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Full-Text Articles in Physical Sciences and Mathematics
Origin And Geochemical Evolution Of Mafic Magmas From Mount Baker In The Northern Cascade Arc, Washington: Probes Into The Mantle And Crustal Processes, Nicole E. Moore
Origin And Geochemical Evolution Of Mafic Magmas From Mount Baker In The Northern Cascade Arc, Washington: Probes Into The Mantle And Crustal Processes, Nicole E. Moore
WWU Graduate School Collection
Five mafic lava flows located on the southern flank of Mount Baker are among the most primitive in the volcanic field. A comprehensive whole rock and mineral chemistry dataset (including major, trace, REE and isotopic abundances as well as petrography and mineral chemistry) reveals the diversity between these mafic lavas, which come from distinct sources and have been variably affected by ascent through the crust. Disequilibrium textures present in all of the lavas indicate that crustal processes have affected the magmas. Despite this evidence, mantle source characteristics have been retained, demonstrated by a lack of variation in the most highly …
Magmatic Processes In The Jurassic Bonanza Arc: Insights From The Alberni Region Of Vancouver Island, Canada, Benjamin D. (Benjamin David) Paulson
Magmatic Processes In The Jurassic Bonanza Arc: Insights From The Alberni Region Of Vancouver Island, Canada, Benjamin D. (Benjamin David) Paulson
WWU Graduate School Collection
The Early to Middle Jurassic Bonanza island arc on Vancouver Island, Canada, exposes the middle and upper crust of an ancient arc crustal section. The arc is exposed for a length of ~500 km along the west coast of Vancouver Island. The three components of the Bonanza arc represent different crustal levels of magmatism. The deepest level of magmatism is represented by the Westcoast Crystalline Complex, the intermediate level is represented by the Island Intrusions Suite, and the surficial level is the represented by Bonanza Group volcanics. Samples of the volcanic section were collected in the Pemberton Hills region of …
The Structural And Tectonic History Of The Mt. Formidable Region, North Cascades, Washington, Julia E. (Julia Eileen) Labadie
The Structural And Tectonic History Of The Mt. Formidable Region, North Cascades, Washington, Julia E. (Julia Eileen) Labadie
WWU Graduate School Collection
Deformation events associated with crustal thickening are preserved in the Mt. Formidable region of the North Cascades, a Cretaceous orogen and continental arc at the southern end of the Coast Plutonic Complex. The kinematics and timing of deformation in this area during burial, magmatism and metamorphism are the focus of this study. Rocks in the Mt. Formidable region span from at least the Late Triassic to the Early Cretaceous and include supracrustal units and associated metaplutonic rocks that have been interpreted as an island arc sequence. Rocks within the study region include the sub-arc Marblemount Meta-Quartz Diorite, the supra-arc metaclastic …
Modeling The Effects Of Climate Change Forecasts On Streamflow In The Nooksack River Basin, Susan E. Dickerson
Modeling The Effects Of Climate Change Forecasts On Streamflow In The Nooksack River Basin, Susan E. Dickerson
WWU Graduate School Collection
The Nooksack River has its headwaters in the North Cascade Mountains and drains an approximately 2300 km2 watershed in northwestern Washington State. The timing and magnitude of streamflow in a high relief, snow-dominated drainage basin such as the Nooksack River basin is strongly influenced by temperature and precipitation. Forecasts of future climate made by general circulation models (GCMs) predict increases in temperature and variable changes to precipitation in western Washington, which will affect streamflow, snowpack, and glaciers in the Nooksack River basin. Anticipating the response of the river to climate change is crucial for water resources planning because municipalities, tribes, …
Development Of A New Method For Measuring Metamorphic Kinetics, Jennifer B. (Jennifer Bernadette) Wright
Development Of A New Method For Measuring Metamorphic Kinetics, Jennifer B. (Jennifer Bernadette) Wright
WWU Graduate School Collection
Because garnet strongly fractionates Mn, spessartine (XSps) content can be treated as a rock-wide proxy for time. By using Sm-Nd isotopic dating to discretely date cores and rims of garnet crystals, I associated an age with a XSps content, and used this association to indirectly date a set of garnets in a subvolume from the specimen, a Grt-Chl-Pg-Bt-Ms schist from the Pinney Hollow Formation collected at Townshend Dam, VT. Using high-resolution X-ray computed tomographic data, two garnets were selected based on size and accessibility for Sm-Nd dating. These garnets yielded rim ages of 372.8±5.7 Ma and 372.8±4.0 Ma (2σ); EPMA …
Kink Band Development In The Darrington Phyllite On Samish Island, Northwestern Washington, Rachel E. (Rachel Eliades) Dunham
Kink Band Development In The Darrington Phyllite On Samish Island, Northwestern Washington, Rachel E. (Rachel Eliades) Dunham
WWU Graduate School Collection
Kink bands are sharp-hinged monoclinal folds that are common contractional deformation features in fine-grained, foliated rocks. Two competing geometric models of kink band formation are mobile-hinge kinking, where a kink band grows by lateral expansion of kink band hinges, and fixed-hinge kinking, where a kink band initiates at a given width and rotates to accommodate shortening. This study investigates previously identified but poorly characterized kink bands in the Darrington Phyllite on Samish Island, northwestern Washington, in order to evaluate the applicability of each model and to characterize the complex geometries of kink bands in plan view. Two sets of kink …
Naturally Occurring Aqueous Arsenic And Seawater Intrusion On Lummi Island, Wa, Erica Martell
Naturally Occurring Aqueous Arsenic And Seawater Intrusion On Lummi Island, Wa, Erica Martell
WWU Graduate School Collection
Two different types of groundwater contamination may be present in the aquifers on northern Lummi Island, Washington: naturally occurring arsenic and seawater intrusion. Freshwater on northern Lummi Island is stored in bedrock and unconsolidated glacial sediments. The naturally occurring arsenic, sourced from an undetermined stratigraphic layer, varies spatially throughout the island. Additionally, seawater may be intruding into the groundwater supply, which is the primary source of drinking water for the residents of the island. The process of mobilization of the naturally occurring arsenic and the extent of the seawater intrusion has not been fully explored. The purpose of my study …
Paleomagnetism And Rock Magnetism Of Remagnetized Carbonate Rocks From The Helena Salient, Southwest Montana, Benjamin F. (Benjamin Franklin) Baugh
Paleomagnetism And Rock Magnetism Of Remagnetized Carbonate Rocks From The Helena Salient, Southwest Montana, Benjamin F. (Benjamin Franklin) Baugh
WWU Graduate School Collection
The Helena salient is an arcuate curve in the southwest Montana fold and thrust belt, characterized by thin-skinned folding and thrusting. Ages from volcanic sills imply that deformation in the region began 77 million years ago during the Late Cretaceous (Harlan et al., 2008). This study investigates the nature of curvature associated with this salient using paleomagnetic techniques. Carbonate rocks of the Mississippian Madison Group were sampled from 24 sites across three folds: the Devil's Fence anticline, the Three Forks anticline and the Turner anticline (near Townsend, MT). Results from 16 sites have well defined, but very weak, magnetizations. At …