Physical Sciences and Mathematics Commons^™

Grain Size Variability Spanning The Paleocene-Eocene Thermal Maximum In Laramide Basins: Reconstructing Paleoslopes And Overbank Erodibility, Delaney Todd

WWU Graduate School Collection

The Paleocene-Eocene Thermal Maximum (PETM) is an extensively studied global warming event occurring approximately 56 Ma and lasting around 200 kyr. Marked by a negative ¹³C excursion from a massive influx of CO₂ to the atmosphere, the PETM caused environmental alterations including increases in global temperature, changes in hydrology and ocean chemistry, and floral and faunal overturns. Evidence of these alterations during the PETM is found within both marine and continental basins. During the early Paleogene, the Laramide Orogeny formed a series of nonmarine basins within the Western Interior of the United States. Three of these basins, the …

Marine Ecosystem Response To Late Pleistocene Rapid Climate Change In The Salish Sea, Alex Victor Hernandez

WWU Graduate School Collection

The ecologic response of marine invertebrates during collapse of the Cordilleran Ice-sheet through the Late Pleistocene has been insufficiently studied across the lowlands of northwestern Washington State and southern Fraser Valley, British Columbia. Assessment of the response of these nearshore marine assemblages to climatic shifts will improve our understanding of closely related modern taxa in analogous climate-stressed conditions. If we understand the former vulnerability of related genera, meaningful predictions may thus be provided for extant taxa in current and future time. In this thesis, I establish a compilation dataset of all relevant specimens collected within the Salish Sea and Puget …

Martian Spectroscopy: Laboratory Calibration Of The Perseverance Rover’S Mastcam-Z And Photometric Investigation Of Mars-Analog Ferric-Coated Sand, Kristiana Lapo

WWU Graduate School Collection

The Mars 2020 rover Perseverance will search for signs of past habitability and biosignatures after landing in Jezero Crater in February 2021. Spectroscopy is a vital tool for planetary remote sensing and Perseverance is equipped with Mastcam-Z, a stereoscopic, zoom-enabled, multispectral imager that can acquire true color images with red, green, and blue (RGB) color filters, and visible- to near-infrared images with 12 narrowband science filters between 400 and 1100 nm. Mastcam-Z will provide operational support for the rover as well as directly contribute to Perseverance’s geologic investigations. Given the integral role of Mastcam-Z in the Mars 2020 mission, calibration …

Provenance Of Early Paleogene Strata In The Bighorn Basin (Wyoming, U.S.A.): Implications For Laramide Tectonism And Basin-Scale Stratigraphic Patterns, Jessica L. Welch

WWU Graduate School Collection

The Bighorn Basin (Wyoming, U.S.A.) contains some of the best exposed and studied nonmarine early Paleogene strata. Over a century of research has produced a highly resolved record of early Paleogene terrestrial climatic and biotic change as well as extensive documentation of spatiotemporal variability in basin-scale stratigraphy. The basin also offers the opportunity to integrate these data with the uplift and erosional history of the Laramide uplifts that surround the Bighorn Basin. Herein we provide a comprehensive provenance analysis of the early Paleogene Fort Union and Willwood formations in the Bighorn Basin from paleocurrent measurements (n = 510 measurements), detrital …

Floodplain Response To Eocene Thermal Maximum 2 In The Southern Bighorn Basin, Wyoming, U.S.A., Eve Lalor

WWU Graduate School Collection

Paleosols in the Willwood Formation of the Bighorn Basin, Wyoming contain a sedimentary and geochemical record of several early Eocene hyperthermal (rapid, global warming) events including the Paleocene-Eocene Thermal Maximum (PETM) and the Eocene Thermal Maximum 2 (ETM2). Numerous studies of the PETM indicate environmental shifts including an overall decrease in precipitation and soil moisture, but the hydrologic response to the subsequent smaller Eocene hyperthermals remains poorly understood. In order to estimate potential precipitation changes during ETM2, I sampled floodplain paleosol horizons from Willwood Formation strata below, within, and above the stratigraphic carbon isotope excursion (CIE) that marks the ETM2. …

Reidentifying Sources Of Tephra In The Izu-Bonin Arc: Recognizing Recent Rear-Arc Volcanism 1.1 – 2.7 Ma, Cassandra King

WWU Graduate School Collection

The focus of volcanic activity in the Izu-Bonin arc has migrated across the arc over time, creating distinct across-arc geochemical regions including the arc front, rift region, and the rear arc seamount chains (RASC). This study challenges the previously held assumptions that the rear arc was inactive after 2.8 Ma and that tephra deposited in the arc younger than 2.8 Ma with K₂O > 1 wt.% and La/Yb > 2.2 was sourced from the SW Japan arc. I studied 1.1 - 2.7 Ma tephra retrieved from core from the rear arc at Site U1437, IODP Expedition 350, in order to …

Evaluating Thresholds In Fluvial Response To The Eocene Thermal Maximum 2 In The Bighorn Basin (Wyoming, U.S.A), Grace Marie Sutherland

WWU Graduate School Collection

Earth's climate experienced a set of hyperthermal events during the greenhouse climate state of the early Paleogene. The Paleocene-Eocene Thermal Maximum (PETM) was the largest of these abrupt global warming events, occurring at ~56 Ma and lasting for ~200,000 years. The PETM is identifiable by a large negative carbon isotope excursion and associated with significant changes in global temperature, hydrology, ocean chemistry, and biology. Subsequent smaller hyperthermal events appear to have commensurately smaller effects on marine environments, but the scaling of the complementary nonmarine environmental responses is unclear.

The Bighorn Basin of northwest Wyoming contains the most detailed nonmarine record …

Revaluating The Use Of Mollusks For Estimating Paleodepth In The Pacific Northwest, E Worthington

WWU Graduate School Collection

Fossil records have the potential to extract important paleoenvironmental records, and by ground truthing our assumptions with modern mollusks we can improve our interpretations of the fossil record. Modern molluscan death assemblages from Rosario Strait were analyzed to: 1) determine to what extent the molluscan communities were controlled by grain size or depth; and 2) determine the extent to which age mixing was occurring in the death assemblage. Twenty-eight Van Veen grab samples were collected in Rosario Strait to represent range of depth and grain sizes. All samples were wet sieved to isolate mature mollusks (> 2.00 mm), and sediment …