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Showing 1 to 10 of 10 for “"pyroclastic deposits"”.
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Geology of the late precambrian Flat River complex and associated volcanic rocks near Durham, North Carolina
… data, the presence of vent breccias and related pyroclastic deposits, and consideration of age relations between the intrusive and extrusive rocks indicate that the Flat River was emplaced at very shallow levels (< l km) and acted as the source for most of the volcanic material surrounding the …
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Planet Mercury: volatile release on a contracting world
… depressions known as ‘hollows’, and pits and deposits thought to be the products of explosive volcanism. For hollows, I seek to clarify the nature of the substance lost to form them and the mechanisms by which this has been introduced to, and lost from, the surface recently enough to explain …
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Volcanostratigraphy using geophysical methods on La Fossa di Vulcano (S-Italy)
… of the volcanostratigraphy, because the deposits provoke information on the potential behaviour during a new activity cycle. Pyroclastic deposits, however, may vary widely in thickness and distribution over very short lateral distances. High resolution characterisation of single strata …
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Intense Shallow Magma Sediment Mingling within Dikes at Guffey Butte Maar, Idaho
… of magma and water or wet sediment and their deposits are evidence of this interaction. The relative influence of internal magmatic and external environmental factors that control magma sediment interaction are not well constrained. This study focuses on exposed dike structures in an eroded …
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Characterization of a volcanically impacted, overfilled continental rift basin within the southeastern Jemez Mountains, New Mexico
… the basin with about 550 m of lava and primary pyroclastic deposits and minor fluvial sediments. As a result, little or no coarse-grained epiclastic sediments were shed from adjacent footwall highlands and deposited into the basin along its margins, which is a trait of conventional rift basin …
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Small-volume volcanism associated with polygenetic volcanoes, Taupo Volcanic Zone, New Zealand : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Earth Science at Massey University, Palmerston North, New Zealand
… by explosive activity. However, the associated pyroclastic deposits are characterised by a low preservation potential. The most likely scenario for future eruptions is a rhyolitic eruption with an initial phreatomagmatic phase followed by the effusive emplacement of lava with or without …
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Tectono-hydrothermal evolution of the Neoarchean Abitibi greenstone belt, Canada
… belt of Ontario and Quebec, Canada. The deposits of the Timiskaming assemblage include deep-water turbidites, alluvial-fluvial conglomerates and sandstones, as well as alkalic volcanic and intrusive rocks. The sedimentary and volcanic rocks of the Timiskaming assemblage record a special …
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Dynamics of deep-submarine explosive eruptions
… the deep-ocean. Motivated by the observations of pyroclastic deposits on the sea floor at depths of up to 4 km, we investigate the initial mixing of erupted hot fragmented magma with the ambient seawater and explore the density and spatial evolution of the subsequent flow that forms. In chapter 2, …
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Recalibrating the breakup history of SW Gondwana: the first U-Pb chronostratigraphy for the Uitenhage Group, South Africa
Syn-rift deposits often provide the only means to determine the processes for initiation and evolution of rift basins and passive margins. The structurally preserved erosional remnants of several rift basins that formed during the Mesozoic breakup of Gondwana are located within the southern Cape …