georefid:2007-025132georefid:2007-025129SEDIS Publication Catalogueana.macario@awi.dehttp://sedis.iodp.org/pub-catalogue/informationpointOfContact2011-06-23T00:00:00Zhttp://sedis.iodp.org/pub-catalogue/index.php?id=10.2973/odp.proc.sr.205.207.2006<gco:CharacterString>Geochemical analyses of hydrothermally altered sediments from the convergent Costa Rican margin</gco:CharacterString>2006-01-01publicationgeorefid:2007-025132doi:10.2973/odp.proc.sr.205.207.2006Chavagnac, Valerie M. C.Southampton Oceanography Centre, School of Ocean and Earth Sciences, Southampton, United KingdomauthorFont, LauraUniversitaet Bremen, Federal Republic of GermanyauthorMilton, J. AndyTexas A&M University, United StatesauthorCroudace, Ian W.Southampton Oceanography Centre, United KingdomauthorTexas A&M University, Ocean Drilling Program, College Station, TX, United StatespublisherdocumentDigitalIn: Morris, Julie D., Villinger, Heinrich W., Klaus, Adam, Cardace, Dawn M., Chavagnac, Valerie M. C., Clift, Peter D., Haeckel, Matthias, Hisamitsu, Toshio, Kastner, Miriam, Pfender, Marion, Saffer, Demian M., Santelli, Cara, Schramm, Burkhard, Screaton, Elizabeth J., Solomon, Evan A., Strasser, Michael, Moe, Kyaw Thu, Vannucchi, Paola, Proceedings of the Ocean Drilling Program; scientific results; fluid flow and subduction fluxes across the Costa Rica convergent margin; implications for the seismogenic zone and subduction factory; covering Leg 205 of the cruises of the Drilling Vessel JOIDES Resolution; Victoria, Canada, to Balboa, Panama; Sites 1253-1255; 2 September-6 November 2002205Bulk geochemical analyses were carried out on 27 sediment samples located just above the igneous section of the incoming plate along the Costa Rican convergent margin. This pilot study was intended to determine whether hydrothermal activity within the sediment section could be detected within the bulk sediment. The metaliferous index (100 X Al/ [Al + Fe + Mn]) values on bulk sediment (24.3 < X < 43.3) are all much lower than the value for deep pelagic sediment (50.8) but higher than the value for the hydrothermal sulfide from the East Pacific Rise (1). The high Zn, Cu, and Co concentrations associated with high Ba content for a constant detrital input (molar Ti/Al = 0.121 + or - 0.026) indicate that the transition metal enrichment is not related to volcanic ash but rather to Fe-Mn oxides, sulfides, and barite. These observations testify to a record of hydrothermal activity within the 70 m of sediment overlying the basement.completedGeochemistry of rocks, soils, and sedimentsOceanographyCentral AmericaconcentrationCosta RicaEast Pacificgeochemistryhydrochemistryhydrothermal alterationLeg 205marine sedimentsmetalsmetasomatismMiddle America TrenchNorth PacificNortheast PacificOcean Drilling ProgramPacific Oceanpore watersedimentsurn:org.iodp:exp:205urnlargerWorkCitationcampaignEnglishgeoscientificInformation-86.1200-86.10009.38009.4000Data report; available only on CD-ROM in PDF format and on the Web in PDF or HTML; data reportapplication/pdfunknownSEDIS Publication Catalogueana.macario@awi.dehttp://sedis.iodp.org/pub-catalogue/informationpointOfContacthttp://www-odp.tamu.edu/publications/205_SR/VOLUME/CHAPTERS/207.PDFdownload