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 44 for “"Mantle wedge"”.
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Mantle Wedge Evolution beneath the Northern Mariana Forearc
… characteristics of a supra-subduction zone mantle wedge and how it has evolved in response to subduction of the Pacific Plate, forearc peridotites (dunites and harzburgites) were collected by dredging the landward slope of the Northern Mariana trench wall. High concentration of fluid mobile …
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Absarokites from the Western Mexican Volcanic Belt : constraints on mantle wedge conditions
… olivine phenocrysts, indicating it is primitive mantle melt. High-pressure experiments on a synthetic analogue of the absarokite composition with a H2O content of either -1 7 wt% or -5.1 wt% were cared out in a piston cylinder apparatus. The composition with -1.7 wt% H2O is multiply saturated …
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Absarokites from the Western Mexican Volcanic Belt : constraints on mantle wedge conditions
… olivine phenocrysts, indicating it is primitive mantle melt. Highpressure experiments on a synthetic analogue of the absarokite composition with a H20 content of either -1.7 wt% or -5.1 wt% were carried out in a piston cylinder apparatus. The composition with -1.7 wt% H20 is multiply saturated …
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Experimental investigation of the fluid driven carbonation of serpentinites and spinel-peridotites: implications for the carbon and trace element cycle in the forearc region of the mantle wedge
… arc volcanoes implying the storage of C in the mantle wedge. This experimental study investigates the fate of C bearing aqueous fluids when they travel through the (partially) hydrated forearc mantle targeting the forearc mantle as a potentially relevant carbon reservoir. Thermodynamic modelling …
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Experimental investigation of the fluid driven carbonation of serpentinites and spinel-peridotites: implications for the carbon and trace element cycle in the forearc region of the mantle wedge
… arc volcanoes implying the storage of C in the mantle wedge. This experimental study investigates the fate of C bearing aqueous fluids when they travel through the (partially) hydrated forearc mantle targeting the forearc mantle as a potentially relevant carbon reservoir. Thermodynamic modelling …
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Investigation of the upper mantle as a source for contribution to magnetic anomalies
… testing of the hypothesis that the lithospheric mantle contains significant magnetic regions that contribute to the magnetism observed/measured, either at or close to the Earth’s surface, or from satellite data. Chapter 1 “Eight good reasons why the mantle could be magnetic” (2014) published in …
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Mass transfer and chemical interactions in subduction zones
… rocks at conditions relevant to the slab-mantle interface and show that Mg-metasomatism of mafic rocks to form chlorite-rich assemblages is favored and is likely more pervasive in subduction zones than in oceanic settings. Contrary to common belief, talc is unlikely to form in high …
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Mass Transfer and Chemical Interactions in Subduction Zones
… rocks at conditions relevant to the slab-mantle interface and show that Mg-metasomatism of mafic rocks to form chlorite-rich assemblages is favored and is likely more pervasive in subduction zones than in oceanic settings. Contrary to common belief, talc is unlikely to form in high …
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Anisotropy and deformation in the Earth's mantle : seismological observations, geodynamical models, and laboratory experiments
… anisotropy and deformation in the Earth's mantle, using shear wave splitting measurements, numerical models of geodynamical processes, and laboratory experiments on mantle minerals. I evaluate the performance of several methods for measuring shear wave splitting at broadband stations, and …
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Hydrous melt generation in the Earth's mantle
… of H₂O in the generation and modification of mantle melts at shallow pressures in subduction zones. In the first and second chapters, two experimental studies are presented that investigate direct mantle melting and then subsequent reaction of deeper mantle melts with overlying, cooler …
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3D trench-parallel flow in the subduction region and correlation with seismic anisotropy direction
… direction of shear wave, are observed. In the mantle the general assumption is that seismic anisotropy is caused by Lattice Preferred Orientation (LPO) of olivine minerals and that the direction of anisotropy is an indicator of the direction of mantle flow. The complex pattern of seismic …
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The Structure and Behavior of Plate Boundary Regions Through the Wilson Cycle
… constraints on the extent of enriched mantle from upwelling mantle plumes relative to the observed extent of topographic swells related to mantle flow. It builds on this data by presenting a new geophysical model of mantle flow around mantle plumes that constrains the viscosity …
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The timescales of andesite generation at Mount Ruapehu, New Zealand
… Major element extrapolations suggest that the mantle wedge beneath the TVZ was relatively fertile. Modelling of the trace element budgets in relatively primitive lavas suggests that a three component model is required for magma generation. Partial melts of sediments were added to the mantle …
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ΜΕΛΕΤΗ ΤΗΣ ΟΡΥΚΤΟΛΟΓΙΑΣ, ΠΕΤΡΟΛΟΓΙΑΣ, ΓΕΩΧΗΜΕΙΑΣ ΚΑΙ ΤΩΝ ΦΑΙΝΟΜΕΝΩΝ ΜΕΤΑΜΟΡΦΩΣΕΩΣ ΒΑΣΙΚΩΝ ΚΑΙ ΥΠΕΡΒΑΣΙΚΩΝ ΠΕΤΡΩΜΑΤΩΝ ΤΗΣ ΠΕΡΙΡΟΔΟΠΙΚΗΣ ΖΩΝΗΣ ΣΤΗΝ ΠΕΡΙΟΧΗ ΤΗΣ ΘΡΑΚΗΣ
… DEGREES OF PARTIAL MELTING OF THE HETEROGENESIS MANTLE WEDGE. THE MAGMA OF 15-20% PARTIAL MELTING, AFTER FRACTIONAL CRYSTALIZATION, DEVELOPED GABBROIC ANDVOLCANIC ROCKS, WHICH AFTER REGIONAL METAMORPHISM OF GREENSCHISTS FACIES FORMED METAGABBROS AND GREENSCHISTS. THE MAGMA OF 30% PARTIAL MELTING …
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Evidence From High Ni Olivine For Diverse Primitive Magmas In Cascade Volcanism
… produced by processes occurring in the Cascade mantle wedge, and were not substantially affected by magma mixing and crustal contamination in shallow volcanic plumbing systems. The propinquity of these distinctive primitive lava types along the length of the arc suggests that a thermally and …
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B isotope variations at variable scales in arc volcanoes: a case study of lavas from Paniri and Toconce, Northern Chile
… tracer for the hydration of the overlying mantle wedge at subduction zones. The boron isotope composition of magmas is useful in detecting and quantifying the exchange process between the slab and the mantle. This is due to the large boron isotopic difference between the subducting altered …
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INTEGRATION OF NATURAL DATA WITHIN NUMERICAL MODEL TO THE GEODYNAMICS RECONSTRUCTION OF AN INNER PART OF THE ALPINE BELT.
… out that a direct relationship exists between mantle rheology and the amount of recycled crustal material: the larger the viscosity contrast between hydrated and dry mantle, the larger the percentage of recycled material into the mantle wedge. Slab dip variation has an impact on the amount of …
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Geochemistry of the Northern Izu-Bonin arc: implications for crustal recycling and mantle processes
… the exchange of elements between flux<br/>and mantle that lead to the creation of arc magmas. These calculations allow the changes in<br/>fluid flux from the slab and the variations of mantle composition to be correlated with the<br/>variations in across-arc geochemistry.<br/>All of the …
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Evolution of oceanic margins : rifting in the Gulf of California and sediment diapirism and mantle hydration during subduction
… plate in subduction zones and rise into the mantle wedge, delivering the sedimentary component widely observed in arc magmas. Chapter 4 presents measurements of seismic anisotropy from wide-angle, active-source data from the Middle America Trench that address the hypothesis that the upper …
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Evolution of oceanic margins : rifting in the Gulf of California and sediment diapirism and mantle hydration during subduction
… plate in subduction zones and rise into the mantle wedge, delivering the sedimentary component widely observed in arc magmas. Chapter 4 presents measurements of seismic anisotropy from wide-angle, active-source data from the Middle America Trench that address the hypothesis that the upper …
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