georefid:2012-070586SEDIS Publication Catalogueana.macario@awi.dehttp://sedis.iodp.org/pub-catalogue/informationpointOfContact2013-07-08T00:00:00Zhttp://sedis.iodp.org/pub-catalogue/index.php?id=2012-070586<gco:CharacterString>Diagenetic control of nitrogen isotope ratios in Holocene sapropels and Recent sediments from the eastern Mediterranean Sea</gco:CharacterString>2010-01-01publicationgeorefid:2012-070586Moebius, JuergenUniversity of Hamburg, Institute of Biogeochemistry and Marine Chemistry, Hamburg, GermanyauthorLahajnar, NikoauthorEmeis, Kay-ChristianauthorCopernicus GmbH on behalf of the European Union, Katlenburg-Lindau, InternationalpublisherdocumentDigitalBiogeosciences7 (11)3901-3914The enhanced accumulation of organic matter in Eastern Mediterranean sapropels and their unusually low delta (super 15) N values have been attributed to either enhanced nutrient availability which led to elevated primary production and carbon sequestration or to enhanced organic matter preservation under anoxic conditions. In order to evaluate these two hypothesis we have determined Ba/Al ratios, amino acid composition, N and organic C concentrations and delta (super 15) N in sinking particles, surface sediments, eight spatially distributed core records of the youngest sapropel S1 (10-6 ka) and older sapropels (S5, S6) from two locations. These data suggest that (i) temporal and spatial variations in delta (super 15) N of sedimentary N are driven by different degrees of diagenesis at different sites rather than by changes in N-sources or primary productivity and (ii) present day TOC export production would suffice to create a sapropel like S1 under conditions of deep-water anoxia. This implies that both enhanced TOC accumulation and delta (super 15) N depletion in sapropels were due to the absence of oxygen in deep waters. Thus preservation plays a major role for the accumulation of organic-rich sediments casting doubt on the need of enhanced primary production for sapropel formation.completedQuaternary geologyalkaline earth metalsaluminumamino acidsbariumcarboncarbon sequestrationCenozoicdeep-water environmentdepletiondiagenesisdissolved materialsEast MediterraneanHoloceneisotope ratiosisotopesLeg 160Mediterranean RidgeMediterranean SeametalsN-15N-15/N-14nitrogennutrientsOcean Drilling Programoceanic anoxic eventsODP Site 971organic acidsorganic carbonorganic compoundsoxygenpaleo-oceanographyQuaternarysapropelsea surface watersea watersedimentsspatial variationsstable isotopestotal carbonurn:org.iodp:exp:160urnlargerWorkCitationcampaignurn:org.iodp:exp:160:site:971urnlargerWorkCitationstudyurn:org.iodp:exp:160urnlargerWorkCitationcampaignEnglishgeoscientificInformation-5.300042.000032.000042.0000Published in Biogeosciences Discussion: 17 February 2010, http://www.biogeosciences-discuss.net/7/1131/2010/bgd-7-1131-2010.html; accessed in Jan., 2012application/pdfunknownSEDIS Publication Catalogueana.macario@awi.dehttp://sedis.iodp.org/pub-catalogue/informationpointOfContacthttp://www.biogeosciences.net/7/3901/2010/bg-7-3901-2010.pdfdownload