In eastern Washington and western Oregon, southwest-northeast striking thrust faults and folds of the Yakima Fold and Thrust Belt (YFTB) and northwest-striking dextral strike-slip faults accommodate north-south contraction resulting from clockwise rotation of the North American Plate. Though present to the east and west of the Cascade Range, the connectivity...
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....
In this study, 3D finite difference and 2D finite element forward modeling were used to create an electromagnetic sensitivity analysis for the Cotopaxi volcano in Ecuador. Magnetotellurics (MT) is a natural-source electromagnetic geophysical technique that images electrical conductivity. Measuring strong contrasts in electrical conductivity in volcanic materials allows for the...
Studies reveal differences in slip segmentation and plate coupling along the Cascadia subduction zone. The segment between 44.0°N and 45.0°N exhibited reduced slip in the 1700 megathrust earthquake (Wang et al., 2013) and corresponds with previous rupture boundaries inferred from paleoseismic data (Leonard et al., 2010). Notably, this segment of...
Changes in the stable carbon isotope composition of carbonate rocks (𝛿13Ccarb) are used to establish the relative temporal framework for geological events, such as evolutionary extinction or radiation, between two or more locations. As every local stratigraphic record is intermittent, aligning 𝛿13Ccarb records from two or more locations, a process...
Oregon’s foredunes are part of a dynamic coastal environment that constantly evolves in response to both ecological and physical forces. Invasive beachgrasses have outcompeted native dune grass in the region and have influenced the shape of Oregon’s foredunes via species-specific biophysical feedback mechanisms. As climate change induced sea-level rise will...
Rates of sediment transport were determined using tracer gravel and a RFID antenna array at Oak Creek (Oregon) to compare a new method with an existing transport relation created from data previously collected in the same study reach. Close to 3,000 tracers were deployed throughout the study reach and were...
This research presents a u-channel based study of the natural remanent magnetization (NRM), the laboratory magnetization, Anhysteretic Remanent Magnetization (ARM), and magnetic susceptibility (k), from the upper 100 m of International Ocean Discovery Program (IODP) Expedition 383 Site U1543 in the eastern South Pacific sector of the Southern Ocean. Alternating...
Magmatic-hydrothermal ore deposits are giant geochemical anomalies in the earth’s crust most often generated by normal magmatic terrestrial processes. They are often associated with oxidized and hydrous intermediate to highly evolved magmas that have concentrated metals and have the necessary components to efficiently extract and transport them as ascending magmatic-hydrothermal...
The ~5 km3, 4.54 to 4.09 Ma Caspana Ignimbrite of the Altiplano-Puna Volcanic Complex (APVC) of the Central Andes records the eruption of an andesite and two distinct rhyolitic magmas. It provides a unique opportunity to investigate the production of silicic magmas in a continental arc flare-up, where small volumes...