georefid:2004-011447georefid:2004-011446SEDIS 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.ir.204.101.20032003-01-01publicationgeorefid:2004-011447doi:10.2973/odp.proc.ir.204.101.2003Trehu, Anne M.Oregon State University, College of Oceanic and Atmospheric Sciences, Corvallis, OR, United StatesauthorBohrmann, GerhardChristian-Albrechts-Universitaet, Federal Republic of GermanyauthorRack, Frank R.Joint Oceanographic Institutions, United StatesauthorTorres, Marta E.University of Texas at Austin, United StatesauthorBangs, Nathan L.University of Leicester, United KingdomauthorBarr, Samantha R.Eastern Kentucky University, United StatesauthorBorowski, Walter S.U. S. Geological Survey, United StatesauthorClaypool, George E.Idaho National Engineering and Environmental Laboratory, United StatesauthorCollett, Timothy S.Rice University, United StatesauthorDelwiche, Mark E.Lamont-Doherty Earth Observatory, United StatesauthorDickens, Gerald R.Centre Mediterrani d'Investigacions Marines i Ambientals, SpainauthorGoldberg, David S.Arizona State University, United StatesauthorGracia, EulaliaKorea Institute of Geoscience and Mineral Resources, South KoreaauthorGuerin, GillesNational Taiwan University, TaiwanauthorHolland, MelaniePacific Northwest National Laboratory, United StatesauthorJohnson, Joel E.Woods Hole Oceanographic Institution, United StatesauthorLee, Young-JooGeological Survey of Canada, CanadaauthorLiu, Char-ShineGeotek, United KingdomauthorLong, Philip E.China University of Geosciences, ChinaauthorMilkov, Alexei V.University of Tokyo, JapanauthorRiedel, MichaelUniversitetet i Tromso, NorwayauthorSchultheiss, PeterGeological Survey of Japan, JapanauthorSu XinScripps Institution of Oceanography, United StatesauthorTeichert, BarbaraChristian-Albrechts-Universitaet zu Kiel, Federal Republic of GermanyauthorTomaru, HitoshiJoint Oceanographic Institutions, United StatesauthorVanneste, MaartenUniversity of Texas at Austin, United StatesauthorWatanabe, MahitoUniversity of Leicester, United KingdomauthorWeinberger, Jill L.Eastern Kentucky University, United StatesauthorTexas A&M University, Ocean Drilling Program, College Station, TX, United StatespublisherdocumentDigitalIn: Trehu, Anne M., Bohrmann, Gerhard, Rack, Frank R., Torres, Marta E., Bangs, Nathan L., Barr, Samantha R., Borowski, Walter S., Claypool, George E., Collett, Timothy S., Delwiche, Mark E., Dickens, Gerald R., Goldberg, David S., Gracia, Eulalia, Guerin, Gilles, Holland, Melanie, Johnson, Joel E., Lee, Young-Joo, Liu, Char-Shine, Long, Philip E., Milkov, Alexei V., Riedel, Michael, Schultheiss, Peter, Su Xin, Teichert, Barbara, Tomaru, Hitoshi, Vanneste, Maarten, Watanabe, Mahito, Weinberger, Jill L., Chapman, Mary (editor), Proceedings of the Ocean Drilling Program, initial reports, drilling gas hydrates on Hydrate Ridge, Cascadia continental margin; covering Leg 204 of the cruises of the drilling vessel JOIDES Resolution Victoria, British Columbia, Canada, to Victoria, British Columbia, Canada; sites 1244-1252, 7 July-2 September 2002204During Leg 204, we cored and logged nine sites on the Oregon continental margin to determine the distribution and concentration of gas hydrates in an accretionary ridge and adjacent slope basin, investigate the mechanisms that transport methane and other gases into the gas hydrate stability zone (GHSZ), and obtain constraints on physical properties of gas hydrates in situ. A three-dimensional seismic survey conducted from 19 June through 3 July 2000 provided images of potential subsurface fluid conduits and indicated the depth of the bottom-simulating reflector (BSR), a commonly used proxy for the base of the GHSZ. After coring at the first site, we acquired logging-while-drilling (LWD) data at all but one site to provide an overview of downhole physical properties prior to coring. The LWD data confirmed the general position of key seismic stratigraphic horizons and yielded an initial estimate of gas hydrate concentration through the proxy of in situ electrical resistivity. These records proved to be of great value in planning subsequent coring. We also tested the use of infrared (IR) thermal imaging of cores as a new and effective tool to identify gas hydrates as rapidly as possible after core retrieval. The thermal images were used to estimate the distribution and texture of hydrate within the cores. Geochemical analyses of interstitial waters and of headspace and void gases provided additional information on the distribution and concentration of gas hydrate within the GHSZ, the origin and pathway of fluids into and through the GHSZ, and the rates at which the process of gas hydrate formation is occurring. Biostratigraphic and lithostratigraphic descriptions of cores, measurement of physical properties, in situ pressure core sampling, and thermal measurements complement the data set, providing ground-truth tests of inferred physical and sedimentological properties.completedOceanographyApplied geophysicsaliphatic hydrocarbonsalkanesanomaliesbiostratigraphyboreholesCascadia Basincontinental margincoresEast Pacificgas hydratesgeochemistrygeophysical methodsgeophysical profilesgeophysical surveyshigh-resolution methodsHydrate RidgehydrocarbonsLeg 204lithostratigraphymarine sedimentsmethaneNorth PacificNortheast PacificOcean Drilling Programocean floorsOregonorganic compoundsPacific Oceansedimentsseismic methodsseismic profilessurveysthicknessUnited Statesurn:org.iodp:exp:204urnlargerWorkCitationcampaignEnglishgeoscientificInformation-125.0900-125.030044.330044.3600Also available on CD-ROM in PDF format and in the Web in PDF or HTMLapplication/pdfunknownSEDIS Publication Catalogue

ana.macario@awi.de

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