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Trace element geochemistry of marine biogenic particulate matter

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dc.contributor.author Collier, Robert William
dc.coverage.spatial Galapagos
dc.date.accessioned 2008-05-12T14:47:45Z
dc.date.available 2008-05-12T14:47:45Z
dc.date.issued 1980-11
dc.identifier.uri http://hdl.handle.net/1912/2208
dc.description Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution November 1980 en
dc.description.abstract Plankton samples have been carefully collected from a variety of marine environments under the rigorous conditions necessary to prevent contamination for major and trace-chemical analysis. Immediately after collection, the samples were subjected to a series of physical and chemical leaching-decomposition experiments designed to identify the major and trace element composition of particulate carrier phases. Elements examined through some or all of these experiments were: C, N, P, Mg, Ca, Si, Fe, Mn, Ni, Cu, Cd, Al, Ba, and Zn. Emphasis was placed on the identification of trace element/major element ratios in the biogenic materials. The majority of the trace elements in the samples were directly associated with the non-skeletal organic phases of the plankton. These associations included a very labile fraction which was rapidly released into seawater and a more refractory fraction which involved specific metal-organic binding. Calcium carbonate and opal were not significant carriers for any of the trace elements studied. A refractory phase containing Al and Fe in terrigenous ratios was present in all samples, even from the more remote marine locations. The concentration of this carrier phase within the plankton samples varied in proportion to the estimated rate of supply of terrigenous matter and in opposition to the rate of production of the biogenic particulate matter. The aluminosilicates contributed insignificant amounts to the other trace elements studied. A trace concentration of particulate Al was identified which was more labile and associated with the organic fractions of the samples. Variations in the surface water concentrations of dissolved Cu, Ni, Cd, and Zn with respect to P are compared to the ratios measured in the plankton samples and their regeneration products. The trace element/major element ratios ,in the residual plankton materials can be combined with estimates of the carrier fluxes to account for the transport of trace elements required to maintain their deep enrichment. A variety of processes determining the geochemical cycles of specific trace elements were identified. As much as 50% of the Cd, Ni, Mn, and P are rapidly released from plankton and recycled within the surface ocean. During this process, the metal/P ratio in the residual particles must decrease by 10-30% for Cd and increase by a factor of 2-4 for Ni and Cu to balance their deep enrichments. Although Mn is taken up and regenerated by plankton, the magnitude of this process is small with respect to other non-biogenic Mn fluxes and has very little influence on its dissolved distribution. The Ba content of all known surface carriers is insufficient to account for the deep enrichment of Ba. A secondary concentration process results in the formation of significant particulate Ba within the upper thermocline. en
dc.description.sponsorship Portions of the data in this research have been collected under the NSF grant DES 75-03826 and ONR grant N00014-80-C-0273. I have been supported for the last three years on an NSF National Needs Graduate Traineeship to the MIT-WHOI Joint Program. Ship time was generously provided by various principal investigators of the NSF Galapagos Hydrothermal research program and the NSF-IDOE MANOP program. en
dc.format.mimetype application/pdf
dc.language.iso en_US en
dc.publisher Massachusetts Institute of Technology and Woods Hole Oceanographic Institution en
dc.relation.ispartofseries WHOI Theses en
dc.subject Geochemistry en
dc.subject Chemical oceanography en
dc.subject Trace elements in water en
dc.title Trace element geochemistry of marine biogenic particulate matter en
dc.type Thesis en
dc.identifier.doi 10.1575/1912/2208


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