There is a lack of consensus regarding the roles of sulfide saturation versus volatile degassing on the partitioning of Cu and Ag during differentiation and eruption of convergent margin magmas. Because of their oxidized character, volatile-rich magmas from the Eastern Manus Back-arc Basin (EMBB) only reach sulfide saturation following magnetite-driven...
Altar (31º 29’ S, 70º 28’ W) is a large porphyry Cu-(Au-Mo) deposit with associated
epithermal Au-(Ag-Cu) veins located in the Cordillera Principal of SW San Juan Province
(Argentina). Altar is a complex magmatic-hydrothermal system formed from several
magmatic and hydrothermal pulses during the middle-late Miocene. New LA-ICPMS U-Pb
ages...
Clark volcano of the Kermadec arc, northeast of New Zealand, is a large stratovolcano comprised of two coalescing volcanic cones; an apparently younger, more coherent, twin-peaked edifice to the northwest and a relatively older, more degraded and tectonized cone to the southeast. High-resolution water column surveys show an active hydrothermal...
This dissertation is informally divided into three major sections. In the first section (Chapter 2) I use data from field mapping, isotopic geochronology, whole rock geochemistry and trace element concentrations in zircons to examine the petrology, geochemistry and ages of the Haquira East porphyry copper deposit of southern Peru. In...
Environmental archives provide records of natural and anthropogenic variation in the environment at different temporal and spatial scales. Lead (Pb) concentrations and isotopic ratios are useful tracers of anthropogenic emissions from industrial activities including mining, smelting, and leaded gasoline use, however, methods of measuring Pb are largely limited in low...
The spatial distribution and geologic histories of submarine volcanoes provide insight into submarine eruptive behavior, deep earth processes and plate tectonics. This dissertation examines the evolution of individual submarine volcanic edifices as well as linear trails of seamounts at three spatial and temporal scales.
In order to understand constructive and...
The imposing andesite stratovolcano is the characteristic expression of subduction zone magmatism, posing hazards to coastal populations and bearing insight into deep Earth processes. On a map of a typical volcanic arc, one can easily distinguish the approximately linear alignment and regular spacing of these major edifices that stand out...
Accurate methods are needed to measure changing soil water content from meter to kilometer scales. Laboratory results demonstrate the feasibility of the heat pulse method implemented with fiber optic temperature sensing to obtain accurate distributed measurements of soil water content. A fiber optic cable with an electrically conductive armoring was...
Power can be defined as the ability to influence the processes, decisions, and outcomes of an activity in favor of the will of a strong actor and its allies. Strategic actions in situations where there is asymmetric power can change the result of decisions. In this research, I will examine...
Retreat of glacier ice from Nares Strait and other straits in the Canadian Arctic Archipelago after the end of the last Ice Age initiated an important connection between the Arctic and the North Atlantic Oceans, allowing development of modern ocean circulation in Baffin Bay and the Labrador Sea. As low-salinity,...