Erebus is a well-studied open-vent volcano located on Ross Island, Antarctica (77◦ 32’ S, 167◦ 10’ E). The volcano is the focus of ongoing research aimed at combining petrologic data and experiments with surface gas observations in order to interpret degassing histories and the role of volatiles in magma differentiation, redox evolution, and eruptive style. This research focus has been driven in part by an abundance of studies on various aspects of the Erebus system, such as physical volcanology, gas chemistry, petrology, melt inclusion research, seismic, and more. Despite this large data set, however, interpretations of Erebus rocks, particularly mafic and intermediate lavas, which are thought to originate from deep within the magmatic plumbing system, have been hindered due to a lack of experimental data. Experimental petrology is a common tool used to understand volcanic plumb- ing systems and to tie observations made at the Earth’s surface to the deep pro- cesses responsible for driving volcanic activity. Experimental petrologists essen- tially recreate natural magma chambers in miniature by subjecting lavas to con- ditions of pressure, temperature, and volatile chemistry (P-T-X) relevant to a natural underground volcanic system. Because many important parameters can be constrained in the laboratory, the comparison of experimental products with naturally erupted ones allows for an understanding of the formation conditions of the rocks and gases we see at the surface. In this thesis, I have employed experimental and analytical petrological tech- niques to investigate the magmatic plumbing system of Erebus volcano. Broadly, the research is focused on volatiles (namely H2O, CO2, and S species) in the Ere- bus system: their abundances, solubilities, interactions, evolution, and ultimate contributions to degassing. Specifically, three key themes have been investigated, each employing their own experimental and analytical techniques. Firstly, the mixed volatile H2O-CO2 solubility in Erebus phonotephrite has been investigated under P-T-X conditions representative of the deep plumbing system of Erebus. Understanding the deep system is crucial because the constant supply of deeply derived CO2-rich gases combined with a sustained energy and mass input into the lava lake suggests a direct link between the phonolite lava lake and the volcano’s ultimate mantle source via a deep mafic plumbing system. Secondly, I have mapped the phase equilibria and evolution of primitive, inter- mediate, and evolved Erebus lavas. The chemistries of these experimental products span the full range of lavas on Ross Island and help to constrain magmatic evolu- tion from basanite to phonolite as well as to elucidate the geometry of the deep Ross Island plumbing system. Finally, lower-pressure experiments representing the shallow plumbing system at Erebus have been performed in order to understand the transport properties of sulfur in alkaline magma. Experiments were performed on natural Erebus basanite and phonolite, which represent the most primitive and evolved lavas from Erebus. A distinct cocktail of C-O-H-S fluid was equilibrated with each experiment, and a wide range of experimental oxygen fugacities was explored. Overall, experiments from this work are the first to place constraints on the en- tire magma plumbing system of Erebus volcano. In addition, experimental results foster a new understanding of non-ideal gas behavior at high pressure, the affinity of CO2 to deeply sourced rift magmas, and the effect of alkalis on fluid transport capabilities in melts.

The introductory part provides a relatively detailed description of andosols. It describes their classification according to WRB (2006) and under Slovak classification system (2000). Czech classification of andosol is not defined, because occurrence of these soils in Czech area was not confirmed. It is characterized andosol parent material, chemical and physical properties. There is also a chapter on extending andosol in the world and a summary of factors that influence the pedogenesis of these soils. The following section summarizes the research of volcanic and tectonic evolution of Eger Rift, which is linked to young volcanism in the country. The summary contains also a geological and geomorphological characteristics of the main young volcanic area the Czech Republic (České středohoří, Doupovské hory). To these characteristics I added another summary of Velký Roudný, because these area is by Czech soil scientists appropriate for the occurrence of andosol. We also conducted at the Velký Roudný own legwork. Literature contains a chapter devoted to current knowledge about andosol in the Czech and Slovak Republic. Describe the results of works of authors who have dealt with the issue andosol. The Czech experts that were mostly Holusa O. (2003) and Novák et al. (2010), the Slovak Balkovič (2002) and...

Instances of fault-controlled monogenetic volcanism across the subduction arc of the Central Andes at ~ 23°S illuminate the nature of different parental melts being delivered to the crust. Evidence of magmatic history is preserved in bulk rock geochemistry, the content of melt inclusions, and mineral compositions. Volcanism in this region is dominated by felsic and intermediates lavas as the thickened crust (55 – 65 km) and vast volumes (> 500,000 km3) of mid-crustal magma beneath the Altiplano-Puna high plateau region prevent mafic magmas from reaching the surface (Davidson & De Silva, 1991; Beck et al., 1996; Perkins et al., 2016). However, small volumes of relatively undifferentiated lava have been delivered from the lower crust to the surface along zones of crustal weakness without extensive processing by crustal assimilation and/or extended storage in sub-volcanic magma chambers. Monogenetic eruptions of less-differentiated lava provide important constraints on compositions normally obscured by crustal processing in the Central Andes. Basaltic andesite sampled within the frontal arc (Cerro Overo maar) is a regional mafic end-member and approximates the composition of parental arc magmas derived from partially-molten lower crustal regions where mantle-derived magmas interact with the surrounding lithosphere and undergo density differentiation (MASH zones). Basaltic olivine-hosted melt inclusions from Cerro Overo provide a glimpse of less-evolved melt composition from this region and suggest mobilization of MASH magma by injection of basaltic melt. Basaltic andesite sampled from the eastern (back) margin of the frontal arc (Puntas Negras – El Laco) is another regional mafic endmember, representing a mantle-derived magma composition that is transitional between subduction arc magmatism and intraplate magmatism of the back-arc. The internal crystal architecture revealed by major and trace element zoning of olivine phenocrysts indicates Cerro Overo magma experienced continuous ascent, while Puntas Negras magma experienced a brief period of stalling or storage near the brittle-ductile transition zone (~ 25 km). Aphyric intermediate monogenetic lavas sampled west of (before) the frontal arc display Adakite-like signatures (e.g. high Sr/Y and Sm/Yb) represent small amounts of melt generated with a significant contribution from direct melting of the metabasaltic slab or delaminated lithospheric root at high pressure. These three magmatic regimes sampled at monogenetic centers approximate different end-member compositions being delivered to the lower crust of the Central Andes from which the range of intermediate main arc volcanism in the Altiplano-Puna region is ultimately derived.

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<div>Evidence of past volcanic activity has been found on many planets and moons in our Solar System, and volcanism represents a common process that ties together the geologic history of planetary bodies. Volcanic eruptions are a unique geologic process that link the planet’s interior to the surface and the atmosphere/exosphere. A key planetary science objective described in the 2013-2022 Decadal Survey is to characterize planetary surfaces and understand their modification by geologic processes, including volcanism. The Earth, Moon, and Mars have evidence of past effusive and explosive volcanic eruptions, creating a range of volcanic edifices, landforms, flows, and pyroclastic deposits. This dissertation strives to understand the composition and eruption style of explosive volcanic deposits on the terrestrial bodies of the Earth, the Moon, and Mars. These deposits provide critical insights into the volcanic and volatile histories of the bodies and may provide in situ resources for future planetary explorers. I utilize data from orbital and laboratory spectrometers to analyze volcanic tephras across the solar system. My dissertation uses new techniques from lab studies to inform orbital spectroscopy and geomorphology comparisons of explosive volcanic deposits. By identifying glass and other igneous minerals in the visible/near-infrared and thermal infrared orbital spectra of volcanic deposits we can infer volcanic eruption style and constrain the history of explosive volcanism of planetary bodies. With remote sensing, I investigated a large and ancient volcanic complex, the Marius Hills, with significant implications for the early volcanic history of the Moon and the pyroclastic deposits of a single impact basin, Schrödinger, that has been selected as a landing site for robotic missions in 2024. This dissertation expands on the previous limited understanding of explosive vs effusive volcanism on the Moon, with the ability to further constrain eruption styles with remote sensing. The results presented in this dissertation are directly relevant to the future goals of NASA and the effort to return humans to the lunar surface and have increased the science return of lunar missions like the ISRO/NASA Moon Mineralogy Mapper. </div>

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Sediment deposited in back-arc basins preserves a record of the extensional, volcanic and tectonic history of the arc-backarc systems. Back-arc sedimentation is of particular interest as seafloor massive sulfide deposits may be preserved in back-arc basin sediments. The study of back-arc sedimentation using acoustic data, such as high-resolution sub-bottom profiling data (Parasound) and seismic reflection data, can be a much more cost effective approach than analysis of sediments recovered from drill cores. In this study, we use these two acoustic datasets to build a facies model of sedimentation in the northeast Lau Basin, an actively opening back-arc basin in the southwest Pacific Ocean. Using 830 km of Parasound and 730 km of seismic lines along 4 transects of the Lau Basin, we constructed one of the most detailed models of sedimentation in a back-arc basin to date. Parasound data show distinct echoes with sub-bottom reflections indicative of a high proportion of hemipelagic sediment, whereas the indistinct echoes with few to no sub-bottom reflections indicate a higher proportion of coarse, bedded, volcaniclastic turbidites. Hyperbolic echoes are associated with regions of rugged or uneven terrain characterized by exposed, rough basement or deposits formed by contour currents, turbidity currents, slumps or slides. These relationships form the basis of an echo-facies legend developed for typical back-arc basin sediments. The echo-facies observed in the Parasound, and confirmed by deeper-penetrating seismic reflection data, provide important insights into the sedimentary processes involved in back-arc sedimentation. We observed mass transport deposits (MTDs) in all of the sub-basins and slope deposits within and on the flanks of active rifts (e.g., the Fonualei Rift and Spreading Centre, FRSC), suggesting a direct correlation between MTDs and zones of active rifting. We observed an overall increase in sediment thickness toward the Tofua Arc which suggests it is the main sediment source, but local variations in sediment thickness suggest significant input from local intrabasinal seamounts. The uppermost echo-facies in over 60% of the sub-basins in the study area is dominated by hemipelagic material, which suggests an abrupt transition in the dominant sediment source from volcaniclastic to hemipelagic at around 0.3 Ma, when a period of volcanic quiescence from the Tofua Arc began. The study shows that a near complete record of basin evolution can be constructed using geophysical and acoustic methods and that this work may help to locate future drill sites where in situ data can be collected.

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