Silicic volcanism in the central Oregon Cascade range has decreased in both the size and frequency of eruptions from its initiation at ~40 Ma to present. The reasons for this reduction in silicic volcanism are poorly constrained. Studies of the petrogenesis of these magmas have the potential for addressing this...
Recent geophysical and geological investigations of the Tibetan plateau have given rise to conflicting models of plateau growth and deformation, where the presence and extent of partial melt in the crust could be a determining factor. Here we investigate the attenuation structure of the crust and upper mantle, as attenuation...
This thesis presents a detailed seismotectonic investigation of the Himalayan region and the Tibetan plateau as part of project HiCLIMB to explore the state of stress and the kinematics of the world’s largest continental collision zone. Using full regional waveforms for moment tensor inversion, source parameters for 107 earthquakes were...
The dense Corvallis array deployed in January of 2022 aided in the high-resolution study of local geology. This array was made of 177 SmartSolo 3-component 5 Hz geophones around Corvallis, with a 93 geophone profile going west towards Bald Hill for approximately 5 km at an average of 64 m...
Three broadly interrelated problems of critical significance to the proper interpretation of melt inclusion (MI) data are addressed in this thesis. The first issue, the petrogenesis of anorthitic plagioclase phenocrysts in MORB lavas, has relevance due to the presence of numerous MI in many high-An feldspars. This problem was addressed...
3D laser scanning has been used extensively in engineering reconnaissance surveys to capture perishable data in an efficient, reliable, and precise manner. Many insights on damage can be obtained from the data through various methods of post-processing; however, many of these techniques are often labor intensive. This delay reduces the...
Since 2003, 39 small earthquakes have been detected offshore central Oregon in the nominally locked part of the Cascadia subduction zone, where very little seis- mic activity has been recorded in spite of a paleo-seismic record of great subduction events. Although the regional earthquake bulletin reports depths of 29 and...
During the Late Pre-Hispanic period, settlements in Northern Highland Ecuador were organized under a number of chiefdoms. While a basic hierarchical political system is described in the ethnohistoric literature, the nature of the interactions between specific settlements has remained unknown. This study utilizes two methods for describing the degree and...
Heat flow analysis of the Costa Rica convergent margin is carried out for seven core sites drilled during Integrated Ocean Drilling Program (IODP) Expeditions 334 and 344 as part of the Costa Rica Seismogenesis Project (CRISP). These expeditions were designed to develop a better understanding of erosional subduction zones. Heat...
The Botija Cu-Mo-Au porphyry deposit is located in the Cobre Panamá mining district, which contains several deposits with a global measure and indicated and inferred resource of 14.8 MT of Cu. These deposits are associated with the Cerro Petaquilla batholith, which has U/Pb zircon ages of 26-33 Ma (Whattam et...