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The influence of ridge geometry at the ultraslow-spreading Southwest Indian Ridge (9⁰-25⁰E) : basalt composition sensitivity to variations in source and process
(Massachusetts Institute of Technology, 2006)
Between 90-25° 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 ...
Cenozoic deep-water agglutinated foraminifera in the North Atlantic
(Massachusetts Institute of Technology, 1988)
Seismic and magnetic constraints on the strucutre of upper oceanic crust and fast and slow spreading ridges
(Massachusetts Institute of Technology, 1998)
The upper ocean crust contains a comprehensive record of the shallow geological processes active along the world's mid-ocean ridge system. This thesis examines the magnetic and seismic structure of the upper crust at two ...
Magmatism and dynamics of continental breakup in the presence of a mantle plume
(Massachusetts Institute of Technology, 2000)
This thesis studies the dynamics of mantle melting during continental breakups by geophysical, geochemical, and numerical analyses. The first part focuses on the mantle melting and crustal accretion processes during the ...
Gulf stream temperature, salinity and transport during the last millennium
(Massachusetts Institute of Technology, 2006)
Benthic and planktonic foraminiferal [delta]18O ([delta 18Oc) from a suite of well-dated, high-resolution cores spanning the depth and width of the Straits of Florida reveal significant changes in Gulf Stream cross-current ...
Thermal and mechanical development of the East African Rift System
(Massachusetts Institute of Technology, 1988)
The deep basins, uplifted flanks, and volcanoes of the Western and Kenya rift systems have developed along the western and eastern margins of the 1300 km-wide East African plateau. Structural patterns deduced from field, ...
Overflows and upper ocean interactions : a mechanism for the Azores current
(Massachusetts Institute of Technology, 2006)
The oceanic response to overflows is explored using a two-layer isopycnal model. Overflows are a major source of the dense water of the global deep ocean, originating from only a few marginal seas. They enter the open ocean ...
Interactions between mantle plumes and mid-ocean ridges : constraints from geophysics, geochemistry, and geodynamical modeling
(Massachusetts Institute of Technology, 2001)
This thesis studies interactions between mid-ocean ridges and mantle plumes using geophysics, geochemistry, and geodynamical modeling. Chapter 1 investigates the effects of the Marion and Bouvet hotspots on the ultra-slow ...
Zinc and cadmium in benthic foraminifera as tracers of ocean paleochemistry
(Massachusetts Institute of Technology, 2000)
Benthic foraminiferal δ13C, Cd/Ca, and Ba/Ca are important tools for reconstructing nutrient distributions, and thus ocean circulation, on glacial-interglacial timescales. However, each tracer has its own "artifacts" that ...
Mechanisms of turbulent mixing in the Continental Shelf bottom boundary layer
(Massachusetts Institute of Technology, 2000)
The bottom boundary layer is an important dynamical region of shallow water flows. In this thesis, the problem of turbulent mixing in the coastal bottom boundary layer is investigated with a unique set of field measurements ...