Analysis of sulfides in whole rock matrices by elemental analyzer–continuous flow isotope ratio mass spectrometry

Studley, S. A.; Ripley, Edward M.; Elswick, Erika; Dorais, Michael J.; Fong, Jon; Finkelstein, David I.; Pratt, Lisa M.

doi:10.1016/s0009-2541(02)00162-6

Cited by 90 publications

(45 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For sulfur isotope measurements, whole-rock powders were analyzed using elemental analyzer-continuous flow isotope ratio mass spectrometry (Studley et al, 2002). Sample powders (1 mg to 150 mg) were placed in tin cups with 1 to 5 mg of V 2 O 5 and combusted at ~1800 o C, with a reactor column temperature of 1010 o C. Analyses of SO 2 were made using a Finnigan MAT 252 stable isotope ratio mass spectrometer at Indiana University, with the results reported in standard delta notation relative to CDT (Canyon Diablo Troilite).…”

Section: Methodsmentioning

confidence: 99%

Hydrothermal alteration and isotopic variations of igneous rocks in Barton Peninsula, King George Island, Antarctica

et al. 2009

View full text Add to dashboard Cite

O, H, S and Sr isotopes were investigated to characterize the nature of hydrothermal fluids and alteration processes in volcanic and intrusive rocks in Barton Peninsula, King George Island. The oxygen and hydrogen isotope compositions of altered basaltic andesite and granodiorite are similar to each other. The δ O and δD values gradually decrease from altered basaltic andesite to altered dyke and quartz-veined volcaniclastic rock. The genetic linkage between hydrothermal fluid and granodiorite intrusion accounts for similar δ S values among sulfide minerals, both in the granodiorite stock and in nearby altered basaltic andesite. Broadly positive correlations of δ O-SiO 2 , δ O-( Sr/ Sr/ Sr) i , and Sr/ Sr/ Sr-SiO 2 can be established by siliceous fluids enriched in O as well as Sr. In addition, a positive relationship between (Sr. In addition, a positive relationship between ( Sr/ Sr/ Sr) i values and 1/Sr contents in basaltic andesites can result from mixing between fresh rocks and infiltrating fluids with different endmember Sr/ Sr/ Sr values and Sr contents. The hyperbolic variation of ( Sr/ Sr/ Sr) i -K/Rb suggests that meteoric water participated in hydrothermal activities via mixing with magmatic water, and the contribution of seawater was insignificant. All of the above results indicate that hydrothermal alteration was influenced by fluids related to granodiorite intrusion, and O-and Sr-rich meteoric water circulating in the upper crust significantly contributed to hydrothermal activities in Barton Peninsula.

show abstract

Section: Methodsmentioning

confidence: 99%

Hydrothermal alteration and isotopic variations of igneous rocks in Barton Peninsula, King George Island, Antarctica

et al. 2009

View full text Add to dashboard Cite

show abstract

“…The resulting silver sulfide precipitate was powdered, along with acanthite minerals. These samples were combined with excess V 2 O 5 and combusted to SO 2 and analyzed conventionally for d 34 S using elemental analyzer-isotope ratio mass spectrometry (Studley et al, 2002). Standard deviations (1s) were 0.1% for known standards and precipitated silver sulfide, and B1% for acanthite minerals, presumably due to inhomogeneities between subsampled crystals.…”

Section: Nanosims Analysis and Isotopic Calibrationmentioning

confidence: 99%

Micron-scale mapping of sulfur cycling across the oxycline of a cyanobacterial mat: a paired nanoSIMS and CARD-FISH approach

et al. 2008

View full text Add to dashboard Cite

The metabolic activities of microbial mats have likely regulated biogeochemical cycling over most of Earth's history. However, the relationship between metabolic activity and the establishment of isotopic geochemical gradients in these mats remains poorly constrained. Here we present a parallel microgeochemical and microbiological study of micron-scale sulfur cycling within hypersaline microbial mats from Guerrero Negro, Baja California Sur, Mexico. Dissolved sulfide within the mats was captured on silver discs and analyzed for its abundance and d 34 S isotopic composition using high-resolution secondary ion mass spectrometry (nanoSIMS). These results were compared to sulfide and oxygen microelectrode profiles. Two-dimensional microgeochemical mapping revealed well-defined laminations in sulfide concentration (on scales from 1 to 200 lm), trending toward increased sulfide concentrations at depth. Sulfide d 34 S decreased from B þ 10% to À20% in the uppermost 3 mm and oscillated repeatedly between À10% and À30% down to a depth of 8 mm. These variations are attributed to spatially variable bacterial sulfate reduction within the mat. A parallel examination of the spatial distribution of known sulfate-reducing bacteria within the family Desulfobacteraceae was conducted using catalyzed reporter deposition fluorescence in situ hybridization. Significant concentrations of Desulfobacteraceae were observed in both oxic and anoxic zones of the mat and occurred in several distinct layers, in large aggregates and heterogeneously dispersed as single cells throughout. The spatial distribution of these microorganisms is consistent with the variation in sulfide concentration and isotopic composition we observed. The parallel application of the methodologies developed here can shed light on micronscale sulfur cycling within microbially dominated sedimentary environments.

show abstract

“…The BaSO 4 precipitate was washed and centrifuged three times using distilled, deionized water from a Millipore gradient Mili-Q water filtration system with a QuantumEX and Q-Gard-2 dual-filtration system. Sulfur isotope ratios for BaSO 4 and CdS were determined using an EA1110 elemental analyzer coupled to a Finnigan Mat 252 isotope ratio mass spectrometer via a ConFlo II split interface (57). Isotope data are reported as the ␦ 34 S per mille deviation from the Vienna Cañon Diablo Troilite (VCDT) calculated by using equation 3:…”

mentioning

confidence: 99%

Sulfur Isotope Enrichment during Maintenance Metabolism in the Thermophilic Sulfate-Reducing Bacterium Desulfotomaculum putei

Davidson

Bisher

Pratt

et al. 2009

Appl Environ Microbiol

View full text Add to dashboard Cite

Values of ⌬ 34S SO4 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‰, much greater than the ؊2 to ؊46‰ 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 ␦ 34 S values of the sulfate and sulfide eluting from the retentostat were significantly larger, attaining a maximum ⌬ 34 S of ؊20.9‰, than the ؊9.7‰ observed during the batch culture experiment, but differences did not attain the values observed in marine sediments. Dissimilatory SO 42Ϫ reduction is a geologically ancient, anaerobic, energy-yielding metabolic process during which SO 4 2Ϫ -reducing bacteria (SRB) reduce SO 4 2Ϫ to H 2 S while oxidizing organic molecules or H 2 . SO 4 2Ϫ reduction is a dominant pathway for organic degradation in marine sediments (23) and in terrestrial subsurface settings where sulfur-bearing minerals dominate over Fe 3ϩ -bearing minerals. For example, at depths greater than 1.5 km below land surface in the fractured sedimentary and igneous rocks of the Witwatersrand Basin of South Africa, SO 4 2Ϫ reduction is the dominant electron-accepting process (3,26,46,48,61).The enrichment of S pyrite and ␦ 34 S barite/gypsum are the isotopic compositions of pyrite and barite or gypsum) increases from Ϫ10‰ in the 3.47-billion-year-old North Pole deposits to Ϫ30‰ in late-Archaean deposits (55), to Ϫ75‰ in Neoproterozoic to modern sulfide-bearing marine sediments (13).The kinetic isotopic enrichment, ε 34 S, deduced from trends in the ␦ 34 S values of SO 4 2Ϫ and HS Ϫ in batch culture microbial SO 4 2Ϫ reduction experiments using the Rayleigh relationship, ranges from Ϫ2‰ to Ϫ46‰ (6,7,11,17,22,27,28,30,31,38,39). The variation in ε 34 S values has been attributed to the SO 4 2Ϫ concentration, the type of electron donor and its concentration, the SO 4 2Ϫ reduction rate per cell (csSRR) (22), temperature, and species-specific isotope enrichment effects. In these laboratory experiments, doubling times are on the order of hours and csSRRs range from to 0.1 to 18 fmol cell Ϫ1 h Ϫ1 ...

show abstract

Analysis of sulfides in whole rock matrices by elemental analyzer–continuous flow isotope ratio mass spectrometry

Cited by 90 publications

References 4 publications

Hydrothermal alteration and isotopic variations of igneous rocks in Barton Peninsula, King George Island, Antarctica

Hydrothermal alteration and isotopic variations of igneous rocks in Barton Peninsula, King George Island, Antarctica

Micron-scale mapping of sulfur cycling across the oxycline of a cyanobacterial mat: a paired nanoSIMS and CARD-FISH approach

Sulfur Isotope Enrichment during Maintenance Metabolism in the Thermophilic Sulfate-Reducing Bacterium Desulfotomaculum putei

Contact Info

Product

Resources

About