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Showing 1 to 20 of 42 for “"melt inclusions"”.
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Silicate Melt Inclusions in Igneous Petrogenesis
Silicate melt inclusions are ubiquitous in quartz phenocrysts, yet there are few studies of such inclusions from porphyry copper systems. A melt inclusion forms when magma is trapped in a growing phenocryst. If a phenocryst is able to preserve the original parent magma, then accurate information …
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Applications of Melt Inclusions to Problems in Igneous Petrogenesis
… petrogenetic processes is through the study of melt and fluid inclusions. The research presented here examines melt inclusions through experimental, analytical and field studies to better understand igneous petrogenesis. One potential problem associated with melt inclusions is water-loss during …
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Studies of volatile evolution in magmatic systems using melt inclusions
… physical state (volatiles dissolved in silicate melts vs. volatiles exsolved as vapor). For active volcanic systems studying the volatile evolution can help to assess the potential hazard associated to a certain locality. Also, volatile evolution in magmatic system controls the formation of …
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The volatile contents of melt inclusions and implications for mantle degassing and ocean island evolution
… of volatile elements dissolved in silicate melts is a controlling factor in a range of geologic processes, which include hazardous volcanic eruptions, economically-significant ore-forming systems, and global-scale volatile fluxes, which contribute to planetary evolution. While melt volatile …
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Geochemistry of Melt Inclusions from the Fondo Riccio and Minopoli 1 Eruptions at Campi Flegrei (Italy)
… of eruption and can be assessed from studies of melt inclusions (MI) contained in phenocrysts. Major and trace elements in Fondo Riccio MI show a wider variation compared to those in Minopoli 1 MI suggesting that the Fondo Riccio magma residence time was longer compared to the Minopoli 1 magma. …
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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. …
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Trace element geochemistry of oceanic peridotites and silicate melt inclusions--implications for mantle melting and ocean ridge magmagenesis
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, and Woods Hole Oceanographic Institution, 1990.
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Geochemical Evolution at White Island, New Zealand
… In this study, the geochemistry of the silicate melt at White Island has been characterized through detailed studies of silicate melt inclusions, phenocrysts, and matrix glass contained in recent ejecta (1977-1991). Most melt inclusions contained only glass, however, daughter minerals present in …
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The Role of Fluids in Geological Processes
… and in both synthetic and natural fluid and melt inclusions. One of these studies dealt with the effect of composition on the critical P-T-X properties of aqueous salt solutions approximated by the H₂O-NaCl-KCl-CaCl₂ system. The results indicate a systematic variation in critical properties …
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Transitions between effusive and explosive activity at Merapi volcano, Indonesia: a volcanological and petrological study of the 2006 and 2010 eruptions.
… of volatiles and light lithophile elements in melt inclusions. These data were gathered from a detailed set of stratigraphically controlled samples, correlated to eruptive chronology and style, which were collected during several field campaigns. Both the 2006 and 2010 eruptions produced …
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Microanalytical Constraints on the Geometry and Chemical Evolution of Kīlauea’s Volcanic Plumbing System
… moving away from a model where large vats of melt are stored in the crust, to a model dominated by extensive piles of settled crystals. This thesis examines the petrological evidence for this ‘mush-dominated’ model at Kīlauea Volcano, using a variety of state-of-the-art microanalytical …
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Dismantling the deep earth : geochemical constraints from hotspot lavas for the origin and lengthscales of mantle heterogeneity
… of Sr-isotope variability in olivine-hosted melt inclusions. Melt inclusions in just two Samoan basalt hand samples exhibit most of the total Sr-isotope variability observed in Samoan lavas. Chapter 3 deals with the largest possible scales of mantle heterogeneity, and presents the highest …
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Dismantling the deep earth : geochemical constraints from hotspot lavas for the origin and lengthscales of mantle heterogeneity
… of Sr-isotope variability in olivine-hosted melt inclusions. Melt inclusions in just two Samoan basalt hand samples exhibit most of the total Sr-isotope variability observed in Samoan lavas. Chapter 3 deals with the largest possible scales of mantle heterogeneity, and presents the highest …
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Bubbles matter: An assessment of the contribution of vapor bubbles to melt inclusion volatile budgets
H2O and CO2 concentrations of the glass phase in melt inclusions (MI) are commonly used both as a barometer and to track magma degassing behavior during ascent due to the strong pressure dependence of H2O and CO2 solubilities in silicate melts. A requirement for this method to be valid is that the …
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Deep Earth volatile cycles as revealed by basalt chemistry
… systematics in suites of basaltic glass and melt inclusions have been widely used to infer volatile abundances in the depleted mantle, but have resulted in a large diversity of estimates. In this thesis a new statistical treatment of such datasets is developed, using simple numerical models …
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Carbon systematics of the Icelandic crust and mantle
… to the low solubility of carbon within silicate melt, these undegassed basalt suites are rare. The majority of basalts have lost their mantle carbon information en route to eruption through the crust. Various crustal processes act to modify the geochemistry of melts before eruption, therefore it …
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Evaluating mantle and crustal processes using isotope geochemistry
… crust and the mantle lithosphere, examines melt inclusion from oceanic island basalts to evaluate the scale of the mantle heterogeneities, and uses U-series isotope to constrain geodynamic parameters, such as the upwelling velocities and porosities of mantle plumes. The lower continental …
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Water and fluorine contents in Mt. Hood magmas recorded by plagioclase phenocrysts
… effect on the properties of minerals and melts, even when present in trace amounts. They impact the phase equilibria (Wyllie 1979; Gaetani and Grove 1998), rheological properties (Dingwell et al. 1985; Hirth and Kohlstedt 1996), and volcanic eruption dynamics (Roggensack et al. 1997; …
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Geochemistry and mineralogy of selected Atlantic Ocean basalts
… terms of fractional crystallisation and partial melting models. Samples studied are from the Mid-Atlantic Ridge at 36°49 'N (FAMOUS), from the Islas Orcadas fracture zone on the Southwest Indian Ocean Ridge, from the Conrad fracture zone on the America-Antarctica Ridge and from Bouvet Island, …
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