= = = Molecularlevelstudiesonthedistributionandfateoforganic matteratcontinentalmargins = = = = = Dissertation = zurErlangungdesDoktorgrades derNaturwissenschaften = Dr.rer.nat. = AmFachbereichGeowissenschaften= derUniversitätBremen = vorgelegtvon= FraukeSchmidt = Bremen Mai2009 1.Gutachter:Prof.Dr.KaiUweHinrichs 2.Gutachter:Prof.Dr.BorisKoch Preface Preface= ThestudiespresentedinthisthesiswerefundedbytheDeutscheForschungsgemeinschaft throughtheDFGResearchCenter/=ExcellenceCluster“TheOceanintheEarthSystem”and= theBremenInternationalGraduateSchoolforMarineSciences(GLOMAR).Thethesiswas preparedinthetimefromMarch2006to=May2009intheOrganicGeochemistrygroupof Prof.Dr.KaiUweHinrichsattheUniversityofBremen. This thesiscontributes to a better understanding of the processes and= mechanisms behind= the distribution and early diagenesis of organic matter in= marine sediments. In the first= chaptergeneralaspectsoforganicmattercyclingintheoceanandinmarinesedimentsare examined to provide a= base for the studies in Chapters 2= –= 4. Both study sites, the NW IberianmarginandthenorthernBlackSea,arebrieflyintroducedandthechapterconcludes witha=generaldescriptionofthemethodologicalapproach.Chapter2=(submittedtoMarine Chemistry)investigatesthesources,transportand,distributionoforganicmatterattheNW= Iberian margin. Chapters 3= and 4= focus on early diagenetic processes in the sedimentary dissolvedorganicmatter=poolattheNWIberianmargin(Chapter3,publishedinGeochimica et Cosmochimica Acta) and in the northern Black Sea (Chapter 4, draft in preparation for submission). The data from both chapters were generated in collaboration with Bruker DaltonikGmbH,Bremen,andthecompletedatasetisprovidedintheelectronicappendix. The thesis closes with the major findings of the studies and= perspectives for future investigations. Tableofcontents TABLEOFCONTENTS Abstract= ============4= Zusammenfassung= ===========6= 1Introduction11= 1.1Organicmatterinthecontemporaryocean 12= 1.1.1Compositionoforganicmatter=14= 1.1.2AlterationofOMinthewatercolumn16= 1.1.3EarlydiagenesisofOMinmarinesediments 17= 1.1.4ProductionandsignificanceofDOMinsedimentporewaters = 18 1.2OMatcontinentalmargins 19= 1.2.1Studyarea1:TheGaliciaMinhoShelf20= 1.2.2Studyarea2:ThenorthernBlackSea 21= 1.3Mainobjectivesandthesisoutline 23= 1.4Methodologicalapproach 25= References30= 2Sources,transport,andpartitioningoforganicmatteratahighlydynamic = continentalmargin37= Abstract= 38= 2.1Introduction 39 2.2Studyarea 40= 2.3Materialandmethods= 42= 2.3.1Sampling 42= 2.3.2Totalorganiccarbon,totalcarbonandtotalnitrogen42= 2.3.3Lipidextraction=42= 2.3.4Bacteriohopanepolyols 43= 2.3.5Branchedandisoprenoidtetraetherindex 43= 2.3.6Ligninextraction 43= 2.3.7Gaschromatographycoupledtomassspectrometryor = = flameionizationdetection 44= 2.3.8Highperformanceliquidchromatography= 45= 2.3.9Grainsizeanalysis 46= 2.3.10Correlationanalysis,clusteranalysis,andOceanDataView = 46 2.4Results46= 2.4.1Bulkpropertiesofsediments 46= 2.4.2Distributionsoflipidbiomarkersandligninphenols48= 2.4.2.1Biomarkergrouping 48= 2.4.2.2.Variationofbiomarkerdistributionsbetweensamples = 48 2.4.2.3Terrestrialbiomarkerinput= 49= 2.4.2.4Marinebiomarkerinput= 54= 2.4.3Inventoryoflipidbiomarkersandligninphenolsinthelocal rivers= 56= 2.5Discussion 58= 2.5.1SourcesoforganicmatterattheGaliciaMinhoshelf= = = = 58 2.5.1.1Thecompositionofterrestrialorganicmatterontheshelf = 58 2.5.1.2Marinecontributionstosedimentaryorganicmatter= = = 61 2.5.2Transportanddistributionalpatternsofterrestrialorganicmatter = 64 1 Table of contents 2.5.3SpatialOMdistributioninrelationtoseasonalplanktonecology = 65 2.5.4OMprovincesontheGaliciaMinhoshelf 66= 2.6Conclusions 69= Acknowledgements 70= References 71= 3=Molecularcharacterizationofdissolvedorganicmatterinporewaterof = continentalshelfsediments79= Abstract= 80 = 3.1Introduction 81= 3.2Materialsandmethods 83= 3.2.1Samplingsite= 83= 3.2.2Sampling 83= 3.2.3Dissolvedorganicmatterextraction 84= 3.2.4Fouriertransformioncyclotronresonancemassspectrometry = 85 3.2.5Dissolvedorganiccarbonandtotaldissolvednitrogen = = 86 3.2.6Totalorganiccarbon,totalnitrogenandtotalsulfur== 86= 3.2.7Lipidextraction=87= 3.2.8Ligninextraction 88= 3.2.9Gaschromatographycoupledtomassspectrometryor = flameionizationdetection 88= 3.3Resultsanddiscussion 89= 3.3.1Characterizationofsedimentaryorganicmatter= = = = 89 3.3.2Spatialdistributionofligninphenolsandlipidbiomarkersin = theparticulateorganicmatter= 90= 3.3.3Molecularvariationsindissolvedorganicmatter= 92= 3.3.1DissolvedorganicmattercharacterizationviamolarH/Cand ========O/Cratios 92= 3.3.3.2Dissolvedorganicmattercharacterizationviamolecular = = = ========massandDBE= 96= 3.3.3.3Sourcesandoccurrenceofaromaticringstructures= = = 97 3.3.3.3.1AromaticcompoundswithlowO/C(0.2) = = 98 3.3.3.3.2AromaticcompoundswithhighO/C(>0.4)= = = 99 3.3.3.4Spatialvariationsofnitrogenbearingcompounds = ========100 3.3.3.5Sulfurcompoundsasindicatorsforearlydiagenesis?== ========102 3.4Summaryandconclusions ==============104 = Acknowledgements= ===============105 = References ================106 4=Diagenetictransformationofdissolvedorganicmatterundercontrasting = sedimentaryredoxconditionsintheBlackSea ============111 Abstract= =================112 4.1Introduction ================113 4.2Materialandmethods= ==============114 4.2.1Sampling ===============114 4.2.2Dissolvedorganicmatterextraction ============115 4.2.3Fouriertransformioncyclotronresonancemassspectrometry ========115 4.2.4Dissolvedorganiccarbonandtotaldissolvednitrogen= = ========116 4.2.5Totalhydrolyzabledissolvedaminoacids = = = ========117 2 Tableofcontents 4.2.6Totalorganiccarbonandtotalnitrogen ====117 4.2.7Stableorganiccarbonisotopes= ======118 4.3Resultsanddiscussion =======118 4.3.1Characterizationofsedimentaryorganicmatter= = = = 118 4.3.2Theeffectofearlydiagenesisonmoleculesizeandmolecule== = ========saturation 120 4.3.3VariationsinCHOmolecules= ======121 4.3.4VariationsofNbearingcompoundsinDOM====123 4.3.5Nbearingcompoundsas=productsofproteindegradation = = 124 4.3.6OthersourcesforNbearingcompoundsinDOM 127= 4.4Summaryandconclusions 128= Acknowledgements ========129 References 130= 5Concludingremarksandperspectives ======135 References==========141 AppendixA1 ==========143 AppendixA2 ==========147 Danksagung ==========154 Erklärung= ==========157 ElectronicAppendix = 3 Abstract ABSTRACT Continentalmarginsarea=majorreservoirfororganiccarbon(OC)burialintheoceansand play an essential role in the global carbon cycle. High primary productivity, supply of terrestrialderived organic matter (OM) and reduced remineralization rates during the shortedsinkingtimesof=OMinthewatercolumncompared=totheopenoceanare=themain reasonsforthehighOCaccumulation.However,=continentalmarginsareoftencharacterized byhighwaterandsedimentdynamicspromotingOMremineralization.Thehighlydynamic conditions together with the multiple sources for organic matter complicate an= understanding of the processes, responsible for OM preservation and remineralization in continentalmarginsediments,andatpresent,themainmechanismsremainelusive. ThisthesisprovidesdeeperinsightsintothemolecularcompositionofOMwiththeaimto constrainthesources,distributionandearlydiageneticprocessesinthesedimentary=OMat continentalmargins. Thefirststudyexaminestheeffectof=hydrodynamicandsedimentological=processesonOM= at the NW Iberian margin by comparing the distribution of lipid biomarkers= and lignin phenols to the grain size distribution as well as to the chemical and isotopic bulk= OC= composition. The comprehensive lipid biomarker and lignin phenol analyses indicate OM contributions from various terrestrial and marine sources subjected to different transport mechanisms.TerrestrialOMconsistingofvascular=plantandsoilderivedmaterialismainly supplied by= local rivers= to the shelf. The distribution on the shelf is closely linked to the inorganic sediment fraction which is indicated by the correlation with the grain size= distributioninthesediment.Theabundanceofhigherplantwaxderivedcompounds(long chainnalkanes,nalcoholsandnfattyacids)inthesedimentfromallareasofthecontinental margin, suggestsa= second input pathway by wind. High water dynamics on the shelf are= responsible for an internal sorting of the terrestrial OM according to the hydrodynamic properties, i.e., soft plant tissue (indicated by high ratios of cinnamyl phenols to vanillyl phenols (C/V)) is preferentially transported and deposited offshore, whereas the woody= material (represented by plantderived triterpenoids and low C/V ratios) is primarily= accumulatedclosetothesource=riversinalocalmidshelfmudbelt.Refractorysoilderived organic matter was identified via 3,5dihydroxybenzoic acid (major compound in tannic= acid) and is distributed similar to the soft tissue. Algal lipid biomarkers reflect a= complex marineplanktoncommunityontheshelfanda=distributionofthealgalderivedOM=closely 4 Abstract linked to the nutrient conditions, i.e., accumulation of algalderived OM close to the continent and the NW Iberian upwelling= cell. The interplay of plankton blooms, hydrodynamic and sedimentological= processes results in three different OM provinces on= theshelf:(I)theinnershelfregionwithfreshmarineOM,(II)themidshelfmudbeltasmajor= sinkforterrestrialOM,and(III)theoutershelfwitha=lowaccumulationofratherrefractory terrestrialderived OM.= Based on this characterization, the second study elucidates early diageneticprocessesinthesedimentsfromtheNWIberianmargin.Dissolvedorganicmatter= (DOM)fromsediment=porewaterswasanalyzedforthefirsttimebyhighresolutionFourier transformioncyclotronresonancemassspectrometry(FTICRMS)whichprovidednewand