Studies of Hawaiian volcanoes contribute valuable insights about Earth processes and mantle evolution, and are fundamental for understanding the construction of the largest volcanoes on terrestrial planets. The pre-shield stage exists in every Hawaiian volcano, but is usually blanketed by high volume tholeiitic lava flows during the main shield stage....
Large silicic magmatic systems are responsible for producing the largest explosive volcanic eruptions on earth. These phenomena, although infrequent (i.e., 1 per 100,000 years), impact the global climate, deposit ash over continent sized regions, and significantly alter landscapes. Silicic magmatism also plays important roles in the formation and ongoing evolution...
Silicic caldera-forming eruptions are some of the largest and most destructive volcanic eruptions known, and present significant local and global hazards. The underlying processes within crustal magma plumbing systems that lead to the accumulation and eruption of large volumes of evolved magma remain enigmatic, yet there is broad consensus that...
Western Saudi Arabia hosts a number of young volcanic fields, known as “Harrats”. Harrats cover a significant proportion of western Saudi Arabia and are associated with significant volcanic hazards. However, the ultimate cause of volcanic activity remains unclear. Younger volcanism (<12 Ma) is clearly represented by the north-south-trending region known...
Cinder cones are useful geomorphic features for geological analysis because they generally have known initial states and follow a similar pattern of degradation as they are exposed to erosive processes. This is largely because cinder cones are produced by monogenetic eruptions. Characterizing large cinder cone fields in terms of age...
The eruptive history of the Quaternary Cascades arc has been relatively well characterized. However, much less is known about the frequency and sizes of explosive eruptions produced by earlier stages of the arc. The Late Neogene Deschutes Formation of Central Oregon preserves a remarkable record of heightened pyroclastic activity during...
In volcanic systems, magma is generally stored in the shallow crust prior to eruption. The conditions of this storage directly impact whether the magma eventually erupts, or crystallizes within the crust to form a pluton. In this dissertation I present four studies that investigate the storage conditions of a number...
Supervolcanic eruptions are among the most catastrophic phenomena on Earth,
erupting 100s-1000s of cubic kilometers of magma, and producing devastating local effects and global climate perturbations. The largest supervolcanic eruption of the last 28 Ma was the 74 ka Youngest Toba Tuff (YTT) eruption from Sumatra, Indonesia, which erupted 2,800...
This study is an effort to characterize the magma sources, plumbing system, and eruptive behavior of Mount Hood, a low-explosivity recharge-dominated volcano in the Oregon Cascades. The three manuscripts in this dissertation make use of melt inclusion data, phenocryst compositions, and whole rock petrology and geochemistry to build a schematic...
This dissertation combines volcanological research of three convergent continental margins. Chapters
1 and 5 are general introductions and conclusions, respectively. Chapter 2 examines the spatiotemporal
development of the Altiplano-Puna volcanic complex in the Lípez region of southwest Bolivia, a locus of a
major Neogene ignimbrite flare- up, yet the least...