• Login
    About WHOAS
    View Item 
    •   WHOAS Home
    • Woods Hole Oceanographic Institution
    • Academic Programs
    • WHOI Theses
    • View Item
    •   WHOAS Home
    • Woods Hole Oceanographic Institution
    • Academic Programs
    • WHOI Theses
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.

    Browse

    All of WHOASCommunities & CollectionsBy Issue DateAuthorsTitlesKeywordsThis CollectionBy Issue DateAuthorsTitlesKeywords

    My Account

    LoginRegister

    Statistics

    View Usage Statistics

    Advanced geophysical studies of accretion of oceanic lithosphere in Mid-Ocean Ridges characterized by contrasting tectono-magmatic settings

    Thumbnail
    View/Open
    Xu_Thesis (42.27Mb)
    Date
    2012-02
    Author
    Xu, Min  Concept link
    Metadata
    Show full item record
    Citable URI
    https://hdl.handle.net/1912/5218
    Location
    9°30'-10°00’N
    23°20’-23°38’N
    East Pacific Rise
    DOI
    10.1575/1912/5218
    Keyword
     Geophysics; Mid-ocean ridges; Marcus G. Langseth (Ship) Cruise MGL0808; Marcus G. Langseth (Ship) Cruise MGL0812; Maurice Ewing (Ship) Cruise EW0102; Knorr (Ship : 1970-) Cruise KN1802 
    Abstract
    The structure of the oceanic lithosphere results from magmatic and extensional processes taking place at mid-ocean ridges (MORs). The temporal and spatial scales of the variability of these two processes control the degree of heterogeneity of the oceanic lithosphere, represented by two end-member models: the classical Penrose Model exemplified by layered magmatic crust formed along fast-spreading MORs, e.g., East Pacific Rise (EPR); and the recently defined Chapman Model describing heterogeneous mafic and ultramafic lithosphere formed in settings of oceanic detachment faulting common along slow-spreading MORs, e.g., Mid-Atlantic Ridge (MAR). This thesis is using advanced marine geophysical methods (including finite-difference wave propagation modeling, 3D multi-channel seismic reflection imaging, waveform inversion, streamer tomography, and near-bottom magnetics) to study lithospheric accretion processes in MORs characterized by contrasting tectono-magmatic settings: the magmatically dominated EPR axis between 9°30'-10°00’N, and the Kane Oceanic Core Complex (KOCC), a section of MAR lithosphere (23°20’-23°38’N) formed by detachment faulting. At the EPR study area, I found that the axial magma chamber (AMC) melt sill is segmented into four prominent 2-4-km-long sections spaced every ~5- 10 km along the ridge axis characterized by high melt content (>95%). In contrast, within the intervening sections, the AMC sill has a lower melt content (41-46%). The total magma volume extracted from the AMC sill was estimated of ~46 × 106 m3, with ~24 × 106 m3 left unerupted in the upper crust as dikes after 2005-06 eruption. At the KOCC, I used streamer tomography to constrain the shallow seismic velocity structure. Lithological interpretation of the seismic tomographic models provides insights into the temporal and spatial evolution of the melt supply at the spreading axis as the KOCC formed and evolved. Investigation of a magnetic polarity reversal boundary in crosssection at the northern boundary of KOCC suggests that the boundary (representing both a frozen isotherm and an isochron) dips away from the ridge axis along the Kane transform fault scarp, with a west-dipping angle of ~45° in the shallow (<1 km) crust and <20° in the deeper crust.
    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 February 2012
    Collections
    • WHOI Theses
    • Geology and Geophysics (G&G)
    Suggested Citation
    Thesis: Xu, Min, "Advanced geophysical studies of accretion of oceanic lithosphere in Mid-Ocean Ridges characterized by contrasting tectono-magmatic settings", 2012-02, DOI:10.1575/1912/5218, https://hdl.handle.net/1912/5218
     

    Related items

    Showing items related by title, author, creator and subject.

    • Thumbnail

      The management of ocean and coastal resources in Colombia : an assessment 

      Knecht, Robert W.; Cicin-Sain, Biliana; Broadus, James M.; Silva, Maynard E.; Bowen, Robert E.; Marcus, Henry S.; Peterson, Susan B. (Woods Hole Oceanographic Institution, 1984-06)
      This report summarizes the results of an 18-month study of coastal and marine resources development in Colombia. The study was a result of a request by the Direccion General Maritima y Portuaria (DIMAR) of the Colombian ...
    • Thumbnail

      Effects of variable magma supply on mid-ocean ridge eruptions : constraints from mapped lava flow fields along the Galápagos Spreading Center 

      Colman, Alice; Sinton, John M.; White, Scott M.; McClinton, J. Timothy; Bowles, Julie A.; Rubin, Kenneth H.; Behn, Mark D.; Cushman, Buffy; Eason, Deborah E.; Gregg, Tracy K. P.; Gronvold, Karl; Hidalgo, Silvana; Howell, Julia; Neill, Owen; Russo, Chris (American Geophysical Union, 2012-08-25)
      Mapping and sampling of 18 eruptive units in two study areas along the Galápagos Spreading Center (GSC) provide insight into how magma supply affects mid-ocean ridge (MOR) volcanic eruptions. The two study areas have similar ...
    • Thumbnail

      Interplay between faults and lava flows in construction of the upper oceanic crust : the East Pacific Rise crest 9°25′–9°58′N 

      Escartin, Javier E.; Soule, Samuel A.; Fornari, Daniel J.; Tivey, Maurice A.; Schouten, Hans A.; Perfit, Michael R. (American Geophysical Union, 2007-06-07)
      The distribution of faults and fault characteristics along the East Pacific Rise (EPR) crest between 9°25′N and 9°58′N were studied using high-resolution side-scan sonar data and near-bottom bathymetric profiles. The ...
    All Items in WHOAS are protected by original copyright, with all rights reserved, unless otherwise indicated. WHOAS also supports the use of the Creative Commons licenses for original content.
    A service of the MBLWHOI Library | About WHOAS
    Contact Us | Send Feedback | Privacy Policy
    Core Trust Logo