Geochemistry of deep-sea hydrothermal vent fluids from the Mid-Cayman Rise, Caribbean Sea
McDermott, Jill M.
MetadataShow full item record
LocationVon Damm vent field
Piccard vent field
KeywordAtlantis (Ship : 1996-) Cruise AT18-16; Falkor (Ship) Cruise FK008; Biogeochemical cycles; Chemical oceanography
This thesis examines the controls on organic, inorganic, and volatile species distributions in hydrothermal fluids venting at Von Damm and Piccard, two vent fields at the ultraslow spreading Mid-Cayman Rise, Earth’s deepest mid-ocean ridge. In Chapter 2, abiotic organic synthesis is shown to occur via two distinct mechanisms in the serpentinizing Von Damm system. Chapters 3 and 4 present in-depth studies of the chemical and isotopic compositions of aqueous species in vent fluids at Von Damm and Piccard to elucidate the role of reaction temperature, pressure, substrate composition, and water/rock mass ratios during the chemical evolution of hydrothermal fluids. At Von Damm, sequential reaction of gabbroic and peridotite substrates at intermediate temperatures can explain generation of the observed fluids. At Piccard, extremely high temperature subsurface water/rock reaction results in fluids that are richer in dissolved H2 than any previously observed fluids worldwide. In Chapter 5, multiple sulfur isotopes were measured on metal sulfide deposits, S0, and fluid H2S to constrain sulfur sources and the isotopic systematics of precipitation in a wide variety of seafloor hydrothermal vents. Areas studied include the eastern Manus Basin and Lau Basin back-arc spreading centers, the unsedimented basalt-hosted Southern East Pacific Rise, and the sediment-hosted Guaymas Basin mid-ocean ridge spreading centers.
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 February 2015
Showing items related by title, author, creator and subject.
The ecology of colonial radiolarians : their colony morphology, trophic interactions and associations, behavior, distribution, and the photosynthesis of their symbionts Swanberg, Neil Ralph (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1979-08)Colonial radiolarians (Spumellaria) are among the most common and abundant large zooplankton, but they have been little studied by modern biologists. Colonies were found on 98% of epipelagic diving stations in the period ...
A determination of air-sea gas exchange and upper ocean biological production from five noble gases and tritiugenic helium-3 Stanley, Rachel H. R. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2007-09)The five noble gases (helium, neon, argon, krypton, and xenon) are biologically and chemically inert, making them ideal oceanographic tracers. Additionally, the noble gases have a wide range of solubilities and molecular ...
Elkins, Lynne J. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2009-02)To explore the ability of melting mafic lithologies to produce alkaline ocean-island basalts (OIB), an experimental study was carried out measuring clinopyroxene (Cpx)- melt and garnet (Gt)-melt partition coefficients ...