Biogeochemistry Commons^™

Sulfur Geochemistry And Diagenesis In A Gas Hydrate Terrane, Cascadia Margin, Offshore Oregon: Role Of Anaerobic Methane Oxidation, David Deigert, Walter S. Borowski

EKU Faculty and Staff Scholarship

We present sulfide mineral data from south Hydrate Ridge located in a gas hydrate terrane, offshore Oregon. Sulfide sulfur concentration and the isotopic composition of sulfur (d³⁴S) in authigenic sulfide minerals are analyzed from sediment samples collected on Ocean Drilling Project (ODP) Leg 204. Shallow sediment samples (<25 >mbsf) assess the relative importance of anaerobic methane oxidation (AMO) as a biogeochemical process, both here and at the Blake Ridge, another well known gas hydrate terrane offshore southeastern United States. Deep samples (>25 mbsf) are used to evaluate sulfur diagenesis and its controls from early Pleistocene to the …

Impact Of Anthropogenic Combustion Emissions On The Fractional Solubility Of Aeroosol Iron: Evidence From The Sargasso Sea, Peter N. Sedwick, Edward R. Sholkovitz, Thomas M. Church

OES Faculty Publications

We report empirical estimates of the fractional solubility of aerosol iron over the Sargasso Sea during periods characterized by high concentrations of Saharan dust (summer 2003) and by low concentrations of aerosols in North American/maritime North Atlantic air masses (spring 2004 and early summer 2004). We observed a strong inverse relationship between the operational solubility of aerosol iron (defined using a flow-through deionized-water leaching protocol) and the total concentration of aerosol iron, whereby the operational solubility of aerosol iron was elevated when total aerosol iron loadings were low. This relationship is consistent with source-dependent differences in the solubility characteristics of …

A Preliminary Study Of Sulfide Mineral Formation In Methane-Rich, Marine Sediments Associated With Anaerobic Methane Oxidation, Cascadia Continental Margin, Offshore Oregon, David Deigert, Walter S. Borowski

EKU Faculty and Staff Scholarship

Within gas hydrate settings, sulfide mineralization in marine sediments is likely controlled by two microbially-mediated, sulfate-depleting processes: anaerobic methane oxidation (AMO) and sulfate reduction. If large amounts of methane are delivered to the sulfate-methane interface (SMI), predominantly by diffusion, larger amounts of solid sulfide sulfur should occur there as dissolved sulfide combines with iron, forming an authigenic precipitate. We measure the amount of diagenetic sulfide sulfur at three locations in the Hydrate Ridge vicinity by extracting the bulk sedimentary sulfide-phase minerals (S^o, FeS, and FeS₂) through chromium reduction, precipitating sulfide sulfur as silver sulfide, and gravimetrically …

Data Report: Dissolved Sulfide Concentration And Sulfur Isotopic Composition Of Sulfide And Sulfate In Pore Waters, Odp Leg 204, Hydrate Ridge And Vicinity, Cascadia Margin, Offshore Oregon, Walter S. Borowski

EKU Faculty and Staff Scholarship

We report dissolved sulfide sulfur concentrations and the sulfur isotopic composition of dissolved sulfate and sulfide in pore waters from sediments collected during Ocean Drilling Program Leg 204. Porewater sulfate is depleted rapidly as the depth to the sulfate/methane interface (SMI) occurs between 4.5 and 11 meters below seafloor at flank and basin locations. Dissolved sulfide concentration reaches values as high as 11.3 mM in Hole 1251E. Otherwise, peak sulfide concentrations lie between 3.2 and 6.1 mM and occur immediately above the SMI. The sulfur isotopic composition of interstitial sulfate generally becomes enriched in 34 S with increasing sediment depth. …

A Preliminary Comparison Of The Sulfur Geochemistry Between Two Gas Hydrate Terranes, Michael D. Spicer, Walter S. Borowski

EKU Faculty and Staff Scholarship

We compare the authigenic sulfide mineral geochemistry of two, different gas hydrate terranes: the accretionary wedge of the Cascadia continental margin (offshore Oregon) and the passive margin of the Blake Ridge region (offshore southeastern US). We expect diagenetic processes effecting sulfide mineral formation (elemental sulfur, iron monosulfides, and pyrite) within these sediments to respond to differing geologic conditions at each setting. In both settings, methane diffuses upward from gas hydrates to the methane-sulfate interface (SMI), where it is consumed by reaction with sulfate during anaerobic methane oxidation (AMO). This microbially-mediated, diagenetic process produces an interstitial environment conducive to authigenic sulfide …

Sulfide Mineralization In Deep-Water Marine Sediments Related To Methane Transport, Methane Consumption, And Methane Gas Hydrates, Matthew K. Thompson, Walter S. Borowski, Charles K. Paull, William Ussler Iii

EKU Faculty and Staff Scholarship

Patterns of sulfide sulfur concentration and sulfur isotopic composition (d³⁴ S) are perhaps related to upward methane transport, especially in sediments underlain by methane gas hydrate deposits. Increased methane delivery augments the effect of anaerobic methane oxidation (AMO) occurring at the sulfate-methane interface (SMI). Sulfate and methane co-consumption results in production of dissolved sulfide at the interface that is eventually sequestered within sulfide minerals (elemental sulfur, iron monosulfide, pyrite).

We examine the sediments of two piston cores collected over the Blake Ridge gas hydrate deposits (offshore southeastern United States) by extracting total sedimentary sulfide using chromium reduction. We use …

Sulfide Mineralization Within Modern, Deep-Sea Marine Sediments And Oxygenation Of The Early Earth, Matthew K. Thompson, Walter S. Borowski

EKU Faculty and Staff Scholarship

The Earth’s atmosphere and oceans have not always been oxygenated. The exact pathway and timing of the oxygenation of the Earth’s early oceans is poorly constrained, although it appears that oxygenation was essentially complete by the beginning of the Cambrian (545 million years ago). Indeed, the appearance and diversification of the first animals may have been dependent on threshold levels of oxygen. Eventually we intend to use the sulfur isotopic composition of sulfide minerals (iron monosulfides and pyrite) present in sedimentary rocks to reconstruct the oxygenation of Proterozoic oceans, but first must strive to understand sulfide mineral formation in the …

Sulfide Sulfur Concentration And Sulfur Isotopic Composition Of Methane Seep Sediments, V. Lynn Means, Walter S. Borowski

EKU Faculty and Staff Scholarship

No abstract provided.

Isotopic Concentration Of Sulfide Sulfur And Delta-34s From Methane Seeps On The Blake Ridge Diapir And Monterey Canyon, V. Lynn Means, Walter S. Borowski

EKU Faculty and Staff Scholarship

Marine sediments contain pore water with dissolved sulfate. Pore-water sulfate is depleted by two anaerobic chemical reactions tat involves microbes: 1) oxidation of sedimentary organic matter; and 2) anaerobic methane oxidation (AMO; CH₄ + SO₄ → HCO₃^- + HS^- + H₂O). Both sulfate depletion pathways produce dissolved hydrogen sulfide (∑HS^-), which is scavenged by dissolved iron to produce authigenic sulfide minerals. These minerals crystallize in pore spaces or on grain surfaces. Seafloor seeps are where methane moves upward in the sediments to escape into overlying waters. Additional methane supply should fuel …

Sulfide Mineralization In Deep-Water Marine Sediments Related To Methane Transport, Methane Consumption, And Methane Gas Hydrates, Matthew K. Thompson, Walter S. Borowski, Charles K. Paull, William Ussler Iii

EKU Faculty and Staff Scholarship

Patterns of sulfide sulfur concentration and sulfur isotopic composition (d³⁴ S) are perhaps related to upward methane transport, especially in sediments underlain by methane gas hydrate deposits. Increased methane delivery augments the effect of anaerobic methane oxidation (AMO) occurring at the sulfate-methane interface (SMI). Sulfate and methane co-consumption results in production of dissolved sulfide at the interface that is eventually sequestered within sulfide minerals (elemental sulfur, iron monosulfide, pyrite).

We examine the sediments of two piston cores collected over the Blake Ridge gas hydrate deposits (offshore southeastern United States) by extracting total sedimentary sulfide using chromium reduction. We use …

Changes In Sulfur Concentration And Sulfur Isotopic Composition Within Authigenic Sulfide Minerals From Sediments Of Miocene Age To The Present, Odp Site 995, Blake Ridge, Offshore Southeastern United States, Kathryn G. Takacs, Walter S. Borowski

EKU Faculty and Staff Scholarship

The Blake Ridge area (offshore southeastern United States) consists of deep-water continental margin sediments overlying deposits of methane gas hydrate. Authigenic sulfide minerals (elemental sulfur, S˚; iron monosulfides, ~FeS; and pyrite, FeS₂) are actively deposited in these sediments due to sulfate reduction and focused anaerobic methane oxidation (AMO) at the sulfate-methane interface (SMI). Sulfide minerals at the present SMI are enriched in ³⁴S relative to those produced by sulfate reduction of organic matter higher in the sulfate reduction zone. ³⁴S enrichments preserved in the sediment column may identify relatively high amounts of AMO and thus record …

Sulfide Mineralization In Deep-Water Marine Sediments Related To Methane Transport, Methane Consumption, And Methane Gas Hydrates, Matthew K. Thompson, Walter S. Borowski, Charles K. Paull, William Ussler Iii

EKU Faculty and Staff Scholarship

Patterns of sulfide sulfur concentration and sulfur isotopic composition (d³⁴S) are perhaps related to upward methane transport, especially in sediments underlain by methane gas hydrate deposits. Increased methane delivery augments the affect of anaerobic methane oxidation (AMO) occurring at the sulfate-methane interface (SMI). Sulfate and methane co-consumption results in production of dissolved sulfide at the interface that is eventually sequestered within sulfide minerals (elemental sulfur, iron monosulfide, pyrite).

We examine the sediments of two piston cores collected over the Blake Ridge gas hydrate deposits (offshore southeastern North America) by extracting total sedimentary sulfide using chromium reduction. We use …

Enrichments Of 34s In Sulfide Minerals Of Deep-Water Marine Sediments Of The Blake Ridge, Offshore Southeastern United States, Kathryn G. Takacs, Walter S. Borowski

EKU Faculty and Staff Scholarship

Past research shows that active sulfide mineralization occurs at the base of the sulfate reduction zone (SRZ) in modern, deep-water, continental-margin sediments that overlie methane gas hydrate. These sulfide minerals (elemental sulfur, Sº; iron monosulfides, ~FeS; and pyrite, FeS₂) are enriched in ³⁴S because of sulfate reduction and anaerobic methane oxidation (AMO) processes occurring above and near the sulfate-methane interface (SMI).

The data in this study show that 5 discrete zones of sulfide minerals are preserved in a 703.8-meter sediment column associated with methane gas hydrate. These zones of sulfide minerals are also enriched in ³⁴S. …

Nitrate Anomaly In The Upper Nutricline In The Northern South China Sea - Evidence For Nitrogen Fixation, George T. F. Wong, Shi-Wei Chung, Fuh-Kwo Shiah, Chung-Chi Chen, Liang-Saw Wen, Kon-Kee Liu

OES Faculty Publications

[1] Up to 2 μM of nitrate anomaly, N*, were found in the upper nutricline at the South East Asia Time-series Study (SEATS) site in the northern South China Sea (SCS). These concentrations were among the higher values reported in the Pacific and indicate the significant contribution of the remineralization of nitrogen-rich organic matter formed by nitrogen fixation to the nutrient dynamics of the area. The concentrations were systematically higher, by up to 2.5 μM, in the Fall through the early Spring, during the northeast monsoon, than in the Summer, suggesting that the impact of nitrogen fixation was higher during …

The Meeting Of Two Microbial Worlds: Geochemistry Of The Sulfate-Methane Interface, Walter S. Borowski, Charles K. Paull, William Ussler Iii

EKU Faculty and Staff Scholarship

No abstract provided.

Data Report: Carbon Isotopic Composition Of Dissolved Co2, Co2 Gas, And Methane, Blake-Bahama Ridge And Northeast Bermuda Rise, Odp Leg 172, Walter S. Borowski, Namik Cagatay, Y Tournois, Charles K. Paull

EKU Faculty and Staff Scholarship

Carbon isotopic data of interstitial dissolved CO2 (ΣCO2), CO2 gas, and methane show that a variety of microbial diagenetic processes produce the observed isotopic trends. Anaerobic methane oxidation (AMO) is an important process near the sulfate-methane interface (SMI) that strongly influences the isotopic composition of ΣCO2 in the sulfate reduction and upper methanogenic zones, which in turn impacts methane isotopic composition. Dissolved CO2 and methane are maximally depleted in 3C near the SMI, where C values are as light as –31.8‰ and –101‰ PDB for ΣCO2 and methane, respectively. CO2 reduction links the CO2 and methane pools in the methanogenic …

Nitrogen Isotopic Composition Of Pore Water Ammonium, Blake Ridge, Site 997, Odp Leg 164, Walter S. Borowski, Charles K. Paull

EKU Faculty and Staff Scholarship

Ammonium (NH4 +) concentration profiles in piston-core sediments of the Carolina Rise and Blake Ridge generally have linear concentration profiles within the sulfate reduction zone (Borowski, 1998). Deep Sea Drilling Project (DSDP) Site 533, located on the Blake Ridge, also displayed a linear ammonium concentration profile through the sulfate reduction zone and the profile linearity continues into the upper methanogenic zone to a depth of ~200 meters below seafloor (mbsf), where the first methane gas hydrates probably occur (Jenden and Gieskes, 1983; Kvenvolden and Barnard, 1983). Sediments from the Ocean Drilling Program (ODP) Leg 164 deep holes (Sites 994, 995, …

Significance Of Anaerobic Methane Oxidation In Methane-Rich Sediments Overlying The Blake Ridge Gas Hydrates, Walter S. Borowski, Tori M. Hoehler, Mark J. Alperin, Namcy M. Rodriguez, Charles K. Paull

EKU Faculty and Staff Scholarship

A unique set of geochemical pore-water data, characterizing the sulfate reduction and uppermost methanogenic zones, has been collected at the Blake Ridge (offshore southeastern North America) from Ocean Drilling Program (ODP) Leg 164 cores and piston cores. The δ13 C values of dissolved CO2(Σ CO2) are as 13 C-depleted as –37.7‰ PDB (Site 995) at the sulfate-methane interface, reflecting a substantial contribution of isotopically light carbon from methane. Although the geochemical system is complex and difficult to fully quantify, we use two methods to constrain and illustrate the intensity of anaerobic methane oxidation in Blake Ridge sediments. An estimate using …

A Biogeochemical Comparison Of Fossil (Carboniferous) And Modern Crustose Red Algae, Michael A. Kruge, John E. Utgaard, William Ferry

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

The nature of the contribution of the various types of algae to sedimentary organic matter continues to be a topic of research interest. Crustose red algae have however received less attention than other types. The fossil calcareous red algae (Rhodophyta) analyzed in this study are two relatively unrecrystallized specimens of Parachaetetes (Family Solenoporacea) from the lower part of the Ste. Genevieve Formation (Carboniferous, Visean) in Union County, Illinois, USA. They occurred in the patch reef phase of a small carbonate mudmound-patchreef. The three modern specimens (collected and identified by F. Collier) are the crustose algae Lithothamnion, Clathromorphum and Phymatolithon …

New Technique Detects Gas Hydrates, Walter S. Borowski, Charles K. Paull, William Ussler Iii

EKU Faculty and Staff Scholarship

As exploration and development moves into deep waters, the possibility of encountering gas hydrates within seafloor sediments becomes increasingly likely. The ability to accurately detect gas hydrates is key to producing deepwater fields, allowing operators to safely design and place offshore drilling and production platforms, subsea production equipment and flow lines, as well as pipelines.

Biostratigraphic Analysis Of Southern Florida's Plio-Pleistocene Shell Beds, Dalton L. Rasmussen

OES Theses and Dissertations

Four molluscan assemblage zones in southern Florida corresponding to the Pinecrest Sand Member of the Tamiami Formation, and the Caloosahatchee, Bermont and Fort Thompson shell beds were identified following quantitative and qualitative analyses of the fossil molluscan fauna. Twenty-eight bulk sediment samples collected from 16 localities across southern Florida were processed for fossil material, and yielded nearly 60,000 specimens belonging to 311 species. A Q-mode cluster analysis compared sediment samples on the basis of 188 species whose abundances had been converted to binary presence-absence form. The cluster analysis was run four times using the Jaccard and Dice similarity coefficients as …

A Comparison Of Metals In Several Ahermatypic Corals And Surficial Sediments: Mobile Pinnacles And Hoffa Reef, Northcentral Gulf Of Mexico, Kathryn M. Conko

OES Theses and Dissertations

Metal concentrations in marine sediment and carbonate secreting invertebrates are representative of surrounding environmental chemistry. Aluminum, Ba Ca, Cd, Cr, Cu, Fe, Mg, Mn, Ni, Pb, Sr, and Zn were measured in carbonate and terrigenous phases of the $<$63 um fraction of sediment samples from two locations in the northcentral Gulf of Mexico. Enrichment factors indicate that Al, Ba, Cu, Cr, Mg, Mn, and Ni are all slightly depleted in these sediments relative to crustal abundances. Discriminant function analyses shows that the concentrations of five elements differ between locations.

Ahermatypic coral (106 specimens) from five genera collected from the study sites were analyzed for Cd, Cu, Cr, Pb, Zn, Mn, Sr, Ba, Fe, Ca and Mg. Eight elements vary between some genera, Al and Ba also vary in concentration in corals between either location. All elements except Sr are significantly depleted in the coral with respect to Ca in the …

Identification And Quantitation Of Volatile Amines In Marine Sediments, Chuen Mei Huang

Chemistry & Biochemistry Theses & Dissertations

Pore waters which were taken from sediments of the Chesapeake Bay were analyzed to determine the presence of volatile amines. A purge-and-trap technique was used to concentrate the amines. Then, following derivatization with heptaflourobutyric anhydride, the HFBA-amines were analyzed by gas chromatography with electron capture detection and with mass spectrometric detection. One secondary amine, diethylamine with a concentration of 0.3-0.6 uM, was found in a total of three pore water samples from cores collected on two different dates. A primary amine, sec-butylamine with a concentration of O. 05 AIM, was also found in one of these same samples. Another primary …

Some Effects Of The Polychaete Nereis Succinea Frey And Leukart 1847 On The Distribution Of Copper Cadmium And Zinc In Sediments And Water, Gabriela Kitzig August

OES Theses and Dissertations

Two laboratory experiments, each lasting 216 hours, were conducted in order to determine the effects of a burrowing polychaete, Nereis succinea Frey and Leukart, 1847, on the distribution of copper, cadmium, and zinc in sediments and water in environmentally controlled microcosms. Dissolved metal concentrations in microcosms containing worms (experimental) decreased more rapidly than in microcosms without worms (controls). From 72 hours to 216 hours, suspended metal concentrations in experimental microcosms increased while concentrations in controls remained relatively constant. Sediment cadmium concentrations in experimental microcosms increased more over time than in controls. Polychaetes accumulated significant amounts of all three metals. These …

The Effects Of Elevated Calcium Chloride And Magnesium Chloride Levels On Larval Growth And Survival Of Macrobrachium Rosenbergii (De Man) (Decapoda Palaemonidae) Reared In The Laboratory, James Thomas Michaels Ii

OES Theses and Dissertations

The effects of elevated CaCl₂ , MgCl₂ , combination CaCl₂ and MgCl₂ concentrations and their associated ionic strengths on larval growth and survival of the freshwater prawn, Macrobrachium rosenbergii were investigated in the laboratory. Larvae were reared in diluted seawater of 15 parts per thousand salinity with elevated calcium concentrations of 330 parts per million and elevated magnesium concentrations of 1275 parts per million. Control larvae were also reared with elevated NaCl concentrations to duplicate the ionic strength increases of the combination CaCl₂ - MgCl₂ test solution which had the highest ionic strength. A …

Water Chemistry Survey Of Boulder Basin, Lake Mead, P. R. Tramutt, Bureau Of Reclamation

Publications (WR)

The survey results indicate that the impoundment of water behind Hoover Dam has not adversely affected the dissolved oxygen (DO) content and that water quality and DO content were uniform regardless of depth. The study made in April-May 1964 will provide water quality data of Lake Mead prior to releases from Lake Powell as a basis for evaluating Lake Powell's effect on water quality and limnology of Lake Mead. The performance of a DO analyzer was tested and found unsatisfactory at depths below 150 ft. Parameters tested by standard chemical analyses of water samples in the Denver Laboratory and by …