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 ...
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 ...
Geomagnetic variations in the Northwest Atlantic : implications for the electrical resistivity of the oceanic lithosphere Poehls, Kenneth Allen (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1975-10)A geomagnetic variation study on mature oceanic lithosphere in the North Atlantic just south of Bermuda has revealed the presence of at least one layer of low electrical resistivity. The low resistivity layer of approximately ...