Now showing items 1-15 of 15

  • Geochemical and fluid dynamic investigations into the nature of chemical heterogeneity in the Earth's mantle 

    Hauri, Erik H. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1992-09)
    Variations in the abundances of elements and radiogenic isotopes in mantle derived peridotites and volcanic rocks are chemical integrals over time, space, and process, which ultimately contain information about the role ...
  • Helium isotope geochemistry of oceanic volcanic rocks : implications for mantle heterogeneity and degassing 

    Kurz, Mark D. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1982-06)
    The concentrations and isotopic compositions of helium have been measured in a number of mantle derived oceanic basalts. The goal of this research is to use the helium isotopic systematics to constrain the nature and ...
  • The hydrothermal alteration of oceanic basalts by seawater 

    Humphris, Susan E. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1976-10)
    Considerable geological and geophysical evidence now exists to support the hypothesis that seawater circulates through freshly intruded basalt at the mid-ocean ridges. As a consequence of this process, reactions between ...
  • The influence of ridge geometry at the ultraslow-spreading Southwest Indian Ridge (9º-25ºE) : basalt composition sensitivity to variations in source and process 

    Standish, Jared J. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2006-02)
    Between 9º-25º E on the ultraslow-spreading Southwest Indian Ridge lie two sharply contrasting supersegments. One 630 km long supersegment erupts N-MORB that is progressively enriched in incompatible element concentrations ...
  • The isotope geochemistry of abyssal peridotites and related rocks 

    Snow, Jonathan E. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1993-06)
    This dissertation studies several aspects of the formation of the Earth's oceanic mantle and crust, using a variety of geologic techniques, principally major elements, radiogenic isotopes and trace elements, but including ...
  • The marine geochemistry of methane 

    Scranton, Mary Isabelle (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1977-08)
    In the highly productive coastal surface waters near Walvis Bay, methane is present in concentrations considerably above those which would be predicted from solubility equilibrium with the atmosphere. A one dimensional ...
  • The marine geochemistry of the rare earth elements 

    Baar, Hein J. W. de (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1983-09)
    Novel methods were developed for the determination of 12 of the 14 Rare Earth Elements (REE) in seawater. Initial extractions of the REE by chelating ion exchange chromatography is followed by cation exchange for removal ...
  • The marine geochemistry of thorium and protactinium 

    Anderson, Robert F. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1980-11)
    Suspended particulate matter was collected by sediment traps deployed in the Sargasso Sea (Site S2), the north equatorial Atlantic (Site E), the north equatorial Pacific (Site P), and the Panama Basin (STIE Site). Additional ...
  • The marine geochemistry of trace metals 

    Boyle, Edward A. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1976-04)
    The marine geochemical cycles of iron, copper, nickel, and cadmium were studied in order to provide a basis for oceanographic models for trace metals. Copper, nickel, and cadmium can be determined in a 100 ml seawater ...
  • Nitrogen isotopes in chlorophyll and the origin of Eastern Mediterranean sapropels 

    Sachs, Julian P. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1997-02)
    The goals of this thesis were: (1) to establish methods for the determination of nitrogen and carbon isotope ratios in marine particulate and sedimentary chlorophyll derivatives; (2) to establish chlorophyll δ15N and ...
  • Sedimentary lipids as indicators of depositional conditions in the coastal Peruvian upwelling regime 

    McCaffrey, Mark A. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1990-05)
    This thesis assesses the utility of various sedimentary lipids as indicators of short-term changes in depositional conditions and sedimentary organic matter sources in the coastal upwelling regime off of Peru. A variety ...
  • Stable isotope geochemistry of nitrogen in marine particulates 

    Libes, Susan M. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1983-01)
    Isotope studies of nitrogen and carbon were undertaken to investigate the fate of particulate organic matter (POM) during its residence in the water column and after deposition on the seafloor. The processes focused on ...
  • Surface-cycling of rhenium and its isotopes 

    Miller, Christian A. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2009-06)
    The application of elemental and isotopic metal palaeoredox tracers to the geologic past rests on an understanding of modern metal cycles. This study reevaluates the surface-cycling of Mo and Re in near-surface reservoirs. ...
  • Trace element geochemistry of marine biogenic particulate matter 

    Collier, Robert William (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1980-11)
    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, ...
  • Trace element geochemistry of oceanic peridotites and silicate melt inclusions : implications for mantle melting and ocean ridge magmagenesis 

    Johnson, Kevin T. M. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1990-06-15)
    The mantle melting process is fundamental to basalt genesis and crustal accretion at mid-ocean ridges. It is believed that melts ascend more rapidly than the surrounding mantle, implying a process similar to fractional ...