Seismic constraints on the processes and consequences of secondary igneous evolution of Pacific oceanic lithosphere
Feng, Helen S.-H.
MetadataShow full item record
KeywordMarcus G. Langseth (Ship) Cruise MGL1115; Marcus G. Langseth (Ship) Cruise MGL1204; Lithosphere; Magmatism
This thesis examines the structure of Pacific oceanic lithosphere that has been modified by post-formation magmatism in order to better understand the processes of secondary magmatic evolution of the lithosphere, which can have global-scale implications for oceanic and atmospheric chemistry. In the western Pacific, widespread Cretaceous magmatism has modified oceanic lithosphere over hundreds of millions of square kilometers. Seismic models of the upper crust from within the Jurassic Quiet Zone and the crust and upper mantle near the Mariana Trench reveal crust that is locally thickened via focused extrusive volcanism and crust that is modestly but uniformly thickened over broad regions. These distinct modes of magmatic emplacement suggest the operation of both focused and diffuse modes of melt transport through the lithosphere. Analysis of seismic observations from Guaymas Basin, in the Gulf of California, endeavor to advance our understanding of sill-driven alteration of sediments, an important consequence of secondary magmatism. We show that seismically imaged physical disruption to sediments due to igneous sill intrusion can be related to changes in sediment physical properties that reflect alteration processes. We also show how sill thickness can be estimated, enabling alteration intensity to be related to sill thickness in a variety of settings.
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 2016
Suggested CitationThesis: Feng, Helen S.-H., "Seismic constraints on the processes and consequences of secondary igneous evolution of Pacific oceanic lithosphere", 2016-02, DOI:10.1575/1912/7803, https://hdl.handle.net/1912/7803
Showing items related by title, author, creator and subject.
Bunce, Elizabeth T.; Langseth, Marcus G.; Chase, R. L.; Ewing, W. Maurice (Woods Hole Oceanographic Institution, 1967-07)The western Somali Basin in the northwestern Indian Ocean is covered by thick deposits of terrigenous sediments. Seismic reflection profiles show, however, the northern and southern parts to be very different. The northern ...
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 ...