Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 10 of 10 for “"Conrad (Ship) Cruise"”.
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Petrological and geochemical studies of an abyssal periodotite from the Atlantis II fracture zone
This thesis investigates the petrology and geochemistry of an abyssal peridotite dredged from the Atlantis II Fracture Zone in the southwestern Indian Ocean Ridge. Texturally, this sample is a serpentinized peridotite with a crosscutting coarse-grained clinopyroxenite vein. One of the alteration …
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A search for layering in the oceanic crust
… the oceanic crust, and investigates the relationships between the seismic characteristics of these boundaries and the geological structure of the crust. The seismic signature of the crust/mantle boundary (Moho) is a prominent event on multichannel seismic (MCS) reflection data. In the Western …
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Mass, heat and nutrient fluxes in the Atlantic Ocean determined by inverse methods
Inverse methods are applied to historical hydrographic data to address two aspects of the general circulation of the Atlantic Ocean. The method allows conservation statements for mass and other properties, along with a variety of other constraints, to be combined in a dynamically consistent way to …
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Variations in structure and tectonics along the Mid-Atlantic Ridge, 23⁰N and 26⁰N
The variation in the depth and width of the median valley along the Mid-Atlantic Ridge (MAR) suggests that the formation of ocean crust at slow spreading centers is not a simple two-dimensional process in which crustal accretion occurs uniformly both along the ridge axis and with time. Rather, it …
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A qualitative and quantitative study of the distribution of pelagic sediment in the Atlantic Basin
Pelagic sedimentation is the primary modifier of topography generated by ridge-associated volcanic and tectonic processes. This thesis represents an effort to understand the processes of, and the general distribution of, pelagic sedimentation on rough topography, particularly in the Atlantic Basin …
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Crustal accretion and evolution at slow and ultra-slow spreading mid-ocean ridges
Half of the ocean crust is formed at spreading centers with total opening rates less than 40 km/Myr. The objective of this Thesis is to investigate temporal variations in active ridge processes and crustal aging at slow-spreading centers by comparing axial crustal structure with that on conjugate …
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Seismic and magnetic constraints on the structure of upper oceanic crust at fast and slow spreading ridges
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 contrasting ridges-the fast spreading East Pacific Rise (EPR) and the slow …
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Cenozoic geology of the continental slope and rise off western Nova Scotia
The outer continental margin of Nova Scotia is divided by a diapir province, 40-110 km wide and ~1000km long, that trends subparallel to the shelf edge along the upper continental rise and slope. The growth pattern for a small region of this margin (61°-64°W) during the Late Cretaceous and Cenozoic …
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Studies of deep-sea sedimentary microtopography in the North Atlantic Ocean
Many of the small-scale topographic features (dimensions of centimeters to kilometers) found on the Blake-Bahama Outer Ridge (western North Atiantic, water depth greater than 4000 m) and in the Rockall Trough (northeastern North Atlantic, water depth greater than 2000 m) have been formed as bed …
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Trace element geochemistry of oceanic peridotites and silicate melt inclusions : implications for mantle melting and ocean ridge magmagenesis
The mantle melting process is fundamental to basalt genesis and crustal accretion at mid-ocean ridges. It is believed that melts ascend more rapidly than the surrounding mantle, implying a process similar to fractional melting may be occurring, but geochemical evidence for this has been lacking. …