cam a22 4 4500 555236838 CHVBK 20201202100938.0 190203s2018 sz a m 00 0deng d urn:nbn:ch:bel-1592678 urn (SNL)991017944811803976 (SNL)991018073905703976 (NEBIS)011333055 (Sz)991017944811803976 (Sz)991018073905703976 Sz ger rda eng eng ger 550 23sdnb 560 550 23sdnb Revels Brandi N. 1984- (DE-588)117391014X Verfasser aut The riverine delivery of trace metals and their isotopes to oceans new insights from Mo, Ni, Fe, and Zn in the Amazon basin presented by Brandi Nicole Revels Zurich 2018 xv, 218 Seiten Illustrationen 30 cm Dissertation No. 25458 ETH Zurich, 2018 Literaturverzeichnis application/pdf The transition metals (e.g., Mo, Zn, Ni, Fe, Cu) are integral in surface Earth biogeochemical cycling. Ubiquitous in the environment, their redox sensitivity limits their mobility and gives them central roles in metabolic processes, intimately linking the geosphere with the biosphere. This, coupled with their ability to be archived in the sedimentary record, makes transition metals and their isotopes attractive tracers of biological evolution and oceanic redox in Earth history. Exploitation of this sedimentary archive relies critically on understanding controls of the modern oceanic budgets of these metals and their isotopes. The motivation for this work stems from the observation that, for many transition metals, the dissolved load (<0.45um) of the oceans is isotopically heavier than rivers, themselves isotopically heavier than the upper continental crust (UCC). Assuming this observation describes long-term processes, it gives rise to budgetary problems which necessitate the need for isotopically light sinks in the particulate equivalent of the dissolved phase of both the oceans and rivers, ‘missing' isotopically heavy sources to rivers and oceans, non-steady state behavior of these systems, or a combination of these. Traditionally, research on the riverine source of transition metals has focused on the dissolved load (<0.45um), as this is the most obvious contribution to the dissolved load of the oceans. However, suspended sediments offer an appealing solution to the above mentioned budgetary problem as the particulate phase dominates the riverine load for most transition metals. A large fraction of this particulate load may be chemically labile, enabling the particulate phase to interact with the dissolved phase as both a source and a sink. This thesis presents results from a detailed study of different phases (truly dissolved, colloidal, and particulate) within the largest river in the world, the Amazon. The dissolved phase was filtered by tangential flow to separate colloidal (>1kDA, <0.45um) from truly dissolved (<1kDa) material, while the particulate phase (>0.45um) was sequentially leached to isolate discrete mineral phases (e.g. organic material and Fe-Mn oxides) within the particle itself. The truly dissolved and colloidal phases of Mo and Zn are isotopically similar to global average rivers, near 0.7‰ and 0.33‰, respectively. Subtle basinal and seasonal variability in Mo and Zn and their isotopes are related to weathering regime. For molybdenum, more intense chemical weathering was associated with lower [Mo] and heavier isotopes, while for Zn increased chemical weathering is associated with higher Zn concentrations and lower d66Zn. Concentrations of molybdenum in the particulate phase are very low throughout the basin, suggesting the complementary light Mo reservoir is likely stored in soils rather than suspended particulates. Particulate zinc is enriched in the oxide phase of suspended sediments, but this phase is not isotopically distinct from the dissolved phase. Furthermore, dissolution of the oxide phase does not affect dissolved phase d66Zn, suggesting it does not hold the complementary heavy Zn reservoir and that this may instead reside in soils. Iron and nickel are enriched in the colloidal phase, which, in association with precipitation of secondary Fe-Mn oxides, controls their mobility and isotopic signatures. For iron, d56Fe of the colloidal and particulate phase is a function of both pH and of the type of colloids present, which are in turn correlated with weathering regime. Those basins characterized by less intense chemical weathering are rich in mineral colloids, are isotopically similar to UCC, and precipitated Fe-Mn oxides have a similar isotope signature. Those basins characterized by intense chemical weathering are rich in organo-colloids which preferentially bind heavy iron d56FeUCC-colloids = ~-0.7‰. The residual light isotopes are then incorporated into the particulate oxide phases d56Feoxide-dissolved = -1.1‰. Colloidal and truly dissolved Ni are not isotopically distinct from each other, but do show contrasts between weathering regimes. Less intense chemical weathering is associated with dissolved fractions similar to average rivers while intense chemical weathering is associated with isotopically light dissolved fractions, similar to average UCC. During the dry season, dissolved load d60Ni is controlled by secondary Fe-Mn oxide precipitation within the river, the magnitude of which is a function of the fraction of Ni precipitated and the pH. At the highest pH of the Amazon, 7.5, the river's d60Ni reaches 1.4‰, equivalent to the average deep ocean. These findings suggest that the light Mo and heavy Zn reservoirs are not found in suspended sediments, and are instead likely held in soils. Ni fractionation with secondary minerals drives the dissolved load of rivers to heavier values, closer to that of the deep ocean, which may help to close its budgetary problems. Iron's enrichment in colloidal and oxide phases, each its own unique isotopic signature, may be physiochemically available, ultimately changing the riverine input signature to the oceans. This work has emphasized the importance of the suspended particulate load in controlling the size and isotopic composition of the riverine input to the oceans. The fate of these particulates in estuaries and ocean margins will be key areas for future research as their lability is of critical importance to oceanic budgets. Englischer Text mit englischer und deutscher Zusammenfassung AMAZONASGEBIET (SÜDAMERIKA) ger (ETHUDK)000008150 ethudk BIOGEOCHEMISCHER KREISLAUF (BIOGEOCHEMIE) ger (ETHUDK)000054132 ethudk EROSION + KORROSION + VERWITTERUNG (ABLAGERUNGSMILIEU) ger (ETHUDK)000038691 ethudk HERKUNFT DER SEDIMENTPARTIKEL (ABLAGERUNGSMILIEU) ger (ETHUDK)000047076 ethudk ISOTOPENGEOCHEMIE ger (ETHUDK)000038736 ethudk MARINE ABLAGERUNGEN (GEOLOGIE) ger (ETHUDK)000020098 ethudk SEDIMENTTRANSPORT IN FLÜSSEN (HYDROLOGIE) ger (ETHUDK)000020864 ethudk SEDIMENTTRANSPORT/FLUVIATILER SEDIMENTRANSPORT (ABLAGERUNGSMILIEU) ger (ETHUDK)000047072 ethudk SUSPENSION (HYDROLOGIE, OZEANOGRAPHIE) ger (ETHUDK)000020180 ethudk ÜBERGANGSMETALLISOTOPE ger (ETHUDK)000061086 ethudk Hochschulschrift (DE-588)4113937-9 gnd-content Hochschulschrift gnd-content sb 2019/03 550 zh snl-sb xehelv xediss 2020 560 550 snl ehelv u BIOGEOCHEMISCHER KREISLAUF (BIOGEOCHEMIE) ger 550.47*1 nebis E1 u MARINE ABLAGERUNGEN (GEOLOGIE) ger 551.35 nebis E1 u SUSPENSION (HYDROLOGIE, OZEANOGRAPHIE) ger 551.463.8 nebis E1 u ISOTOPENGEOCHEMIE ger 550.42,1 nebis E1 u ÜBERGANGSMETALLISOTOPE ger 546.6/.8%54.027 nebis E1 u EROSION + KORROSION + VERWITTERUNG (ABLAGERUNGSMILIEU) ger 551.3.053 nebis E1 u HERKUNFT DER SEDIMENTPARTIKEL (ABLAGERUNGSMILIEU) ger 551.3,01.4 nebis E1 u SEDIMENTTRANSPORT IN FLÜSSEN (HYDROLOGIE) ger 556.535.6 nebis E1 u SEDIMENTTRANSPORT/FLUVIATILER SEDIMENTRANSPORT (ABLAGERUNGSMILIEU) ger 551.3,13.5 nebis E1 u AMAZONASGEBIET (SÜDAMERIKA) ger (8-23) nebis E1 u CYCLE BIOGÉOCHIMIQUE (BIOGÉOCHIMIE) fre 550.47*1 nebis E1 u BIOGEOCHEMICAL CYCLE (BIOGEOCHEMISTRY) eng 550.47*1 nebis E1 u DÉPÔTS MARINS (GÉOLOGIE) fre 551.35 nebis E1 u MARINE DEPOSITS (GEOLOGY) eng 551.35 nebis E1 u SUSPENSION (HYDROLOGY, OCEANOGRAPHY) eng 551.463.8 nebis E1 u SUSPENSION (HYDROLOGIE, OCÉANOGRAPHIE) fre 551.463.8 nebis E1 u GÉOCHIMIE DES ISOTOPES fre 550.42,1 nebis E1 u ISOTOPE GEOCHEMISTRY eng 550.42,1 nebis E1 u ISOTOPES DES MÉTAUX DE TRANSITION fre 546.6/.8%54.027 nebis E1 u TRANSITION METALS ISOTOPES eng 546.6/.8%54.027 nebis E1 u EROSION + CORROSION + WEATHERING (SEDIMENTARY ENVIRONMENT) eng 551.3.053 nebis E1 u ÉROSION + CORROSION + ALTÉRATION (ENVIRONNEMENT SÉDIMENTAIRE) fre 551.3.053 nebis E1 u PROVENANCE OF SEDIMENTARY PARTICLES (SEDIMENTARY ENVIRONMENT) eng 551.3,01.4 nebis E1 u ORIGINE/PARTICULES SEDIMENTAIRES (ENVIRONNEMENT SÉDIMENTAIRE) fre 551.3,01.4 nebis E1 u SEDIMENT TRANSPORT IN RIVERS (HYDROLOGY) eng 556.535.6 nebis E1 u TRANSPORT DES SÉDIMENTS PAR LES COURS D'EAU (HYDROLOGIE) fre 556.535.6 nebis E1 u SEDIMENT TRANSPORT/FLUVIATILE SEDIMENT TRANSPORT (SEDIMENTARY ENVIRONMENT) eng 551.3,13.5 nebis E1 u TRANSPORT DE SÉDIMENTS/COURS D'EAU, FLEUVES (ENVIRONNEMENT SÉDIMENTAIRE) fre 551.3,13.5 nebis E1 u AMAZON BASIN (SOUTH AMERICA) eng (8-23) nebis E1 u AMAZONIE (AMÉRIQUE DU SUD) fre (8-23) nebis E1 Eidgenössische Technische Hochschule Zürich (DE-588)2023928-2 Grad-verleihende Institution dgg SNL NB001 NB999 - chb99 - https://opac.admin.ch/toc/toc1902044408.pdf Inhaltsverzeichnis BK020300 XK020000 XK020000 073 E01-20190114 074 E01-20190114 076 E01-20190114 SNL NB001 NB001 Nbq 119217 NB10010 NEBIS E04 E04 E04BI Bg 1087 NEBIS E16 E16 RH Diss ETH 25458 SNL 100 1- Revels Brandi N. 1984- (DE-588)117391014X Verfasser aut SNL 856 41 https://opac.admin.ch/toc/toc1902044408.pdf Inhaltsverzeichnis SNL 710 2- Eidgenössische Technische Hochschule Zürich (DE-588)2023928-2 Grad-verleihende Institution dgg SNL 100 1- Revels Brandi N. Verfasser aut SNL 856 40 http://hdl.handle.net/20.500.11850/304382 SNL 856 4- https://nbn-resolving.org/urn:nbn:ch:bel-1592678 SNL 856 42 http://www.e-helvetica.nb.admin.ch/directAccess?callnumber=bel-1592678 NEBIS 100 1- Revels Brandi N. 1984- (DE-588)117391014X Verfasser aut NEBIS 700 1- Vance Derek 1964- (DE-588)1089642881 Akademischer Betreuer dgs NEBIS 700 1- Rickli Jörg Dominik 1976- (DE-588)1116549875 Akademischer Betreuer dgs SWISSBIB 555236838