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.
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Showing 1 to 20 of 26 for “"Mush"”.
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Modeling fluid interactions with the rigid mush in alloy solidification
… interface between the bulk fluid and the rigid mushy zone. In this region, the non-linear and coupled behavior of heat transfer, fluid mechanics, solute transport, and alloy thermodynamics has a dramatic effect on macrosegregation predictions. This work investigates the impact of numerical …
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Timescales of magma residence and transport underneath Iceland
… melts followed by sequestration in a crystal mush environment and then entrainment into a trace element enriched melt prior to eruption. Equilibrated plagioclase core Mg profiles suggest storage in a mush that was colder than the original primitive liquid, but hotter than the final carrier …
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Petrogenesis of natrocarbonatite at Ol Doinyo Lengai, East Africa—evidence from Fe and U isotope variations
… melt with previous emplaced crystal mush zone, during which Fe2+ preferentially enters the carbonate-rich melt and leaves Fe3+ in the remaining crystal rich mush zone. The carbonate-rich melt degases water as pressure drops causing the observed dry natrocarbonatite lava on the …
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Applications of Machine Learning to the Petrographic Analysis of Icelandic Gabbroic Xenoliths through Light, Electron and X-ray Microscopy
… represent thesolidifed fragments of the source mush made up of cumulate plagioclase from a range ofmagmatic environments; a small subset of the nodules were shown to represent countryrock. There is clear diversity in nodule chemistry which is likely related to the observedobserved diversity in …
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Microanalytical Constraints on the Geometry and Chemical Evolution of Kīlauea’s Volcanic Plumbing System
… examines the petrological evidence for this ‘mush-dominated’ model at Kīlauea Volcano, using a variety of state-of-the-art microanalytical techniques. Chapters 3 and 4 demonstrate the power of electron backscatter diffraction (EBSD) to investigate the processes leading to the formation of …
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Drivers, Dynamics and Hazards of the largest pyroclastic eruptions of Tongariro Volcano, Central North Island, New Zealand
… intrusion - forming a N-S elongated heterogenous mush zone aligned with the graben axis. Mixing of more evolved residual and intruding primitive melt created mainly basaltic-andesitic whole-rock compositions. More evolved andesites, with dacitic to rhyolitic interstitial glass represent …
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Playgod: Entertainment for Fools
… she isn’t real. Whatever’s in her head, it’s all mush. She’s nothing. Not person, not animal. Sometimes, she might be decoration: a pretty painting to hang on the wall, an expensive watch or tie. Therefore, a woman is mineral. She is what she is, nothing more. She believes what she is told. She …
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Geochemical and volcanological aspects of rhyolite eruptions from Taupo Volcanic Zone, New Zealand
… in OVC appear to be derived from crystal-rich mush zones, similar to other calderas (e.g., Long Valley). In the OVC, these melts subsequently migrate into the upper crust (mainly 5-7 km depth) and crystallise, as indicated by phenocryst and glass equilibrium. Geochemical and mineralogical …
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Structural Re-orientation of Magmatic Fabrics and Layering in the Lower Oceanic Crust: Hole GT1, Wadi Tayin Massif, Samail Ophiolite
… and the idea of melt intruding an upper crystal mush reservoir as a mixing bowl that develops layering and fabrics if enough melt is present for further intrusion. The variance in dip azimuth downhole implies that these features formed through local processes, which supports geochemical evidence …
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Petrology of the Gracefield pluton.
… in the upper part of the chamber, and a crystal mush in the lower part. After convection ceased, crystallization of the feldspars, barkevikite, biotite, most of the magnetite, and nepheline and calcite commenced in the larger intrusive.
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Analytical and Computational Studies of Convection in Solidifying Binary Media
… of a layer of dendritic growth called a mushy layer. The mushy layer has both solid and fluid components. We consider the problem of nonlinear steady buoyant convection in horizontal mushy layers during the solidification of binary alloys. Both cases of zero vertical volume flux and …
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Petrofabric investigation of the sulfide-rich basal zone of the Duluth Complex
… sulfide droplets within a flowing, crystal-rich mush prior to deposition.We analyzed oriented drill core samples from eleven closely spaced sites spanning mineralized and unmineralized zones in the SKI, including the unmineralized Duluth Layered Series (DLS) using a combination of techniques. …
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Stability, transport and applications of polyaphrons in porous media
… strategy and initial distribution of DCB, as mush as 97% of the DCB entrapped in the sand column is removed, most of which is in a bulk organic phase lighter than water. Since the coalescence between aphrons is a crucial step in the polyaphron treatment, we develop a boundary element method …
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Magmatic processes recorded in crystals from intraplate basalt volcanoes, Kaikohe-Bay of Islands volcanic field, New Zealand
… KBIVF magmatic system is likely to be a crystal mush column extending vertically through the crust. This is surprisingly similar to that proposed for intermediate arc volcanoes, but the KBIVF system would have been ephemeral. Geophysical data indicates the presence of a body of partial melt at …
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Crystallisation history of rhyolite magmas at Tarawera volcano, New Zealand, from in-situ 238U-230Th disequilibrium dating and trace element geochemistry of zircon
… %) and low degrees of crystallinity in the mush inferred from fractional crystallisation modelling of U, Th, and Th/U. The continuity of zircon growth throughout the eruptions from Tarawera and even the ~45 ka OVC caldera-forming event suggest a decoupling between the crystallisation state …
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Variations in δ56Fe during magma differentiation at Cedar Butte volcano: signatures of thermal diffusion?
… material). Ultimately, the compositionally zoned mush is heated by arriving basaltic magmas leading to eruption.
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Volcanic deformation as an indicator of mechanical stability and eruption susceptibility
… are likely reactivated from cold, crystalline “mush” storage on short timescales of decades to thousands of years (in agreement with recent geochemical investigations). In another series of numerical experiments, I identify the submarine volcano, Axial Seamount, as a system which has experienced …
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The convective desalination of sea ice
… considers a class of physical systems called mushy layers, of which sea ice is an example. Mushy layers are multi-component systems consisting of a porous matrix of solid phase whose interstices contain the same substance in the liquid phase. I develop a mathematical description of these …
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Origin of net-veined and mixed-magma ring intrusions
… into hot intermediate and mafic magma/crystal mush, producing pillows and net-veining in the ring fracture. Mixing is incomplete due to contrasting viscosities and solidus temperatures of the different magmas. Volatile exsolution enhances mixing and net-veining and leads to the violent, …
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Examining the past to prepare for the future: Quaternary magma storage in the Main Ethiopian Rift and implications for volcanic hazard and resource potential
… They are then later entrained from a ‘crystal-mush’ region into more evolved residual melts during large, explosive eruptions. Melt volatile contents are also inconsistent with a simple fractional crystallisation model. Basalts stored both on and off axis are saturated in H2O and CO2 at depths …
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