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 16 of 16 for “"Magma storage"”.
-
The record of magma storage conditions in mineral compositions below a glacial to ice-free Askja volcano, Iceland
… and textures from basaltic lavas to reconstruct magma chamber conditions before, during and after glaciation. In this study, 36 lava flow and gabbro xenolith samples were collected from seven separate units: two glacial, the Early Holocene, and four historical. These samples were analyzed along …
-
Examining the past to prepare for the future: Quaternary magma storage in the Main Ethiopian Rift and implications for volcanic hazard and resource potential
Understanding how magma is stored within the crust, and what processes it might undergo, is of paramount concern to Earth scientists. Whilst advances in analytical techniques have revealed increasingly complex pictures of magma storage at arc and mid-ocean ridge settings, we still know relatively …
-
MAGMA STORAGE, ASCENT AND DEGASSING HISTORIES TRACED BY TEXTURES AND CHEMICAL ZONING IN CRYSTALS: APPLICATION TO THE CO2-RICH BASALTIC SYSTEM OF MT. ETNA VOLCANO
… all interno del feeding system Etneo di volumi magmatici a basso contenuto in Sr, i quali preservano una signature geochimica simile a quella dei prodotti che hanno alimentato l attivita storica, pre-1971, dell Etna. L analisi della zonatura di Fe e Mg rispetto all anortite in corrispondenza …
-
Planet Mercury: volatile release on a contracting world
… and that its eruptive style indicates magma storage prior to eruption, at greater depths than on the more tectonically-neutral Moon. This indicates that, rather than precluding it, global contraction favoured volcanic explosivity by promoting magma storage during which volatiles could …
-
Evolution of a Flood Basalt Crustal Magmatic System: In Situ Mineral Data and Computational Modeling of the Steens Basalt
… of the crust via intrusion of mantle-derived magma, and change its composition through interaction between magma and crust. The Steens Basalt, located in southeast Oregon, erupted approximately 16.8 million years ago, and is the oldest member of the Columbia River Basalt Group, the youngest …
-
Historic and prehistoric volcanic activity on St Kitts and Nevis, West Indies: Controls on future hazard
… been analysed to characterise the nature of the magma storage conditions below both islands, and to understand the styles of the most recent eruptions. These geochemical analyses have shown that open-system processes dominated the magma storage conditions at both St Kitts and Nevis, and recharges …
-
Timing and Source of Alkali Enrichment at Mt. Etna, Sicily: Constraints from Clinopyroxene Geobarometry and In Situ SR Isotope Data
… characterize the evolution of the subvolcanic magma storage and transport system, as well as the timing and source of alkali-enrichment, clinopyroxene from ten samples erupted between 1329 and 2004 was targeted for <em>in situ</em> textural, major element and Sr isotope analysis. Clinopyroxene …
-
Quantifying magma recharge at Parinacota volcano, northern Chile (52 ka - recent): Insight from the Magma Chamber Simulator
The Magma Chamber Simulator (MCS; Bohrson et al., 2014) was used to produce new thermodynamic models that constrain and quantify recharge and fractional crystallization (RFC) processes for the Old Cone (OC; 52-20 ka; 56-66 wt.% SiO<sub>2</sub>) and Healing Flows (HF; >8 ka-recent; 58-64 wt.% …
-
Petrological insights into pre- and syn-eruptive degassing at Ambrym volcano, Vanuatu
… This study is a petrological investigation of magmatic conditions and degassing processes at Ambrym volcano, a basaltic island arc volcano recently identified as a prodigious emitter of volcanic gases. Typical activity at this volcano entails heavy degassing from quasipermanent lava lakes, with …
-
Probing the interior of an active volcano: Three-dimensional seismic tomography at Montserrat
Constraining the magmatic systems of active volcanoes is important for comprehending the mechanisms that drive magma supply. Particularly important are the geometry and characteristics of magma storage regions in the upper and middle crust, which can influence the style and time-scales of …
-
Geophysical models of Mount Etna, Sicily : its structural evolution and implications for slope stability
… and is interpreted as an area of shallow level magma storage within the upper flanks of the volcano. A negative gravity anomaly of 10mGal towards the coast, over the Chiancone sedimentary fan deposit, is interpreted as reworked debris flow material, derived from the Valle del Bove. The shape of …
-
The 2014-15 Bárðarbunga-Holuhraun magmatic rifting episode: A seismic study
… at 6-8 km b.s.l. I hypothesise that the magma storage region is likely located at 4-6 km b.s.l. (6-8 km below the caldera surface), just below the most active caldera seismicity and at similar depth levels to the dyke. Thus, this thesis details the melt distribution and movement at depth …
-
Magmatic processes at basaltic volcanoes: insights from the crystal cargo
A plethora of magmatic processing occurs in magma reservoirs, where melts are stored prior to eruption. Magma reservoirs are complex, open systems, and often multiple reservoirs are partially inter-connected from source to surface, giving rise to the term 'volcanic plumbing system'. Parental melts …
-
Prelude to the Tshirege caldera-forming eruption of the Bandelier magmatic system, New Mexico, USA
… eruptions have occurred in the Bandelier magmatic system of the Jemez Mountains of northern New Mexico, the latter of which formed Valles caldera during the Tshirege eruption at 1232 ka. Despite no eruptions at Valles in the last ca. 70 kyr, the presence of partially molten magma bodies at …
-
The Role of Cumulate Plagioclase Entrainment in the Steens Basalt, SE Oregon: Insights from the Magma Chamber Simulator
… of these giant plagioclase yields insight into magmatic processes like recharge, crustal assimilation, cumulate entrainment, and fractional crystallization. Because large and abundant plagioclase are found in other flood basalt provinces worldwide, these results could also enhance understanding …
-
Timescales of magma residence and transport underneath Iceland
… from Iceland with different compositions and storage depths in order to characterise the timescales of pre-eruptive residence and transport: the Skuggafjöll eruption, Bárðarbunga volcanic system; the Borgahraun eruption, Theistareykir volcanic system; and the Laki eruption, Grímsvötn volcanic …