; Liu, Rong; Butkiewicz, Nancy; Chase, Robert; Hart, Andrea; Agrawal, Sony; Ingravallo, Paul; Pichardo, John; Kong, Rong; Baroudy, Bahige; Malcolm, Bruce; Guo, Zhuyan; Prongay, Andrew; Madison, Vincent; Broske, Lisa; Cui, Xiaoming; Cheng, Kuo-Chi; Hsieh, Yunsheng; Brisson, Jean-Marc; Prelusky, Danial; Korfmacher, Walter; White, Ronald; Bogdanowich-Knipp, Susan; Pavlovsky, Anastasia; Bradley, Prudence; Saksena, Anil K.; Ganguly, Ashit; Piwinski, John; Girijavallabhan, Viyyoor; Njoroge, F. George

    2008-06-30

    Hepatitis C virus (HCV) infection is the major cause of chronic liver disease, leading to cirrhosis and hepatocellular carcinoma, which affects more than 170 million people worldwide. Currently the only therapeutic regimens are subcutaneous interferon-{alpha} or polyethylene glycol (PEG)-interferon-{alpha} alone or in combination with oral ribavirin. Although combination therapy is reasonably successful with the majority of genotypes, its efficacy against the predominant genotype (genotype 1) is moderate at best, with only about 40% of the patients showing sustained virological response. Herein, the SAR leading to the discovery of 70 (SCH 503034), a novel, potent, selective, orally bioavailable NS3 protease inhibitor that has been advanced to clinical trials in human beings for the treatment of hepatitis C viral infections is described. X-ray structure of inhibitor 70 complexed with the NS3 protease and biological data are also discussed.

  8. No oxygen isotope exchange between water and APS-sulfate at surface temperature: Evidence from quantum chemical modeling and triple-oxygen isotope experiments

    NASA Astrophysics Data System (ADS)

    Kohl, Issaku E.; Asatryan, Rubik; Bao, Huiming

    2012-10-01

    In both laboratory experiments and natural environments where microbial dissimilatory sulfate reduction (MDSR) occurs in a closed system, the δ34S ((34S/32S)sample/(34S/32S)standard - 1) for dissolved SO42- has been found to follow a typical Rayleigh-Distillation path. In contrast, the corresponding δ18O ((18O/16O)sample/(18O/16O)standard) - 1) is seen to plateau with an apparent enrichment of between 23‰ and 29‰ relative to that of ambient water under surface conditions. This apparent steady-state in the observed difference between δ18O and δ18OO can be attributed to any of these three steps: (1) the formation of adenosine-5'-phosphosulfate (APS) from ATP and SO42-, (2) oxygen exchange between sulfite (or other downstream sulfoxy-anions) and water later in the MDSR reaction chain and its back reaction to APS and sulfate, and (3) the re-oxidation of produced H2S or precursor sulfoxy-anions to sulfate in environments containing Fe(III) or O2. This study examines the first step as a potential pathway for water oxygen incorporation into sulfate. We examined the structures and process of APS formation using B3LYP/6-31G(d,p) hybrid density functional theory, implemented in the Gaussian-03 program suite, to predict the potential for oxygen exchange. We conducted a set of in vitro, enzyme-catalyzed, APS formation experiments (with no further reduction to sulfite) to determine the degree of oxygen isotope exchange between the APS-sulfate and water. Triple-oxygen-isotope labeled water was used in the reactor solutions to monitor oxygen isotope exchange between water and APS sulfate. The formation and hydrolysis of APS were identified as potential steps for oxygen exchange with water to occur. Quantum chemical modeling indicates that the combination of sulfate with ATP has effects on bond strength and symmetry of the sulfate. However, these small effects impart little influence on the integrity of the SO42- tetrahedron due to the high activation energy required for

  9. Sulfur Isotopic Compositions of Sulfides From the Lower Huronian Supergroup, Ontario, Canada

    NASA Astrophysics Data System (ADS)

    Tachibana, S.; Hirai, T.; Goto, K.; Yamamoto, S.; Isozaki, Y.; Tada, R.; Tajika, E.; Shimoda, G.; Morishita, Y.; Kita, N. T.

    2004-12-01

    Mass-independent isotopic fractionation (MIF) of sulfur found in sedimentary rocks older than 2470 Ma implies that the atmospheric oxygen level was lower than 10-5 PAL (present atmospheric level) in the Archean atmosphere [e.g., 1, 2]. Sulfides from the Rooihoogte and Timeball Hill Formations, Transvaal Supergroup, South Africa, (2316 Ma [3]) show only a small degree of MIF [4], which suggests that the atmospheric oxygen level reached 10-5 PAL by 2316 Ma [4]. The Huronian Supergroup in E. Canada recording three Paleoproterozoic glaciatial events between 2450 and 2220 Ma is correlated with the Rooihootge and Timeball Hill Formations, and may record the evidence of the great oxygenation event. The sulfur isotopic compositions of sulfides in the Matinenda to Gordon Lake Formations of the Huronian Supergroup exhibit D33S, deviation from a mass-dependent fractionation line, of less than 0.5 permil [e.g., 1]. This suggests that the atmospheric oxygen reached a level high enough to vanish the MIF signature before the Matinenda deposition. Here we report sulfur isotopic compositions of sulfides from the Livingstone Creek, Thessalon, and Matinenda Formations of the Lower Huronian Supergroup in the Elliot lake area. The Livingstone Creek and Thessalon Formations underlie the uraniferous Matinenda Formation. In-situ ion microprobe measurements showed that most of sulfides have a small degree of sulfur MIF, as seen in other formations, except for clastic sulfide blocks in the polymictic conglomerates of the Livingstone Creek Formation, the lowermost Huronian Supergroup. The sulfides in the Livingstone sulfide blocks show a clear evidence of MIF (D33S = -1.7 to +3.6 permil) with d34S of _|4 to +2 permil. The range of MIF from the sulfide blocks is an order of magnitude larger than that for other sulfides from the Huronian Supergroup. This indicates that the atmospheric oxygen may have started to increase after the formation of the sulfide blocks and before the deposition of the

  10. Matrix and energy effects during in-situ determination of Cu isotope ratios by ultraviolet-femtosecond laser ablation multicollector inductively coupled plasma mass spectrometry

    NASA Astrophysics Data System (ADS)

    Lazarov, Marina; Horn, Ingo

    2015-09-01

    Copper isotope compositions in Cu-bearing metals and minerals have been measured by deep (194 nm) ultraviolet femtosecond laser ablation multi-collector inductively coupled plasma mass spectrometry (UV-fsLA-MC-ICP-MS). Pure Cu-metal, brass, and several Cu-rich minerals (chalcopyrite, enargite, covellite, malachite and cuprite) have been investigated. A long-term reproducibility of better than 0.08‰ at the 95% confidence limit on the NIST SRM 976 (National Institute of Standards and Technology) Cu-metal standard has been achieved with this technique. The δ65Cu values for all samples have been calculated by standard-sample-standard bracketing with NIST SRM 976. All analyses have been carried out using Ni as a mass discrimination monitor added by nebulization prior to entering the plasma torch. For further verification samples have been analysed by conventional solution nebulization MC-ICP-MS and the results obtained have been compared with those from UV-fsLA-MC-ICP-MS. Several potential matrix-induced molecular interferences on the mineral copper isotope ratio, such as (32S33S)+ and (32S-16O17O)+ do not affect the Cu isotope measurements on sulfides, while hydrides, such as Zn-H or doubly-charged Sn2 + that interfere Ni isotopes can be either neglected or stripped by calculation. Matrix independent Cu-isotope measurements are sensitive to the energy density (fluence) applied onto the sample and can produce artificial shifts in the obtained δ65Cu values which are on the order of 3‰ for Cu-metal, 0.5‰ for brass and 0.3‰ for malachite when using energy density of up to 2 J/cm2 for ablation. A positive correlation between applied energy density and the magnitude of the isotope ratio shift has been found in the energy density range from 0.2 to 1.3 J/cm2 which is below the ablation threshold for ns-laser ablation. The results demonstrate that by using appropriate low fluence it is possible to measure Cu isotopic ratios in native copper and Cu-bearing sulfides

  11. Spatial distributions of sulphur species and sulphate-reducing bacteria provide insights into sulphur redox cycling and biodegradation hot-spots in a hydrocarbon-contaminated aquifer

    NASA Astrophysics Data System (ADS)

    Einsiedl, Florian; Pilloni, Giovanni; Ruth-Anneser, Bettina; Lueders, Tillman; Griebler, Christian

    2015-05-01

    Dissimilatory sulphate reduction (DSR) has been proven to be one of the most relevant redox reactions in the biodegradation of contaminants in groundwater. However, the possible role of sulphur species of intermediate oxidation state, as well as the role of potential re-oxidative sulphur cycling in biodegradation particularly at the groundwater table are still poorly understood. Here we used a combination of stable isotope measurements of SO42-, H2S, and S0 as well as geochemical profiling of sulphur intermediates with special emphasis on SO32-, S2O32-, and S0 to unravel possible sulphur cycling in the biodegradation of aromatics in a hydrocarbon-contaminated porous aquifer. By linking these results to the quantification of total bacterial rRNA genes and respiratory genes of sulphate reducers, as well as pyrotag sequencing of bacterial communities over depth, light is shed on possible key-organisms involved. Our results substantiate the role of DSR in biodegradation of hydrocarbons (mainly toluene) in the highly active plume fringes above and beneath the plume core. In both zones the concentration of sulphur intermediates (S0, SO32- and S2O32-) was almost twice that of other sampling-depths, indicating intense sulphur redox cycling. The dual isotopic fingerprint of oxygen and sulphur in dissolved sulphate suggested a re-oxidation of reduced sulphur compounds to sulphate especially at the upper fringe zone. An isotopic shift in δ34S of S0 of nearly +4‰ compared to the δ34S values of H2S from the same depth linked to a high abundance (∼10%) of sequence reads related to Sulphuricurvum spp. (Epsilonproteobacteria) in the same depth were indicative of intensive oxidation of S0 to sulphate in this zone. At the lower plume fringe S0 constituted the main inorganic sulphur species, possibly formed by abiotic re-oxidation of H2S with Fe(III)oxides subsequent to sulphate reduction. These results provide first insights into intense sulphur redox cycling in a hydrocarbon

  12. Linking the Fe-, Mo-, and Cr isotope records with the multiple S isotope record of Archean sedimentary rocks

    NASA Astrophysics Data System (ADS)

    Ohmoto, H.; Watanabe, Y.

    2011-12-01

    Researchers have interpreted the isotopic data of redox sensitive elements (e.g., Fe, Mo and Cr) in Archean- and Proterozoic-aged sedimentary rocks within a framework of an atmospheric O2 evolution model that relied on an interpretation of the multiple sulfur isotopic record of sedimentary rocks. The current paradigm is that the anomalous isotopic fractionations of sulfur (AIF-S, or MIF-S) in sedimentary rocks were created by the UV photolysis of volcanic SO2 in an O2-poor (i.e., pO2 < 1 ppm) atmosphere, and that the rise of atmospheric pO2 to > 1 ppm occurred at ~2.45 Ga. However, this paradigm has recently encountered the following serious problems: (1) UV photolysis of SO2 by a broad-band UV lamp, which simulates the UV spectra of the sun light, produced the δ34S33S values for the S0 and SO4 that are significantly different from >90% of data on natural samples. (2) Many Archean-age sedimentary rocks do not exhibit AIF-S signatures. (3) Strong AIF-S signatures are typically found in organic C- and pyrite rich Archean-age black shales that were altered by submarine hydrothermal fluids during the early diagenetic stage of the rocks. (4) H2S, rather than SO2, was probably the dominant S-bearing volcanic gas on an anoxic Earth. Yet, UV photolysis of H2S does not generate AIF-S. (5) Some post-2.0 Ga natural samples were found to possess strong AIF-S signatures, such as sulfates in air pollutants that were produced by coal burning in an oxygen-rich atmosphere. Lasaga et al. (2008) demonstrated theoretically that chemisorption reactions between some solid surfaces and S-bearing aqueous (or gaseous) species, such as between organic matter and aqueous sulfate, may generate AIF-S. Watanabe et al. (2009; in prep.) demonstrated experimentally that reactions between simple amino acid crystals and sulfate under hydrothermal conditions produced AIF-S signatures that matched with more than 90% of data on natural samples. These studies, as well as the observed correlations

  13. Energy cost of sport rock climbing in elite performers

    PubMed Central

    Booth, J.; Marino, F.; Hill, C.; Gwinn, T.

    1999-01-01

    OBJECTIVES: To assess oxygen uptake (VO2), blood lactate concentration ([La(b)]), and heart rate (HR) response during indoor and outdoor sport climbing. METHODS: Seven climbers aged 25 (SE 1) years, with a personal best ascent without preview or fall (on sight) ranging from 6b to 7a were assessed using an indoor vertical treadmill with artificial rock hand/foot holds and a discontinuous protocol with climbing velocity incremented until voluntary fatigue. On a separate occasion the subjects performed a 23.4 m outdoor rock climb graded 5c and taking 7 min 36 s (SE 33 s) to complete. Cardiorespiratory parameters were measured using a telemetry system and [La(b)] collected at rest and after climbing. RESULTS: Indoor climbing elicited a peak oxygen uptake (VO2climb-peak) and peak HR (HRpeak) of 43.8 (SE 2.2) ml/kg/min and 190 (SE 4) bpm, respectively and increased blood lactate concentration [La(b)] from 1.4 (0.1) to 10.2 (0.6) mmol/l (p < 0.05). During outdoor climbing VO2 and HR increased to about 75% and 83% of VO2climb-peak and HRpeak, respectively. [La(b)] increased from 1.3 (0.1) at rest to 4.5 mmol/l (p < 0.05) at 2 min 32 s (8 s) after completion of the climb. CONCLUSIONS: The results suggest that for elite climbers outdoor sport rock climbs of five to 10 minutes' duration and moderate difficulty require a significant portion of the VO2climb-peak. The higher HR and VO2 for outdoor climbing and the increased [La(b)] could be the result of repeated isometric contractions, particularly from the arm and forearm muscles. 


 PMID:10027051

  14. The theory of equilibrium and gravitational field of the Galilean satellite Io. The second approximation

    NASA Astrophysics Data System (ADS)

    Zharkov, V. N.

    There have been constructed the theory of figures and gravitational field of the Galilean satellite Io to within terms of second orders in the small parameter α=ω^2s_1^3/Gm_0, where ω, s_1, G and m_0 are the angular velocity, the radius of a sphere of equivalent volume (the average radius), the gravitational constant and mass of Io, respectively. In a second approximation of the theory of figurs the radius r is represented as the sum of the following figure functions: s_2(s), s22(s), s31(s), s33(s), s_4(s), s42(s) and s44(s), multiplied by corresponding spherical harmonics. Integrodifferential equations, the solutions of which determine the values of figure parameters and gravitational moments of equilibrium Io have been derived. Figure parameters (at s=s_1) and gravitational moments for s_2, s22, J_2 and C22 are determined by Love numbers h_2 and α; for s31, s33, C31 and C33 (J_3=s31=s32=s33=C32=0) are determined by Love numbers h_3 and the small parameter α_1=(s_1/R)α, where R is the radius of Io's orbit. For the uniform model of Io the values of figure parameters and gravitational moments of the forth order are the following: s_4=885/224 α^2, s42=-75/224 α^2, s44=15/896 α^2, J_4=-885/224α^2, C42=-75/224α^2, C44=15/896α^2.

  15. Dipole-dipole resonance line shapes in a cold Rydberg gas

    NASA Astrophysics Data System (ADS)

    Richards, B. G.; Jones, R. R.

    2016-04-01

    We have explored the dipole-dipole mediated, resonant energy transfer reaction, 32 p3 /2+32 p3 /2→32 s +33 s , in an ensemble of cold 85Rb Rydberg atoms. Stark tuning is employed to measure the population transfer probability as a function of the total electronic energy difference between the initial and final atom-pair states over a range of Rydberg densities, 2 ×108≤ρ ≤3 ×109 cm-3. The observed line shapes provide information on the role of beyond nearest-neighbor interactions, the range of Rydberg atom separations, and the electric field inhomogeneity in the sample. The widths of the resonance line shapes increase approximately linearly with the Rydberg density and are only a factor of 2 larger than expected for two-body, nearest-neighbor interactions alone. These results are in agreement with the prediction [B. Sun and F. Robicheaux, Phys. Rev. A 78, 040701(R) (2008), 10.1103/PhysRevA.78.040701] that beyond nearest-neighbor exchange interactions should not influence the population transfer process to the degree once thought. At low densities, Gaussian rather than Lorentzian line shapes are observed due to electric field inhomogeneities, allowing us to set an upper limit for the field variation across the Rydberg sample. At higher densities, non-Lorentzian, cusplike line shapes characterized by sharp central peaks and broad wings reflect the random distribution of interatomic distances within the magneto-optical trap (MOT). These line shapes are well reproduced by an analytic expression derived from a nearest-neighbor interaction model and may serve as a useful fingerprint for characterizing the position correlation function for atoms within the MOT.

  16. Coupled Fe and S isotope variations in pyrite nodules from Archean shale

    NASA Astrophysics Data System (ADS)

    Marin-Carbonne, Johanna; Rollion-Bard, Claire; Bekker, Andrey; Rouxel, Olivier; Agangi, Andrea; Cavalazzi, Barbara; Wohlgemuth-Ueberwasser, Cora C.; Hofmann, Axel; McKeegan, Kevin D.

    2014-04-01

    Iron and sulfur isotope compositions recorded in ancient rocks and minerals such as pyrite (FeS2) have been widely used as a proxy for early microbial metabolisms and redox evolution of the oceans. However, most previous studies focused on only one of these isotopic systems. Herein, we illustrate the importance of in-situ and coupled study of Fe and S isotopes on two pyrite nodules in a c. 2.7 Ga shale from the Bubi Greenstone Belt (Zimbabwe). Fe and S isotope compositions were measured both by bulk-sample mass spectrometry techniques and by ion microprobe in-situ methods (Secondary Ion Mass Spectrometry, SIMS). Spatially-resolved analysis across the nodules shows a large range of variations at micrometer-scale for both Fe and S isotope compositions, with δ56Fe and δ34S values from -2.1 to +0.7‰ and from -0.5 to +8.2‰, respectively, and Δ33S values from -1.6 to +2.9‰. The Fe and S isotope variations in these nodules cannot be explained by tandem operation of Dissimilatory Iron Reduction (DIR) and Bacterial Sulfate Reduction (BSR) as was previously proposed, but rather they reflect the contributions of different Fe and S sources during a complex diagenetic history. Pyrite formed from two different mineral precursors: (1) mackinawite precipitated in the water column, and (2) greigite formed in the sediment during early diagenesis. The in-situ analytical approach reveals a complex history of the pyrite nodule growth and allows us to better constrain environmental conditions during the Archean.

  17. Volcanic sulfate aerosol formation in the troposphere

    NASA Astrophysics Data System (ADS)

    Martin, Erwan; Bekki, Slimane; Ninin, Charlotte; Bindeman, Ilya

    2014-11-01

    The isotopic composition of volcanic sulfate provides insights into the atmospheric chemical processing of volcanic plumes. First, mass-independent isotopic anomalies quantified by Δ17O and to a lesser extent Δ33S and Δ36S in sulfate depend on the relative importance of different oxidation mechanisms that generate sulfate aerosols. Second, the isotopic composition of sulfate (δ34S and δ18O) could be an indicator of fractionation (distillation/condensation) processes occurring in volcanic plumes. Here we present analyses of O- and S isotopic compositions of volcanic sulfate absorbed on very fresh volcanic ash from nine moderate historical eruptions in the Northern Hemisphere. Most of our volcanic sulfate samples, which are thought to have been generated in the troposphere or in the tropopause region, do not exhibit any significant mass-independent fractionation (MIF) isotopic anomalies, apart from those from an eruption of a Mexican volcano. Coupled to simple chemistry model calculations representative of the background atmosphere, our data set suggests that although H2O2 (a MIF-carrying oxidant) is thought to be by far the most efficient sulfur oxidant in the background atmosphere, it is probably quickly consumed in large dense tropospheric volcanic plumes. We estimate that in the troposphere, at least, more than 90% of volcanic secondary sulfate is not generated by MIF processes. Volcanic S-bearing gases, mostly SO2, appear to be oxidized through channels that do not generate significant isotopically mass-independent sulfate, possibly via OH in the gas phase and/or transition metal ion catalysis in the aqueous phase. It is also likely that some of the sulfates sampled were not entirely produced by atmospheric oxidation processes but came out directly from volcanoes without any MIF anomalies.

  18. A Rare Glimpse of Paleoarchean Life: Geobiology of an Exceptionally Preserved Microbial Mat Facies from the 3.4 Ga Strelley Pool Formation, Western Australia.

    PubMed

    Duda, Jan-Peter; Van Kranendonk, Martin J; Thiel, Volker; Ionescu, Danny; Strauss, Harald; Schäfer, Nadine; Reitner, Joachim

    2016-01-01

    Paleoarchean rocks from the Pilbara Craton of Western Australia provide a variety of clues to the existence of early life on Earth, such as stromatolites, putative microfossils and geochemical signatures of microbial activity. However, some of these features have also been explained by non-biological processes. Further lines of evidence are therefore required to convincingly argue for the presence of microbial life. Here we describe a new type of microbial mat facies from the 3.4 Ga Strelley Pool Formation, which directly overlies well known stromatolitic carbonates from the same formation. This microbial mat facies consists of laminated, very fine-grained black cherts with discontinuous white quartz layers and lenses, and contains small domical stromatolites and wind-blown crescentic ripples. Light- and cathodoluminescence microscopy, Raman spectroscopy, and time of flight-secondary ion mass spectrometry (ToF-SIMS) reveal a spatial association of carbonates, organic material, and highly abundant framboidal pyrite within the black cherts. Nano secondary ion mass spectrometry (NanoSIMS) confirmed the presence of distinct spheroidal carbonate bodies up to several tens of μm that are surrounded by organic material and pyrite. These aggregates are interpreted as biogenic. Comparison with Phanerozoic analogues indicates that the facies represents microbial mats formed in a shallow marine environment. Carbonate precipitation and silicification by hydrothermal fluids occurred during sedimentation and earliest diagenesis. The deciphered environment, as well as the δ13C signature of bulk organic matter (-35.3‰), are in accord with the presence of photoautotrophs. At the same time, highly abundant framboidal pyrite exhibits a sulfur isotopic signature (δ34S = +3.05‰; Δ33S = 0.268‰; and Δ36S = -0.282‰) that is consistent with microbial sulfate reduction. Taken together, our results strongly support a microbial mat origin of the black chert facies, thus providing

  19. Millimetre spectral line mapping observations towards four massive star-forming H II regions

    NASA Astrophysics Data System (ADS)

    Li, Shanghuo; Wang, Junzhi; Zhang, Zhi-Yu; Fang, Min; Li, Juan; Zhang, Jiangshui; Fan, Junhui; Zhu, Qingfeng; Li, Fei

    2017-04-01

    We present spectral line mapping observations towards four massive star-forming regions - Cepheus A, DR21S, S76E and G34.26+0.15 - with the IRAM 30-m telescope at the 2 and 3 mm bands. In total, 396 spectral lines from 51 molecules, one helium recombination line, 10 hydrogen recombination lines and 16 unidentified lines were detected in these four sources. An emission line of nitrosyl cyanide (ONCN, 140, 14-130, 13) was detected in G34.26+0.15, as the first detection in massive star-forming regions. We found that c-C3H2 and NH2D show enhancement in shocked regions, as suggested by the evidence of SiO and/or SO emission. The column density and rotational temperature of CH3CN were estimated with the rotational diagram method for all four sources. Isotope abundance ratios of 12C/13C were derived using HC3N and its 13C isotopologue, which were around 40 in all four massive star-forming regions and slightly lower than the local interstellar value (∼65). The 14N/15N and 16O/18O abundance ratios in these sources were also derived using the double isotopic method, which were slightly lower than in the local interstellar medium. Except for Cep A, the 33S/34S ratios in the other three targets were derived, which were similar to that in the local interstellar medium. The column density ratios of N(DCN)/N(HCN) and N(DCO+)/N(HCO+) in these sources were more than two orders of magnitude higher than the elemental [D]/[H] ratio, which is 1.5 × 10-5. Our results show that the later stage sources, G34.26+0.15 in particular, present more molecular species than earlier stage sources. Evidence of shock activity is seen in all stages studied.

  20. A Rare Glimpse of Paleoarchean Life: Geobiology of an Exceptionally Preserved Microbial Mat Facies from the 3.4 Ga Strelley Pool Formation, Western Australia

    PubMed Central

    Duda, Jan-Peter; Van Kranendonk, Martin J.; Thiel, Volker; Ionescu, Danny; Strauss, Harald; Schäfer, Nadine; Reitner, Joachim

    2016-01-01

    Paleoarchean rocks from the Pilbara Craton of Western Australia provide a variety of clues to the existence of early life on Earth, such as stromatolites, putative microfossils and geochemical signatures of microbial activity. However, some of these features have also been explained by non-biological processes. Further lines of evidence are therefore required to convincingly argue for the presence of microbial life. Here we describe a new type of microbial mat facies from the 3.4 Ga Strelley Pool Formation, which directly overlies well known stromatolitic carbonates from the same formation. This microbial mat facies consists of laminated, very fine-grained black cherts with discontinuous white quartz layers and lenses, and contains small domical stromatolites and wind-blown crescentic ripples. Light- and cathodoluminescence microscopy, Raman spectroscopy, and time of flight—secondary ion mass spectrometry (ToF-SIMS) reveal a spatial association of carbonates, organic material, and highly abundant framboidal pyrite within the black cherts. Nano secondary ion mass spectrometry (NanoSIMS) confirmed the presence of distinct spheroidal carbonate bodies up to several tens of μm that are surrounded by organic material and pyrite. These aggregates are interpreted as biogenic. Comparison with Phanerozoic analogues indicates that the facies represents microbial mats formed in a shallow marine environment. Carbonate precipitation and silicification by hydrothermal fluids occurred during sedimentation and earliest diagenesis. The deciphered environment, as well as the δ13C signature of bulk organic matter (-35.3‰), are in accord with the presence of photoautotrophs. At the same time, highly abundant framboidal pyrite exhibits a sulfur isotopic signature (δ34S = +3.05‰; Δ33S = 0.268‰; and Δ36S = -0.282‰) that is consistent with microbial sulfate reduction. Taken together, our results strongly support a microbial mat origin of the black chert facies, thus

  1. The Fundamental Structure of UV-Irradiated Cloud Edges: Combined ALMA and IRAM-30m Observations of the Orion Bar

    NASA Astrophysics Data System (ADS)

    Goicoechea, J.; Cuadrado, S.; Pety, J.; Ag'undez, M.; Cernicharo, J.; Chapillon, E.; Dumas, G.; Fuente, A.; Gerin, M.; Joblin, C.; Marcelino, N.; Müller, H. S. P.; Pilleri, P.

    2015-12-01

    The Orion Bar is the prototypical photodissociation region (PDR) exposed to a far-UV radiation field (FUV) of a few 104 times the mean interstellar field. Because of its proximity and nearly edge-on orientation, it provides a unique laboratory to study the physical and chemical gradients of a strongly FUV-illuminated molecular cloud. Using ALMA at ˜350 GHz, we have observed a field-of-view of ˜40”×40” toward the Orion Bar PDR consisting of a mosaic of 27 Nyquist-sampled pointings. These observations provide an unprecedented high angular resolution view (˜1” or ˜414 AU at the distance to Orion) of the most exposed molecular cloud edge. In addition, ACA and IRAM-30m maps were used to produce the short-spacing visibilities filtered out by the ALMA array. These interferometric observations complement a complete line survey we have carried out using the IRAM-30m telescope between ˜80 GHz and ˜360 GHz. Despite being a harsh environment, over 60 species with up to 6 atoms have been identified, including main isotopologues (D, 13C, 18O, 17O, 34S, 33S, and 15N). The first molecular line images of the Orion Bar obtained with ALMA at ˜1” resolution reveal the fundamental structure in density and temperature of the molecular gas as well as its complex kinematics at an unprecedented spatial resolution. This early data set also allowed us to compute corrected line frequencies for SH+, an interesting hydride tracing reactions of S+ with vibrationally excited H2 in the PDR edge.

  2. A COMPLETE SPECTROSCOPIC CHARACTERIZATION OF SO AND ITS ISOTOPOLOGUES UP TO THE TERAHERTZ DOMAIN

    SciTech Connect

    Martin-Drumel, M. A.; Hindle, F.; Mouret, G.; Cuisset, A.; Cernicharo, J.

    2015-02-01

    In order to obtain accurate terahertz center frequencies for SO and its isotopologues, we have studied the absorption spectrum of SO, {sup 34}SO, and {sup 33}SO up to 2.5 THz using continuous-wave terahertz photomixing based on a frequency comb providing an accuracy down to 10 kHz. Sulfur monoxide was produced in a radio frequency discharge of air in a cell containing pure sulfur. Together with the strong absorption signal of the main isotopologue, transitions of {sup 34}SO ({sup 34}S: 4.21%) and {sup 33}SO ({sup 33}S: 0.75%) were observed in natural abundance. The newly observed transitions constitute an extension of the observed rotational quantum numbers of the molecule toward higher N values, allowing an improvement of the molecular parameters for the three species. An isotopically invariant fit has been performed based on pure rotational and ro-vibrational transitions of all SO isotopologues, enabling their accurate line position prediction at higher frequencies. Thanks to this new set of parameters, it is now possible to predict with very high accuracy the frequencies of the ro-vibrational lines. This should enable the research of SO in the mid-IR using ground-based IR telescopes, space-based telescope archives (Infrared Space Observatory, Spitzer), and future space missions such as the James Webb Space Telescope. This set of parameters is particularly well adapted for the detection of SO lines in O-rich evolved stars or in molecular clouds in absorption against bright IR sources.

  3. Geochemical study of the Sakalol-Harralol geothermal field (Republic of Djibouti): Evidences of a low enthalpy aquifer between Manda-Inakir and Asal rift settings

    NASA Astrophysics Data System (ADS)

    Awaleh, Mohamed Osman; Boschetti, Tiziano; Soubaneh, Youssouf Djibril; Baudron, Paul; Kawalieh, Ali Dirir; Dabar, Omar Assowe; Ahmed, Moussa Mahdi; Ahmed, Samaleh Idriss; Daoud, Mohamed Ahmed; Egueh, Nima Moussa; Mohamed, Jalludin

    2017-02-01

    Eighty-six sodium bicarbonate to sodium chloride hot springs and four water wells in the Tadjourah Region of Djibouti were investigated for major, minor (B, Br, F, Sr, Li) chemistry and isotope composition of water and dissolved components (87Sr/86Sr, 11B/10B, 13C/12C and 14C of DIC, 34S/32S and 18O/16O of sulfate). The deep saline Na-Cl reservoir at 143 °C shows affinity with the shallow geothermal water from the "active" Asal rift. Asal water is a diluted and recycled seawater component with the major cation composition obliterated by equilibration with Stratoid basalt. Locally, the deep reservoir is differentiated in term of recharge, and re-equilibration with rocks and mixing. In particular, two spring groups reveal contributions from evaporites typical of the "passive" graben setting of the Afar. A model on 34S/32S and 18O/16O demonstrates the isotope imprint of magmatic SO2 disproportionation on dissolved and solid sulfate, whose values probably persists in a sedimentary environment without trace of seawater. On the other hand a seawater signature, modified by mixing and secondary fractionation effects, is partially maintained according to the boron isotope composition (up to + 27.4‰). Temperature estimation in low-enthalpy geothermal reservoirs is notoriously difficult, especially where mixing with fluids of differing genesis and/or conduction cooling take place. From a geothermometric point of view, the multi-method approach followed in this study (up-to-date theoretical and thermodynamic equations, ad-hoc silica geothermometers inferred from local rocks, checking of the results on a 18Oαsulfate-water vs. temperature diagram) provides some insights and perspectives on how to tackle the problem. Table S2. Sampling locations, T, pH, EC, TDS and hydrochemical types of the sampled waters. Table S3. Chemical analyses of thermal and cold waters from Sakalaol-Haralol geothermal field. Table S4. Mineral saturation indices of SHGF hot springs waters calculated

  4. Sulfur isotope fractionation during incorporation of sulfur nucleophiles into organic compounds.

    PubMed

    Amrani, Alon; Ma, Qisheng; Ahmad, Ward Said; Aizenshtat, Zeev; Tang, Yongchun

    2008-03-21

    (34)S enrichment is shown to occur during sulfurization reactions and for the first time conclusively attributed to an isotope equilibrium effect rather than selective addition of (34)S enriched nucleophiles.

  5. The microbial methane cycle in subsurface sediments. Final project report, July 1, 1993--August 31, 1997

    SciTech Connect

    Grossman, E.L.; Ammerman, J.W.; Suflita, J.M.

    1997-12-31

    The objectives of this study were to determine the factors controlling microbial activity and survival in the subsurface and, specifically, to determine whether microbial communities in aquitards and in aquifer microenvironments provide electron donors and/or acceptors that enhance microbial survival in aquifers. Although the original objectives were to focus on methane cycling, the authors pursued an opportunity to study sulfur cycling in aquifer systems, a process of much greater importance in microbial activity and survival, and in the mobility of metals in the subsurface. Furthermore, sulfur cycling is pertinent to the Subsurface Science Program`s study at Cerro Negro, New Mexico. The study combined field and laboratory approaches and microbiological, molecular, geochemical, and hydrogeological techniques. During drilling operations, sediments were collected aseptically and assayed for a variety of microorganisms and metabolic capabilities including total counts, viable aerobic heterotrophs, total anaerobic heterotrophs, sulfate reducing bacteria (SRB) and sulfate reduction activity (in situ and in slurries), methanogens, methanotrophs, and Fe- and S-oxidizers, among others. Geochemical analyses of sediments included organic carbon content and {sup 13}C/{sup 12}C ratio, sulfur chemistry (reduced sulfur, sulfate), {sup 34}S/{sup 32}S, {sup 13}C/{sup 12}C, {sup 14}C, tritium, etc. The authors drilled eight boreholes in the Eocene Yegua formation at four localities on the Texas A&M University campus using a hollow-stem auger drilling rig. The drilling pattern forms a T, with three well clusters along the dip direction and two along strike. Four boreholes were sampled for sediments and screened at the deepest sand interval encountered, and four boreholes were drilled to install wells in shallower sands. Boreholes range in depth from 8 to 31 m, with screened intervals ranging from 6 to 31 m. Below are the results of these field studies.

  6. Elemental Sulfur and Thiol Accumulation in Tomato and Defense against a Fungal Vascular Pathogen1

    PubMed Central

    Williams, Jane S.; Hall, Sharon A.; Hawkesford, Malcolm J.; Beale, Michael H.; Cooper, Richard M.

    2002-01-01

    The occurrence of fungicidal, elemental S is well documented in certain specialized prokaryotes, but has rarely been detected in eukaryotes. Elemental S was first identified in this laboratory as a novel phytoalexin in the xylem of resistant genotypes of Theobroma cacao, after infection by the vascular, fungal pathogen Verticillium dahliae. In the current work, this phenomenon is demonstrated in a resistant line of tomato, Lycopersicon esculentum, in response to V. dahliae. A novel gas chromatography-mass spectroscopy method using isotope dilution analysis with 34S internal standard was developed to identify unambiguously and quantify 32S in samples of excised xylem. Accumulation of S in vascular tissue was more rapid and much greater in the disease-resistant than in the disease-susceptible line. Levels of S detected in the resistant variety (approximately 10 μg g−1 fresh weight excised xylem) were fungitoxic to V. dahliae (spore germination was inhibited >90% at approximately 3 μg mL−1). Scanning electron microscopy-energy dispersive x-ray microanalysis confirmed accumulation of S in vascular but not in pith cells and in greater amounts and frequency in the Verticillium spp.-resistant genotype. More intensive localizations of S were occasionally detected in xylem parenchyma cells, vessel walls, vascular gels, and tyloses, structures in potential contact with and linked with defense to V. dahliae. Transient increases in concentrations of sulfate, glutathione, and Cys of vascular tissues from resistant but not susceptible lines after infection may indicate a perturbation of S metabolism induced by elemental S formation; this is discussed in terms of possible S biogenesis. PMID:11788760

  7. Kinetics of muscle deoxygenation are accelerated at the onset of heavy-intensity exercise in patients with COPD: relationship to central cardiovascular dynamics.

    PubMed

    Chiappa, Gaspar R; Borghi-Silva, Audrey; Ferreira, Leonardo F; Carrascosa, Claúdia; Oliveira, Cristino Carneiro; Maia, Joyce; Gimenes, Ana Cristina; Queiroga, Fernando; Berton, Danilo; Ferreira, Eloara M V; Nery, Luis Eduardo; Neder, J Alberto

    2008-05-01

    Patients with chronic obstructive pulmonary disease (COPD) have slowed pulmonary O(2) uptake (Vo(2)(p)) kinetics during exercise, which may stem from inadequate muscle O(2) delivery. However, it is currently unknown how COPD impacts the dynamic relationship between systemic and microvascular O(2) delivery to uptake during exercise. We tested the hypothesis that, along with slowed Vo(2)(p) kinetics, COPD patients have faster dynamics of muscle deoxygenation, but slower kinetics of cardiac output (Qt) following the onset of heavy-intensity exercise. We measured Vo(2)(p), Qt (impedance cardiography), and muscle deoxygenation (near-infrared spectroscopy) during heavy-intensity exercise performed to the limit of tolerance by 10 patients with moderate-to-severe COPD and 11 age-matched sedentary controls. Variables were analyzed by standard nonlinear regression equations. Time to exercise intolerance was significantly (P < 0.05) lower in patients and related to the kinetics of Vo(2)(p) (r = -0.70; P < 0.05). Compared with controls, COPD patients displayed slower kinetics of Vo(2)(p) (42 +/- 13 vs. 73 +/- 24 s) and Qt (67 +/- 11 vs. 96 +/- 32 s), and faster overall kinetics of muscle deoxy-Hb (19.9 +/- 2.4 vs. 16.5 +/- 3.4 s). Consequently, the time constant ratio of O(2) uptake to mean response time of deoxy-Hb concentration was significantly greater in patients, suggesting a slower kinetics of microvascular O(2) delivery. In conclusion, our data show that patients with moderate-to-severe COPD have impaired central and peripheral cardiovascular adjustments following the onset of heavy-intensity exercise. These cardiocirculatory disturbances negatively impact the dynamic matching of O(2) delivery and utilization and may contribute to the slower Vo(2)(p) kinetics compared with age-matched controls.

  8. Atmospheric DMS and Biogenic Sulfur aerosol measurements in the Arctic

    NASA Astrophysics Data System (ADS)

    Ghahremaninezhadgharelar, R.; Norman, A. L.; Wentworth, G.; Burkart, J.; Leaitch, W. R.; Abbatt, J.; Sharma, S.; Desiree, T. S.

    2014-12-01

    Dimethyl Sulfide (DMS) and its oxidation products were measured on the board of the Canadian Coast Guard Ship (CCGS) Amundsen and above melt ponds in the Arctic during July 2014 in the context of the NETCARE study which seeks to understand the effect of DMS and its oxidation products with respect to aerosol nucleation, as well as its effect on cloud and precipitation properties. The objective of this study is to quantify the role of DMS in aerosol growth and activation in the Arctic atmosphere. Atmospheric DMS samples were collected from different altitudes, from 200 to 9500 feet, aboard the POLAR6 aircraft expedition to determine variations in the DMS concentration and a comparison was made to shipboard DMS measurements and its effects on aerosol size fractions. The chemical and isotopic composition of sulfate aerosol size fractions was studied. Sulfur isotope ratios (34S/32S) offer a way to determine the oceanic DMS contribution to aerosol growth. The results are expected to address the contribution of anthropogenic as well as biogenic sources of aerosols to the growth of the different aerosol size fractions. In addition, aerosol sulfate concentrations were measured at the same time within precipitation and fogs to compare with the characteristics of aerosols in each size fraction with the characteristics of the sulfate in each medium. This measurement is expected to explain the contribution of DMS oxidation in aerosol activation in the Arctic summer. Preliminary results from the measurement campaign for DMS and its oxidation products in air, fog and precipitation will be presented.

  9. SIMS and NanoSIMS analyses of Mesoproterozoic individual microfossils indicating continuous oxygen-producing photosynthesis in Proterozoic Ocean

    NASA Astrophysics Data System (ADS)

    Peng, X.; Guo, Z.; House, C. H.; Chen, S.; Ta, K.

    2015-12-01

    Well-preserved microfossils in the stromatolites from the Gaoyuzhuang Formation (~1500Ma), which is younger than the Gunflint Formation (~1880Ma) and older than the Bitter Springs Formation (~850Ma), may play key roles in systematizing information about the evolution of early life and environmental changes in the Proterozoic Ocean. Here, a combination of light microscopy (LM), scanning electron microscopy (SEM), focused ion beam (FIB), nano-scale secondary ion mass spectrometry (NanoSIMS) and secondary ion mass spectrometry (SIMS) were employed to characterize the morphology, elemental distributions and carbon isotope values of individual microfossils in the stromatolites from the Gaoyuahzuang Formation. Light microscopy analyses show that abundant filamentous and coccoid microfossils are exceptionally well preserved in chert. NanoSIMS analyses show that metabolically important elements such as 12C-, 13C-, 12C14N-, 32S-, and 34S- are concentrated in these microfossils and that the variations in the concentrations of these elements are similar, establishing the elemental distributions in incontestably biogenic microstructures. Carbon isotope (δ13C) values of individual microfossils range from -32.2‰ ± 0.9‰ to -23.3‰ ± 1.0‰ (weighted mean= -28.9‰ ± 0.1‰), consistent with carbon fixation via the Calvin cycle. The elevated δ13C values of the microfossils from Early-, Meso- to Late Proterozoic Era, possibly indicate decreasing CO2 and increasing O2 concentrations in the Proterozoic atmosphere. Our results, for the first time, provided the element distributions and cell specific carbon isotope values on convincing Mesoproterozoic cyanobacterial fossils, supporting continuous oxygen-producing photosynthesis in the Proterozoic Ocean.

  10. NEW MASER EMISSION FROM NONMETASTABLE AMMONIA IN NGC 7538. II. GREEN BANK TELESCOPE OBSERVATIONS INCLUDING WATER MASERS

    SciTech Connect

    Hoffman, Ian M.; Seojin Kim, Stella

    2011-12-15

    We present new maser emission from {sup 14}NH{sub 3} (9,6) in NGC 7538. Our observations include the known spectral features near v{sub LSR} = -60 km s{sup -1} and -57 km s{sup -1} and several more features extending to -46 km s{sup -1}. In three epochs of observation spanning two months we do not detect any variability in the ammonia masers, in contrast to the >10-fold variability observed in other {sup 14}NH{sub 3} (9,6) masers in the Galaxy over comparable timescales. We also present observations of water masers in all three epochs for which emission is observed over the velocity range -105 km s{sup -1} < v{sub LSR} < -4 km s{sup -1}, including the highest velocity water emission yet observed from NGC 7538. Of the remarkable number of maser species in IRS 1, H{sub 2}O and, now, {sup 14}NH{sub 3} are the only masers known to exhibit emission outside of the velocity range -62 km s{sup -1} < v{sub LSR} < -51 km s{sup -1}. However, we find no significant intensity or velocity correlations between the water emission and ammonia emission. We also present a non-detection in the most sensitive search to date toward any source for emission from the CC{sup 32}S and CC{sup 34}S molecules, indicating an age greater than Almost-Equal-To 10{sup 4} yr for IRS 1-3. We discuss these findings in the context of embedded stellar cores and recent models of the region.

  11. Genetic diversity of Rhizobium from nodulating beans grown in a variety of Mediterranean climate soils of Chile.

    PubMed

    Baginsky, Cecilia; Brito, Belén; Scherson, Rosita; Pertuzé, Ricardo; Seguel, Oscar; Cañete, Alejandro; Araneda, Cristian; Johnson, Warren E

    2015-04-01

    In spite of potentially being an important source of rhizobial diversity and a key determinant of common bean productivity, there is a paucity of data on Rhizobium genetic variation and species composition in the important bean producing area of Chile and only one species has been documented (Rhizobium leguminosarum). In this study, 240 Rhizobium isolates from Torcaza bean (Phaseolus vulgaris L.) nodules established in the highest bean producing area in Chile (33°34'S-70°38'W and 37°36'S-71°47'W) were characterized by PCR-RFLP markers for nodC gene, revealing eight banding patterns with the polymorphic enzyme Hinf I. The locality of San Agustín de Aurora in Central Chile (35°32'S-71°29'W) had the highest level of diversity. Isolates were classified by species using PCR-RFLP markers for 16S rDNA gene and were confirmed by sequencing an internal fragment of the 16S rDNA gene. The results confirmed the presence of R. leguminosarum and three other species of rhizobia nodulating beans in South Central Chile (R. etli, R. tropici and R. leucaenae). R. tropici and R. leucaenae showed the least genetic variation and were most commonly identified in acid soils, while R. etli was the most common species in slightly acidic to moderately alkaline soils, with higher levels of organic matter content. R. leguminosarum was identified in almost all soils, was the most genetically diverse, and was the most common, being documented in soils with pH that ranged between 5.3 and 8.2, and with organic matter content between 2.1 and 4 %.

  12. Microbial sulfate reduction and metal attenuation in pH 4 acid mine water

    USGS Publications Warehouse

    Church, C.D.; Wilkin, R.T.; Alpers, C.N.; Rye, R.O.; Blaine, R.B.

    2007-01-01

    Sediments recovered from the flooded mine workings of the Penn Mine, a Cu-Zn mine abandoned since the early 1960s, were cultured for anaerobic bacteria over a range of pH (4.0 to 7.5). The molecular biology of sediments and cultures was studied to determine whether sulfate-reducing bacteria (SRB) were active in moderately acidic conditions present in the underground mine workings. Here we document multiple, independent analyses and show evidence that sulfate reduction and associated metal attenuation are occurring in the pH-4 mine environment. Water-chemistry analyses of the mine water reveal: (1) preferential complexation and precipitation by H2S of Cu and Cd, relative to Zn; (2) stable isotope ratios of 34S/32S and 18O/16O in dissolved SO4 that are 2-3 ??? heavier in the mine water, relative to those in surface waters; (3) reduction/oxidation conditions and dissolved gas concentrations consistent with conditions to support anaerobic processes such as sulfate reduction. Scanning electron microscope (SEM) analyses of sediment show 1.5-micrometer, spherical ZnS precipitates. Phospholipid fatty acid (PLFA) and denaturing gradient gel electrophoresis (DGGE) analyses of Penn Mine sediment show a high biomass level with a moderately diverse community structure composed primarily of iron- and sulfate-reducing bacteria. Cultures of sediment from the mine produced dissolved sulfide at pH values near 7 and near 4, forming precipitates of either iron sulfide or elemental sulfur. DGGE coupled with sequence and phylogenetic analysis of 16S rDNA gene segments showed populations of Desulfosporosinus and Desulfitobacterium in Penn Mine sediment and laboratory cultures. ?? 2007 Church et al; licensee BioMed Central Ltd.

  13. Is white clover able to switch to atmospheric sulphur sources when sulphate availability decreases?

    PubMed

    Varin, Sébastien; Lemauviel-Lavenant, Servane; Cliquet, Jean-Bernard

    2013-05-01

    Sulphur (S) is one of the very few nutrients that plants can absorb either through roots as sulphate or via leaves in a gas form such as SO2 or H2S. This study was realized in a non-S-enriched atmosphere and its purpose was to test whether clover plants can increase their ability to use atmospheric S when sulphate availability decreases. A novel methodology measuring the dilution of (34)S provided from a nutrient solution by atmospheric (32)S was developed to measure S acquisition by Trifolium repens L. Clones of white clover were grown for 140 d in a hydroponic system with three levels of sulphate concentrations. S concentration in plants decreased with S deficiency and plant age. In the experimental conditions used here, S derived from atmospheric deposition (Sdad) constituted from 36% to 100% of the total S. The allocation of S coming from atmospheric and pedospheric sources depends on organs and compounds. Nodules appeared as major sinks for sulphate. A greater proportion of atmospheric S was observed in buffer-soluble proteins than in the insoluble S fraction. Decreasing the S concentration in the nutrient solution resulted in an increase in the Sdad:leaf area ratio and in an increase in the leaf:stolon and root:shoot mass ratios, suggesting that a plasticity in the partitioning of resources to organs may allow a higher gain of S by both roots and leaves. This study shows that clover can increase its ability to use atmospheric S even at low concentration when pedospheric S availability decreases.

  14. Mass-independent sulfur isotopic compositions in stratospheric volcanic eruptions.

    PubMed

    Baroni, Mélanie; Thiemens, Mark H; Delmas, Robert J; Savarino, Joël

    2007-01-05

    The observed mass-independent sulfur isotopic composition (Delta33S) of volcanic sulfate from the Agung (March 1963) and Pinatubo (June 1991) eruptions recorded in the Antarctic snow provides a mechanism for documenting stratospheric events. The sign of Delta33S changes over time from an initial positive component to a negative value. Delta33S is created during photochemical oxidation of sulfur dioxide to sulfuric acid on a monthly time scale, which indicates a fast process. The reproducibility of the results reveals that Delta33S is a reliable tracer to chemically identify atmospheric processes involved during stratospheric volcanism.

  15. Isotopic mass independent signature of black crusts: a proxy for atmospheric aerosols formation in the Paris area (France).

    NASA Astrophysics Data System (ADS)

    Genot, Isabelle; Martin, Erwan; Yang, David Au; De Rafelis, Marc; Cartigny, Pierre; Wing, Boswell; Le Gendre, Erwann; Bekki, Slimane

    2016-04-01

    In view of the negative forcing of the sulfate aerosols on climate, a more accurate understanding of the formation of these particles is crucial. Indeed, despite the knowledge of their effects, uncertainties remain regarding the formation of sulfate aerosols, particularly the oxidation processes of S-bearing gases. Since the discovery of oxygen and sulfur mass independent fractionation (O- and S-MIF) processes on Earth, the sulfate isotopic composition became essential to investigate the atmospheric composition evolution and its consequences on the climate and the biosphere. Large amount of S-bearing compounds (SO2 mainly) is released into the atmosphere by anthropogenic and natural sources. Their oxidation in the atmosphere generates sulfate aerosols, H2SO4, which precipitate on the earth surface mainly as acid rain. One consequence of this precipitation is the formation of black crust on buildings made of carbonate stones. Indeed the chemical alteration of CaCO3 by H2SO4 leads to gypsum (CaSO4·2H2O) concretions on building walls. Associated to other particles, gypsum forms black-crusts. Therefore, black crusts acts as 'sulfate aerosol traps', meaning that their isotopic composition reveals the composition and thus the source and formation processes of sulfate aerosols in the atmosphere in a specific region. In this study we collected 37 black crusts on a 300km NW-SE profile centered on Paris (France). In our samples, sulfate represent 40wt.% and other particles 60wt.% of the black crusts. After sulfate extraction from each samples we measured their O- and S-isotopes composition. Variations of about 10‰ in δ18O and δ34S are observed and both O-MIF (Δ17O from 0 to 1.4‰) and S-MIF (Δ33S from 0 to -0.3‰) compositions have been measured. In regards to these compositions we can discuss the source and formation (oxidation pathways) of the sulfate aerosols in troposphere above the Paris region that covers urban, rural and coastal environments. Furthermore

  16. Microbial mediated formation of low-temperature hydrothermal barite chimneys

    NASA Astrophysics Data System (ADS)

    Thorseth, I. H.; Steen, I. H.; Eickmann, B.; Dahle, H.; Baumberger, T.; Peters, M.; Strauss, H.; Pedersen, R. B.

    2012-12-01

    A low-temperature (20 degrees C) venting area with numerous active and extinct barite chimneys (up to 1 m tall) are located on the eastern flank of the hydrothermal mound of Loki's Castle black smoker field at the Mohns-Knipovich bend of the Arctic Mid-Ocean Ridge. The active barite chimneys are covered by white mats containing abundant microbial cells and extracellular material with attached barite crystals. Within the chimneys microbial cells are partly embedded in barite and crystals are covered by extracellular material. These observations indicate that the microbial material serve as a substrate for nucleation and precipitation of barite with the potential of having an important control on the construction of the chimneys. In addition, the presence of framboidal pyrite in black interior flow channels and in the underlying hydrothermal sediment further suggests that the chimney formation is linked to microbial sulphate reduction (MSR). To further investigate the relationship between chimney growth and microbial activity we used a combination of biomolecular and isotope analyses. Pyrosequencing of PCR amplicons of 16S rRNA followed by taxonomic classification revealed that sulphide oxidizers (Sulfurimonas) within the Epsilonproteobacteria dominate the microbial mats and the white barite of the chimney wall. In the black interior flow channel a more diverse microbial community was observed indicating methane, sulphur and ammonia oxidation as well as heterotrophic processes. Multiple isotope analyses (δ18O, δ34S, Δ33S) reveal that the barite chimneys precipitated from a fluid that was modified by subseafloor MSR in the sulphide mound. This is supported by the sulphur isotope signature of the framboidal pyrite, pore water, and mono- and disulphides extracted from the hydrothermal sediment as well as the biomolecular data. We suggest that the MSR was triggered by mixing of the H2 and CH4 rich high-temperature (320 degrees C) fluids and percolating seawater, which

  17. Endothelial dysfunction following prolonged sitting is mediated by a reduction in shear stress.

    PubMed

    Restaino, Robert M; Walsh, Lauren K; Morishima, Takuma; Vranish, Jennifer R; Martinez-Lemus, Luis A; Fadel, Paul J; Padilla, Jaume

    2016-03-01

    We and others have recently reported that prolonged sitting impairs endothelial function in the leg vasculature; however, the mechanism(s) remain unknown. Herein, we tested the hypothesis that a sustained reduction in flow-induced shear stress is the underlying mechanism by which sitting induces leg endothelial dysfunction. Specifically, we examined whether preventing the reduction in shear stress during sitting would abolish the detrimental effects of sitting on popliteal artery endothelial function. In 10 young healthy men, bilateral measurements of popliteal artery flow-mediated dilation were performed before and after a 3-h sitting period during which one foot was submerged in 42°C water (i.e., heated) to increase blood flow and thus shear stress, whereas the contralateral leg remained dry and served as internal control (i.e., nonheated). During sitting, popliteal artery mean shear rate was reduced in the nonheated leg (pre-sit, 42.9 ± 4.5 s(-1); and 3-h sit, 23.6 ± 3.3 s(-1); P < 0.05) but not in the heated leg (pre-sit, 38.9 ± 3.4 s(-1); and 3-h sit, 63.9 ± 16.9 s(-1); P > 0.05). Popliteal artery flow-mediated dilation was impaired after 3 h of sitting in the nonheated leg (pre-sit, 7.1 ± 1.4% vs. post-sit, 2.8 ± 0.9%; P < 0.05) but not in the heated leg (pre-sit: 7.3 ± 1.5% vs. post-sit, 10.9 ± 1.8%; P > 0.05). Collectively, these data suggest that preventing the reduction of flow-induced shear stress during prolonged sitting with local heating abolishes the impairment in popliteal artery endothelial function. Thus these findings are consistent with the hypothesis that sitting-induced leg endothelial dysfunction is mediated by a reduction in shear stress.

  18. Triple oxygen and sulfur isotope analyses of sulfate extracted from voluminous volcanic ashes in the Oligocene John Day Formation: insight into dry climate conditions and ozone contribution to supereruptions

    NASA Astrophysics Data System (ADS)

    Workman, J.; Bindeman, I. N.; Martin, E.; Retallack, G.; Palandri, J. L.; Weldon, N.

    2014-12-01

    Large volume pyroclastic silicic eruptions emit hundreds of megatons of SO2 into the troposphere and stratosphere that is oxidized into sulfuric acid (H2SO4) by a variety of reactions with mass independent oxygen signatures (MIF), Δ17O>0. Sulfuric acid is then preserved as gypsum in parental volcanic deposits. Diagenic effects are mass dependent and can dilute, but otherwise do not affect MIF ratios. Pleistocene Yellowstone and Bishop tuffs and modern volcanic eruptions preserved under arid climate conditions in North American playa lakes, preserve small amounts of volcanic sulfate as gypsum. This gypsum's Δ17O>0, in combination with isotopic variations of δ18O, δ33S and δ34S is distinct from sedimentary sulfate and reveals its original MIF sulfate isotopic signal and the effect of super eruptions on the atmosphere, and ozone consumption in particular. We use linear algebraic equations to resolve volcanic versus sedimentary (MIF=0) sources. We have found that many large volume ignimbrites have very high initial Δ17O in volcanic sulfate that can only be acquired from reaction with stratospheric ozone. We here investigate nine thick (>2 m) ash beds ranging in age from ~33-23 Ma in the John Day Formation of central Oregon, including massive 28.6 Ma Picture Gorge tuff of newly identified Crooked River supercaldera. The 28.6 Ma Picture Gorge tuff (PGT) has the highest measured Δ17O of 3.5‰, and other tuffs (Tin Roof, Biotite, Deep Creek) have +1.3 to 3.4‰ Δ17O excesses. Sulfate from modern smaller tropospheric eruptions studied for comparison have a resolvable 0.4‰ range consistent with liquid-phase based H2O2 oxidation. The PGT is coeval with the ignimbrite flare-up in western N. America, the 28-29 Ma eruption of the 5000 km3 Fish Canyon tuff and the 28 Ma Never Summer Field eruption in Nebraska-Colorado that have the highest measured Δ17O of 6‰ (Bao et al. 2003). We speculate on the climatic/atmospheric effects of these multiple ~28 Ma supereruptions

  19. Measurements of radioactive and stable sulfur isotopes at Mt. Everest and its geochemical implications

    NASA Astrophysics Data System (ADS)

    Lin, M.; Thiemens, M. H.; Zhang, Q.; Li, C.; Kang, S.; Hsu, S. C.; Zhang, Z.; Su, L.

    2015-12-01

    The Himalayas were recently identified as a global hotspot for deep stratosphere-to-troposphere transport (STT) during spring [1]. Although STT transport in this region may play a vital role in tropospheric chemistry, the hydrological cycle and aquatic ecosystems in Asia, there is no direct measurement of a specific chemical stratospheric tracer to verify and evaluate its possible impact. Here, cosmogenic 35S tracer (half-life: ~87 days) produced in the stratosphere was measured for the first time in surface snow and river runoff samples collected at Mt. Everest in April 2013 using a low-noise liquid scintillation spectroscopy [2]. Strikingly, we find extraordinarily high concentrations of 35S in these samples (>10 times higher than the southern Tibetan Plateau), verifying the Himalayas as a gateway of springtime STT. In light of this, two studies were conducted: a) Measurements of 35SO2 and 35SO42- at the southern Tibetan Plateau reveals that the oxidative life time of SO2 is reduced to 2.1 days under the influence of aged stratospheric air masses from the Himalayas. A concept box model for estimating the influence of STT on surface O3 using 35S tracer is proposed. b) Quadruple stable sulfur isotopes in a sediment core (~250 years) from the Gokyo Lake (the world's highest freshwater lake) [3] near Mt. Everest are being measured to investigate the possible impact of STT on sulfur budget at the Himalayas. The absence of sulfide suggests that bacterial sulfate reduction may be negligible in this lake. Enrichment of uranium (EF ≈ 10) in 20th century samples highlights the impact of atmospheric deposition. S-isotope sulfate anomalies are not found (∆33S and ∆36S ≈ 0‰), implying that sulfate in this lake may be mainly contributed by eolian dust or derived from rock. This is also supported by the low enrichments of most trace elements (EF ≈ 1). Rare earth elements will be used to assist in identifying the potential sources and interpreting the variation of

  20. A Precambrian-Cambrian oil play in southern Utah

    SciTech Connect

    Lillis, P.G.; Palacas, J.G.; Warden, A.

    1995-06-01

    The potential of the Precambrian Chuar Group as a petroleum source rock in southern Utah and northern Arizona resulted in the drilling of two wildcat wells in 1994. Both wells penetrated the Cambrian Tapeats Sandstone (the target reservoir rock) and presumably Precambrian rocks. The first well, Burnett Federal 36-1, was drilled east of Kanab, Utah (sec.36, T.34S., R.3W.) to a total depth of 5,365 ft and encountered Precambrian (?) reddish-brown sedimentary rocks at 4,790 ft. The Tapeats Sandstone had live oil shows and minor CO{sub 2} (?) gas shows. The second well, BHP Federal 28-1, was drilled near Capitol Reef (sec.28, T.33S., R.7E.) to a total depth of 6,185 ft and encountered the Tapeats Sandstone at 5,922 ft and Precambrian (?) phyllite at 6,125 ft. The upper Paleozoic rocks had abundant live oil/tar shows, and the Cambrian Bright Angel Shale and Tapeats Sandstone had numerous oil shows. There were no gas shows in the well except for a large CO{sub 2} gas kick in the Tapeats Sandstone. A drill-stem test from 5,950 to 6,185 ft yielded mostly CO{sub 2} (92%) and nitrogen gas (6%) and minor amounts of helium, argon, hydrogen, and methane. The {delta}{sup 13}C of the CO{sub 2} is -3.9 per mil PDB. The chemical composition of the extracted oil in the Cambrian sandstones is significantly different than oils produced from the Upper Valley field (upper Paleozoic reservoirs) and the tar sands that are widespread throughout southern and central Utah. However, the oil composition is similar in several aspects to the composition of some of the Precambrian Chuar Group bitumen extracts from the Grand Canyon area in Arizona. The encouraging features of both wells are the good reservoir characteristics and oil shows in the Tapeats Sandstone. In the BHP well the oil appears to be a new oil type, possibly derived from Precambrian or Cambrian source rocks.

  1. Tracing sources of crustal contamination using multiple S and Fe isotopes in the Hart komatiite-associated Ni-Cu-PGE sulfide deposit, Abitibi greenstone belt, Ontario, Canada

    NASA Astrophysics Data System (ADS)

    Hiebert, R. S.; Bekker, A.; Houlé, M. G.; Wing, B. A.; Rouxel, O. J.

    2016-10-01

    Assimilation by mafic to ultramafic magmas of sulfur-bearing country rocks is considered an important contributing factor to reach sulfide saturation and form magmatic Ni-Cu-platinum group element (PGE) sulfide deposits. Sulfur-bearing sedimentary rocks in the Archean are generally characterized by mass-independent fractionation of sulfur isotopes that is a result of atmospheric photochemical reactions, which produces isotopically distinct pools of sulfur. Likewise, low-temperature processing of iron, through biological and abiotic redox cycling, produces a range of Fe isotope values in Archean sedimentary rocks that is distinct from the range of the mantle and magmatic Fe isotope values. Both of these signals can be used to identify potential country rock assimilants and their contribution to magmatic sulfide deposits. We use multiple S and Fe isotopes to characterize the composition of the potential iron and sulfur sources for the sulfide liquids that formed the Hart deposit in the Shaw Dome area within the Abitibi greenstone belt in Ontario (Canada). The Hart deposit is composed of two zones with komatiite-associated Ni-Cu-PGE mineralization; the main zone consists of a massive sulfide deposit at the base of the basal flow in the komatiite sequence, whereas the eastern extension consists of a semi-massive sulfide zone located 12 to 25 m above the base of the second flow in the komatiite sequence. Low δ56Fe values and non-zero δ34S and Δ33S values of the komatiitic rocks and associated mineralization at the Hart deposit is best explained by mixing and isotope exchange with crustal materials, such as exhalite and graphitic argillite, rather than intrinsic fractionation within the komatiite. This approach allows tracing the extent of crustal contamination away from the deposit and the degree of mixing between the sulfide and komatiite melts. The exhalite and graphitic argillite were the dominant contaminants for the main zone of mineralization and the eastern

  2. Multiple S isotopes, zircon Hf isotopes, whole-rock Sr-Nd isotopes, and spatial variations of PGE tenors in the Jinchuan Ni-Cu-PGE deposit, NW China

    NASA Astrophysics Data System (ADS)

    Duan, Jun; Li, Chusi; Qian, Zhuangzhi; Jiao, Jiangang; Ripley, Edward M.; Feng, Yanqing

    2016-04-01

    Previous geochemical data for the Jinchuan Ni-Cu-(platinum-group elements, PGE) deposit, the single largest magmatic sulfide deposit in the world, are derived primarily from the upper parts of the deposit. This paper reports new PGE and S-Hf-Sr-Nd isotope data for the lower parts of the deposit that have become accessible for sampling by ongoing underground mining activity. New PGE data from this study, together with previous results, indicate that PGE tenors in the bulk sulfide ores of the deposit increase eastward, except for two fault-offset ore zones which occur together within the western part of the deposit. Generally, these two ore zones show depletions in IPGE (Ir, Ru, Rh) but not in PPGE (Pt, Pd) and Cu, and more fractionated olivine and Cr-spinel compositions than the rest of the deposit. These differences can be explained by a more evolved parental magma for the IPGE-depleted ore zones. The eastward increase of PGE tenors in the rest of the deposit can be explained by upgrading of preexisting sulfide liquid in a subhorizontal conduit by a new surge of magma moving through the conduit from west to east, which took place before the formation of the IPGE-depleted ore zones. The Jinchuan ultramafic rocks are characterized by elevated initial 87Sr/86Sr ratios from 0.7077 to 0.7093, negative ɛ Nd values from -9.2 to -10.5, and zircon ɛ Hf values from -4 to -7. These data indicate up to 20 % of crustal contamination in the Jinchuan magma. Four of nine multiple sulfur isotope analyses for the Jinchuan deposit show anomalous ∆33S values varying from 0.12 to 2.67 ‰. These results, together with elevated δ34S values (>2 ‰) for some of the samples analyzed previously by other researchers, indicate the involvement of external sulfur from Archean and Proterozoic sedimentary rocks. Modeling results based on our olivine data and magma compositions estimated previously by other researchers indicate that fractional crystallization did not play a major role in

  3. Barite in hydrothermal environments as a recorder of subseafloor processes: a multiple-isotope study from the Loki's Castle vent field.

    PubMed

    Eickmann, B; Thorseth, I H; Peters, M; Strauss, H; Bröcker, M; Pedersen, R B

    2014-07-01

    Barite chimneys are known to form in hydrothermal systems where barium-enriched fluids generated by leaching of the oceanic basement are discharged and react with seawater sulfate. They also form at cold seeps along continental margins, where marine (or pelagic) barite in the sediments is remobilized because of subseafloor microbial sulfate reduction. We test the possibility of using multiple sulfur isotopes (δ34S, Δ33S, ∆36S) of barite to identify microbial sulfate reduction in a hydrothermal system. In addition to multiple sulfur isotopes, we present oxygen (δ18O) and strontium (87Sr/86Sr) isotopes for one of numerous barite chimneys in a low-temperature (~20 °C) venting area of the Loki's Castle black smoker field at the ultraslow-spreading Arctic Mid-Ocean Ridge (AMOR). The chemistry of the venting fluids in the barite field identifies a contribution of at least 10% of high-temperature black smoker fluid, which is corroborated by 87Sr/86 Sr ratios in the barite chimney that are less radiogenic than in seawater. In contrast, oxygen and multiple sulfur isotopes indicate that the fluid from which the barite precipitated contained residual sulfate that was affected by microbial sulfate reduction. A sulfate reduction zone at this site is further supported by the multiple sulfur isotopic composition of framboidal pyrite in the flow channel of the barite chimney and in the hydrothermal sediments in the barite field, as well as by low SO4 and elevated H2S concentrations in the venting fluids compared with conservative mixing values. We suggest that the mixing of ascending H2- and CH4-rich high-temperature fluids with percolating seawater fuels microbial sulfate reduction, which is subsequently recorded by barite formed at the seafloor in areas where the flow rate is sufficient. Thus, low-temperature precipitates in hydrothermal systems are promising sites to explore the interactions between the geosphere and biosphere in order to evaluate the microbial impact on

  4. Response Allocation in Concurrent Chains when Terminal-Link Delays Follow an Ascending and Descending Series

    ERIC Educational Resources Information Center

    Christensen, Darren R.; Grace, Randolph C.

    2009-01-01

    Eight pigeons were trained in a concurrent-chains procedure in which the terminal-link immediacy ratio followed an ascending or descending series. Across sessions, one terminal-link delay changed from 2 s to 32 s to 2 s or from 32 s to 2 s to 32 s, while the other was always 8 s. For all pigeons, response allocation tracked changes in delay and…

  5. High Resolution Cl and S Isotope Analyses in Rocks and Minerals Using NanoSIMS

    NASA Astrophysics Data System (ADS)

    Kagoshima, T.; Takahata, N.; Ishida, A.; Sano, Y.

    2014-12-01

    We have developed highly spatial resolution isotope analysis with cycling magnetic fields on NanoSIMS 50 (Cameca, Gennevilliers, France) housed at Atmosphere and Ocean Research Institute, Japan. This technique requires two unmovable EM detectors (EM1 and EM2) and three magnetic fields (B1, B2, and B3). For Cl measurements, the following configuration was applied: (B1-EM1) 35Cl-; (B2-EM1) 37Cl-; (B2-EM2) 35Cl-; (B3-EM2) 37Cl-, in the form of "(B and EM configurations) target ions" (Table 1). When magnetic fields are in a cycling mode and moving next to next, we can obtain three isotopic ratios from the same spot: 37ClEM1/35ClEM1, 37ClEM2/35ClEM2, and 37ClEM1/35ClEM2 where subscripts show corresponding detectors. Considering the average of 37ClEM1/35ClEM1 and 37ClEM2/35ClEM2, reproducibility gets higher because total counts increase and analytical artifacts due to difference between detectors' sensitivity are offset. 10-μm spots were used for analyses. Reproducibility of 37Cl/35Cl in an apatite crystal from Imilchil/Errachidia region in Morroco was 1.1‰ (1σ; N=10), and that in RY380-R03b (EPR basalt: 17.4S, 113.2W) was 1.3‰ (1σ; N=8). These values may be small enough to evaluate aqueous alteration on mantle-derived materials because it causes 6‰ variation in reaction related reservoirs such as sediments and pore fluids[1]. There were no apparent correlations between Cl contents and 37Cl/35Cl in RY380-R03b, supporting that strong correlations between them found in MORB by a pyrohydrolysis method[2] may be analytical artifacts[1]. We also measured S isotope ratios based on the same method as Cl. 5-μm spots were used for analyses. Reproducibility of 34S/32S in a pyrite crystal from Udo mine in Japan[3] was 1.8‰ (1σ; N=6), and that in CH98 DR12 (MAR basalt: 30.1N, 41.9W) was 1.7‰ (1σ; N=5). These values are small enough to evaluate S fractionation or mixing in the basalt-seawater system which have 20‰ difference in δ34S. This technique will enable us

  6. Submillimetric study of nearby galaxies: A tool for new extragalactic molecules

    NASA Astrophysics Data System (ADS)

    Villicana Pedraza, Ilhuiyolitzin; Guesten, Rolf; Armijos Abendaño, Jairo; Carreto, Francisco; Martin, Sergio; Martin-Pintado, Jesus; Requena-Torres, Miguel; Perez-Beaupuits, Juan Pablo

    2016-07-01

    We present the first submillimetre line survey of extragalactic sources carried out by APEX, the results were presented inside of Villicana-Pedraza phd thesis in 2015. The surveys cover the 0.8 mm atmospheric window toward NGC253, NGC4945 and Arp220. We found HCN, C2H, CN, CS, C34S, HCO+, HNC, CO, N2H+, CH3OH are presents in all the sources, while 13CO,C18O and C17O, HNCO, H2CO, H2CS, SO, NO, SO2 were detected toward NGC253 and NGC4945, 13CN, *CO+, OCS, H2S in Arp220, 13CS, NH2CN, SiO in NGC253, and c-C3H2 in NGC4945 were detected. Column densities and rotation temperatures have been determinate using the Local Thermodinamical Equilibrium(LTE) line profile simulation and fitting in the MADCUBA IJ software. The differences found in the 32S/34S and 18O/17O ratios between the GC and the starburst galaxies NGC 4945 and NGC 253 suggest that the gas is less processed in the latter than in the GC. The high 18O/17O ratios in the galaxies NGC 4945 and NGC 253 suggest also material less processed in the nuclei of these galaxies than in the GC. This is consistent with the claim that 17O is a more representative primary product than 18O in stellar nucleosynthesis (Wilson and Rood 1994); Also, we did a Multitransitions study of H3O+ at 307GHz, 364GHz, 388GHz and 396GHz. From our non-LTE analysis of H3O+ in NGC253 with RADEX we found that the collisional excitation cannot explain the observed intensity of the ortho 396 GHz line. Excitation by radiation from the dust in the Far-IR can roughly explain the observations if the H2 densities are relatively low. From the derived H3O+ column densities we conclude that the chemistry of this molecule is dominated by ionization produce by the starburst in NGC253 (UV radiation from the O stars) and Arp 220 (cosmic rays from the supernovae) and likely from the AGN in NGC4549 (X-rays ); We report, for the first time, the tentative detection of the molecular ion HCNH+ (precursor of HCN and HNC) toward a galaxy, NGC4945, the abundance is much

  7. STELLAR ORIGINS OF EXTREMELY {sup 13}C- AND {sup 15}N-ENRICHED PRESOLAR SIC GRAINS: NOVAE OR SUPERNOVAE?

    SciTech Connect

    Liu, Nan; Nittler, Larry R.; Alexander, Conel M. O’D.; Wang, Jianhua; Pignatari, Marco; José, Jordi; Nguyen, Ann

    2016-04-01

    Extreme excesses of {sup 13}C ({sup 12}C/{sup 13}C < 10) and {sup 15}N ({sup 14}N/{sup 15}N < 20) in rare presolar SiC grains have been considered diagnostic of an origin in classical novae, though an origin in core collapse supernovae (CCSNe) has also been proposed. We report C, N, and Si isotope data for 14 submicron- to micron-sized {sup 13}C- and {sup 15}N-enriched presolar SiC grains ({sup 12}C/{sup 13}C < 16 and {sup 14}N/{sup 15}N < ∼100) from Murchison, and their correlated Mg–Al, S, and Ca–Ti isotope data when available. These grains are enriched in {sup 13}C and {sup 15}N, but with quite diverse Si isotopic signatures. Four grains with {sup 29,30}Si excesses similar to those of type C SiC grains likely came from CCSNe, which experienced explosive H burning occurred during explosions. The independent coexistence of proton- and neutron-capture isotopic signatures in these grains strongly supports heterogeneous H ingestion into the He shell in pre-supernovae. Two of the seven putative nova grains with {sup 30}Si excesses and {sup 29}Si depletions show lower-than-solar {sup 34}S/{sup 32}S ratios that cannot be explained by classical nova nucleosynthetic models. We discuss these signatures within the CCSN scenario. For the remaining five putative nova grains, both nova and supernova origins are viable because explosive H burning in the two stellar sites could result in quite similar proton-capture isotopic signatures. Three of the grains are sub-type AB grains that are also {sup 13}C enriched, but have a range of higher {sup 14}N/{sup 15}N. We found that {sup 15}N-enriched AB grains (∼50 < {sup 14}N/{sup 15}N < ∼100) have distinctive isotopic signatures compared to putative nova grains, such as higher {sup 14}N/{sup 15}N, lower {sup 26}Al/{sup 27}Al, and lack of {sup 30}Si excess, indicating weaker proton-capture nucleosynthetic environments.

  8. Calculation of the properties of the S3- radical anion and its complexes with Cu+ in aqueous solution

    NASA Astrophysics Data System (ADS)

    Tossell, J. A.

    2012-10-01

    A species observed in aqueous sulfidic solutions at high T and P has recently been identified as the anion radical S3-, based on the Raman spectrum obtained in a hydrothermal diamond-anvil cell (Pokrovski and Dubrovinsky, 2011, Science, 331, 1052-1054). Such a species had not been expected to occur in such environments, although S3- as an component of lapis lazuli, other solids and even albite melt has been well studied (Winther et al., 1998; Reinen and Lindner, 1999; Arieli et al., 2004; Shnitko et al., 2008; Bacci et al., 2009). We have calculated the structures, energetics, vibrational and UV-visible spectra of S3- and several other similar species and confirm the species identification of Pokrovski and Dubrovinsky, although we are still somewhat concerned about the apparent lack of a third peak which we calculate to be present in the Raman spectrum of S3-. Our calculations indicate that the reaction: S6-2⇒2S3- in aqueous solution has a free energy change of +3 kcal/mol at 298 K and 1 atm pressure but -13 kcal/mol at 723 K and 1 atm pressure, consistent with the disappearance of disulfide species and the appearance of S3-at high T. Likewise, the free energy for the reaction: 2HS+SO4-2+H⇒S3-+.75O+2.5HO decreases from 44.1 to 19.0 kcal/mol between 298 and 723 K (again at 1 atm). This is consistent with the decrease in concentrations of SH- and SO4-2 and the formation of S3- observed by Pokrovski and Dubrovinski over this temperature range. The corresponding log K values are in semiquantitative agreement with those found by Pokrovski and Dubrovinsky. The main contribution to these changes in reaction free energy with temperature come from the VRT (vibrational-rotational-translational) contribution to the gas-phase free energy, while the hydration free energy difference changes little. Calculation of 34S-32S isotopic fractionations for S3- at 298 K give δ values of around +4.3% relative to H2S, a value intermediate between that of S3 and S3-2. Calculated free

  9. Gusev-Meridiani-Type Soil Component Dissolved in Some Shock Glasses in Shergottites

    NASA Technical Reports Server (NTRS)

    Ross, D. K.; Rao, M. N.; Nyquist, L. E.; Shi, C. Y.; Sutton, S.; Harrison, D. H.

    2015-01-01

    Modal analysis, based on APXS, MiniTES and Mossbauer results obtained at Gusev and Meridiani sites on Mars, indicates that Martian soils consist predominantly of igneous minerals such as olivine, pyroxene and feldspar (approximately70 - 80%), with the balance consisting of alteration minerals such as sulfates, silica and chlorides]. These studies also showed that soil alteration did not occur in-situ and igneous and alteration components are derived from different sources. Below, we analyse the chemical abundance data obtained from shock glasses in shergottites using mass balance mixing models. In these models, the two main end members used are (a) host rock chemical composition and (b) the GM soils average composition as the second component. Here, we consider the S-bearing phases as indicators of added alteration phases in the shock glasses and GM soils. Although the S-bearing phase in shock glasses occurs as micron sized sulfide blebs, we showed in earlier abstracts that sulfur was originally present as sulfate in impact glass-precursor materials and was subsequently reduced to sulfide during shock melting. This conclusion is based on results obtained from S-K XANES studies, Fe/S atomic ratios in sulfide blebs and 34S/32S isotopic measurements in these sulfide blebs. Additionally, sulfur in several EET79001 Lith. A glasses is found to correlate positively with Al2O3 and CaO (and negatively with FeO and MgO), suggesting the presence of Al- and Ca- sul-fate-bearing phases. The distribution of the 87Sr/86Sr iso-topic ratios determined in Lith. A glasses (,27 &,188 and,54) indicate that Martian soil gypsum and host rock material were mixed with each other in the glass precursors. In some vugs in Lith A glass,27 detected gypsum laths. Furthermore, the Martian regolith-de-rived component (where sulfur typically occurs as sul-fate) is identified in these glasses by determining neutron produced isotopic excesses/deficits in 80Kr and 149Sm isotopes. Moreover, the

  10. A Coordinated Research Project on the Implementation of Nuclear Techniques to Improve Food Traceability

    NASA Astrophysics Data System (ADS)

    Frew, Russell; Cannavan, Andrew; Zandric, Zora; Maestroni, Britt; Abrahim, Aiman

    2013-04-01

    coffee, the adulteration of milk with soy protein, chemical contamination of food products, and inhomogeneity in isotopic ratios in poultry and eggs as a means to determine production history. Analytical techniques include stable isotope ratio measurements (2H/1H, 13C/12C, 15N/14N, 18O/16O, 34S/32S, 87Sr/86Sr, 208Pb/207Pb/206Pb), elemental analysis, DNA fingerprinting, fatty acid and other biomolecule profiling, chromatography-mass spectrometry and near infra-red spectroscopy.

  11. Geochemistry of sulfur in the Florida Everglades; 1994 through 1999

    USGS Publications Warehouse

    Bates, Anne L.; Orem, W.H.; Harvey, J.W.; Spiker, E. C.

    2000-01-01

    In this report, we present data on the geochemistry of sulfur in sediments and in surface water, groundwater, and rainwater in the Everglades region in south Florida. The results presented here are part of a larger study intended to determine the roles played by the cycling of carbon, nitrogen, phosphorus, and sulfur in the ecology of the south Florida wetlands. The geochemistry of sulfur in the region is particularly important because of its link to the production of toxic methylmercury through processes mediated by sulfate reducing bacteria. Sediment cores were collected from the Everglades Agricultural Area (EAA), Water Conservation Areas (WCAs) 1A and 2A, from Lake Okeechobee, and from Taylor Slough in the southern Everglades. Water collection was more widespread and includes surface water from WCAs 1A, 2A, 3A, 2B, the EAA, Taylor Slough, Lake Okeechobee, and the Kissimmee River. Groundwater was collected from The Everglades Nutrient Removal Area (ENR) and from WCA 2A. Rainwater was collected at two month intervals over a period of one year from the ENR and from WCA 2A. Water was analyzed for sulfate concentration and sulfate sulfur stable isotopic ratio (34S/32S). Sediment cores were analyzed for total sulfur concentration and/or for concentrations of sulfur species (sulfate, organic sulfur, disulfides, and acid volatile sulfides (AVS)) and for their stable sulfur isotopic ratio. Results show a decrease in total sulfur content (1.57 to 0.61 percent dry weight) with depth in two sediment cores collected in WCA 2A, indicating that there has been an increase in total sulfur content in recent times. A sediment core from the center of Lake Okeechobee shows a decrease in total sulfur content with depth (0.28 to 0.08 percent dry weight). A core from the periphery of the lake (South Bay) likewise shows a decrease in total sulfur content with depth (1.00 to 0.69 percent dry weight), however, the overall sulfur content is greater than that near the center at all depths

  12. Clinically relevant multidrug resistant Salmonella enterica in swine and meat handlers at the abattoir.

    PubMed

    Gomes-Neves, Eduarda; Antunes, Patrícia; Manageiro, Vera; Gärtner, Fátima; Caniça, Manuela; da Costa, José Manuel Correia; Peixe, Luísa

    2014-01-10

    The presence of multidrug resistant (MDR) Salmonella serotypes in slaughtered swine, carcasses, meat and meat handlers is scarcely evaluated. Recently we demonstrated that diverse Salmonella serotypes are frequently present in swine, pork meat and carcasses, and meat handlers at Portuguese abattoirs. Here we have characterized their antibiotic resistance phenotypes and genotypes, helping elucidate the flow of MDR Salmonella in the food chain. Testing 60 Salmonella isolates from different serotypes, the highest frequencies of resistance were observed for tetracycline (T) [70% (n=42/60), tet(A)/tet(B)/tet(G)], streptomycin (S) [63% (n=38/60), aadA2/strA/strB], sulfamethoxazole (Sul) [62% (n=37/60), sul1/sul2/sul3] and ampicillin (A) [57% (n=34/60), blaPSE-1/blaTEM]. Thirty-seven percent (n=22/60) carried class 1 integrons and multidrug resistance was frequently observed (63% n=38/60), including those serotypes common to human infections [S. Typhimurium 78% n=25/32; S. 4,[5],12:i:- 67% n=2/3; S. Rissen 75% (n=3/4); S. London 67% n=2/3; S. Derby 55%; n=6/11)]. The emergent S. 4,[5],12:i:- isolates were mostly characterized by ASSuT phenotype [blaTEM/strA-strB/sul2/tet(B)], typical of the European clone, while for the first time the ST phenotype [strA-strB-tet(A)-tet(B)] was also observed. Moreover, we report a first finding of a MDR phenotype in S. London [ANSSuT; blaTEM-strA-strB-sul2-tet(A)]. Our findings suggest that the abattoir environment and the slaughter operations seem not only to harbor MDR serotypes that originated in the pig reservoir, but also propagate them through cross-contamination processes, involving meat handlers. The present study suggests a probable relationship between swine and human salmonellosis throughout the food chain, which is of interest for epidemiological, animal health and public health purposes.

  13. Major and trace-element analyses of acid mine waters in the Leviathan Mine drainage basin, California/Nevada; October, 1981 to October, 1982

    USGS Publications Warehouse

    Ball, J.W.; Nordstrom, D.K.

    1985-01-01

    Water issuing from the inactive Leviathan open-pit sulfur mine has caused serious degradation of the water quality in the Leviathan/Bryant Creek drainage basin which drains into the East Fork of the Carson River. As part of a pollution abatement project of the California Regional Water Quality Control Board, the U.S. Geological Survey collected hydrologic and water quality data for the basin during 1981-82. During this period a comprehensive sampling survey was completed to provide information on trace metal attenuation during downstream transport and to provide data for interpreting geochemical processes. This report presents the analytical results from this sampling survey. Sixty-seven water samples were filtered and preserved on-site at 45 locations and at 3 different times. Temperature, discharge, pH, and Eh and specific conductance were measured on-site. Concentrations of 37 major and trace constituents were determined later in the laboratory on preserved samples. The quality of the analyses was checked by using two or more techniques to determine the concentrations including d.c.-argon plasma emission spectrometry (DCP), flame and flameless atomic absorption spectrophotometry, UV-visible spectrophotometry, hydride-generation atomic absorption spectrophotometry and ion chromatography. Additional quality control was obtained by comparing measured to calculated conductance, comparing measured to calculated Eh (from Fe-2 +/Fe-3+ determinations), charge balance calculations and mass balance calculations for conservative constituents at confluence points. Leviathan acid mine waters contain mg/L concentrations of As, Cr, Co, Cu, Mn, Ni, T1, V and Zn, and hundreds to thousands of mg/L concentrations of Al, Fe, and sulfate at pH values as low as 1.8. Other elements including Ba, B, Be, Bi, Cd , Mo, Sb, Se and Te are elevated above normal background concentrations and fall in the microgram/L range. The chemical and 34 S/32 S isotopic analyses demonstrate that these

  14. Formation and resulfidization of a South Texas roll-type uranium deposit

    USGS Publications Warehouse

    Goldhaber, Martin B.; Reynolds, Richard L.; Rye, Robert O.

    1979-01-01

    Core samples from a roll type uranium deposit in Live Oak County, south Texas have been studied and results are reported for Se, Mo, FeS2 and organic-carbon distribution, sulfide mineral petrology, and sulfur isotopic composition of iron-disulfide phases. In addition, sulfur isotopic compositions of dissolved sulfate and sulfide from the modern ground water within the ore bearing sand have been studied. The suite of elements in the ore sand and their geometric relationships throughout the deposit are those expected for typical roll-type deposits with well-developed oxidation-reduction interfaces. However, iron-disulfide minerals are abundant in the altered tongue, demonstrating that this interval has been sulfidized after mineralization (resulfidized or rereduced). Iron disulfide minerals in the rereduced interval differ mineralogically and isotopically from those throughout the remainder of the deposit. The resulfidized sand contains dominantly pyrite that is enriched in 34S, whereas the sand beyond the altered tongue contains abundant marcasite that is enriched in the light isotope, 32S. Textural relationships between pyrite and marcasite help to establish relative timing of iron disulfide formation. In reduced rock outside the altered tongue, three distinct generations of iron disulfide are present. The oldest of these generations consists largely of pyrite with lesser amounts of marcasite. A major episode of marcasite formation contemporaneous with ore genesis postdates the oldest pyrite generation but predates a younger pyrite generation. Resulfidization probably led to the final pyrite stage recognized beyond the altered tongue. Stable isotope data establish that the source of sulfur for the resulfidization was fault-leaked H2S probably derived from the Edwards Limestone of Cretaceous age which underlies the deposit. The deposit formed in at least two stages: (1) a pre-ore process of host rock sulfidization which produced disseminated pyrite as the dominant

  15. Experimentally determined sulfur isotope fractionation between metal and silicate and implications for planetary differentiation

    NASA Astrophysics Data System (ADS)

    Labidi, J.; Shahar, A.; Le Losq, C.; Hillgren, V. J.; Mysen, B. O.; Farquhar, J.

    2016-02-01

    The Earth's mantle displays a subchondritic 34S/32S ratio. Sulfur is a moderately siderophile element (i.e. iron-loving), and its partitioning into the Earth's core may have left such a distinctive isotope composition on the terrestrial mantle. In order to constrain the sulfur isotope fractionation occurring during core-mantle differentiation, high-pressure and temperature experiments were conducted with synthetic mixtures of metal and silicate melts. With the purpose to identify the mechanism(s) responsible for the S isotope fractionations, we performed our experiments in different capsules - namely, graphite and boron nitride capsules - and thus at different fO2, with varying major element chemistry of the silicate and metal fractions. The S isotope fractionations Δ34Smetal-silicate of equilibrated metal alloys versus silicate melts is +0.2 ± 0.1‰ in a boron-free and aluminum-poor system quenched at 1-1.5 GPa and 1650 °C. The isotope fractionation increases linearly with increasing boron and aluminum content, up to +1.4 ± 0.2‰, and is observed to be independent of the silicon abundance as well as of the fO2 over ∼3.5 log units of variations explored here. The isotope fractionations are also independent of the graphite or nitride saturation of the metal. Only the melt structural changes associated with aluminum and boron concentration in silicate melts have been observed to affect the strength of sulfur bonding. These results establish that the structure of silicate melts has a direct influence on the S2- average bonding strengths. These results can be interpreted in the context of planetary differentiation. Indeed, the structural environments of silicate evolve strongly with pressure. For example, the aluminum, iron or silicon coordination numbers increase under the effect of pressure. Consequently, based on our observations, the sulfur-bonding environment is likely to be affected. In this scheme, we tentatively hypothesize that S isotope fractionations

  16. Mineralogical and Sulfur Isotopic Study on Volcanic Ash of the 2014 Eruption at Ontake Volcano, Central Honshu, Japan

    NASA Astrophysics Data System (ADS)

    Imura, T.; Minami, Y.; Ohba, T.; Takahashi, R.; Imai, A.; Hayashi, S.

    2015-12-01

    Ontake volcano erupted on 27th September 2014. Components in fallout samples were analyzed with microscope, XRD, and SEM-EDS. Pyrophyllite, smectite, muscovite, kaoline group minerals, quartz, cristobalite, tridymite, pyrite, alunite, gypsum and anhydrite were identified from bulk samples. Coarse ash fraction (> 125 µm) consists mainly of siliceous fragments that are intensely altered and contain pyrite and rutile. Weakly-altered dark-gray volcanic rock fragments are also contained. Fine fraction is abundant in euhedral free crystals of alunite and gypsum and aggregates of silica minerals. The 34S/32S ratios of bulk ash samples were analyzed for sulfur leached by water (water-soluble sulfate), gastric (HCl-soluble sulfate), and HNO3 (sulfide). Gastric and HNO3 leaching methods were applied to coarse fraction too. The bulk δ34SCDT compositions of water-soluble sulfate, HCl-soluble sulfate and sulfide were +14.7 ‰, +15.7 ‰, and -4.7 ‰, respectively. Those of HCl-soluble sulfate and sulfide in coarse fraction were +9.1 ‰ and -4.3 ‰, respectively. Paragenesis of quartz and pyrophyllite in single grain implies hydrothermal alteration by hot (> 230 °C), acidic fluid in the sub-volcanic system. The sulfur isotope geothermometry (Ohmoto and Rye, 1979) applied to the pair of water-soluble sulfate and bulk sulfide resulted in 306 °C. Similar temperature (ca. 296 °C) was estimated for the pair of HCl-soluble sulfate and sulfide in bulk ash. The mineralogy and sulfur isotopic study indicate that the 2014 Ontake eruption was derived from an acidic high-temperature (ca. 300 °C) sub-volcanic hydrothermal fluid. However, the estimated temperature for the pair of HCl-soluble sulfate and sulfide from coarse fraction resulted in higher temperature (ca. 482 °C). The coarse fraction preserved the past temperature record of the hydrothermal fluid, because the coarse lithic fragments were derived from pre-existing altered rocks.

  17. Ground-water and stream-water interaction in the Owl Creek basin, Wyoming

    USGS Publications Warehouse

    Ogle, K.M.

    1996-01-01

    Understanding of the interaction of ground-water and surface-water resources is vital to water management when water availability is limited.Inflow of ground water is the primary source ofwater during stream base flow. The water chemistry of streams may substantially be affected by that inflow of ground water. This report is part of a study to examine ground-water and surface-water interaction in the Owl Creek Basin, Wyoming, completed by the U.S. Geological Survey incooperation with the Northern Arapaho Tribe and the Shoshone Tribe. During a low flow period between November\\x1113 - 17, 1991, streamflowmeasurements and water-quality samples were collected at 16 selected sites along major streams and tributaries in the Owl Creek Basin,Wyoming. The data were used to identify stream reaches receiving ground-water inflow and to examine causes of changes in stream chemistry.Streamflow measurements, radon-222 activity load, and dissolved solids load were used to identified stream reaches receiving ground-water inflow.Streamflow measurements identified three stream reaches receiving ground-water inflow. Analysis of radon-222 activity load identified five stream reaches receiving ground-water inflow. Dissolvedsolids load identified six stream reaches receiving ground-water inflow. When these three methods were combined, stream reaches in two areas, theEmbar Area and the Thermopolis Anticline Area, were identified as receiving ground-water inflow.The Embar Area and the Thermopolis Anticline Area were then evaluated to determine the source of increased chemical load in stream water. Three potential sources were analyzed: tributary inflow, surficial geology, and anticlines. Two sources,tributary inflow and surficial geology, were related to changes in isotopic ratios and chemical load in the Embar Area. In two reaches in the Embar Area, isotopic ratios of 18O/16O, D/H, and 34S/32S indicated that tributary inflow affected stream-water chemistry. Increased chemical load of

  18. NanoSIMS STUDIES OF SMALL PRESOLAR SiC GRAINS: NEW INSIGHTS INTO SUPERNOVA NUCLEOSYNTHESIS, CHEMISTRY, AND DUST FORMATION

    SciTech Connect

    Hoppe, Peter; Leitner, Jan; Groener, Elmar; Marhas, Kuljeet K.; Meyer, Bradley S.; Amari, Sachiko

    2010-08-20

    We have studied more than 2000 presolar silicon carbide (SiC) grains from the Murchison CM2 chondrite in the size range 0.2-0.5 {mu}m for C- and Si-isotopic compositions. In a subset of these grains, we also measured N-, Mg-Al-, S-, and Ca-Ti-isotopic compositions as well as trace element concentrations. The overall picture emerging from the isotope data is quite comparable with that of larger grains, except for the abundances of grains from Type II supernovae (SNeII) and low-metallicity asymptotic giant branch (AGB) stars. Especially, the latter are much more abundant among submicrometer-sized grains than among micrometer-sized grains. This implies that SiC grains from lower-than-solar-metallicity AGB stars are on average smaller than those from solar metallicity AGB stars which provided the majority of presolar SiC grains. We identified five grains with large enrichments in {sup 29}Si (up to 3.5x solar) and {sup 30}Si (up to 3.9x solar in three of these grains). These grains are most likely from SNeII. The isotopically light S ({sup 32}S/{sup 34}S of 2x solar) together with the heavy Si in one of these grains suggests that molecule formation precedes macroscopic mixing and dust formation in SNII ejecta. This adds to the complexity of SN mixing calculations and should be considered in future studies. In total, about 2% of the presolar SiC grains in the size range 0.2-0.5 {mu}m appear to come from SNeII. This is about a factor of 2 higher than for micrometer-sized grains and suggests that SNeII, on average, produce smaller SiC grains than solar metallicity AGB stars. The high {sup 29}Si/{sup 30}Si ratio in one of the SN grains suggests that current SN models underestimate the {sup 29}Si production in the C- and Ne-burning regions by about a factor of 2. It is shown that with this adjustment the solar {sup 29}Si/{sup 28}Si ratio can be well reproduced in Galactic chemical evolution models and that a merger of our Galaxy with a low-metallicity satellite some 1.5 Gyr

  19. Sulfur isotopic signatures in rainwater and moss Haplocladium microphyllum indicating atmospheric sulfur sources in Nanchang City (SE China).

    PubMed

    Xiao, Hua-Yun; Zhu, Ren-Guo; Lin, Bi-Na; Liu, Cong-Qiang

    2011-05-01

    Sulfur source identification previously reported has been based on sulfur isotopic ratios in either rainwater or mosses. The δ(34)S values of rainwater sulfate and the epilithic moss Haplocladium microphyllum in Nanchang region (China) were determined for comparisons and used to delineate atmospheric sulfur sources. At the urban and rural sites, similar mean δ(34)S values were observed between rainwater sulfate (+1.6‰ and -0.2‰, respectively) and epilithic mosses (+1.7‰ and +0.6‰, respectively), suggesting that mosses acquire δ(34)S values similar to those found for rainwater sulfate. This has further demonstrated that moss δ(34)S signatures hold valuable source-specific information as rainwater δ(34)S values do. The δ(34)S values of both rainwater sulfate and epilithic mosses indicated that atmospheric sulfur in Nanchang region was mainly associated with coal combustion. The lower δ(34)S values at the rural site can be explained by higher contribution of local coals (lower δ(34)S values relative to those of north Chinese coals) and biogenic sulfur.

  20. Effect of temperature, ration, body size and age on sulphur isotope fractionation in fish.

    PubMed

    Barnes, Carolyn; Jennings, Simon

    2007-01-01

    Sulphur isotope analysis (delta(34)S) is increasingly identified as a valuable tool for source differentiation and the determination of trophic level in food webs, but there are still many uncertainties associated with the interpretation of delta(34)S data. To investigate the effects of temperature, ration, body size and age on sulphur trophic fractionation (Deltadelta(34)S) in fish, we reared European sea bass (Dicentrarchus labrax) on identical diets at 11 and 16 degrees C at three ration levels for over 600 days. Deltadelta(34)S was between 0 and -1 per thousand. The effect of temperature on Deltadelta(34)S was small and inconsistent, varying over the course of the experiment and depending on ration. This contrasts with temperature effects on bass Deltadelta(13)C and Deltadelta(15)N, where Deltadelta(13)C increases at warm temperatures while Deltadelta(15)N falls. Body size and age had a positive relationship with Deltadelta(34)S but the relationship with size was not significant for bass that weighed >20 g. As Deltadelta(34)S is small and the range in delta(34)S of potential diet items can be much greater than the range in delta(13)C or delta(15)N, our results show that sulphur stable isotopes are particularly useful for source differentiation in fish.

  1. Isotopic evidence in tree rings for historical changes in atmospheric sulfur sources.

    PubMed

    Kawamura, Hidehisa; Matsuoka, Nobuaki; Momoshima, Noriyuki; Koike, Masami; Takashima, Yoshimasa

    2006-09-15

    Little is understood about the usefulness of sulfur isotopic ratios (sigma 34S) in tree rings because the sulfur content in rings is generally insufficient for analysis using conventional methods. We present sigma 34S values of the water-soluble and the organically bound sulfur fractions in rings of coniferous trees grown in Japan, analyzed using a large-volume oxygen bomb. Comparing the sigma 34S values of the organically bound fraction in tree rings with past atmospheric sulfur concentrations and with those of their sources, we find clear evidence that the sigma 34S values of the organically bound fraction in the rings are dependent upon the values of the atmospheric sulfur sources. The evidence suggests that the sigma 34S values in tree rings are a useful chronological proxy for evaluating possible causes of past atmospheric sulfur pollution.

  2. Role of crude oil in the genesis of Mississippi Valley-type deposits. Evidence from the Cincinnati arch

    SciTech Connect

    Kesler, S.E.; Jones, H.D. ); Furman, F.C. ); Sassen, R. ); Anderson, W.H. ); Kyle, J.R. )

    1994-07-01

    Mississippi Valley-type (MVT) sulfide minerals and oil from deposits along the Cincinnati arch have almost identical [delta][sup 34]S values (-9% to +9% for MVT sulfides, -12% to +9% for oils). These values are very similar to those for MVT sulfides and oil in the Illinois-Kentucky district and support their proposed inclusion in a regional hydrothermal system. Many MVT deposits with low [delta][sup 34]S values are closely associated with oil, whereas MVT deposits with high [delta][sup 34]S values often contain bitumen. Reduced sulfur in MVT deposits with high [delta][sup 34]S values probably came from thermochemical sulfate reduction, whereas that in MVT deposits with low [delta][sup 34]S values probably came from oil and related organic matter. Oil-related sulfur could have been derived from oil fields or disseminated oil and other organic matter in regional wallrocks. 44 refs., 3 figs., 2 tabs.

  3. Sulfur isotopic composition of surface snow along a latitudinal transect in East Antarctica

    NASA Astrophysics Data System (ADS)

    Uemura, Ryu; Masaka, Kosuke; Fukui, Kotaro; Iizuka, Yoshinori; Hirabayashi, Motohiro; Motoyama, Hideaki

    2016-06-01

    The sulfur stable isotopic values (δ34S) of sulfate aerosols can be used to assess oxidation pathways and contributions from various sources, such as marine biogenic sulfur, volcanoes, and sea salt. However, because of a lack of observations, the spatial distribution of δ34S values in Antarctic sulfate aerosols remains unclear. Here we present the first sulfur isotopic values from surface snow samples along a latitudinal transect in eastern Dronning Maud Land, East Antarctica. The δ34S values of sulfate showed remarkably uniform values, in the range of 14.8-16.9‰, and no significant decrease toward the inland part of the transect was noted. These results suggest that net isotopic fractionation during long-range transport is insignificant. Thus, the δ34S values can be used to infer source contributions. The δ34S values suggest that marine biogenic sulfur is the dominant source of sulfate aerosols, with a fractional contribution of 84 ± 16%.

  4. Use of isotopic sulfur to determine whitebark pine consumption by Yellowstone bears: a reassessment

    USGS Publications Warehouse

    Schwartz, Charles C.; Teisberg, Justin E.; Fortin, Jennifer K.; Haroldson, Mark A.; Servheen, Christopher; Robbins, Charles T.; van Manen, Frank T.

    2014-01-01

    Use of naturally occurring stable isotopes to estimate assimilated diet of bears is one of the single greatest breakthroughs in nutritional ecology during the past 20 years. Previous research in the Greater Yellowstone Ecosystem (GYE), USA, established a positive relationship between the stable isotope of sulfur (δ34S) and consumption of whitebark pine (Pinus albicaulis) seeds. That work combined a limited sample of hair, blood clots, and serum. Here we use a much larger sample to reassess those findings. We contrasted δ34S values in spring hair and serum with abundance of seeds of whitebark pine in samples collected from grizzly (Ursus arctos) and American black bears (U. americanus) in the GYE during 2000–2010. Although we found a positive relationship between δ34S values in spring hair and pine seed abundance for grizzly bears, the coefficients of determination were small (R2 ≤ 0.097); we failed to find a similar relationship with black bears. Values of δ34S in spring hair were larger in black bears and δ34S values in serum of grizzly bears were lowest in September and October, a time when we expect δ34S to peak if whitebark pine seeds were the sole source of high δ34S. The relationship between δ34S in bear tissue and the consumption of whitebark pine seeds, as originally reported, may not be as clean a method as proposed. Data we present here suggest other foods have high values of δ34S, and there is spatial heterogeneity affecting the δ34S values in whitebark pine, which must be addressed.

  5. Evaluating the relationship between the carbon and sulfur cycles in the later Cambrian ocean: An example from the Port au Port Group, western Newfoundland, Canada

    NASA Astrophysics Data System (ADS)

    Hurtgen, Matthew T.; Pruss, Sara B.; Knoll, Andrew H.

    2009-05-01

    We present a high-resolution δ34S (sulfate and pyrite) and δ13C carbonate record from the Middle-Upper Cambrian Port au Port Group, a mixed carbonate-siliciclastic succession exposed in western Newfoundland, Canada. The results illustrate systematic δ34S sulfate shifts of > 15‰ over relatively short stratigraphic intervals (10 m, likely < 1 m.y.), low average Δ 34S sulfate-pyrite (ca. 23‰) and a generally positive coupling between changes in δ13C carbonate and δ34S sulfate. Together, these results indicate that Middle to Late Cambrian sulfate concentrations were low and that the sulfate reservoir was more sensitive to change than it was in either terminal Neoproterozoic or Cenozoic oceans. However, a simple carbon (C) and sulfur (S) isotope box model of the Late Cambrian ocean illustrates that low sulfate concentrations alone fail to account for the > 15‰ δ34S sulfate shifts recognized in Port au Port strata. Such large shifts can be generated only if fluctuating oceanic redox is invoked; marine anoxia forces reduced C/S burial and elevated Δ 34S, driving larger δ34S changes per mole of organic carbon buried. The conclusion that later Cambrian oceans featured both low sulfate levels and widespread subsurface anoxia supports hypotheses that link fluctuating marine redox conditions in the delayed recovery of skeletal animals and metazoan reefs from late Early Cambrian extinction.

  6. NMR study of black-phase in SmS

    NASA Astrophysics Data System (ADS)

    Koyama, T.; Yamada, H.; Ueda, K.; Mito, T.; Haga, Y.

    2015-03-01

    We report the result of the 33S nuclear magnetic resonance (NMR) measurement on the nonmagnetic semiconductor SmS at ambient pressure. For this measurement, the 33S isotope enriched powder sample of SmS was prepared to increase the 33S NMR intensity. We have attempted 33S NMR measurement on SmS and successfully observed the signal of it. With decreasing temperature, the spectrum measured at the constant magnetic field shifted to lower frequency and became weakly temperature dependent below 50 K. The presence of the energy gap was microscopically established by the rapid decrease in the nuclear spin-lattice relaxation rate 1/T1. The activation energy was deduced to be 625 K from an Arrhenius plot of T1.

  7. 75 FR 79837 - Semiannual Agenda and Fiscal Year 2011 Regulatory Plan

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-20

    ...-5132 Email: elizabeth.baltierra@fincen.gov Koko (Nettie) Ives, Department of the Treasury, Financial... Email: koko.ives@fincen.gov RIN: 1506-AB07 BILLING CODE 4810--33--S ] Department of the Treasury...

  8. Department of the Treasury Semiannual Regulatory Agenda

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-20

    ...-5132 Email: elizabeth.baltierra@fincen.gov Koko (Nettie) Ives, Department of the Treasury, Financial... Email: koko.ives@fincen.gov RIN: 1506-AB07 BILLING CODE 4810--33--S ] Department of the Treasury...

  9. Sulfur and Oxygen Isotopic Analysis of a Cosmic Symplectite from a Comet Wild 2 Stardust Terminal Particle

    NASA Astrophysics Data System (ADS)

    Nguyen, A. N.; Berger, E. L.; Nakamura-Messenger, K.; Messenger, S.

    2015-07-01

    The S isotopic composition of a cosmic symplectite in a Stardust terminal particle is found to be isotopically heavy with a large 33S-enrichment. This mass-independent fractionation likely resulted from photochemical irradiation of solar nebula gas.

  10. Effects of thermal maturation and thermochemical sulfate reduction on compound-specific sulfur isotopic compositions of organosulfur compounds in Phosphoria oils from the Bighorn Basin, USA

    USGS Publications Warehouse

    Ellis, Geoffrey S.; Said-Ahamed, Ward; Lillis, Paul G.; Shawar, Lubna; Amrani, Alon

    2017-01-01

    Compound-specific sulfur isotope analysis was applied to a suite of 18 crude oils generated from the Permian Phosphoria Formation in the Bighorn Basin, western USA. These oils were generated at various levels of thermal maturity and some experienced thermochemical sulfate reduction (TSR). This is the first study to examine the effects of thermal maturation on stable sulfur isotopic compositions of individual organosulfur compounds (OSCs) in crude oil. A general trend of 34S enrichment in all of the studied compounds with increasing thermal maturity was observed, with the δ34S values of alkyl-benzothiophenes (BTs) tending to be enriched in 34S relative to those of the alkyl-dibenzothiophenes (DBTs) in lower-maturity oils. As thermal maturity increases, δ34S values of both BTs and DBTs become progressively heavier, but the difference in the average δ34S value of the BTs and DBTs (Δ34S BT-DBT) decreases. Differences in the isotopic response to thermal stress exhibited by these two compound classes are considered to be the result of relative differences in their thermal stabilities. TSR-altered Bighorn Basin oils have OSCs that are generally enriched in 34S relative to non-TSR-altered oils, with the BTs being enriched in 34S relative to the DBTs, similar to the findings of previous studies. However, several oils that were previously interpreted to have been exposed to minor TSR have Δ34S BT-DBT values that do not support this interpretation. The δ34S values of the BTs and DBTs in some of these oils suggest that they did not experience TSR, but were derived from a more thermally mature source. The heaviest δ34S values observed in the OSCs are enriched in 34S by up to 10‰ relative to that of Permian anhydrite in the Bighorn Basin, suggesting that there may be an alternate or additional source of sulfate in some parts of the basin. These results indicate that the sulfur isotopic composition of OSCs in oil provides a sensitive indicator for the extent of TSR

  11. Clinical Utility and Pitfalls of Ultrasound Guided Foreign Body Removal in War Fighters

    DTIC Science & Technology

    2014-10-01

    ultrasound guided foreign body removal P4 #5861 Female Right leg 68 years old Cause of death: Huntington &#34 s Chorea 1 5 Yes 23 23 0 N/A...68 years old Cause of death: Huntington &#34 s Chorea 1 5 Yes 26 26 0 N/A Radiological Procedure Removal Technique - Percutaneous - interventional...radiological ultrasound guided foreign body removal P6 #5861 Female Right leg 68 years old Cause of death: Huntington &#34 s Chorea 1 9 Yes 17 17 0 N/A

  12. Progression in sulfur isotopic compositions from coal to fly ash: Examples from single-source combustion in Indiana

    USGS Publications Warehouse

    Yaofa, Jiang; Elswick, E.R.; Mastalerz, Maria

    2008-01-01

    Sulfur occurs in multiple mineral forms in coals, and its fate in coal combustion is still not well understood. The sulfur isotopic composition of coal from two coal mines in Indiana and fly ash from two power plants that use these coals were studied using geological and geochemical methods. The two coal beds are Middle Pennsylvanian in age; one seam is the low-sulfur ( 5%) Springfield Coal Member of the Petersburg Formation. Both seams have ash contents of approximately 11%. Fly-ash samples were collected at various points in the ash-collection system in the two plants. The results show notable difference in ??34S for sulfur species within and between the low-sulfur and high-sulfur coal. The ??34S values for all sulfur species are exclusively positive in the low-sulfur Danville coal, whereas the ??34S values for sulfate, pyritic, and organic sulfur are both positive and negative in the high-sulfur Springfield coal. Each coal exhibits a distinct pattern of stratigraphic variation in sulfur isotopic composition. Overall, the ??34S for sulfur species values increase up the section in the low-sulfur Danville coal, whereas they show a decrease up the vertical section in the high-sulfur Springfield coal. Based on the evolution of ??34S for sulfur species, it is suggested that there was influence of seawater on peat swamp, with two marine incursions occurring during peat accumulation of the high-sulfur Springfield coal. Therefore, bacterial sulfate reduction played a key role in converting sulfate into hydrogen sulfide, sulfide minerals, and elemental sulfur. The differences in ??34S between sulfate sulfur and pyritic sulfur is very small between individual benches of both coals, implying that some oxidation occurred during deposition or postdeposition. The ??34S values for fly ash from the high-sulfur Springfield coal (averaging 9.7???) are greatly enriched in 34S relative to those in the parent coal (averaging 2.2???). This indicates a fractionation of sulfur isotopes

  13. Early inner solar system origin for anomalous sulfur isotopes in differentiated protoplanets.

    PubMed

    Antonelli, Michael A; Kim, Sang-Tae; Peters, Marc; Labidi, Jabrane; Cartigny, Pierre; Walker, Richard J; Lyons, James R; Hoek, Joost; Farquhar, James

    2014-12-16

    Achondrite meteorites have anomalous enrichments in (33)S, relative to chondrites, which have been attributed to photochemistry in the solar nebula. However, the putative photochemical reactions remain elusive, and predicted accompanying (33)S depletions have not previously been found, which could indicate an erroneous assumption regarding the origins of the (33)S anomalies, or of the bulk solar system S-isotope composition. Here, we report well-resolved anomalous (33)S depletions in IIIF iron meteorites (<-0.02 per mil), and (33)S enrichments in other magmatic iron meteorite groups. The (33)S depletions support the idea that differentiated planetesimals inherited sulfur that was photochemically derived from gases in the early inner solar system (<∼2 AU), and that bulk inner solar system S-isotope composition was chondritic (consistent with IAB iron meteorites, Earth, Moon, and Mars). The range of mass-independent sulfur isotope compositions may reflect spatial or temporal changes influenced by photochemical processes. A tentative correlation between S isotopes and Hf-W core segregation ages suggests that the two systems may be influenced by common factors, such as nebular location and volatile content.

  14. Early inner solar system origin for anomalous sulfur isotopes in differentiated protoplanets

    PubMed Central

    Antonelli, Michael A.; Kim, Sang-Tae; Peters, Marc; Labidi, Jabrane; Cartigny, Pierre; Walker, Richard J.; Lyons, James R.; Hoek, Joost; Farquhar, James

    2014-01-01

    Achondrite meteorites have anomalous enrichments in 33S, relative to chondrites, which have been attributed to photochemistry in the solar nebula. However, the putative photochemical reactions remain elusive, and predicted accompanying 33S depletions have not previously been found, which could indicate an erroneous assumption regarding the origins of the 33S anomalies, or of the bulk solar system S-isotope composition. Here, we report well-resolved anomalous 33S depletions in IIIF iron meteorites (<−0.02 per mil), and 33S enrichments in other magmatic iron meteorite groups. The 33S depletions support the idea that differentiated planetesimals inherited sulfur that was photochemically derived from gases in the early inner solar system (<∼2 AU), and that bulk inner solar system S-isotope composition was chondritic (consistent with IAB iron meteorites, Earth, Moon, and Mars). The range of mass-independent sulfur isotope compositions may reflect spatial or temporal changes influenced by photochemical processes. A tentative correlation between S isotopes and Hf-W core segregation ages suggests that the two systems may be influenced by common factors, such as nebular location and volatile content. PMID:25453079

  15. Association of gold with uraninite and pyrobitumen in the metavolcanic rock hosted hydrothermal Au-U mineralisation at Rompas, Peräpohja Schist Belt, northern Finland

    NASA Astrophysics Data System (ADS)

    Molnár, Ferenc; Oduro, Harry; Cook, Nick D. J.; Pohjolainen, Esa; Takács, Ágnes; O'Brien, Hugh; Pakkanen, Lassi; Johanson, Bo; Wirth, Richard

    2016-06-01

    -ordered graphite in calcsilicate veins. Mean random reflectance data for pyrobitumen indicate 270-340 °C maximum temperature of thermal maturation—this temperature range is also considered as the temperature of gold deposition. Results of multiple sulphur isotope analyses of organic material-, pyrite- and acid-volatile-bound sulphur show distinct ranges of δ34S values for SORG and SCRS in uraninite-pyrobitumen (from -6.99 to -3.55‰ and from -10.02 to -4.41‰, respectively) and uraninite-pyrobitumen-native gold mineral associations (from +1.36 to +6.87‰ and from +0.42 to +9.7‰, respectively). Δ33S data indicate local occurrence of nonmass-dependent sulphur isotope fractionation owing to interaction of fluids with organic material. Concentration of lead in uraninite is depleted along the gold mineral filled fractures whereas the uranogenic lead isotope contents of galena, altaite and hunchuite deposited in the same fractures are extremely high, suggesting that the dominant source of lead for the crystallisation of these minerals was the radiogenic lead content of uraninite. Taking into account this source of radiogenic lead, the calculated Pb-Pb model ages for the lead minerals are between 1.75 and 1.70 Ga. Sulphur and tellurium removal from the fluid by reaction with radiogenic lead released by uraninite appears to be an important mechanism in the strongly localised deposition of gold minerals. Scavenging of sulphur by pyrobitumen nodules from gold transporting fluids was an additional process triggering precipitation of gold. Carbon particles and organic functional groups in pyrobitumen probably acted as nucleation and adsorption centres for gold minerals.

  16. Isotopic ratios of H, C, N, O, and S in comets C/2012 F6 (Lemmon) and C/2014 Q2 (Lovejoy)

    NASA Astrophysics Data System (ADS)

    Biver, N.; Moreno, R.; Bockelée-Morvan, D.; Sandqvist, Aa.; Colom, P.; Crovisier, J.; Lis, D. C.; Boissier, J.; Debout, V.; Paubert, G.; Milam, S.; Hjalmarson, A.; Lundin, S.; Karlsson, T.; Battelino, M.; Frisk, U.; Murtagh, D.; Odin Team

    2016-05-01

    The apparition of bright comets C/2012 F6 (Lemmon) and C/2014 Q2 (Lovejoy) in March-April 2013 and January 2015, combined with the improved observational capabilities of submillimeter facilities, offered an opportunity to carry out sensitive compositional and isotopic studies of the volatiles in their coma. We observed comet Lovejoy with the IRAM 30 m telescope between 13 and 26 January 2015, and with the Odin submillimeter space observatory on 29 January-3 February 2015. We detected 22 molecules and several isotopologues. The H216O and H218O production rates measured with Odin follow a periodic pattern with a period of 0.94 days and an amplitude of ~25%. The inferred isotope ratios in comet Lovejoy are 16O/18O = 499 ± 24 and D/H = 1.4 ± 0.4 × 10-4 in water, 32S/34S = 24.7 ± 3.5 in CS, all compatible with terrestrial values. The ratio 12C/13C = 109 ± 14 in HCN is marginally higher than terrestrial and 14N/15N = 145 ± 12 in HCN is half the Earth ratio. Several upper limits for D/H or 12C/13C in other molecules are reported. From our observation of HDO in comet C/2014 Q2 (Lovejoy), we report the first D/H ratio in an Oort Cloud comet that is not larger than the terrestrial value. On the other hand, the observation of the same HDO line in the other Oort-cloud comet, C/2012 F6 (Lemmon), suggests a D/H value four times higher. Given the previous measurements of D/H in cometary water, this illustrates that a diversity in the D/H ratio and in the chemical composition, is present even within the same dynamical group of comets, suggesting that current dynamical groups contain comets formed at very different places or times in the early solar system. Based on observations carried out with the IRAM 30 m telescope. IRAM is supported by INSU/CNRS (France), MPG (Germany) and IGN (Spain).Odin is a Swedish-led satellite project funded jointly by the Swedish National Space Board (SNSB), the Canadian Space Agency (CSA), the National Technology Agency of Finland (Tekes) and the

  17. Fractionation of Sulfur Isotopes by Desulfovibrio vulgaris Mutants Lacking Periplasmic Hydrogenases or the Type I Tetraheme Cytochrome c3

    NASA Astrophysics Data System (ADS)

    Sim, M.; Ono, S.; Bosak, T.

    2012-12-01

    A large fraction of anaerobic mineralization of organic compounds relies on microbial sulfate reduction. Sulfur isotope fractionation by these microbes has been widely used to trace the biogeochemical cycling of sulfur and carbon, but intracellular mechanisms behind the wide range of fractionations observed in nature and cultures are not fully understood. In this study, we investigated the influence of electron transport chain components on the fractionation of sulfur isotopes by culturing Desulfovibrio vulgaris Hildenborough mutants lacking hydrogenases or type I tetraheme cytochrome c3 (Tp1-c3). The mutants were grown both in batch and continuous cultures. All tested mutants grew on lactate or pyruvate as the sole carbon and energy sources, generating sulfide. Mutants lacking cytoplasmic and periplasmic hydrogenases exhibited similar growth physiologies and sulfur isotope fractionations to their parent strains. On the other hand, a mutant lacking Tp1-c3 (ΔcycA) fractionated the 34S/32S ratio more than the wild type, evolving H2 in the headspace and exhibiting a lower specific respiration rate. In the presence of high concentrations of pyruvate, the growth of ΔcycA relied largely on fermentation rather than sulfate reduction, even when sulfate was abundant, producing the largest sulfur isotope effect observed in this study. Differences between sulfur isotope fractionation by ΔcycA and the wild type highlight the effect of electron transfer chains on the magnitude of sulfur isotope fractionation. Because Tp1-c3 is known to exclusively shuttle electrons from periplasmic hydrogenases to transmembrane complexes, electron transfers in the absence of Tp1-c3 should bypass the periplasmic hydrogen cycling, and the loss of reducing equivalents in the form of H2 can impair the flow of electrons from organic acids to sulfur, increasing isotope fractionation. Larger fractionation by ΔcycA can inform interpretations of sulfur isotope data at an environmental scale as well

  18. Formation of Saturn and Jupiter and their Atmospheres

    NASA Astrophysics Data System (ADS)

    Atreya, S. K.; Lunine, J. I.; Simon-Miller, A. A.; Atkinson, D. H.; Brinckerhoff, W. B.; Coustenis, A.; Mahaffy, P. R.; Spilker, T. R.; Colaprete, A.; Reh, K.

    2012-04-01

    disequilibrium in the upper atmosphere. If Saturn's O/H is subsolar, a measurement of water even at shallow depths could allow its determination. CO could also provide a handle on O/H, but requires a knowledge of vertical mixing in Saturn's interior. The measurement of water and phosphine, respectively by the MWR and the Jovian InfraRed Auroral Mapper (JIRAM) on Juno, together with prior data on CO at Jupiter will provide a useful guide for determining convective mixing in Saturn as well. As in the case of Jupiter, an entry probe is essential for determining the bulk composition in Saturn's atmosphere, especially the elemental abundances of He, Ne, Ar, Kr, Xe, O, N and S and the critical isotopes, D/H, 3He/4He, 18O/16O, 13C/12C, 15N/14N, 34S/32S and the isotopes of the heavy noble gases. This would enable the type of comparative study of Saturn and Jupiter that is crucial to unraveling the mystery of the formation and evolution of the solar system and, by extension, extrasolar systems. [www.umich.edu/~atreya to download pdf's of related publications

  19. Biogeochemical fingerprints of life: earlier analogies with polar ecosystems suggest feasible instrumentation for probing the Galilean moons

    NASA Astrophysics Data System (ADS)

    Chela-Flores, J.; Cicuttin, A.; Crespo, M. L.; Tuniz, C.

    2015-07-01

    1960s) that the distribution range of 32S/34S in analysed extra-terrestrial material appears to be narrower than the isotopic ratio of H, C or N and may be the most reliable for estimating biological effects. In addition, we discuss the necessary instruments that can test our biogenic hypothesis. First of all we hasten to clarify that the last-generation miniaturized mass spectrometer we discuss in the present paper are capable of reaching the required accuracy of ‰ for the all-important measurements with JGO of the thin atmospheres of the icy satellites. To implement the measurements, we single out miniature laser ablation time-of-flight mass spectrometers that are ideal for the forthcoming JUICE probing of the exoatmospheres, ionospheres and, indirectly, surficial low-albedo regions. Ganymede's surface, besides having ancient dark terrains covering about one-third of the total surface, has bright terrains of more recent origin, possibly due to some internal processes, not excluding biological ones. The geochemical test could identify bioindicators on Europa and exclude them on its large neighbour by probing relatively recent bright terrains on Ganymede's Polar Regions.

  20. Stable sulphur isotope ratios in the moss species Hylocomium splendens (Hedw.) B.S.G. and Pleurozium schreberi (Brid.) Mitt. from the Kielce area (south-central Poland).

    PubMed

    Migaszewski, Zdzisław M; Dołegowska, Sabina; Hałas, Stanisław; Trembaczowski, Andrzej

    2010-06-01

    Stable sulphur isotope determinations were performed on 18 moss samples collected at nine sites in forested areas of the city of Kielce. The delta(34)S of Hylocomium splendens varied from 4.4 to 7.1 per thousand, whereas the delta(34)S of Pleurozium schreberi was in the range of 3.7-9.1 per thousand. The Holy Cross Mountains mosses display a positive delta(34)S signature of airborne SO(2) and sulphates of anthropogenic origin, which is characteristic for this part of Europe. Some spatial variations in the delta(34)S of mosses are due to the interactions that occur between coal combustion emissions with diverse isotopic imprints, variations in wind direction and topographic features combined with biological fractionation.

  1. Application of sulphur isotope ratios to examine weaning patterns and freshwater fish consumption in Roman Oxfordshire, UK

    NASA Astrophysics Data System (ADS)

    Nehlich, Olaf; Fuller, Benjamin T.; Jay, Mandy; Mora, Alice; Nicholson, Rebecca A.; Smith, Colin I.; Richards, Michael P.

    2011-09-01

    This study investigates the application of sulphur isotope ratios (δ 34S) in combination with carbon (δ 13C) and nitrogen (δ 15N) ratios to understand the influence of environmental sulphur on the isotopic composition of archaeological human and faunal remains from Roman era sites in Oxfordshire, UK. Humans ( n = 83), terrestrial animals ( n = 11), and freshwater fish ( n = 5) were analysed for their isotope values from four locations in the Thames River Valley, and a broad range of δ 34S values were found. The δ 34S values from the terrestrial animals were highly variable (-13.6‰ to +0.5‰), but the δ 34S values of the fish were clustered and 34S-depleted (-20.9‰ to -17.3‰). The results of the faunal remains suggest that riverine sulphur influenced the terrestrial sulphur isotopic signatures. Terrestrial animals were possibly raised on the floodplains of the River Thames, where highly 34S-depleted sulphur influenced the soil. The humans show the largest range of δ 34S values (-18.8‰ to +9.6‰) from any archaeological context to date. No differences in δ 34S values were found between the males (-7.8 ± 6.0‰) and females (-5.3 ± 6.8‰), but the females had a linear correlation ( R2 = 0.71; p < 0.0001) between their δ 15N and δ 34S compositions. These δ 34S results suggest a greater dietary variability for the inhabitants of Roman Oxfordshire than previously thought, with some individuals eating solely terrestrial protein resources and others showing a diet almost exclusively based on freshwater protein such as fish. Such large dietary variability was not visible by analysing only the carbon and nitrogen isotope ratios, and this research represents the largest and most detailed application of δ 34S analysis to examine dietary practices (including breastfeeding and weaning patterns) during the Romano-British Period.

  2. The sources and evolution of sulfur in the hypersaline Lake Lisan (paleo-Dead Sea)

    NASA Astrophysics Data System (ADS)

    Torfstein, Adi; Gavrieli, Ittai; Stein, Mordechai

    2005-07-01

    δ34S values in gypsum are used to evaluate the fate of sulfur in the hypersaline Lake Lisan, the late Pleistocene precursor of the Dead Sea (70-14 ka BP), and applied as a paleo-limnological tracer. The Ca-chloride Lake Lisan evolved through meromictic periods characterized by precipitation of authigenic aragonite and holomictic episodes characterized by enhanced gypsum precipitation. The lake deposited two major gypsum units: the "Lower Gypsum unit" (deposited at ˜56 ka) showing δ34S values of 18-20‰, and the "Upper Gypsum unit" (deposited at 17 ka) displaying significantly higher δ34S values of 26-28‰. Laminated and disseminated gypsum, residing within the aragonite, exhibit δ34S values in the range of - 26‰ to 1‰. The isotopic composition of the gypsum was dictated by freshwater sulfate input that replenished the upper layer of the lake (the mixolimnion), bacterial sulfate reduction (BSR) that occurred under the anoxic conditions of the lower brine (the monimolimnion), and mixing between these two layers. During meromictic periods, the sulfate reservoir in the lower brine was replenished by precipitation of gypsum from the upper layer, and its subsequent dissolution due to sulfate deficiency induced by BSR activity. This process describes a "sulfur pump" mechanism and its effect on δ34S in the water can be modeled by a modified Rayleigh distillation equation. Steady state δ34S values (˜40‰) were reached in the lower brine after long meromictic periods. Following overturn episodes, induced by diminishing freshwater input and lake level decline, large quantities of δ34S enriched gypsum precipitated. The negative δ34S values in laminated and disseminated gypsum provide evidence for BSR activity in the lower brine that removed isotopically depleted sulfides from the water column, causing significant isotopic enrichment of remaining sulfate. Following the lake desiccation, the sediments were exposed and the latter sulfides oxidized and re

  3. Using sulfur stable isotopes to assess mercury bioaccumulation and biomagnification in temperate lake food webs.

    PubMed

    Clayden, Meredith G; Lescord, Gretchen L; Kidd, Karen A; Wang, Xiaowa; Muir, Derek C G; O'Driscoll, Nelson J

    2017-03-01

    Nitrogen and carbon stable isotopes (δ(15) N, δ(13) C) are commonly used to understand mercury (Hg) bioaccumulation and biomagnification in freshwater food webs. Though sulfur isotopes (δ(34) S) can distinguish between energy sources from the water column (aqueous sulfate) and from sediments to freshwater organisms, little is known about whether δ(34) S can help interpret variable Hg concentrations in aquatic species or food webs. Seven acidic lakes in Kejimkujik National Park (Nova Scotia, Canada) were sampled for biota, water, and sediments in 2009 and 2010. Fishes, zooplankton, and macroinvertebrates were analyzed for δ(34) S, δ(15) N, δ(13) C, and Hg (methyl Hg in invertebrates, total Hg in fishes); aqueous sulfate and profundal sediments were analyzed for δ(34) S. Within lakes, mean δ(34) S values in sediments and sulfate differed between 0.53‰ and 1.98‰, limiting their use as tracers of energy sources to the food webs. However, log-Hg and δ(34) S values were negatively related (slopes -0.14 to -0.35, R(2) 0.20-0.39, p < 0.001-0.01) through each food web, and slopes were significantly different among lakes (analysis of covariance, lake × δ(34) S interaction term p = 0.04). Despite these relationships, multiple regression analyses within each taxon showed that biotic Hg concentrations were generally better predicted by δ(15) N and/or δ(13) C. The results indicate that δ(34) S values are predictive of Hg concentrations in these food webs, although the mechanisms underlying these relationships warrant further study. Environ Toxicol Chem 2017;36:661-670. © 2016 SETAC.

  4. The age curves of sulfur and oxygen isotopes in marine sulfate and their mutual interpretation

    USGS Publications Warehouse

    Claypool, George E.; Holser, William T.; Kaplan, Isaac R.; Sakai, Hitoshi; Zak, Israel

    1980-01-01

    Three hundred new samples of marine evaporite sulfate, of world-wide distribution, were analyzed for δ34S, and 60 of these also for δ18O in the sulfate ion. Detailed δ34S age curves for Tertiary—Cretaceous, Permian—Pennsylvanian, Devonian, Cambrian and Proterozoic times document large variations in δ34S. A summary curve forδ18O also shows definite variations, some at different times than δ34S, and always smaller. The measured δ34S and δ18O correspond to variations in these isotopes in sulfate of the world ocean surface. The variations of δ18O are controlled by input and output fluxes of sulfur in the ocean, three of which are the same that control δ34S: deposition and erosion of sulfate, and deposition of sulfide. Erosion of sulfide differs in its effect on the S and O systems. δ18O in the sulfate does not seem to be measurably affected by equilibration with either seawater or with subsurface waters after crystallization. In principle, the simultaneous application of both δ34S and δ18O age curves should help reduce the number of assumptions in calculations of the cycles of sulfur and oxygen through geological time, and a new model involving symmetrical fluxes is introduced here to take advantage of the oxygen data. However, all previously published models as well as this one lead to anomalies, such as unreasonable calcium or oxygen depletions in the ocean—atmosphere system. In addition, most models are incapable of reproducing the sharp rises of the δ34S curve in the late Proterozoic, the Devonian and the Triassic which would be the result of unreasonably fast net sulfide deposition. This fast depletion could result from an ocean that has not always been mixed (as previously assumed in all model calculations).

  5. Information on Over-the-Horizon Radar. Part 2

    DTIC Science & Technology

    1964-06-01

    each megacycle of the desired frequency range. TARGET CHAMATERISTICS EML experience shows that aircraft targets are characterized in a coherent pulse ...The duty factor will vary for pulse periods of 20 to 400 pps with corresponding pulse lengths from 1000 &#34s down to 100 &#34s. In addition, three...slowed-down readout of storage is employed stretching pulse widths, then certain factors previously discussed will have to be scaled accordingly

  6. [Sulfur isotopic ratios indicating sulfur cycling in slope soils of karst areas].

    PubMed

    Zhang, Wei; Liu, Cong-qiang; Li, Xiao-dong; Liu, Tao-ze; Zhang, Li-li

    2010-02-01

    Sequential extraction methods for soil sulfur were used to determine delta34 S ratios and sulfur contents of total sulfur, organic sulfur, SO4(21) and FeS2 in slope soils of karst areas. In general, FeS2 has the lowest delta34 S ratios, ranging from -6.86% per hundred to -4.229% per hundred, followed in ascending order by SO4(2-) (-2.64% per hundred - -1.34% per hundred), total sulfur (-3.25% per hundred - -1.03% per hundred) and organic sulfur (-1.63% per hundred -0.50% per hundred) in surface soils of profiles, and delta34 S ratios in different sulfur forms all show increasing trend with profiles deepening. Covariations of delta34 S ratios of SO4(2-) and FeS2 with increasing depth are related to SO4(2-) dissimilatory reduction, while the increase in parallel of delta34 S ratios of total sulfur and organic sulfur could be resulted from organic sulfur cycling. delta34 S ratios have been extensively used to indicate sulfur sources, moreover, SO4(2-) dissimilatory reduction and organic sulfur mineralization result in significant sulfur isotopic fractionation, and sulfides oxidation and SO4(2-) assimilation have no isotopic fractionation occurred, the vertical variations of delta34 S ratios in different sulfur forms can therefore be good records for depth-dependant sulfur cycling processes. Furthermore, by comparing depth distributions of sulfur contents and delta34 S ratios in different sulfur forms, it is easily to discuss the migration of SO4(-1) and organic sulfur fractions in soil profiles.

  7. Sulfur isotope enrichment during maintenance metabolism in the thermophilic sulfate-reducing bacterium Desulfotomaculum putei.

    PubMed

    Davidson, Mark M; Bisher, M E; Pratt, Lisa M; Fong, Jon; Southam, Gordon; Pfiffner, Susan M; Reches, Z; Onstott, Tullis C

    2009-09-01

    Values of Delta(34)S (=delta(34)S(HS)-delta(34)S(SO(4)), where delta(34)S(HS) and delta(34)S(SO(4)) indicate the differences in the isotopic compositions of the HS(-) and SO(4)(2-) in the eluent, respectively) for many modern marine sediments are in the range of -55 to -75 per thousand, much greater than the -2 to -46 per thousand epsilon(34)S (kinetic isotope enrichment) values commonly observed for microbial sulfate reduction in laboratory batch culture and chemostat experiments. It has been proposed that at extremely low sulfate reduction rates under hypersulfidic conditions with a nonlimited supply of sulfate, isotopic enrichment in laboratory culture experiments should increase to the levels recorded in nature. We examined the effect of extremely low sulfate reduction rates and electron donor limitation on S isotope fractionation by culturing a thermophilic, sulfate-reducing bacterium, Desulfotomaculum putei, in a biomass-recycling culture vessel, or "retentostat." The cell-specific rate of sulfate reduction and the specific growth rate decreased progressively from the exponential phase to the maintenance phase, yielding average maintenance coefficients of 10(-16) to 10(-18) mol of SO(4) cell(-1) h(-1) toward the end of the experiments. Overall S mass and isotopic balance were conserved during the experiment. The differences in the delta(34)S values of the sulfate and sulfide eluting from the retentostat were significantly larger, attaining a maximum Delta(34)S of -20.9 per thousand, than the -9.7 per thousand observed during the batch culture experiment, but differences did not attain the values observed in marine sediments.

  8. Sulfur isotope fractionation in modern euxinic systems: Implications for paleoenvironmental reconstructions of paired sulfate-sulfide isotope records

    NASA Astrophysics Data System (ADS)

    Gomes, Maya L.; Hurtgen, Matthew T.

    2015-05-01

    The sulfur (S) isotope difference between sulfates and sulfides preserved in sedimentary rocks (Δ34S) has been utilized to reconstruct ancient marine sulfate levels with implications for oxygenation of the Earth surface and biogeochemical cycling. S isotope data from modern, low-sulfate euxinic systems illustrate that preserved Δ34S values are positively correlated with sulfate concentration. However, absolute constraints on the range of low-sulfate levels over which preserved Δ34S values vary with sulfate concentration remain poorly constrained. Here, we present a compilation of S isotope data for modern euxinic systems demonstrating that preserved Δ34S values increase with sulfate concentration at low sulfate levels and approach values that are similar to in situ S isotope fractionation values from microbial sulfate reduction at high sulfate levels. We compare these results to a closed system model of S isotope cycling in a euxinic ocean in order to evaluate when the size of the sulfate reservoir is sufficiently small that Rayleigh fractionation affects the preservation of S isotope signatures. We conclude that the reservoir effect places constraints on Δ34S values deposited in euxinic settings at sulfate concentrations <5 mM. Thus, over this range, Δ34S values can be used to evaluate ancient sulfate levels. At higher sulfate levels (>10 mM), Δ34S values are similar to the kinetic isotope fractionation due to microbial sulfate reduction and therefore provide information about biological and environmental controls on sulfate reduction rates and location of pyrite formation. The results of this compilation provide an improved model for the use of Δ34S records to evaluate paleoenvironmental conditions in euxinic depositional environments.

  9. Molecular Studies of Alphavirus Immunogenicity.

    DTIC Science & Technology

    1992-04-23

    Griffin, D. E. (1986). Alphavirus pathogenesis and immunity. In " The Togaviridae and Flaviviridae &#34 (S. Schlesinger and M. J. Schlesinger, Ed.), pp...Strauss, J. H. (1986). Structure and replication of the alphavirus genome. In " The Togaviridae and Flaviviridae &#34 (S. Schlesinger and M. J. Schlesinger...5012 DISTRIBUTION STATEMENT: Approved for public release; distribution unlimited The findings in this report are not to be construed as an official

  10. Characterization of sulfur deposition over the period of industrialization in Japan using sulfur isotope ratio in Japanese cedar tree rings taken from stumps.

    PubMed

    Ishida, Takuya; Tayasu, Ichiro; Takenaka, Chisato

    2015-07-01

    We characterized the sulfur deposition history over the period of industrialization in Japan based on the sulfur isotope ratio (δ(34)S) in tree rings of Japanese cedar (Cryptomeria japonica D. Don) stumps. We analyzed and compared δ(34)S values in the rings from two types of disk samples from 170-year-old stumps that had been cut 5 years earlier (older forest stand) and from 40-year-old living trees (younger forest stand) in order to confirm the validity of using stump disks for δ(34)S analysis. No differences in δ(34)S values by age were found between the sample types, indicating that stump disks can be used for δ(34)S analysis. The δ(34)S profile in tree rings was significantly correlated with anthropogenic SO2 emissions in Japan (r = -0.76, p < 0.05) and, thus, tree rings serve as a record of anthropogenic sulfur emissions. In addition, the values did not change largely from pre-industrialization to the 1940s (+4.2 to +6.1‰). The values before the 1940s are expected to reflect the background sulfur conditions in Japan and, thus, disks containing rings formed before the 1940s contain information about the natural environmental sulfur, which is useful for biogeochemical studies.

  11. From acute to chronic pancreatitis: the role of mutations in the pancreatic secretory trypsin inhibitor gene.

    PubMed

    Hirota, Masahiko; Kuwata, Kinuko; Ohmuraya, Masaki; Ogawa, Michio

    2003-03-01

    Pancreatic secretory trypsin inhibitor (PSTI) is a potent natural inhibitor of trypsin. We proposed the hypothesis that, if the function of the PSTI is impaired by its genetic mutation, trypsin may easily promote autodigestion causing pancreatitis and we performed a mutational analysis of the PSTI gene in patients with pancreatitis. Two exonic mutations (N34S and R67C) were thought to be associated with a predisposition to pancreatitis. The N34S mutation was co-segregated with two intronic mutations, IVS1-37T>C and IVS3-69insTTTT. Although we analyzed the function of the recombinant N34S protein, we could not demonstrate the loss of function of this protein. Intronic mutations, rather than N34S itself (IVS1-37T>C + N34S + IVS3-69insTTTT complex), may be associated with the decreased function of the PSTI. Alternatively, increased digestion of N34S in vivo may be applicable. As for R67C, the conformational alteration of the protein by forming intra-molecular or inter-molecular disulfide bonds with 67Cys was strongly suggested. These results, along with the brand-new findings in PSTI knockout mice, suggest that the genetic mutation of the PSTI is one of the important mechanisms for predisposition to pancreatitis by lowering the trypsin inhibitory function.

  12. Characteristics of a strong promoter from figwort mosaic virus: comparison with the analogous 35S promoter from cauliflower mosaic virus and the regulated mannopine synthase promoter.

    PubMed

    Sanger, M; Daubert, S; Goodman, R M

    1990-03-01

    A segment of DNA from the genome of figwort mosaic virus (FMV) strain M3 possesses promoter activity when tested in electroporated protoplasts from, and transgenic plants of, Nicotiana tabacum cv. Xanthi nc. The 1.1 kb DNA segment, designated the '34S' promoter, is derived from a position on the FMV genome comparable to the position on the cauliflower mosaic virus (CaMV) genome containing the 35S promoter. The 34S and 35S promoters show approximately 63% nucleotide homology in the TATA, CCACT, and -18 to +1 domains, but in sequences further upstream the homology drops below 50%. Promoter activities were estimated using beta-glucuronidase and neomycin phosphotransferase II reporter gene systems. The activity of the 34S promoter segment approximates that of the 35S promoter in both protoplast transient expression assays and in stably transformed tobacco plants. Truncation of 5' sequences from the 34S promoter indicates that promoter strength depends upon DNA sequences located several hundred nucleotides upstream from the TATA box. In leaf tissue the 34S promoter is 20-fold more active than the mannopine synthase (MAS) promoter from Agrobacterium tumefaciens T-DNA. The 34S promoter lacks the root-specific and wound-stimulated expression of the MAS promoter, showing relatively uniform root, stem, leaf, and floral activities.

  13. Open-system degassing of sulfur from Krakatau 1883 magma

    NASA Astrophysics Data System (ADS)

    Mandeville, Charles W.; Sasaki, Akira; Saito, Genji; Faure, Kevin; King, Robert; Hauri, Erik

    1998-08-01

    We present the first sulfur and oxygen isotopic data for tephra from the catastrophic 1883 eruption of Krakatau. Sulfur isotopic ratios in unaltered Krakatau tephra erupted August 26-27, 1883 are markedly enriched in 34S relative to mantle sulfur. High δ34S values of +6.3 to +16.4‰ can best be explained by open-system or multi-stage degassing of SO 2 from the oxidized rhyodacitic and gray dacitic magmas with 34S enrichment of SO 2-4 remaining in the melt. Lower whole-rock δ34S values of +2.6‰ and +4.0‰ in two oxidized gray dacitic samples indicate more primitive subarc mantle sulfur in the 1883 magma chamber. Initial δ34S of the rhyodacitic magma was probably in the +1.5‰ to +4.0‰ range and similar to δ34S values measured in arc volcanic rocks from the Mariana Arc.

  14. Compound-specific sulfur isotope analysis of thiadiamondoids of oils from the Smackover Formation, USA

    NASA Astrophysics Data System (ADS)

    Gvirtzman, Zvi; Said-Ahmad, Ward; Ellis, Geoffrey S.; Hill, Ronald J.; Moldowan, J. Michael; Wei, Zhibin; Amrani, Alon

    2015-10-01

    Thiadiamondoids (TDs) are diamond-like compounds with a sulfide bond located within the cage structure. These compounds were suggested as a molecular proxy for the occurrence and extent of thermochemical sulfate reduction (TSR). Compound-specific sulfur-isotope analysis of TDs may create a multi-parameter system, based on molecular and δ34S values that may be sensitive over a wider range of TSR and thermal maturation stages. In this study, we analyzed a suite of 12 Upper Jurassic oil and condensate samples generated from source rocks in the Smackover Formation to perform a systematic study of the sulfur isotope distribution in thiadiamondoids (one and two cages). For comparison we measured the δ34S composition of benzothiophenes (BTs) and dibenzothiophenes (DBTs). We also conducted pyrolysis experiments with petroleum and model compounds to have an insight into the formation mechanisms of TDs. The δ34S of the TDs varied significantly (ca 30‰) between the different oils depending on the degree of TSR alteration. The results showed that within the same oil, the one-cage TDs were relatively uniform, with 34S enriched values similar to those of the coexisting BTs. The two-cage TDs had more variable δ34S values that range from the δ34S values of BTs to those of the DBTs, but with general 34S depletion relative to one cage TDs. Hydrous pyrolysis experiments (360 °C, 40 h) with either CaSO4 or elemental S (equivalent S molar concentrations) and adamantane as a model compound demonstrate the formation of one cage TDs in relatively low yields (<0.2%). Higher concentrations of TDs were observed in the elemental sulfur experiments, most likely because of the higher rates of reaction with adamantane under these experimental conditions. These results show that the formation of TDs is not exclusive to TSR reactions, and that they can also form by reaction with reduced S species apart from sulfate reduction, though at low yields. Oxygenated compounds, most notably 2

  15. Compound-specific sulfur isotope analysis of thiadiamondoids of oils from the Smackover Formation, USA

    USGS Publications Warehouse

    Zvi Gvirtzman,; Ward Said-Ahmad,; Ellis, Geoffrey S.; Ronald J. Hill,; J. Michael Moldowan,; Zhibin Wei,; Alon Amrani,

    2015-01-01

    Thiadiamondoids (TDs) are diamond-like compounds with a sulfide bond located within the cage structure. These compounds were suggested as a molecular proxy for the occurrence and extent of thermochemical sulfate reduction (TSR). Compound-specific sulfur-isotope analysis of TDs may create a multi-parameter system, based on molecular and δ34S values that may be sensitive over a wider range of TSR and thermal maturation stages. In this study, we analyzed a suite of 12 Upper Jurassic oil and condensate samples generated from source rocks in the Smackover Formation to perform a systematic study of the sulfur isotope distribution in thiadiamondoids (one and two cages). For comparison we measured the δ34S composition of benzothiophenes (BTs) and dibenzothiophenes (DBTs). We also conducted pyrolysis experiments with petroleum and model compounds to have an insight into the formation mechanisms of TDs. The δ34S of the TDs varied significantly (ca 30‰) between the different oils depending on the degree of TSR alteration. The results showed that within the same oil, the one-cage TDs were relatively uniform, with 34S enriched values similar to those of the coexisting BTs. The two-cage TDs had more variable δ34S values that range from the δ34S values of BTs to those of the DBTs, but with general 34S depletion relative to one cage TDs. Hydrous pyrolysis experiments (360 °C, 40 h) with either CaSO4 or elemental S (equivalent S molar concentrations) and adamantane as a model compound demonstrate the formation of one cage TDs in relatively low yields (<0.2%). Higher concentrations of TDs were observed in the elemental sulfur experiments, most likely because of the higher rates of reaction with adamantane under these experimental conditions. These results show that the formation of TDs is not exclusive to TSR reactions, and that they can also form by reaction with reduced S species apart from sulfate reduction, though at low yields. Oxygenated compounds, most notably 2

  16. High arsenic concentrations and enriched sulfur and oxygen isotopes in a fractured-bedrock ground-water system

    USGS Publications Warehouse

    Lipfert, G.; Sidle, W.C.; Reeve, A.S.; Ayuso, R.A.; Boyce, A.J.

    2007-01-01

    Ground water with high arsenic concentrations (up to 26.6????mol L- 1) has sulfate enriched in 34S and 18O in the fractured-bedrock, ground-water system of the Kelly's Cove watershed, Northport, Maine, USA. The ranges of sulfur and oxygen isotope values in aqueous sulfate, ??34S[SO4] and ??18O[SO4], at the Kelly's Cove watershed are + 3.4 to + 4.9??? and - 2.0 to + 6.7???, respectively. These isotope values are strikingly similar to those of the Goose River, Maine watershed which has ??34S[SO4] and ??18O[SO4] ranges of + 3.7 to + 4.6 ??? and - 2.6 to + 7.5???, respectively. In both systems, high arsenic concentrations occur with high ??34S[SO4] and ??18O[SO4] values, yet redox conditions and underlying rock types are quite different. The isotope values of sulfide minerals, ??34S[min], from four bedrock cores vary over short distances and range from - 5.1 to + 7.5???. The ??34S[SO4] values are controlled by the ??34S[min] values with minor input of atmospheric SO4. The much narrower range in ??34S[SO4] values than ??34S[min] values is probably due to sufficient ground-water mixing at a scale greater than the ??34S[min] variability. The ??34S[SO4] values are about 2??? higher than the average ??34S[min] value and fall within the range of ??34S[min] values, indicating only minor fractionation due to bacterial reduction of SO4. The highest ??18O[SO4] values were measured in the downgradient, confined, arsenic-rich ground water. High ??18O[SO4] values there cannot be due to aeration by atmospheric oxygen, but may arise from reoxidation of reduced SO4 products. The enrichment factors of ??18O in SO4 compared to H2O, + 7.2 to + 15.5???, in the Kelly's Cove ground water and the negligible 34S enrichment is very similar to those derived from experimental data of anaerobic sulfide oxidation in the presence of Mn and Fe oxides. Sea level at the Kelly's Cove watershed was approximately 80??m above present sea level about 13 000??years before present, imposing reducing

  17. Sulfur isotope dynamics in two central european watersheds affected by high atmospheric deposition of SO x

    NASA Astrophysics Data System (ADS)

    Novák, Martin; Kirchner, James W.; Groscheová, Hana; Havel, Miroslav; Černý, Jiří; Krejčí, Radovan; Buzek, František

    2000-02-01

    Sulfur fluxes and δ34S values were determined in two acidified small watersheds located near the Czech-German border, Central Europe. Sulfur of sulfate aerosol in the broader region (mean δ 34S of 7.5‰ CDT) was isotopically heavier than sulfur of airborne SO 2 (mean δ 34S of 4.7‰). The annual atmospheric S deposition to the Jezeřı´ watershed decreased markedly in 1993, 1994, and 1995 (40, 33, and 29 kg/ ha · yr), reflecting reductions in industrial S emissions. Sulfur export from Jezeří via surface discharge was twice atmospheric inputs, and increased from 52 to 58 to 85 kg/ha · yr over the same three-year period. The δ 34S value of Jezeřı´ streamflow was 4.5 ± 0.3‰, intermediate between the average atmospheric deposition (5.4 ± 0.2‰) and soil S (4.0 ± 0.5‰), suggesting that the excess sulfate in runoff comes from release of S from the soil. Bedrock is not a plausible source of the excess S, because its S concentration is very low (<0.003 wt.%) and because its δ 34S value is too high (5.8‰) to be consistent with the δ 34S of runoff. A sulfur isotope mixing model indicated that release of soil S accounted for 64 ± 33% of sulfate S in Jezeřı´ discharge. Approximately 30% of total sulfate S in the discharge were organically cycled. At Načetı´n, the same sequence of δ34S IN > δ34S OUT > δ34S SOIL was observed. The seasonality found in atmospheric input (higher δ 34S in summer, lower δ 34S in winter) was preserved in shallow (<10 cm) soil water, but not in deeper soil water. δ 34S values of deeper (>10 cm) soil water (4.8 ± 0.2‰) were intermediate between those of atmospheric input (5.9 ± 0.3‰) and Nac̆etín soils (2.4 ± 0.1‰), again suggesting that remobilization of soil S accounts for a significant fraction (roughly 40 ± 10%) of the S in soil water at Načetı´n. The inventories of soil S at both of these sites are legacies of more intense atmospheric pollution during previous decades, and are large enough (740

  18. The multiple sulfur isotopic composition of iron meteorites: Implications for nebular evolution

    NASA Astrophysics Data System (ADS)

    Antonelli, Michael Ariel

    2013-12-01

    Multiple sulfur isotopic measurements of troilite from 61 different iron meteorites were undertaken in order to test for sulfur isotopic homogeneity within (and between) 8 different iron meteorite groups. It was found that different members within a given group of iron meteorites have homogeneous Delta 33S compositions, but that these Delta33S compositions differ between groups. This thesis shows that iron meteorites from the groups IC, IIAB, IIIAB, IIIF, and IVA have small yet resolvable enrichments or depletions in Delta33S relative to Canyon Diablo Troilite (CDT) and troilite from other non-magmatic (IAB and IIE) iron meteorites. The observed anomalous sulfur isotopic compositions in magmatic iron meteorites are most consistent with Lyman-alpha photolysis of H2S, pointing towards inheritance of an unexpected photolytically-derived sulfur component in magmatic iron meteorite groups which is absent in non-magmatic iron meteorites, chondrites, and the Earth-Moon System.

  19. Protein unfolding as a switch from self-recognition to high-affinity client binding

    PubMed Central

    Groitl, Bastian; Horowitz, Scott; Makepeace, Karl A. T.; Petrotchenko, Evgeniy V.; Borchers, Christoph H.; Reichmann, Dana; Bardwell, James C. A.; Jakob, Ursula

    2016-01-01

    Stress-specific activation of the chaperone Hsp33 requires the unfolding of a central linker region. This activation mechanism suggests an intriguing functional relationship between the chaperone's own partial unfolding and its ability to bind other partially folded client proteins. However, identifying where Hsp33 binds its clients has remained a major gap in our understanding of Hsp33's working mechanism. By using site-specific Fluorine-19 nuclear magnetic resonance experiments guided by in vivo crosslinking studies, we now reveal that the partial unfolding of Hsp33's linker region facilitates client binding to an amphipathic docking surface on Hsp33. Furthermore, our results provide experimental evidence for the direct involvement of conditionally disordered regions in unfolded protein binding. The observed structural similarities between Hsp33's own metastable linker region and client proteins present a possible model for how Hsp33 uses protein unfolding as a switch from self-recognition to high-affinity client binding. PMID:26787517

  20. Dynamic Response of an Ice-Breaker Hull to Ice Breaking

    DTIC Science & Technology

    1984-02-01

    CNN ) SiN3W0W S S ® iS ® C33S/W) AiI0013A...J . . . 1 (S !S CS (S cs CN!) 33yOJ CNN ) SiN3W0W C33S/N) AiI3013A 87 w (S CO o z a UJ CO N. r CM CM CS I _1 UJ > u u CO CO...UJ (/) s Id z: H .00 ,(D ,C\\J s s CM S .(S S s iS CN!) 33yOJ CNN ) SiN3W0N C33S/W) AiI3013A 88 e» CO o z Of u UJ CO N.

  1. Large sulfur isotope fractionations associated with Neoarchean microbial sulfate reduction.

    PubMed

    Zhelezinskaia, Iadviga; Kaufman, Alan J; Farquhar, James; Cliff, John

    2014-11-07

    The minor extent of sulfur isotope fractionation preserved in many Neoarchean sedimentary successions suggests that sulfate-reducing microorganisms played an insignificant role in ancient marine environments, despite evidence that these organisms evolved much earlier. We present bulk, microdrilled, and ion probe sulfur isotope data from carbonate-associated pyrite in the ~2.5-billion-year-old Batatal Formation of Brazil, revealing large mass-dependent fractionations (approaching 50 per mil) associated with microbial sulfate reduction, as well as consistently negative Δ(33)S values (~ -2 per mil) indicative of atmospheric photochemical reactions. Persistent (33)S depletion through ~60 meters of shallow marine carbonate implies long-term stability of seawater sulfate abundance and isotope composition. In contrast, a negative Δ(33)S excursion in lower Batatal strata indicates a response time of ~40,000 to 150,000 years, suggesting Neoarchean sulfate concentrations between ~1 and 10 μM.

  2. Correlations Between Surficial Sulfur and a REE Crustal Assimilation Signature in Martian Shergottites

    NASA Technical Reports Server (NTRS)

    Jones, J. H.; Franz, H. B.

    2015-01-01

    Compared to terrestrial basalts, the Martian shergottite meteorites have an extraordinary range of Sr and Nd isotopic signatures. In addition, the S isotopic compositions of many shergottites show evidence of interaction with the Martian surface/ atmosphere through mass-independent isotopic fractionations (MIF, positive, non-zero delta(exp 33)S) that must have originated in the Martian atmosphere, yet ultimately were incorporated into igneous sulfides (AVS - acid-volatile sulfur). These positive delta(exp 33)S signatures are thought to be governed by solar UV photochemical processes. And to the extent that S is bound to Mars and not lost to space from the upper atmosphere, a positive delta(exp 33)S reservoir must be mass balanced by a complementary negative reservoir.

  3. Sulphur isotope geochemistry of the ores and country rocks at the Almadén mercury deposit, Ciudad Real, Spain

    NASA Astrophysics Data System (ADS)

    Saupé, Francis; Arnold, Michel

    1992-10-01

    Seventy-four new S isotope analyses of ore minerals and country rocks are given for the Hg deposit of Almadén. The spread of the cinnabar δ34S is narrow within each of the three orebodies, but the δ34S average values differ sufficiently between them (mean δ34S: San Nicolas = 0.2 ± 1.1 %., San Francisco = 8.1 ± 0.7%., San Pedro = 5.9 ± 1.0%.) to indicate three different mineralization episodes and possibly processes. The unweighted mean for all cinnabar samples is 5.6%. and the S source is considered to be the host-rocks, either the Footwall Shales ( δ34S = 5.5%.) or the spilites ( δ34 S = 5.1 ± 1.3%.). For geometric and chronologic reasons, the former seem the best potential source. However, the high δ34 S values of the San Francisco cinnabar cannot be explained without addition of heavy S from reduction of seawater sulphate. Orderly distributions of the δ34S values are observed in all three orebodies: (1) their increase from the stratigraphic bottom to the top in the San Pedro orebody is explained by a Rayleigh process, and (2) the maxima in the centres of the San Francisco and San Nicolas orebodies are explained by mixing of the S transporting hydrothermal fluids with seawater within the sediments. Associated pyrite and cinnabar were deposited under isotopic disequilibrium, probably because the low solubility of cinnabar caused rapid precipitation of cinnabar. The different morphological pyrite types have their own isotopic δ34S signatures. The spilites are notably enriched in S ( n = 3; average S content = 0.56%) compared to normal basalts (1000 ppm) and have an average δ34S = 5.1 ± 1.3%.. The linear relationship between the δ34S and the S content of the spilites is interpreted as a mixing line between mantle S and a constant S source, probably an infinite open reservoir. An incomplete basalt-seawater reaction at nearly constant temperature is the best explanation for this relation. The S (predominantly pyrite) of the black shales ( n = 3; δ34S

  4. Sulfur Isotope Variation in Melt Inclusions From Arc Basalts Revealed By Secondary Ion Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    Mandeville, C. W.; Shimizu, N.; Kelley, K. A.

    2009-12-01

    Subduction zones are sites where elements once at the Earth’s surface are recycled back to the mantle. Arc volcanoes return volatiles and hydrous melts to the surface. Understanding of sulfur recycling in magmatic arcs is hampered by insufficient data on net sulfur isotopic composition of slab inputs, that range from δ34S of seawater (21‰) to negative δ34S of -70‰ for secondary sulfides, to values of 0 ± 3‰ in relict magmatic sulfides. We lack sufficient knowledge of the sulfur concentration and isotopic composition of the mantle wedge. Degassing and assimilation of crustal sulfur may produce changes to initial sulfur isotope ratios of magmas. To preclude degassing effects, we measured S isotope ratios in mafic melt inclusions by secondary ionization mass spectrometry (SIMS) from three arc volcanoes, Galunggung, and Krakatau in Indonesia, and Augustine, in Alaska. These data provide a view of the variability of initial sulfur isotope ratios of mafic arc magmas and are being evaluated for correlations with sulfur and iron oxidation state, dissolved volatiles, trace elements, and degassing effects in order to determine the origin(s) of dissolved S. Olivine-hosted melt inclusions from a basaltic bomb from the 1982-1983 Galunggung eruption represent the relatively dry adiabatic decompression melting end member of primary arc magma genesis (Sisson and Bronto,1998). New SIMS δ34S measurements of Galunggung melt inclusions yield ratios from -3.0‰ to +5.0‰ with S concentrations of 1950 ppm - 990 ppm. A few Galunggung inclusions have δ34S between 0.5‰ and 1.4‰ with S conc.'s of 1690 - 1760 ppm, that are within the mantle range, and have low water contents of 0.25 to 0.30 wt.% (Kelley et al. 2005). A subgroup of inclusions yield δ34S of 2.8‰ to 5.0‰ and 990 - 1920 ppm S. Pre-1883 basaltic scoria from Krakatau volcano contain olivine-hosted melt inclusions with water and CO2 concentrations from 1.8 - 4.1 wt.% and 79 - 1017 ppm, respectively

  5. Influence of structural setting on sulphur isotopes in Archean orogenic gold deposits, Eastern Goldfields Province, Yilgarn, Western Australia

    NASA Astrophysics Data System (ADS)

    Hodkiewicz, P. F.; Groves, D. I.; Davidson, G. J.; Weinberg, R. F.; Hagemann, S. G.

    2009-02-01

    The published mean δ34S values of ore-related pyrites from orogenic gold deposits of the Eastern Goldfields Province, Yilgarn Craton lie between -4‰ and +4‰. As for orogenic gold deposits worldwide, most deposits have positive means and a restricted range of δ34S values, but some have negative means and wider ranges of δ34S values. Wall-rock carbonation and back-mixing of similar-source fluids with different fluid pathways can explain some of the more negative δ34S signatures. However, structural setting appears to be the most important factor controlling ore-fluid oxidation state and hence the distribution of δ34S values in gold-related pyrites. Shear-hosted deposits appear to have experienced fluid-dominated processes such as phase separation, whereas stockwork, vein-hosted or disseminated deposits formed under conditions of greater rock buffering. At Victory-Defiance, in particular, negative δ34S values are more common in gently dipping dilational structures, compared to more compressional steeply dipping structures. It appears most likely that fluid-pressure fluctuations during fault-valve cycles establish different fluid-flow regimes in structures with different orientations. Rapid fluid-pressure fluctuations in dilational structures during seismic activity can cause partitioning of reduced gas phases from the ore fluid during extreme phase separation and hence are an effective method of ore-fluid oxidation, leading to large, local fluctuations in oxidation state. It is thus not necessary to invoke mixing with oxidised magmatic fluids to explain δ34S signatures indicative of oxidation. In any case, available, robust geochronology in the Eastern Goldfields Province does not support the direct involvement of oxidised magmatic fluids from adjacent granitic intrusions in orogenic gold genesis. Thus, negative mean δ34S values and large variations in δ34S values of ore-related pyrites in world-class orogenic gold deposits are interpreted to result from

  6. Assessing the Influences of Mercury Bioaccumulation and Bioavailability in Everglades Food Webs

    NASA Astrophysics Data System (ADS)

    Kendall, C.; Bemis, B. E.

    2005-05-01

    Eastern mosquitofish are an important sentinel species used to monitor mercury contamination of the aquatic ecosystem in the Everglades. Like other freshwater fish, the primary route of mercury uptake into mosquitofish tissues is through diet as bioavailable methylmercury. Yet, it is unclear whether variations in mosquitofish mercury observed across the Everglades are due primarily to differences in bioaccumulation (i.e., increase of mercury at higher trophic levels) or abundance of methylmercury available to the food web base. We use isotopic methods to investigate the importance of these two controls on mosquitofish mercury at the landscape scale. As part of the USEPA REMAP project, mosquitofish, periphyton, and sediments were collected during September 1996 from over one hundred sites throughout the Everglades and analyzed for mercury concentration and many other parameters. The USGS analyzed splits of the samples for d15N, d13C, and d34S. Mosquitofish were analyzed as composites of 5-10 fish and periphyton and 0-5 cm sediment samples were analyzed in bulk. Tissue d15N is widely used to estimate the relative trophic positions of organisms in a food web, and should correlate positively with tissue mercury if bioaccumulation is an important control on mosquitofish mercury concentration. Tissue d34S values potentially indicate the extent of dissimilatory sulfate reduction in sediments, a process used by sulfate-reducing bacteria (SRB) during conversion of inorganic Hg(II) to bioavailable methylmercury. Because this process increases the d34S value of remaining sulfate (assimilated by the food web base), mosquitofish d34S should show positive correlations with SRB activity, methylmercury production, and mosquitofish mercury concentrations. Mosquitofish and periphyton isotopes are significantly correlated (d15N-Mosq vs. d15N-Peri, d34S-Mosq vs. d34S-Peri), indicating that a component of the bulk periphyton analyzed in this study is part of the mosquitofish food web

  7. Origin of Sulfur in Diet Drives Spatial and Temporal Mercury Trends in Seabird Eggs From Pacific Canada 1968-2015.

    PubMed

    Elliott, Kyle H; Elliott, John E

    2016-12-20

    Mercury (Hg) is a neurotoxin that can be particularly harmful to top predators because it biomagnifies through the food web. Due to variation in the food web structure, variation in Hg exposure in predators may represent variation in diet rather than Hg availability. We measured Hg in eggs from six seabird species (N = 537) over 47 years. In contrast to expectation, storm-petrels feeding partially on invertebrates had the highest Hg burden while herons feeding on large fish had the lowest Hg burden. A multiple regression showed that Hg correlated with δ(34)S (R(2) = 0.86) rather than trophic level (δ(15)N of "trophic" amino acids). Sulfate-rich environments (high δ(34)S) have sulfate-reducing bacteria that produce methylmercury. Variation in Hg within and among seabirds near the top of the food web was associated with variation in δ(34)S at the base of the food web more so than trophic position within the food web. Hg levels in seabirds only changed over time for those species where δ(34)S also varied in tandem; after accounting for diet (δ(34)S), there was no variation in Hg levels. Variation in Hg in seabirds across space and time was associated with the origin of sulfur in the diet.

  8. Stable isotopic evidence for anaerobic maintained sulphate discharge in a polythermal glacier

    NASA Astrophysics Data System (ADS)

    Ansari, A. H.

    2016-03-01

    To understand the sources and sinks of sulphate and associated biogeochemical processes in a High Arctic environment, late winter snowpacks, the summer melt-waters and rock samples were collected and analysed for major ions and stable isotope tracers (δ18O, δ34S). The SO42bar/Clbar ratio reveal that more than 87% of sulphate (frequently > 95%) of total sulphate carried by the subglacial runoff and proglacial streams was derived from non-snowpack sources. The proximity of non-snowpack sulphate δ34S (∼8-19‰) to the δ34S of the major rocks in the vicinity (∼-6 to +18‰) suggest that the non-snowpack sulphate was principally derived from rock weathering. Furthermore, Ca2++Mg2+/SO42ˉ molar shows that sulphate acquisition in the meltwaters was controlled by two major processes: 1) coupled-sulphide carbonate weathering (molar ratio ∼ 2) and, 2) re-dissolution of secondary salts (molar ratio ∼ 1). The δ34S-SO4 = +19.4‰ > δ34S-S of rock, accompanied by increased sulphate concentration also indicates an input from re-dissolution of secondary salts. Overall, δ18O composition of these non-snowpack sulphate (-11.9 to -2.2‰) mostly stayed below the threshold δ18O value (-6.7 to -3.3‰) for minimum O2 condition, suggesting that certain proportion of sulphate was regularly supplied from anaerobic sulphide oxidation.

  9. Indicating atmospheric sulfur by means of S-isotope in leaves of the plane, osmanthus and camphor trees.

    PubMed

    Xiao, Hua-Yun; Wang, Yan-Li; Tang, Cong-Guo; Liu, Cong-Qiang

    2012-03-01

    Foliar δ(34)S values of three soil-growing plant species (Platanus Orientalis L., Osmanthus fragrans L. and Cinnamomum camphora) have been analyzed to indicate atmospheric sulfur. The foliar δ(34)S values of the three plant species averaged -3.11±1.94‰, similar to those of both soil sulfur (-3.73±1.04‰) and rainwater sulfate (-3.07±2.74‰). This may indicate that little isotopic fractionation had taken place in the process of sulfur uptake by root or leaves. The δ(34)S values changed little in the transition from mature leaves to old/senescing leaves for both the plane tree and the osmanthus tree, suggestive of little isotope effect during sulfur redistribution in plant tissues. Significantly linear correlation between δ(34)S values of leaves and rainwater sulfate for the plane and osmanthus trees allowed the tracing of temporal variations of atmospheric sulfur by means of foliar sulfur isotope, while foliage δ(34)S values of the camphor is not an effective indicator of atmospheric sulfur.

  10. Sulfur redox reactions: Hydrocarbons, native sulfur, Mississippi Valley-type deposits, and sulfuric acid karst in the Delaware Basin, New Mexico and Texas

    SciTech Connect

    Hill, C.A.

    1995-02-01

    Hydrocarbons, native sulfur, Mississippi Valley-type (MVT) deposits, and sulfuric acid karst in the Delaware Basin, southeastern New Mexico, and west Texas, USA, are all genetically related through a series of sulfur redox reactions. The relationship began with hydrocarbons in the basin that reacted with sulfate ions from evaporite rock to produce isotopically light ({delta}{sup 34}S = -22 to -12) H{sub 2}S and bioepigenetic limestone (castiles). This light H{sub 2}S was then oxidized at the redox interface to produce economic native sulfur deposits ({delta}{sup 34}S = -15 to +9) in the castiles, paleokarst, and along graben-boundary faults. This isotopically light H{sub 2}S also migrated from the basin into its margins to accumulate in structural (anticlinal) and stratigraphic (Yates siltstone) traps, where it formed MVT deposits within the zone of reduction ({delta}{sup 34}S = -15 to +7). Later in time, in the zone of oxidation, this H{sub 2}S reacted with oxygenated water to produce sulfuric acid, which dissolved the caves (e.g., Carlsbad Cavern and Lechuguilla Cave, Guadalupe Mountains). Massive gypsum blocks on the floors of the caves ({delta}{sup 34}S = -25 to +4) were formed as a result of this reaction. The H{sub 2}S also produced isotopically light cave sulfur ({delta}{sup 34}S = -24 to -15), which is now slowly oxidizing to gypsum in the presence of vadose drip water. 16 refs., 10 figs.

  11. CTC Sentinel. Volume 7, Issue 10, October 2014

    DTIC Science & Technology

    2014-10-01

    objective was to 7 United States of America v Liberty Reserve S.A, No. USA -33s-274 (Ed. 9-25-58), United States District Court, Southern District of...Ross William Ulbricht, USA - 33s-274 (Ed. 9-25-58), United States District Court, Southern District of New York, February 4, 2014. 12 Tor is free...20 These discussions were posted to the Shumukh al- Islam Network on April 29, 2013. oCToBeR 2014 . VoL 7. IssUE 10 “Cryptography is a never- ending

  12. Variations in the magnitude of non mass dependent sulfur fractionation in the Archean atmosphere

    NASA Astrophysics Data System (ADS)

    Claire, M.; Kasting, J. F.

    2010-12-01

    Recent experimental data have enabled quantitatively meaningful computations of the non-mass dependent fractionation of sulfur’s isotopes (Δ33S) that exemplify the Archean rock record. The Δ33S signal originates as a result of fine structure in the absorption cross-section of SO2 isotopologues [1], which only undergo significant photolysis in reducing atmospheres [2]. The Δ33S signal produced by SO2 photolysis varies significantly between 190 and 220 nm, and thus is strongly dependent on any other atmospheric gases which absorb photons in this range [3], as well as the height at which photolysis occurs. A model that is capable of resolving the altitude-dependent radiative transfer through a realistic self-consistent reducing atmosphere is therefore essential when making direct comparisons between atmospheric Δ33S production and the rock record. In this work, we investigate how the magnitude of Δ33S might vary as function of atmospheric composition, which in turn allows the rock record to constrain the Archean atmosphere. Other recent work on this topic using simplied atmospheric models has implicated large concentrations of SO2 [5], OCS [3], and CO2 [6] as being responsible for the variations in Archean Δ33S. We present results from an altitude-dependent photochemical model of Archean photochemistry [4] of necessary complexity to resolve the complicated redox structure of the Archean atmosphere. We show that while increased concentrations of these gases all affect Δ33S in an unconstrained model, the atmospheric conditions required for OCS or SO2 shielding are unlikely to occur in an Archean atmosphere constrained by reasonable expectations of volcanic and biogenic fluxes. Within the context of plausible Archean atmospheres, we investigate how shielding due to changing amounts of CO2, biogenic sulfur gases, and fractal organic haze [7] affect the magnitude of Δ33S produced by the Archean atmosphere, and show why simplified atmospheric modeling may lead to

  13. TR-LIF LIFETIME MEASUREMENTS AND HFR+CPOL CALCULATIONS OF RADIATIVE PARAMETERS IN VANADIUM ATOM (V I)

    SciTech Connect

    Wang, Q.; Jiang, L. Y.; Shang, X.; Tian, Y. S.; Dai, Z. W.; Quinet, P.; Palmeri, P.; Zhang, W. E-mail: Pascal.quinet@umons.ac.be

    2014-04-01

    Radiative lifetimes of 79 levels belonging to the 3d {sup 3}4s4p, 3d {sup 4}4p, 3d {sup 3}4s5p, 3d {sup 4}5p, and 3d {sup 3}4s4d configurations of V I with energy from 26,604.807 to 46,862.786 cm{sup –1} have been measured using time-resolved laser-induced fluorescence (TR-LIF) spectroscopy in laser-produced plasma. The lifetime values reported in this paper are in the range of 3.3-494 ns, and the uncertainties of these measurements are within ±10%. A good agreement was obtained with previous data. HFR+CPOL calculations have been performed and used to combine the calculated branching fractions with the available experimental lifetimes to determine semi-empirical transition probabilities for 784 V I transitions.

  14. DMS Sulphate and MSA as tracers of marine biogenic productivity in an Arctic snowpack

    NASA Astrophysics Data System (ADS)

    Wasiuta, V.; Norman, A.; Marshall, S.

    2007-12-01

    Sources, seasonal patterns, and spatial variations of snowpack sulphate of the Prince of Wales Icefield, Ellesmere Island were assessed using δ34S values along with major ion and MSA concentrations. Snowpack sulphate concentrations and δ34S values diminished with elevation and inland distance suggesting that the proximal North Water Polynya was the major sulphate source with additional sources affecting specific regions. Snowpack δ34S values in depth profile reflected seasonal cycles of marine biogenic, anthropogenic, and sea-salt aerosols with appreciable contributions of marine biogenic sulphate to virtually every depth horizon. A proximal April/May marine biogenic source was indicated, with DMS oxidation occurring near the marine boundary layer, and the possibility of additional oxidation at higher atmospheric levels. Depositional patterns of DMS sulphate and MSA indicate they were oxidized from DMS at different elevations in the atmosphere and that their deposition routes differed.

  15. In situ sulfur isotope analysis of sulfide minerals by SIMS: Precision and accuracy, with application to thermometry of ~3.5Ga Pilbara cherts

    USGS Publications Warehouse

    Kozdon, R.; Kita, N.T.; Huberty, J.M.; Fournelle, J.H.; Johnson, C.A.; Valley, J.W.

    2010-01-01

    Secondary ion mass spectrometry (SIMS) measurement of sulfur isotope ratios is a potentially powerful technique for in situ studies in many areas of Earth and planetary science. Tests were performed to evaluate the accuracy and precision of sulfur isotope analysis by SIMS in a set of seven well-characterized, isotopically homogeneous natural sulfide standards. The spot-to-spot and grain-to-grain precision for δ34S is ± 0.3‰ for chalcopyrite and pyrrhotite, and ± 0.2‰ for pyrite (2SD) using a 1.6 nA primary beam that was focused to 10 µm diameter with a Gaussian-beam density distribution. Likewise, multiple δ34S measurements within single grains of sphalerite are within ± 0.3‰. However, between individual sphalerite grains, δ34S varies by up to 3.4‰ and the grain-to-grain precision is poor (± 1.7‰, n = 20). Measured values of δ34S correspond with analysis pit microstructures, ranging from smooth surfaces for grains with high δ34S values, to pronounced ripples and terraces in analysis pits from grains featuring low δ34S values. Electron backscatter diffraction (EBSD) shows that individual sphalerite grains are single crystals, whereas crystal orientation varies from grain-to-grain. The 3.4‰ variation in measured δ34S between individual grains of sphalerite is attributed to changes in instrumental bias caused by different crystal orientations with respect to the incident primary Cs+ beam. High δ34S values in sphalerite correlate to when the Cs+ beam is parallel to the set of directions , from [111] to [110], which are preferred directions for channeling and focusing in diamond-centered cubic crystals. Crystal orientation effects on instrumental bias were further detected in galena. However, as a result of the perfect cleavage along {100} crushed chips of galena are typically cube-shaped and likely to be preferentially oriented, thus crystal orientation effects on instrumental bias may be obscured. Test were made to improve the analytical

  16. Microwave, Semiconductor Research - Materials, Devices and Circuits.

    DTIC Science & Technology

    1984-03-01

    Appl. Phys., 53 (9) 6208-6213 (Sept. 1982). 1. 2. "Investigation of Capless Heat Treatment of MBE n-GaAs&#34, S.H. Xin, W.J. Schaff, C.E.C. Wood and L.F...4 I 4. "Capped Versus Capless Heat Treatment of MBE n-GaAs&#34, S.H. Xin, W.J. Schaff, C.E.C. Wood and L.F. Eastman, Appl. Phys. Lett., 41 (8) 742...Capless Heat Treatment of Molecular Beam Epitaxial GaAs&#34, S.H. Xin, W.J. Schaff, C.E.C. Wood and L.F. Eastman, Appl. Phys. Lett., 41 (8) 742-744 (Oct

  17. Sulphur diagenesis in the sediments of the Kiel Bight, SW Baltic Sea, as reflected by multiple stable sulphur isotopes.

    PubMed

    Strauss, Harald; Bast, Rebecca; Cording, Anja; Diekrup, David; Fugmann, Artur; Garbe-Schönberg, Dieter; Lutter, Andreas; Oeser, Martin; Rabe, Katharina; Reinke, Debora; Teichert, Barbara M A; Westernströer, Ulrike

    2012-01-01

    In this work, the biogeochemistry of marine sediments from the Kiel Bight, coastal SW Baltic Sea, is studied based on the abundance and isotopic composition of organic carbon and different forms of sedimentary sulphur. Active bacterial sulphate reduction, partly under sulphate-limiting conditions, is evident from paired δ(34)S and δ(18)O values of pore water sulphate. The resulting pore water sulphide is partly precipitated as acid-volatile iron sulphide and subsequently forms sedimentary pyrite, partly serves in later diagenetic sulphurisation of organic matter, or remains dissolved in the pore water, all evident from the respective δ(34)S values. Microbial sulphate turnover is associated with an apparent isotopic fractionation between dissolved sulphate and dissolved sulphide (Δ(34)S) that varies between 46 and 66‰.

  18. Origin and Migration of the Pollutants in Precipitation and Surface Water in Seoul, Korea

    NASA Astrophysics Data System (ADS)

    Lee, I.; Lim, C.; Yu, J.

    2002-12-01

    Variations in abundance of stable isotopes of sulfur, hydrogen, and oxygen are studied on snow and rainwater samples from Seoul area. Their suitability as a tool for characterizing the seasonality and source of regions near Korea, which contribute to the pollution in Seoul Area was investigated. Also stable isotopic and chemical evidence has been used to trace the sources of sulfate in precipitation at study area and to distinguish sulfate between natural and anthropogenic origins. The contribution of different sources to a specific receptor site depends on emission patterns and meteorological conditions. Measured isotope ratios reflect the actual superposition of the distinct source types based on the assumption that no major isotope fractionation occurs during the transportation process between source region and sampling site. The sulfur isotopic composition of sulfate (δ34S) in precipitation decreased during spring and summer. The δ34S values ranged from +4.4 to +6.5› (mean +5.9›) in winter and from +3.7 to 4.8› (mean +4.3›) in summer. Furthermore, the isotope ratios of hydrogen and oxygen in the snow and rainwater samples were used to support the meteorological information. The δ34S value of the sulfate in precipitation shows characteristic patterns of seasonal variation in the present research. Seasonal variations of the δ34S values and their relation to chemical composition of the atmospheric pollutants are discussed taking into account the δ34S values of sulfur originating from sea salt, oil and coal combustion, and biogenic activity. Also, the δ34S values of sulfate in the atmospheric pollutants show a remarkable seasonal variation depending on the wind directions. The relationship between wind direction and seasonal variation can be explained by contribution of sulfur from coal combustion in northern China and southern China.

  19. VizieR Online Data Catalog: Transition rates on 2s2p3 configurations in N+ (Shen+, 2016)

    NASA Astrophysics Data System (ADS)

    Shen, X.; Liu, J.; Zhou, F.

    2016-07-01

    Wavefunctions were determined using the Multi-Configuration Dirac-Hartree-Fock (MCDHF) method. The core-core, core-valence, valence correlation, Breit interaction and quantum electrodynamics (QED) effects, as well as some higher order correlation effects, were considered to obtain accurate wavelengths (lambda), oscillator strengths (gf) and transition rates (A) of 2s22p2-2s2p3, 2s2p3-2s22pnl (n>=3) and 2s2p3-2s2p23s E1 transitions. (2 data files).

  20. Advanced Technology for Improved Quantum Device Properties Using Highly Strained Materials

    DTIC Science & Technology

    1989-06-15

    PREPARED BY: W.J. Schaff S.D. OffseyI DL)L.,C ;.. $T A H. Park At~pio-ved tc- ;p7ua~ic tel-e:a~o L.F. Eastman q uoig4 04 Table of Contents Page...Graded-Index Separate-Confinement Heterostructure Single Quantum Well Lasers Grown by Molecular Beam Epitaxy&#34, S.D. Offsey, W.J. Schaff , P.J. Tasker, H...gle Confinement Single Quantum Well Lasers Grown by Molecular Beam Epitaxy&#34, S.D. Offsey, W.J. Schaff , P.J. Tasker and L.F. Eastman, Device Research

  1. A sulfur isotope study of pyrite genesis: The mid-proterozoic Newland formation, belt supergroup, Montana

    NASA Astrophysics Data System (ADS)

    Strauss, Harald; Schieber, Jürgen

    1990-01-01

    Different generations of sedimentary pyrite from the Mid-Proterozoic Newland Formation, USA, have been analysed for their sulfur isotopic compositions. The results indicate bacterial sulfate reduction as the pyrite forming process. The δ 34S values for early diagenetic pyrite, around -14%., are in contrast to dominantly more positive values for many other Middle Proterozoic units. A progressive reduction of sulfate availability during diagenesis can be recognized by an increase in 34S content (Rayleigh Distillation) as well as through detailed petrographic observations. Contemporaneous seawater had a sulfur isotopic ratio between +14 and +18%. as measured from sedimentary barite within the unit.

  2. Clinical Utility and Pitfalls of Ultrasound Guided Foreign Body Removal in War Fighters

    DTIC Science & Technology

    2013-10-01

    81 years old Cause of death: Liver Disease 1 38 Yes 2 6 6 interrupted Page 6 DoDCadaverCohortStudy5-13-09.xls Th igh # Ca da ve r S pe cim en In...body removal P4 #5861 Female Right leg 68 years old Cause of death: Huntington &#34 s Chorea 1 5 Yes 23 23 0 N/A Radiological Procedure Removal... Huntington &#34 s Chorea 1 5 Yes 26 26 0 N/A Radiological Procedure Removal Technique - Percutaneous - interventional radiological ultrasound

  3. Stable sulfur isotope hydrogeochemical studies using desert shrubs and tree rings, Death Valley, California, USA

    SciTech Connect

    Yang, Wenbo; Spencer, R.J.; Krouse, H.R.

    1996-08-01

    The {delta}{sup 34}S values of two dominant xerophytes, Atriplex hymenehytra and Larrea tridentata, in Death Valley, California, vary similarly from +7 to +18{per_thousand}, corresponding isotopically to sulfate in the water supplies at a given location. Going radially outwards, tree ring data from a phreatophyte tree, Tamarix aphylla, show a distinct time dependence, with {delta}{sup 34}S values increasing from +13.5 to +18{per_thousand} for soluble sulfate and from +12 to +17% for total sulfur. These data are interpreted in terms of sulfur sources, water sources and flow paths, and tree root growth. 32 refs., 3 figs., 3 tabs.

  4. Machine Casting of Ferrous Alloys

    DTIC Science & Technology

    1975-10-01

    C-0110 June 1975 by M. C. Flemings, R. Mehrabian, J. R. Melcher, R. G. Riek, K. P. Young N. Matsumoto, D. G. Backman, F. S. Blackall , &E. Bond, E...17. F. Blackall , "The Delivery and Casting of Semi-Solid Metals&#34, S.M. Thesis, 1975, M.I.T. 18. V. Laxmanan, "Rheocasting of Superalloys&#34, S.M...Flemings, R. Mehrabian, J.R. Melcher, R.G. Riek, K.P. Young, N. Matsumoto D.G.Backman, F.S. Blackall , B.E. Bond, E.J. McHal^ S. Schottman 8. CONTRACT

  5. Sulfur isotope fractionation during the May 2003 eruption of Anatahan volcano, Mariana Islands: Implications for sulfur sources and plume processes

    NASA Astrophysics Data System (ADS)

    de Moor, J. Maarten; Fischer, Tobias P.; Sharp, Zachary D.; Hauri, Erik H.; Hilton, David R.; Atudorei, Viorel

    2010-09-01

    Sulfur isotope compositions of pumice and adsorbed volatiles on ash from the first historical eruption of Anatahan volcano (Mariana arc) are presented in order to constrain the sources of sulfur erupted during the period 10-21 May, 2003. The isotopic composition of S extracted from erupted pumice has a narrow range, from δ 34S V-CDT +2.6‰ to +3.2‰, while the composition of sulfur adsorbed onto ash has a larger range (+2.8‰ to +5.3‰). Fractionation modeling for closed and open system scenarios suggests that degassing of SO 2 raised the δ 34S V-CDT value of S dissolved in the melt from an initial composition of between +1.6‰ and +2.6‰ for closed-system degassing, or between -0.5‰ and +1.5‰ for open-system degassing, however closed-system degassing is the preferred model. The calculated values for the initial composition of the magma represent a MORB-like (δ 34S V-CDT ˜ 0‰) mantle source with limited contamination by subducted seawater sulfate (δ 34S V-CDT +21‰). Modeling also suggests that the δ 34S V-CDT value of SO 2 gas in closed-system equilibrium with the degassed magma was between +0.9‰ and +2.5‰. The δ 34S V-CDT value of sulfate adsorbed onto ash in the eruption plume (+2.8‰ to +5.1‰) is consistent with sulfate formation by oxidation of magmatic SO 2 in the eruption column. The sulfur isotope composition of sulfate adsorbed to ash changes from lower δ 34S values for ash erupted early in the eruption to higher δ 34S values for ash erupted later in the eruption. We interpret the temporal/stratigraphic change in sulfate isotopic composition to primarily reflect a change in the isotopic composition of magmatic SO 2 released from the progressively degassing magma and is attributed to the expulsion of an accumulated gas phase at the beginning of the eruption. More efficient oxidation of magmatic SO 2 gas to sulfate in the early water-rich eruption plume probably contributed to the change in S isotope compositions observed in the

  6. Sedimentary sulfur geochemistry of the Paleogene Green River Formation, western USA: Implications for interpreting depositional and diagenetic processes in saline alkaline lakes

    NASA Astrophysics Data System (ADS)

    Tuttle, Michele L.; Goldhaber, Martin B.

    1993-07-01

    The sulfur geochemistry of the lacustrine Paleogene Green River Formation (Colorado, Utah, and Wyoming, USA) is unlike that of most marine and other lacustrine rocks. Distinctive chemical, isotopic, and mineralogical characteristics of the formation are pyrrhotite and marcasite, high contents of iron mineral sulfides strikingly enriched in 34S, cyclical trends in sulfur abundance and δ 34S values, and long-term evolutionary trends in δ 34S values. Analyses that identified and quantified these characteristics include carbonate-free abundance of organic carbon (0.13-47 wt%), total iron (0.31-13 wt%), reactive iron (>70% of total iron), total sulfur (0.02-16 wt%), acid-volatile monosulfide (S Av), disulfide (S Di > 70% of total sulfur), sulfate (S SO4) and organosulfur (S Org); isotopic composition of separated sulfur phases (δ 34S Di,Av up to +49‰); and mineralogy, morphology and paragenesis of sulfide minerals. Mineralogy, morphology, δ 34S Di,Av, and δ 34S Org have a distinctive relation, reflecting variable and unique depositional and early diagenetic conditions in the Green River lakes. When the lakes were brackish, dissimilatory sulfate-reducing bacteria in the sediment produced H 2S, which initially reacted with labile iron to form pyrite framboids and more gradually with organic matter to form organosulfur compounds. During a long-lived stage of saline lake water, the amount of sulfate supplied by inflow decreased and alkalinity and pH of lake waters increased substantially. Extensive bacterial sulfate reduction in the water column kept lake waters undersaturated with sulfate minerals. A very high H 2S:SO 4 ratio developed in stagnant bottom water aided by the high pH that kinetically inhibited iron sulfidization. Progressive removal of H 2S by coeval formation of iron sulfides and organosulfur compounds caused the isotopic composition of the entire dissolved sulfur reservoir to evolve to δ 34S values much greater than that of inflow sulfate, which is

  7. Stable sulfur isotope partitioning during simulated petroleum formation as determined by hydrous pyrolysis of Ghareb Limestone, Israel

    USGS Publications Warehouse

    Amrani, A.; Lewan, M.D.; Aizenshtat, Zeev

    2005-01-01

    Hydrous pyrolysis experiments at 200 to 365??C were carried out on a thermally immature organic-rich limestone containing Type-IIS kerogen from the Ghareb Limestone in North Negev, Israel. This work focuses on the thermal behavior of both organic and inorganic sulfur species and the partitioning of their stable sulfur isotopes among organic and inorganic phases generated during hydrous pyrolyses. Most of the sulfur in the rock (85%) is organic sulfur. The most dominant sulfur transformation is cleavage of organic-bound sulfur to form H2 S(gas). Up to 70% of this organic sulfur is released as H2S(gas) that is isotopically lighter than the sulfur in the kerogen. Organic sulfur is enriched by up to 2??? in 34S during thermal maturation compared with the initial ??34S values. The ??34S values of the three main organic fractions (kerogen, bitumen and expelled oil) are within 1??? of one another. No thermochemical sulfate reduction or sulfate formation was observed during the experiments. The early released sulfur reacted with available iron to form secondary pyrite and is the most 34S depleted phase, which is 21??? lighter than the bulk organic sulfur. The large isotopic fractionation for the early formed H2S is a result of the system not being in equilibrium. As partial pressure of H2S(gas) increases, retro reactions with the organic sulfur in the closed system may cause isotope exchange and isotopic homogenization. Part of the ??34S-enriched secondary pyrite decomposes above 300??C resulting in a corresponding decrease in the ??34S of the remaining pyrite. These results are relevant to interpreting thermal maturation processes and their effect on kerogen-oil-H2S-pyrite correlations. In particular, the use of pyrite-kerogen ??34S relations in reconstructing diagenetic conditions of thermally mature rocks is questionable because formation of secondary pyrite during thermal maturation can mask the isotopic signature and quantity of the original diagenetic pyrite. The

  8. Managing and Securing Critical Infrastructure - A Semantic Policy and Trust Driven Approach

    DTIC Science & Technology

    2011-08-01

    at the lowest level detail. The resulting configurations have no usable semantics associated with them, and consequently cannot be verified for...Conference on Data Engineering Workshops (ICDEW’06), (Washington, DC, USA), p. 77, IEEE Computer Society, 2006. [33] S. Kent, C. Lynn, and K. Seo , “Secure

  9. 40 CFR 81.329 - Nevada.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...-64E) X Colorado River Valley (213) (22-33S, 63-66E) X 1 Rest of County 2 X Carson Desert (101)(15-24..., 212, 213, 214, 216, 217, and 218 but excluding the Moapa River Indian Reservation and the Fort...

  10. 40 CFR 81.329 - Nevada.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...-64E) X Colorado River Valley (213) (22-33S, 63-66E) X 1 Rest of County 2 X Carson Desert (101)(15-24..., 213, 214, 216, 217, and 218 but excluding the Moapa River Indian Reservation and the Fort...

  11. 40 CFR 81.329 - Nevada.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...-64E) X Colorado River Valley (213) (22-33S, 63-66E) X 1 Rest of County 2 X Carson Desert (101)(15-24..., 213, 214, 216, 217, and 218 but excluding the Moapa River Indian Reservation and the Fort...

  12. Geochemical behavior of sulfur in granitoids during intrusion of the South Mountain batholith, Nova Scotia, Canada

    NASA Astrophysics Data System (ADS)

    Poulson, Simon R.; Kubilius, Walter P.; Ohmoto, Hiroshi

    1991-12-01

    A detailed stable isotope (S, O) and elemental (major, trace, S content) study of peraluminous S-type granites and granodiorites of the South Mountain Batholith and the Meguma Group metasediments into which the batholith was intruded has been conducted on a regional and local scale near Mt. Uniacke. Sulfur contents of the metasediments range from 5 to 2440 ppm, and δ 34S ranges from -3.7 to +26.3%. Sulfur contents of the igneous rocks range from 6 to 570 ppm, with the granites ( ≈20 ppm) having lower sulfur contents than the granodiorites ( ≈300 ppm). Approximately 30 to 60% of the sulfur in the granodiorites is present as pyrrhotite (a late phase), with most of the remainder being present as sulfur substituted into biotite (an early phase). δ 18OQ Quartz values of the Mt. Uniacke granodiorites are heavy (≈a + 12.2%.) indicating formation of the magmas by partial melting of sedimentary rocks. Major element variations suggest that the granites are related to the granodiorites by fractional crystallization of plagioclase, quartz, and biotite. Comparison of the sulfur contents of the granodiorites with experimental determinations of sulfur solubility suggest that the distribution coefficient of sulfur ( Ds) between the cumulate and the magma during fractional crystallization ≈4. The regional granodiorites have a relatively restricted range of δ 34S values (+5.4 to + 8.4%.), while the regional granites have a wide range of δ 34S values ( + 1.6 to + 15.0%.). Granodiorites at Mt. Uniacke with normal magmatic values (+0.76 to +1.42%.) for Δ 18O (Quartz-Feldspar) have δ 34S values between +6.6 and +12.3%., and show good negative correlations between δ 34S and S, FeO, and MgO contents. Some granodiorites at Mt. Uniacke have anomalously low sulfur contents for their major element composition, and Δ 18O (Quartz-Feldspar) values (-0.45 to +0.67%. ) indicate that these samples have undergone hydrothermal alteration, and this alteration event is probably

  13. Atmospheric sulfur rearrangement 2.7 billion years ago: Evidence for oxygenic photosynthesis

    NASA Astrophysics Data System (ADS)

    Kurzweil, Florian; Claire, Mark; Thomazo, Christophe; Peters, Marc; Hannington, Mark; Strauss, Harald

    2013-03-01

    Mass-independently fractionated sulfur isotopes (MIF-S) provide strong evidence for an anoxic atmosphere during the Archean. Moreover, the temporal evolution of MIF-S shows increasing magnitudes between 2.7 and 2.5 Ga until the start of the Great Oxidation Event (G.O.E.) at around 2.4 Ga. The conclusion of a completely anoxic atmosphere up to the G.O.E. is in contrast to recent studies on redox-sensitive elements, which suggest slightly oxidizing conditions during continental weathering already several hundred million years prior to the G.O.E. In order to investigate this apparent inconsistency, we present multiple sulfur isotopes for 2.71 Ga pyritic black shales derived from the Kidd Creek area, Ontario, Canada. These samples display high positive Δ33S values up to 3.8‰ and the typical late Archean slope in Δ36S/Δ33S of -0.9. In contrast, the time period before (3.2-2.73 Ga) is characterized by greatly attenuated MIF-S magnitudes and a slope in Δ36S/Δ33S of -1.5. We attribute the increase in Δ33S magnitude as well as the contemporaneous change in the slope of Δ36S/Δ33S to changes in the relative reaction rate of different MIF-S source reactions and changes in atmospheric sulfur exit channels. Both of these are dependent on atmospheric CH4:CO2 and O2 mixing ratios. We propose a distinct change in atmospheric composition at 2.7 Ga resulting from increased fluxes of oxygen and methane as the best explanation for the observed Neoarchean MIF-S record. Our data and modeling results suggest that oxygenic photosynthesis was a major contributor to primary productivity 2.7 billion years ago.

  14. Genetic Suppression of Inflammation Blocks the Tumor-Promoting Effects of TGF-β in Gastric Tissue

    PubMed Central

    Ota, Mitsuhiko; Horiguchi, Masahito; Fang, Victoria; Shibahara, Kotaro; Kadota, Kyuichi; Loomis, Cynthia; Cammer, Michael; Rifkin, Daniel B.

    2014-01-01

    The contributions of TGF-β signaling to cancer are complex but involve the inflammatory microenvironment as well as cancer cells themselves. In mice encoding a TGF-β mutant that precludes its binding to the latent TGF-β binding protein (Tgfb1−/C33S), we observed multiorgan inflammation and an elevated incidence of various types of gastrointestinal solid tumors due to impaired conversion of latent to active TGF-β1. By genetically eliminating activators of latent TGF-β1, we further lowered the amount of TGF-β, which enhanced tumor frequency and multiorgan inflammation. This model system was used to further investigate the relative contribution of TGF-β1 to lymphocyte-mediated inflammation in gastrointestinal tumorigenesis. Toward this end, we generated Tgfb1−/C33S;Rag2−/− mice that lacked adaptive immune function, which eliminated tumor production. Analysis of tissue from Tgfb1−/C33S mice indicated decreased levels of P-Smad3 compared to wild type animals, whereas tissue from Tgfb1−/C33S;Rag2−/− mice had normal P-Smad3 levels. Inhibiting the inflammatory response normalized levels of IL-1β and IL-6 and reduced tumor cell proliferation. Additionally, Tgfb1−/C33S;Rag2−/− mice exhibited reduced paracrine signaling in the epithelia, mediated by hepatocyte growth factor produced by gastric stroma. Together, our results indicate that many of the responses of the gastric tissue associated with decreased TGF-β1 may be directly or indirectly affected by inflammatory processes, which accompany loss of TGF-β1, rather than a direct effect of loss of the cytokine. PMID:24590056

  15. 78 FR 5196 - Notice of Invitation To Participate; Exploration for Coal in Colorado License Application COC-75642

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-24

    ... the exploration of coal deposits owned by the United States of America on lands located in Las Animas... Las Animas, Colorado: Sixth Principal Meridian T. 32 S., R. 64 W., 6th P.M. Sec. 19, lots 1, 3, and...

  16. Effect of some xenobiotics on oxidative metabolism of human blood neutrophils.

    PubMed

    Mushtakova, V M; Fomina, V A; Rogovin, V V

    2007-03-01

    The effect of SO3(2-), S(2-), NOs(-), and NH4(+) on activity of the peroxidase-hydrogen peroxide system in human peripheral blood neutrophils was studied by the cytochemical method. We showed that the effect of these xenobiotics on neutrophils is similar to that on plants.

  17. Project CHECO Southeast Asia Report. Khe Sanh (Operation NIAGARA) 22 January - 31 March 68

    DTIC Science & Technology

    1968-09-13

    two A-lEs (Hobo 35) loaded with two BLU 32s, four LAU 59s, two Mll7s, and four frag bombs each. These Hobos worked the area for almost one hour, and...altertate targets would preferably be located in the Kontum/ Dak To area. These targetsI must be capable :f aupporiing the entire efort Once fragged, the

  18. A DFT study of the role of water in the rhodium-catalyzed hydrogenation of acetone.

    PubMed

    Polo, Victor; Schrock, Richard R; Oro, Luis A

    2016-11-24

    The positive effect of the addition of water to acetone hydrogenation by [RhH2(PR3)2S2](+) catalysts has been studied by DFT calculations. The studied energetic profiles reveal that the more favourable mechanistic path involves a hydride migration to the ketone followed by a reductive elimination that is assisted by two water molecules.

  19. Reactions between methanethiol and biologically produced sulfur particles.

    PubMed

    van Leerdam, R C; van den Bosch, P L F; Lens, P N L; Janssen, A J H

    2011-02-15

    Recently, new biotechnological processes have been developed to enable the sustainable removal of organic and inorganic sulfur compounds from liquid and gaseous hydrocarbon streams. In comparison to existing technologies (e.g., caustic scrubbing or iron based redox technologies) far less chemicals are consumed, while reusable elemental sulfur is formed as the main end-product. This research shows that in these processes a number of consecutive reactions occur between methanethiol (MT) from the hydrocarbon stream and the formed biosulfur particles, leading to the formation of (dimethyl) polysulfides. This is an important feature of this family of new bioprocesses as it improves the MT removal efficiency. The reaction kinetics depend on the MT and biosulfur concentration, temperature, and the nature of the biosulfur particles. The first reaction step involves a S8 ring-opening by nucleophilic attack of MT molecules to form CH3S9(-). This work shows that CH3S9(-) reacts to polysulfides (S3(2-), S4(2-), S5(2-)), dimethyl polysulfides [(CH3)2S2, (CH3)2S3], and dissociated H2S, while also some longer-chain dimethyl polysulfides [(CH3)2S4-7] are formed at μM levels. Control experiments using orthorhombic sulfur flower (S8) did not reveal these reactions.

  20. Volatile Organic Sulfur Compounds of Environmental Interest: Dimethyl Sulfide and Methanethiol

    ERIC Educational Resources Information Center

    Chasteen, Thomas G.; Bentley, Ronald

    2004-01-01

    Volatile organic sulfur compounds (VOSCs) have been assigned environmental roles in global warming, acid precipitation, and cloud formation where two important members dimethyl sulfide (CH3)2 S, DMS, and methanethiol, CH3SH, MT, of VOSC group are involved.

  1. 2DRMP: A suite of two-dimensional R-matrix propagation codes

    NASA Astrophysics Data System (ADS)

    Scott, N. S.; Scott, M. P.; Burke, P. G.; Stitt, T.; Faro-Maza, V.; Denis, C.; Maniopoulou, A.

    2009-12-01

    within each subregion and used to propagate a global R-matrix, ℜ, across the internal region. On the boundary of the internal region ℜ is transformed onto the IERM target state basis. Thus, the two-dimensional R-matrix propagation technique transforms an intractable problem into a series of tractable problems enabling the internal region to be extended far beyond that which is possible with the standard one-sector codes. A distinctive feature of the method is that both electrons are treated identically and the R-matrix basis states are constructed to allow for both electrons to be in the continuum. The subregion size is flexible and can be adjusted to accommodate the number of cores available. Restrictions: The implementation is currently restricted to electron scattering from H-like atoms and ions. Additional comments: The programs have been designed to operate on serial computers and to exploit the distributed memory parallelism found on tightly coupled high performance clusters and supercomputers. 2DRMP has been systematically and comprehensively documented using ROBODoc [4] which is an API documentation tool that works by extracting specially formatted headers from the program source code and writing them to documentation files. Running time: The wall clock running time for the small test run using 16 cores and performed on [3] is as follows: bp (7 s); rint2 (34 s); newrd (32 s); diag (21 s); amps (11 s); prop (24 s). References:HECToR, CRAY XT4 running UNICOS/lc, http://www.hector.ac.uk/, accessed 22 July, 2009. HPCx, IBM eServer 575 running IBM AIX, http://www.hpcx.ac.uk/, accessed 22 July, 2009. HP Cluster, Itanium II cluster running Red Hat Linux Enterprise AS, Queen s University Belfast, http://www.qub.ac.uk/directorates/InformationServices/Research/HighPerformanceComputing/Services/Hardware/HPResearch/, accessed 22 July, 2009. Automating Software Documentation with ROBODoc, http://www.xs4all.nl/~rfsber/Robo/, accessed 22 July, 2009.

  2. MONITORING FOOD WEB CHANGES IN TIDE-RESTORED SALT MARSHES: A CARBON STABLE ISOTOPE APPROACH

    EPA Science Inventory

    Primary producer (angiosperms, macroalgae, submerged aquatic vegetation), suspended particulate matter, and Fundulus heteroclitus isotope values (d13C , d15N, d34S) were examined to assess their use as an indicator for changes in food web support functions in tidally-restored sal...

  3. In-Situ Detection of Contaminant Plumes in Ground Water

    DTIC Science & Technology

    1990-08-01

    direct forms of spectroscopy that can pleniented through optical fiber (Foulk and Gaz -gus be implemented through fiber opt&#