http://lod.bco-dmo.org/id/dataset/994391
eng; USA
utf8
dataset
Highest level of data collection, from a common set of sensors or instrumentation, usually within the same research project
Biological and Chemical Oceanography Data Management Office (BCO-DMO)
Unavailable
508-289-2009
WHOI MS#36
Woods Hole
MA
02543
USA
info@bco-dmo.org
http://www.bco-dmo.org
Monday - Friday 8:00am - 5:00pm
For questions regarding this resource, please contact BCO-DMO via the email address provided.
pointOfContact
2026-03-10
ISO 19115-2 Geographic Information - Metadata - Part 2: Extensions for Imagery and Gridded Data
ISO 19115-2:2009(E)
Sulfur cycling and sulfur stable isotopes in subsurface sediments from R/V JOIDES Resolution IODP-385 drilling expedition in the Guaymas Basin between September and November, 2019
2026-03-10
publication
2026-03-10
revision
BCO-DMO Linked Data URI
2026-03-10
creation
http://lod.bco-dmo.org/id/dataset/994391
Samantha B. Joye
University of Georgia
principalInvestigator
Biological and Chemical Oceanography Data Management Office (BCO-DMO)
Unavailable
508-289-2009
WHOI MS#36
Woods Hole
MA
02543
USA
info@bco-dmo.org
http://www.bco-dmo.org
Monday - Friday 8:00am - 5:00pm
For questions regarding this resource, please contact BCO-DMO via the email address provided.
publisher
Cite this dataset as: Joye, S. B. (2026) Sulfur cycling and sulfur stable isotopes in subsurface sediments from R/V JOIDES Resolution IODP-385 drilling expedition in the Guaymas Basin between September and November, 2019. Biological and Chemical Oceanography Data Management Office (BCO-DMO). (Version 1) Version Date 2026-03-10 [if applicable, indicate subset used]. http://lod.bco-dmo.org/id/dataset/994391 [access date]
Leg 385 Sulfur Stable Isotope Biogeochemistry Dataset Description: Methods and Sampling: <p>Subsurface sediment samples were collected from four drilling sites in the Guaymas Basin, Gulf of California, during IODP Expedition 385 “Guaymas Basin Tectonics and Biosphere” using the research vessel R/V JOIDES Resolution between September and November of 2019. Rates of methanogenesis were determined at four sites and presented in the related dataset. Sites 1545 (27º38.230’N, 111º53.329’W) and 1546 (27º37.884’N, 111º52.781’W) were located roughly 52 km and 51 km, respectively, northwest of the axial graben of the northern spreading segment. Both sites are highly sedimented and a 75-meter thick inactive (~thermally equilibrated) basaltic/doleritic/gabbroic sill was present at site 1546 between ~355 to 431 meters below the seafloor (mbsf). Site U1545B is considered a reference site since it was free of sill intrusions and unaffected by active hydrothermal circulation. The geothermal gradient in hole U1545B was 227ºC/km. The geothermal gradient in hole U1546C, 221ºC/km, was similar to that measured in hole U1545B. Sites U1547 and U1548 were located inside the periphery of an active, sill-associated hydrothermal mound located about 27 km northwest of the axial graben of the northern spreading segment. Temperatures in hole U1547B &nbsp;(27º30.413’N, 111º40.734’W, water depth 1585.6m) exceeded 50°C in the upper 50 mbsf. The geothermal gradient in the U1547B hole was 529ºC/km. The geothermal gradient in the U1548C hole was 958ºC/km. Site U1549 was located near a cold seep sustained by a deeply buried, thermally equilibrated sill intrusion at several hundred meters depth. The geothermal gradient at hole U1549B was 194ºC/km. Site U1550 (27°15.170′N, 111°30.445′W, water depth 2001.2 ) was located near a cold seep sustained by a deeply buried, thermally equilibrated sill intrusion at several hundred meters depth. The geothermal gradient at hole U1550B was 135ºC/km. These sites are described in more detail in Teske et al. (2021).</p>
<p>To preserve sediment for solid-phase sulfur analysis and incubation experiments, sectioned core samples were placed in N<sub>2</sub>-filled gas-tight bags, and subsequently transferred to anoxic glass bottles and stored at 4℃ until further subsampling. Porewater concentrations of sulfate, methane and sulfide, and solid phase parameters, including total organic carbon and total sulfur, were analyzed onboard using established IODP protocols (Teske, 2021). These data were obtained from the IODP database&nbsp;(Teske, 2021). Briefly, methane concentrations were determined using a gas chromatograph (Agilent 7890A), sulfate concentrations were analyzed by ion chromatography (Metrohm 850 Professional IC), and sulfide samples were fixed with zinc acetate solution and measured spectrophotometrically (Cline, 1969). For total carbon (TC) and total sulfur (TS) contents, samples were freeze-dried and powdered, and ~15 mg was accurately weighed. Analysis was conducted using an elemental analyzer (Thermo Finnigan FlashEA 1112 CHNS). Inorganic carbon (IC) content was measured using a Coulometrics 5012 CO<sub>2</sub> coulometer. Freeze-dried and powdered sediments was reacted with 6.5 mL of 2 mol L<sup>–1 </sup>HCl in a glass vial to liberate CO<sub>2</sub>. Total organic carbon (TOC) content was quantified by the subtraction of IC from TC content. The statistical ANOVA of TOC to TS (C/S) ratios at the six sites was performed using Origin 2025 software (OriginLab Corporation). Significance was determined at a threshold of p &lt; 0.05.</p>
<p>For solid-phase sulfur species extraction, ~1.5 g subsamples were transferred to centrifuge tubes containing &nbsp;5% zinc acetate solution. After centrifugation to remove the supernatant, elemental sulfur (ES) was first extracted via sustained agitation for 15 hours with 30 mL 100% methanol (Zopfi et al. 2004). Dissolved ES was quantified via reversed-phase liquid chromatography (Agilent, 1260 Infinity III) with a C-18 column (Agilent ZORBAX Eclipse XDB-C18), using 100% methanol as the eluent. The pump speed was set to 1 mL min<sup>–1</sup>, and absorbance at 265 nm was measured via UV detection. The detection limit for this method is &lt;1 µmol L<sup>–1</sup>, and the analytical precision (relative standard deviation, RSD) was better than 0.7%.</p>
<p>The separated solid residue was subsequently treated with a cold chromium distillation procedure (Kallmeyer et al. 2004, Røy et al. 2014), where acid volatile sulfur (AVS) was released with 6 mol L<sup>–1</sup> HCl, and chromium reducible sulfur (CRS, mainly pyrite) was sequentially extracted with an acidified chromium chloride solution (CrCl<sub>2</sub>). The sulfide liberated from these solid-phase sulfur species was trapped by 5% (w/v) zinc acetate to form ZnS precipitate and then the concentration of each species was determined spectrophotometrically (Cline, 1969).</p>
<p>For porewater sulfate sulfur isotope analysis, a thawed pore fluid volume (5 ml) was fixed with saturated barium chloride solution to precipitate sulfate as barium sulfate. The BaSO<sub>4 </sub>was then rinsed with 6 mol L<sup>–1</sup> HCl and Milli-Q water. After determination, the precipitated zinc sulfide from CRS was subsequently converted to Ag<sub>2</sub>S by addition of silver nitrate and ammonium hydroxide to the recovery vessel. Cleaned and dried BaSO<sub>4</sub> and Ag<sub>2</sub>S was mixed with excess V<sub>2</sub>O<sub>5</sub> and the stable sulfur isotopic ratio was measured on an isotope ratio monitoring mass spectrometer (IRMS; Thermo Delta V Plus) coupled to a Flash elemental analyzer. Standard deviations were better than 0.3‰ (n ≥3), estimated using one International Atomic Energy Agency (IAEA-3) standard (–32.30‰) and two national (China) first level sulfur isotope standards (–0.07‰ and 22.15‰), respectively. The stable sulfur isotope values, δ<sup>34</sup>S, were calculated using the following formula:</p>
<blockquote>
<p>δ<sup>34</sup>S = [{(<sup>34</sup>S/<sup>32</sup>S)<sub>sample</sub>/(<sup>34</sup>S/<sup>32</sup>S)<sub>standard</sub>} - 1] × 1000</p>
</blockquote>
<p>The units of δ<sup>34</sup>S are per mil (‰) and are reported relative to the Vienna Canyon Diablo Troilite (VCDT) standard.&nbsp;&nbsp;</p>
<p>For the determination of potential rates of sulfate reduction (SR) and anaerobic oxidation of methane (AOM), 10 g sediment subsamples were weighed in a N<sub>2</sub>-filled glove box and transferred into 120 mL glass vials. Next, 40 mL artificial seawater medium was added and the vials were closed with blue butyl rubber stoppers and crimped. The seawater media for sediment slurry incubations were prepared as follows: 200 mg KH<sub>2</sub>PO<sub>4</sub>, 250 mg NH<sub>4</sub>Cl, 25 g NaCl, 0.5 g MgCl<sub>2</sub> × 6H<sub>2</sub>O, 0.5 g KCl and 150 mg CaCl<sub>2 </sub>× 2H<sub>2</sub>O, dissolved with 1 L Mill-Q water in a glass bottle (Heuer 2017). Sediment samples collected from above the sulfate-methane transition zone (SMTZ) were supplemented with 5 mmol L<sup>–</sup>1 sulfate in the artificial seawater medium, whereas samples from below the SMTZ were maintained without the addition of Na<sub>2</sub>SO<sub>4</sub>. After autoclaving, 5 mL sterile-filtered 154 mM Na<sub>2</sub>S and 1 M NaHCO<sub>3</sub> was added to the media to assure anoxia and to modulate the pH, respectively.</p>
<p>Then ~3 mL sediment slurry was introduced into a modified cut-end Hungate tube sealed with a gray chlorobutyl stopper and a screw cap. 100 µL of radiolabeled<sup> 35</sup>S-Na<sub>2</sub>SO<sub>4</sub> solution (~167 kBq) and<sup> 14</sup>C-CH<sub>4</sub> solution (~17 kBq) was injected into the quadruplicate sediment samples (one killed control and three live samples) for SR and AOM rate measurements, respectively. Samples were incubated concurrently under in situ temperature for 20 days. After incubation, microbial activities of SR and AOM were terminated by injecting 3 mL 20% (w/v) zinc acetate and 3 mL 2 mol L<sup>–1</sup> NaOH, respectively.</p>
<p>Zinc acetate-fixed slurry samples were transferred to falcon tubes and then centrifuged. The supernatant was obtained to count unreacted <sup>35</sup>S-SO<sub>4</sub><sup>2</sup>- radioactivity, and the pool of total reduced sulfur species in the remaining sediment was recovered by the cold chromium distillation (Røy et al. 2014). The extracted sulfide was trapped with 5% (w/v) zinc acetate solution to measure <sup>35</sup>S-H<sub>2</sub>S radioactivity. The sulfate reduction rates were calculated from the following formula:</p>
<blockquote>
<p>SRR = {(<sup>35</sup>S-H<sub>2</sub>S ) / [(<sup>35</sup>S-H<sub>2</sub>S ) + (<sup>35</sup>S-SO<sub>4</sub><sup>2-</sup> )]} × &nbsp;[SO<sub>4</sub><sup>2-</sup> ] × 1.06 / t × 1,000,000</p>
</blockquote>
<p>where SRR is the sulfate reduction rate presented in pmol cm<sup>–3</sup> day<sup>–1</sup>; (<sup>35</sup>S-H<sub>2</sub>S) is the measured <sup>35</sup>S-H<sub>2</sub>S radioactivity (decays per minute, dpm); (<sup>35</sup>S-SO<sub>4</sub><sup>2-</sup>) is the radioactivity of unreacted <sup>35</sup>S-SO<sub>4</sub><sup>2-</sup> (dpm); [SO<sub>4</sub><sup>2-</sup>] is the total sulfate concentration of slurry (i.e. sediment porewater sulfate plus added sulfate times the porosity); 1.06 is the correction factor for the expected isotopic fractionation; t is incubation time in days; 1,000,000 is the unit conversion factor. The units of sulfate reduction are pmol cm<sup>-3</sup> d<sup>-1</sup>.</p>
<p>For AOM rate measurements, <sup>14</sup>C-CO<sub>2</sub> production from <sup>14</sup>C-CH<sub>4</sub> was quantified with the acid digestion method (Joye et al. 2004, Zhuang et al. 2019). Briefly, homogenized sediment slurries were transferred to a 250 mL glass bottle and purged with air to remove unreacted <sup>14</sup>C-CH<sub>4</sub>. Then 5 mL of 30% (v/v) sulfuric acid was added to the bottle and then liberated <sup>14</sup>C-CO<sub>2</sub> &nbsp;was trapped with 3-methoxypropylamine. AOM rates were calculated using the following equation:</p>
<blockquote>
<p>AOM= {(<sup>14</sup>C-CO<sub>2</sub>) / [(<sup>14</sup>C-CO<sub>2</sub>) + (<sup>14</sup>C-CH<sub>4</sub> )]} × &nbsp;[CH<sub>4</sub> ] × 1.06 / t × 1,000</p>
</blockquote>
<p>where AOM is the anaerobic oxidation of methane calculated in pmol cm<sup>–3</sup> day<sup>–1</sup>; (<sup>14</sup>C-CO<sub>2</sub>) is the <sup>14</sup>C-CO<sub>2</sub> counts (dpm); (<sup>14</sup>C-CH<sub>4</sub>) is the total injected <sup>14</sup>C-CH<sub>4</sub> (dpm); [CH<sub>4</sub>] is the methane concentration of sediment slurry (µmol L<sup>–</sup>1); 1.01 is the carbon isotopic fractionation correction factor; t is incubation duration in days; 1,000 is the unit conversion factor. The units of anaerobic oxidation of methane are pmol cm<sup>-3</sup> d<sup>-1</sup>.</p>
<p>The reported microbial activity rates reflected the potential metabolic capacity of the <em>in situ</em> microbial community within the sediment, constrained by ambient geochemical conditions and substrate availability.</p>
Funding provided by NSF Division of Ocean Sciences (NSF OCE) Award Number: OCE-2023575 Award URL: https://www.nsf.gov/awardsearch/show-award?AWD_ID=2023575
onGoing
Samantha B. Joye
University of Georgia
706-542-5893
Dept. of Marine Sciences 325 Sanford Drive
Athens
GA
30602
USA
mjoye@uga.edu
pointOfContact
asNeeded
Dataset Version: 1
Unknown
Site
Hole
Latitude
Longitude
Water_Depth
Sediment_Depth
CH4
Sulfate
H2S
Total_Sulfur
Total_Organic_Carbon
CS_ratio
Acid_Volatile_Sulfur
Elemental_Sulfur
Chromium_Reducible_Sulfur
d34S_sulfate
d34S_pyrite
Sulfate_Reduction_Rate_SRR
Anaerobic_Oxidation_Methane_AOM
Centrifuge tubes
Coulometrics 5012 CO2 coulometer
Gas chromatograph (Agilent 7890A)
Liquid Chromatograph
Ion Chromatograph (Metrohm 850 Professional IC)
Spectrometer
Mass spectrometer (IRMS; Thermo Delta V Plus)
Elemental Analyzer (Thermo Finnigan FlashEA 1112 CHNS)
theme
None, User defined
site
site description
latitude
longitude
depth
depth below seafloor
methane
sulfate
H2S
Sulfur (S)
total organic Carbon
ratio
AVS
sulfate_reduction
FeS2
oxidation
featureType
BCO-DMO Standard Parameters
Centrifuge
CO2 Coulometer
Gas Chromatograph
High-Performance Liquid Chromatograph
Ion Chromatograph
Spectrometer
Thermo Fisher Scientific DELTA V Plus isotope ratio mass spectrometer
Thermo Fisher Scientific Flash EA 1112 elemental analyzer
instrument
BCO-DMO Standard Instruments
IODP-385
service
Deployment Activity
Guaymas Basin 27 N 111 W
place
Locations
otherRestrictions
otherRestrictions
Access Constraints: none. Use Constraints: Please follow guidelines at: http://www.bco-dmo.org/terms-use Distribution liability: Under no circumstances shall BCO-DMO be liable for any direct, incidental, special, consequential, indirect, or punitive damages that result from the use of, or the inability to use, the materials in this data submission. If you are dissatisfied with any materials in this data submission your sole and exclusive remedy is to discontinue use.
Pathways and regulation of transformation of low molecular weight carbon compounds in subseafloor sediments from the Guaymas Basin (Gulf of California)
https://osprey.bco-dmo.org/project/853204
Pathways and regulation of transformation of low molecular weight carbon compounds in subseafloor sediments from the Guaymas Basin (Gulf of California)
<p><em>NSF Award Abstract:</em><br />
This research will explore carbon cycling in one of the largest carbon reservoirs on Earth, marine sediments, located at bottom of the ocean. This carbon is recycled gradually over time through interacting geological, chemical, and biological processes. This project will document how each of these processes transforms carbon in marine sediments from the Guaymas Basin (Gulf of California). This setting offers the chance to study carbon cycling across a broad range of chemical and temperature gradients, providing an opportunity to tease apart the factors regulating carbon cycling in marine sediments. This project will investigate the role of ocean sediments in the global carbon cycle. These research objectives represent key science priorities in a time of global environmental change. For outreach activities, the scientist, in collaboration with Jim Toomey Education, would continue the "Adventures of Zack and Molly" educational video series. In this instance, the video would document results from this study and its broader significance. The scientist also would create a learning guide for teachers. Both the video and the learning guide would be disseminated to educators. One graduate and one undergraduate student would be supported and trained as part of this project.</p>
<p>Subsurface sediments in the Guaymas Basin (Gulf of California) offer an accessible window for investigating carbon cycling in a dynamic, yet tractable, marine environment. This work will study how heating of subsurface sediments affects the production, consumption, and fate of low molecular weight dissolved organic carbon. The research will track the fate of key carbon species – including formate, acetate, and methanol – as they are processed through a gauntlet of microbial-mediated processes. Samples were collected during Expedition 385 of the International Ocean Discovery Program in September-October 2019. Some experiments were conducted on the research vessel and additional experiments will be conducted in the laboratory. The study will constrain the magnitudes of transformation and the fate of low molecular weight carbon substrates using a combination of direct rate, pool size, and stable isotopic measurements coupled to thermodynamic modeling and probative laboratory experiments. Key topics for investigation include: (1) What is the dominant production mode for organic compounds in subsurface sediments? (2) What are the dominant pathways of methanogenesis along geochemical and temperature gradients? (3) What are the temperature limits of microbially-driven carbon cycling processes? (4) How does the fate of organic compounds change along geochemical and/or temperature gradients?</p>
<p>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.</p>
Guaymas Basin Sediments
largerWorkCitation
project
eng; USA
oceans
Guaymas Basin 27 N 111 W
-111.889
-111.48
27.263
27.637
2019-09-15
2019-11-15
Guaymas Basin (Gulf of California)
0
BCO-DMO catalogue of parameters from Sulfur cycling and sulfur stable isotopes in subsurface sediments from R/V JOIDES Resolution IODP-385 drilling expedition in the Guaymas Basin between September and November, 2019
Biological and Chemical Oceanography Data Management Office (BCO-DMO)
Unavailable
508-289-2009
WHOI MS#36
Woods Hole
MA
02543
USA
info@bco-dmo.org
http://www.bco-dmo.org
Monday - Friday 8:00am - 5:00pm
For questions regarding this resource, please contact BCO-DMO via the email address provided.
pointOfContact
http://lod.bco-dmo.org/id/dataset-parameter/994660.rdf
Name: Site
Units: unitless
Description: <p>Site name</p>
http://lod.bco-dmo.org/id/dataset-parameter/994661.rdf
Name: Hole
Units: unitless
Description: <p>Hole Designation (A, B, C)</p>
http://lod.bco-dmo.org/id/dataset-parameter/994662.rdf
Name: Latitude
Units: decimal degrees
Description: <p>Sampling latitude</p>
http://lod.bco-dmo.org/id/dataset-parameter/994664.rdf
Name: Longitude
Units: decimal degrees
Description: <p>Sampling longitude</p>
http://lod.bco-dmo.org/id/dataset-parameter/994666.rdf
Name: Water_Depth
Units: m
Description: <p>Water depth at the drilling site</p>
http://lod.bco-dmo.org/id/dataset-parameter/994668.rdf
Name: Sediment_Depth
Units: mbsf
Description: <p>Depth below the seafloor</p>
http://lod.bco-dmo.org/id/dataset-parameter/994669.rdf
Name: CH4
Units: mM
Description: <p>Methane concentration in the pore fluid</p>
http://lod.bco-dmo.org/id/dataset-parameter/994670.rdf
Name: Sulfate
Units: mM
Description: <p>Sulfate concentration in the pore fluid</p>
http://lod.bco-dmo.org/id/dataset-parameter/994671.rdf
Name: H2S
Units: μM
Description: <p>Sulfide concentration in the pore fluid</p>
http://lod.bco-dmo.org/id/dataset-parameter/994672.rdf
Name: Total_Sulfur
Units: weight percent (%)
Description: <p>Total sulfur in the solid phase (mg/g = weight% × 10)</p>
http://lod.bco-dmo.org/id/dataset-parameter/994673.rdf
Name: Total_Organic_Carbon
Units: weight percent (%)
Description: <p>Total organic carbon in the solid phase (mg/g = weight% × 10)</p>
http://lod.bco-dmo.org/id/dataset-parameter/994674.rdf
Name: CS_ratio
Units: unitless
Description: <p>Weight ratio of TOC/TS</p>
http://lod.bco-dmo.org/id/dataset-parameter/994675.rdf
Name: Acid_Volatile_Sulfur
Units: µmol/g
Description: <p>Acid volatile sulfur in the solid phase</p>
http://lod.bco-dmo.org/id/dataset-parameter/994676.rdf
Name: Elemental_Sulfur
Units: µmol/g
Description: <p>Elemental sulfur in the solid phase</p>
http://lod.bco-dmo.org/id/dataset-parameter/994677.rdf
Name: Chromium_Reducible_Sulfur
Units: µmol/g
Description: <p>Chromium reducible sulfur in the solid phase</p>
http://lod.bco-dmo.org/id/dataset-parameter/994678.rdf
Name: d34S_sulfate
Units: ‰
Description: <p>Stable sulfur isotope ratio of porewater sulfate. δ34S = [{(34S/32S)sample/(34S/32S)standard} - 1] × 1000</p>
http://lod.bco-dmo.org/id/dataset-parameter/994679.rdf
Name: d34S_pyrite
Units: ‰
Description: <p>Stable sulfur isotope ratio of pyrite. δ34S = [{(34S/32S)sample/(34S/32S)standard} - 1] × 1000</p>
http://lod.bco-dmo.org/id/dataset-parameter/994680.rdf
Name: Sulfate_Reduction_Rate_SRR
Units: pmol cm⁻³ d⁻¹
Description: <p>Microbial activity (SRR)</p>
http://lod.bco-dmo.org/id/dataset-parameter/994681.rdf
Name: Anaerobic_Oxidation_Methane_AOM
Units: pmol cm⁻³ d⁻¹
Description: <p>Microbial activity (AOM)</p>
GB/NERC/BODC > British Oceanographic Data Centre, Natural Environment Research Council, United Kingdom
Biological and Chemical Oceanography Data Management Office (BCO-DMO)
Unavailable
508-289-2009
WHOI MS#36
Woods Hole
MA
02543
USA
info@bco-dmo.org
http://www.bco-dmo.org
Monday - Friday 8:00am - 5:00pm
For questions regarding this resource, please contact BCO-DMO via the email address provided.
pointOfContact
https://osprey.bco-dmo.org/dataset/994391/data/download
download
onLine
dataset
<p>Subsurface sediment samples were collected from four drilling sites in the Guaymas Basin, Gulf of California, during IODP Expedition 385 “Guaymas Basin Tectonics and Biosphere” using the research vessel R/V JOIDES Resolution between September and November of 2019. Rates of methanogenesis were determined at four sites and presented in the related dataset. Sites 1545 (27º38.230’N, 111º53.329’W) and 1546 (27º37.884’N, 111º52.781’W) were located roughly 52 km and 51 km, respectively, northwest of the axial graben of the northern spreading segment. Both sites are highly sedimented and a 75-meter thick inactive (~thermally equilibrated) basaltic/doleritic/gabbroic sill was present at site 1546 between ~355 to 431 meters below the seafloor (mbsf). Site U1545B is considered a reference site since it was free of sill intrusions and unaffected by active hydrothermal circulation. The geothermal gradient in hole U1545B was 227ºC/km. The geothermal gradient in hole U1546C, 221ºC/km, was similar to that measured in hole U1545B. Sites U1547 and U1548 were located inside the periphery of an active, sill-associated hydrothermal mound located about 27 km northwest of the axial graben of the northern spreading segment. Temperatures in hole U1547B &nbsp;(27º30.413’N, 111º40.734’W, water depth 1585.6m) exceeded 50°C in the upper 50 mbsf. The geothermal gradient in the U1547B hole was 529ºC/km. The geothermal gradient in the U1548C hole was 958ºC/km. Site U1549 was located near a cold seep sustained by a deeply buried, thermally equilibrated sill intrusion at several hundred meters depth. The geothermal gradient at hole U1549B was 194ºC/km. Site U1550 (27°15.170′N, 111°30.445′W, water depth 2001.2 ) was located near a cold seep sustained by a deeply buried, thermally equilibrated sill intrusion at several hundred meters depth. The geothermal gradient at hole U1550B was 135ºC/km. These sites are described in more detail in Teske et al. (2021).</p>
<p>To preserve sediment for solid-phase sulfur analysis and incubation experiments, sectioned core samples were placed in N<sub>2</sub>-filled gas-tight bags, and subsequently transferred to anoxic glass bottles and stored at 4℃ until further subsampling. Porewater concentrations of sulfate, methane and sulfide, and solid phase parameters, including total organic carbon and total sulfur, were analyzed onboard using established IODP protocols (Teske, 2021). These data were obtained from the IODP database&nbsp;(Teske, 2021). Briefly, methane concentrations were determined using a gas chromatograph (Agilent 7890A), sulfate concentrations were analyzed by ion chromatography (Metrohm 850 Professional IC), and sulfide samples were fixed with zinc acetate solution and measured spectrophotometrically (Cline, 1969). For total carbon (TC) and total sulfur (TS) contents, samples were freeze-dried and powdered, and ~15 mg was accurately weighed. Analysis was conducted using an elemental analyzer (Thermo Finnigan FlashEA 1112 CHNS). Inorganic carbon (IC) content was measured using a Coulometrics 5012 CO<sub>2</sub> coulometer. Freeze-dried and powdered sediments was reacted with 6.5 mL of 2 mol L<sup>–1 </sup>HCl in a glass vial to liberate CO<sub>2</sub>. Total organic carbon (TOC) content was quantified by the subtraction of IC from TC content. The statistical ANOVA of TOC to TS (C/S) ratios at the six sites was performed using Origin 2025 software (OriginLab Corporation). Significance was determined at a threshold of p &lt; 0.05.</p>
<p>For solid-phase sulfur species extraction, ~1.5 g subsamples were transferred to centrifuge tubes containing &nbsp;5% zinc acetate solution. After centrifugation to remove the supernatant, elemental sulfur (ES) was first extracted via sustained agitation for 15 hours with 30 mL 100% methanol (Zopfi et al. 2004). Dissolved ES was quantified via reversed-phase liquid chromatography (Agilent, 1260 Infinity III) with a C-18 column (Agilent ZORBAX Eclipse XDB-C18), using 100% methanol as the eluent. The pump speed was set to 1 mL min<sup>–1</sup>, and absorbance at 265 nm was measured via UV detection. The detection limit for this method is &lt;1 µmol L<sup>–1</sup>, and the analytical precision (relative standard deviation, RSD) was better than 0.7%.</p>
<p>The separated solid residue was subsequently treated with a cold chromium distillation procedure (Kallmeyer et al. 2004, Røy et al. 2014), where acid volatile sulfur (AVS) was released with 6 mol L<sup>–1</sup> HCl, and chromium reducible sulfur (CRS, mainly pyrite) was sequentially extracted with an acidified chromium chloride solution (CrCl<sub>2</sub>). The sulfide liberated from these solid-phase sulfur species was trapped by 5% (w/v) zinc acetate to form ZnS precipitate and then the concentration of each species was determined spectrophotometrically (Cline, 1969).</p>
<p>For porewater sulfate sulfur isotope analysis, a thawed pore fluid volume (5 ml) was fixed with saturated barium chloride solution to precipitate sulfate as barium sulfate. The BaSO<sub>4 </sub>was then rinsed with 6 mol L<sup>–1</sup> HCl and Milli-Q water. After determination, the precipitated zinc sulfide from CRS was subsequently converted to Ag<sub>2</sub>S by addition of silver nitrate and ammonium hydroxide to the recovery vessel. Cleaned and dried BaSO<sub>4</sub> and Ag<sub>2</sub>S was mixed with excess V<sub>2</sub>O<sub>5</sub> and the stable sulfur isotopic ratio was measured on an isotope ratio monitoring mass spectrometer (IRMS; Thermo Delta V Plus) coupled to a Flash elemental analyzer. Standard deviations were better than 0.3‰ (n ≥3), estimated using one International Atomic Energy Agency (IAEA-3) standard (–32.30‰) and two national (China) first level sulfur isotope standards (–0.07‰ and 22.15‰), respectively. The stable sulfur isotope values, δ<sup>34</sup>S, were calculated using the following formula:</p>
<blockquote>
<p>δ<sup>34</sup>S = [{(<sup>34</sup>S/<sup>32</sup>S)<sub>sample</sub>/(<sup>34</sup>S/<sup>32</sup>S)<sub>standard</sub>} - 1] × 1000</p>
</blockquote>
<p>The units of δ<sup>34</sup>S are per mil (‰) and are reported relative to the Vienna Canyon Diablo Troilite (VCDT) standard.&nbsp;&nbsp;</p>
<p>For the determination of potential rates of sulfate reduction (SR) and anaerobic oxidation of methane (AOM), 10 g sediment subsamples were weighed in a N<sub>2</sub>-filled glove box and transferred into 120 mL glass vials. Next, 40 mL artificial seawater medium was added and the vials were closed with blue butyl rubber stoppers and crimped. The seawater media for sediment slurry incubations were prepared as follows: 200 mg KH<sub>2</sub>PO<sub>4</sub>, 250 mg NH<sub>4</sub>Cl, 25 g NaCl, 0.5 g MgCl<sub>2</sub> × 6H<sub>2</sub>O, 0.5 g KCl and 150 mg CaCl<sub>2 </sub>× 2H<sub>2</sub>O, dissolved with 1 L Mill-Q water in a glass bottle (Heuer 2017). Sediment samples collected from above the sulfate-methane transition zone (SMTZ) were supplemented with 5 mmol L<sup>–</sup>1 sulfate in the artificial seawater medium, whereas samples from below the SMTZ were maintained without the addition of Na<sub>2</sub>SO<sub>4</sub>. After autoclaving, 5 mL sterile-filtered 154 mM Na<sub>2</sub>S and 1 M NaHCO<sub>3</sub> was added to the media to assure anoxia and to modulate the pH, respectively.</p>
<p>Then ~3 mL sediment slurry was introduced into a modified cut-end Hungate tube sealed with a gray chlorobutyl stopper and a screw cap. 100 µL of radiolabeled<sup> 35</sup>S-Na<sub>2</sub>SO<sub>4</sub> solution (~167 kBq) and<sup> 14</sup>C-CH<sub>4</sub> solution (~17 kBq) was injected into the quadruplicate sediment samples (one killed control and three live samples) for SR and AOM rate measurements, respectively. Samples were incubated concurrently under in situ temperature for 20 days. After incubation, microbial activities of SR and AOM were terminated by injecting 3 mL 20% (w/v) zinc acetate and 3 mL 2 mol L<sup>–1</sup> NaOH, respectively.</p>
<p>Zinc acetate-fixed slurry samples were transferred to falcon tubes and then centrifuged. The supernatant was obtained to count unreacted <sup>35</sup>S-SO<sub>4</sub><sup>2</sup>- radioactivity, and the pool of total reduced sulfur species in the remaining sediment was recovered by the cold chromium distillation (Røy et al. 2014). The extracted sulfide was trapped with 5% (w/v) zinc acetate solution to measure <sup>35</sup>S-H<sub>2</sub>S radioactivity. The sulfate reduction rates were calculated from the following formula:</p>
<blockquote>
<p>SRR = {(<sup>35</sup>S-H<sub>2</sub>S ) / [(<sup>35</sup>S-H<sub>2</sub>S ) + (<sup>35</sup>S-SO<sub>4</sub><sup>2-</sup> )]} × &nbsp;[SO<sub>4</sub><sup>2-</sup> ] × 1.06 / t × 1,000,000</p>
</blockquote>
<p>where SRR is the sulfate reduction rate presented in pmol cm<sup>–3</sup> day<sup>–1</sup>; (<sup>35</sup>S-H<sub>2</sub>S) is the measured <sup>35</sup>S-H<sub>2</sub>S radioactivity (decays per minute, dpm); (<sup>35</sup>S-SO<sub>4</sub><sup>2-</sup>) is the radioactivity of unreacted <sup>35</sup>S-SO<sub>4</sub><sup>2-</sup> (dpm); [SO<sub>4</sub><sup>2-</sup>] is the total sulfate concentration of slurry (i.e. sediment porewater sulfate plus added sulfate times the porosity); 1.06 is the correction factor for the expected isotopic fractionation; t is incubation time in days; 1,000,000 is the unit conversion factor. The units of sulfate reduction are pmol cm<sup>-3</sup> d<sup>-1</sup>.</p>
<p>For AOM rate measurements, <sup>14</sup>C-CO<sub>2</sub> production from <sup>14</sup>C-CH<sub>4</sub> was quantified with the acid digestion method (Joye et al. 2004, Zhuang et al. 2019). Briefly, homogenized sediment slurries were transferred to a 250 mL glass bottle and purged with air to remove unreacted <sup>14</sup>C-CH<sub>4</sub>. Then 5 mL of 30% (v/v) sulfuric acid was added to the bottle and then liberated <sup>14</sup>C-CO<sub>2</sub> &nbsp;was trapped with 3-methoxypropylamine. AOM rates were calculated using the following equation:</p>
<blockquote>
<p>AOM= {(<sup>14</sup>C-CO<sub>2</sub>) / [(<sup>14</sup>C-CO<sub>2</sub>) + (<sup>14</sup>C-CH<sub>4</sub> )]} × &nbsp;[CH<sub>4</sub> ] × 1.06 / t × 1,000</p>
</blockquote>
<p>where AOM is the anaerobic oxidation of methane calculated in pmol cm<sup>–3</sup> day<sup>–1</sup>; (<sup>14</sup>C-CO<sub>2</sub>) is the <sup>14</sup>C-CO<sub>2</sub> counts (dpm); (<sup>14</sup>C-CH<sub>4</sub>) is the total injected <sup>14</sup>C-CH<sub>4</sub> (dpm); [CH<sub>4</sub>] is the methane concentration of sediment slurry (µmol L<sup>–</sup>1); 1.01 is the carbon isotopic fractionation correction factor; t is incubation duration in days; 1,000 is the unit conversion factor. The units of anaerobic oxidation of methane are pmol cm<sup>-3</sup> d<sup>-1</sup>.</p>
<p>The reported microbial activity rates reflected the potential metabolic capacity of the <em>in situ</em> microbial community within the sediment, constrained by ambient geochemical conditions and substrate availability.</p>
Specified by the Principal Investigator(s)
- Loaded "OCE-2023575_sulfur_isotopes.csv" as CSV with row 1 as header; row 2 skipped; missing values treated as empty string, "nd", and "n.d."
- Applied BCO-DMO metadata (standard_name_id, units, descriptions) to 19 fields including; Latitude, Longitude, and Water Depth flagged as primary parameters
- Renamed 13 fields to comply with BCO-DMO parameter naming guidance: "Water Depth" → Water_Depth, "Sediment Depth" → Sediment_Depth, "SO42-" → Sulfate, "Total Sulfur\n(TS)" → Total_Sulfur, "Total Organic Carbon\n(TOC)" → Total_Organic_Carbon, "C/S" → CS_ratio, "Acid Volatile Sulfur\n(AVS)" → Acid_Volatile_Sulfur, "Elemental Sulfur\n(ES)" → Elemental_Sulfur, "Chromium Reducible Sulfur\n(CRS)" → Chromium_Reducible_Sulfur, "δ34S-sulfate" → d34S_sulfate, "δ34S-pyrite" → d34S_pyrite, "Sulfate Reduction Rate\n(SRR)" → Sulfate_Reduction_Rate_SRR, "Anaerobic Oxidation of Methane\nAOM" → Anaerobic_Oxidation_Methane_AOM
- Exported file as 994391_v1_sulfur_biogeochem.csv
Specified by BCO-DMO Data Managers
asNeeded
7.x-1.1
Biological and Chemical Oceanography Data Management Office (BCO-DMO)
Unavailable
508-289-2009
WHOI MS#36
Woods Hole
MA
02543
USA
info@bco-dmo.org
http://www.bco-dmo.org
Monday - Friday 8:00am - 5:00pm
For questions regarding this resource, please contact BCO-DMO via the email address provided.
pointOfContact
Centrifuge tubes
Centrifuge tubes
PI Supplied Instrument Name: Centrifuge tubes PI Supplied Instrument Description:For solid-phase sulfur species extraction, ~1.5 g subsamples were transferred to centrifuge tubes containing 5% zinc acetate solution. Instrument Name: Centrifuge Instrument Short Name: Instrument Description: A machine with a rapidly rotating container that applies centrifugal force to its contents, typically to separate fluids of different densities (e.g., cream from milk) or liquids from solids.
Coulometrics 5012 CO2 coulometer
Coulometrics 5012 CO2 coulometer
PI Supplied Instrument Name: Coulometrics 5012 CO2 coulometer PI Supplied Instrument Description:Inorganic carbon (IC) content was measured using a Coulometrics 5012 CO2 coulometer. Instrument Name: CO2 Coulometer Instrument Short Name:CO2 coulometer Instrument Description: A CO2 coulometer semi-automatically controls the sample handling and extraction of CO2 from seawater samples. Samples are acidified and the CO2 gas is bubbled into a titration cell where CO2 is converted to hydroxyethylcarbonic acid which is then automatically titrated with a coulometrically-generated base to a colorimetric endpoint. Community Standard Description: http://vocab.nerc.ac.uk/collection/L05/current/LAB12
Gas chromatograph (Agilent 7890A)
Gas chromatograph (Agilent 7890A)
PI Supplied Instrument Name: Gas chromatograph (Agilent 7890A) PI Supplied Instrument Description: Briefly, methane concentrations were determined using a gas chromatograph (Agilent 7890A), sulfate concentrations were analyzed by ion chromatography (Metrohm 850 Professional IC), and sulfide samples were fixed with zinc acetate solution and measured spectrophotometrically. Instrument Name: Gas Chromatograph Instrument Short Name:Gas Chromatograph Instrument Description: Instrument separating gases, volatile substances, or substances dissolved in a volatile solvent by transporting an inert gas through a column packed with a sorbent to a detector for assay. (from SeaDataNet, BODC) Community Standard Description: http://vocab.nerc.ac.uk/collection/L05/current/LAB02/
Liquid Chromatograph
Liquid Chromatograph
PI Supplied Instrument Name: Liquid Chromatograph PI Supplied Instrument Description:Dissolved ES was quantified via reversed-phase liquid chromatography (Agilent, 1260 Infinity III) with a C-18 column (Agilent ZORBAX Eclipse XDB-C18), using 100% methanol as the eluent. Instrument Name: High-Performance Liquid Chromatograph Instrument Short Name:HPLC Instrument Description: A High-performance liquid chromatograph (HPLC) is a type of liquid chromatography used to separate compounds that are dissolved in solution. HPLC instruments consist of a reservoir of the mobile phase, a pump, an injector, a separation column, and a detector. Compounds are separated by high pressure pumping of the sample mixture onto a column packed with microspheres coated with the stationary phase. The different components in the mixture pass through the column at different rates due to differences in their partitioning behavior between the mobile liquid phase and the stationary phase. Community Standard Description: http://vocab.nerc.ac.uk/collection/L05/current/LAB11/
Ion Chromatograph (Metrohm 850 Professional IC)
Ion Chromatograph (Metrohm 850 Professional IC)
PI Supplied Instrument Name: Ion Chromatograph (Metrohm 850 Professional IC) PI Supplied Instrument Description:Briefly, methane concentrations were determined using a gas chromatograph (Agilent 7890A), sulfate concentrations were analyzed by ion chromatography (Metrohm 850 Professional IC), and sulfide samples were fixed with zinc acetate solution and measured spectrophotometrically. Instrument Name: Ion Chromatograph Instrument Short Name:Ion Chromatograph Instrument Description: Ion chromatography is a form of liquid chromatography that measures concentrations of ionic species by separating them based on their interaction with a resin. Ionic species separate differently depending on species type and size. Ion chromatographs are able to measure concentrations of major anions, such as fluoride, chloride, nitrate, nitrite, and sulfate, as well as major cations such as lithium, sodium, ammonium, potassium, calcium, and magnesium in the parts-per-billion (ppb) range. (from http://serc.carleton.edu/microbelife/research_methods/biogeochemical/ic.html)
Spectrometer
Spectrometer
PI Supplied Instrument Name: Spectrometer PI Supplied Instrument Description:Briefly, methane concentrations were determined using a gas chromatograph (Agilent 7890A), sulfate concentrations were analyzed by ion chromatography (Metrohm 850 Professional IC), and sulfide samples were fixed with zinc acetate solution and measured spectrophotometrically. Instrument Name: Spectrometer Instrument Short Name:Spectrometer Instrument Description: A spectrometer is an optical instrument used to measure properties of light over a specific portion of the electromagnetic spectrum. Community Standard Description: http://vocab.nerc.ac.uk/collection/L22/current/TOOL0460/
Mass spectrometer (IRMS; Thermo Delta V Plus)
Mass spectrometer (IRMS; Thermo Delta V Plus)
PI Supplied Instrument Name: Mass spectrometer (IRMS; Thermo Delta V Plus) PI Supplied Instrument Description:Cleaned and dried BaSO4 and Ag2S was mixed with excess V2O5 and the stable sulfur isotopic ratio was measured on an isotope ratio monitoring mass spectrometer (IRMS; Thermo Delta V Plus) coupled to a Flash elemental analyzer. Instrument Name: Thermo Fisher Scientific DELTA V Plus isotope ratio mass spectrometer Instrument Short Name:Delta V Plus IRMS Instrument Description: The Thermo Scientific DELTA V Plus is an isotope ratio mass spectrometer designed to measure isotopic, elemental and molecular ratios of organic and inorganic compounds. The DELTA V Plus is an enhanced model of the DELTA V series of isotope ratio mass spectrometers, which can be upgraded from the DELTA V Advantage. The DELTA V Plus can be operated in Continuous Flow or Dual Inlet mode and can accommodate up to 10 collectors, ensuring flexibility to cover many applications. The DELTA V Plus is controlled by an automated, integrated Isodat software suite. A magnet, whose pole faces determine the free flight space for the ions, eliminates the traditional flight tube. The magnet is designed for fast mass switching which is further supported by a fast jump control between consecutive measurements of multiple gases within one run. The sample gas is introduced at ground potential, eliminating the need for insulation of the flow path, ensuring 100 percent transfer into the ion source. The amplifiers register ion beams up to 50 V. The DELTA V Plus has refined optics, enabling greater ion transmission than the DELTA V Advantage. It has a sensitivity of 800 molecules per ion (M/I) in Dual Inlet mode and 1100 M/I in Continuous Flow mode. It has a system stability of < 10 ppm and an effective magnetic detection radius of 191 nm. It has a mass range of 1 - 96 Dalton at 3 kV.
Elemental Analyzer (Thermo Finnigan FlashEA 1112 CHNS)
Elemental Analyzer (Thermo Finnigan FlashEA 1112 CHNS)
PI Supplied Instrument Name: Elemental Analyzer (Thermo Finnigan FlashEA 1112 CHNS) PI Supplied Instrument Description:For total carbon (TC) and total sulfur (TS) contents, samples were freeze-dried and powdered, and ~15 mg was accurately weighed. Analysis was conducted using an elemental analyzer (Thermo Finnigan FlashEA 1112 CHNS). Instrument Name: Thermo Fisher Scientific Flash EA 1112 elemental analyzer Instrument Short Name:Flash EA 1112 Instrument Description: The Thermo Finnigan {Thermo Fisher Scientific} Flash EA 1112 elemental analyzer is a laboratory instrument used to determine total carbon, hydrogen, nitrogen, sulphur, and oxygen in a sample. The sample is completely and instantaneously oxidised by flash combustion, which converts all organic and inorganic substances into combustion products. The resulting combustion gases pass through a reduction furnace and are swept into the chromatographic column by the helium carrier gas. The gases are separated in the column and detected by the thermal conductivity detector, which gives an output signal proportional to the concentration of the individual components of the mixture. The instrument was originally manufactured by Thermo Finnigan, which was acquired by Thermo Electron and later Thermo Scientific (part of Thermo Fisher Scientific).
Cruise: IODP-385
IODP-385
R/V JOIDES Resolution
Community Standard Description
International Council for the Exploration of the Sea
R/V JOIDES Resolution
vessel
IODP-385
Andreas Teske
R/V JOIDES Resolution
Community Standard Description
International Council for the Exploration of the Sea
R/V JOIDES Resolution
vessel