georefid:2001-025803georefid:2001-025795SEDIS Publication Catalogue

ana.macario@awi.de

http://sedis.iodp.org/pub-catalogue/informationpointOfContact2011-06-23T00:00:00Zhttp://sedis.iodp.org/pub-catalogue/index.php?id=10.2973/odp.proc.sr.164.242.20002000-01-01publicationgeorefid:2001-025803doi:10.2973/odp.proc.sr.164.242.2000Hoehler, Tori M.University of North Carolina at Chapel Hill, Marine Sciences Department, Chapel Hill, NC, United StatesauthorBorowski, Walter S.University of Tokyo, JapanauthorAlperin, Marc J.Ocean Drilling Program, United StatesauthorRodriguez, Nancy M.U. S. Geological Survey, United StatesauthorPaull, Charles K.University of Texas at Arlington, United StatesauthorTexas A & M University, Ocean Drilling Program, College Station, TX, United StatespublisherdocumentHardcopyIn: Paull, Charles K., Matsumoto, Ryo, Wallace, Paul J., Black, Nancy R., Borowski, Walter S., Collett, Timothy S., Damuth, John E., Dickens, Gerald R., Egeberg, Per Kristian, Goodman, Kim, Hesse, Reinhard F., Hiroki, Yoshihisa, Holbrook, W. Steven, Hoskins, Hartley, Ladd, John, Lodolo, Emanuele, Lorenson, Thomas D., Musgrave, Robert J., Naehr, Thomas H., Okada, Hisatake, Pierre, Catherine, Ruppel, Carolyn D., Satoh, Mikio, Thiery, Regis, Watanabe, Yoshio, Wehner, Hermann, Winters, William J., Wood, Warren T., Miller, Christine M. (editor), Reigel, Ruth (editor), Proceedings of the Ocean Drilling Program; volume 164; scientific results; gas hydrate sampling on the Blake Ridge and Carolina Rise; covering Leg 164 of the cruises of the drilling vessel JOIDES Resolution, Halifax, Nova Scotia, to Miami, Florida, sites 991-997, 31 October-19 December 199516479-85Anaerobic methane oxidation (AMO) was characterized in sediment cores from the Blake Ridge collected during Ocean Drilling Program (ODP) Leg 164. Three independent lines of evidence support the occurrence and scale of AMO at Sites 994 and 995. First, concentration depth profiles of methane from Hole 995B exhibit a region of upward concavity suggestive of methane consumption. Diagenetic modeling of the concentration profile indicates a 1.85-m-thick zone of AMO centered at 21.22 mbsf, with a peak rate of 12.4 nM.d (super -1) . Second, subsurface maxima in tracer-based sulfate reduction rates from Holes 994B and 995B were observed at depths that coincide with the model-predicted AMO zone. The subsurface zone of sulfate reduction was 2 m thick and had a depth integrated rate that compared favorably to that of AMO (1.3 vs. 1.1 nmol.cm (super -2) .d (super -1) , respectively). These features suggest close coupling of AMO and sulfate reduction in the Blake Ridge sediments. Third, measured delta (super 13) CH (sub 4) values are lightest at the point of peak model-predicted methane oxidation and become increasingly (super 13) C-enriched with decreasing sediment depth, consistent with kinetic isotope fractionation during bacterially mediated methane oxidation. The isotopic data predict a somewhat (60 cm) shallower maximum depth of methane oxidation than do the model and sulfate reduction data.completedGeneral geochemistryaliphatic hydrocarbonsalkanesanaerobic environmentAtlantic OceanbathymetryBlake-Bahama Outer RidgeC-13/C-12carbonconcentrationdiagenesisgas hydrateshydrocarbonsisotope ratiosisotopesLeg 164marine sedimentsmethaneNorth AtlanticNorthwest AtlanticOcean Drilling ProgramODP Site 994ODP Site 995organic compoundsreductionsedimentsstable isotopesurn:org.iodp:exp:164urnlargerWorkCitationcampaignurn:org.iodp:exp:164:site:994urnlargerWorkCitationstudyurn:org.iodp:exp:164urnlargerWorkCitationcampaignurn:org.iodp:exp:164:site:995urnlargerWorkCitationstudyurn:org.iodp:exp:164urnlargerWorkCitationcampaignEnglishgeoscientificInformation-75.3245-75.311831.470831.4812