Physical Sciences and Mathematics Commons^™

The Origin Of Serpentinites Associated With The Shuksan Metamorphic Suite Near Gee Point, Washington, Daniel L. Wilson

WWU Graduate School Collection

Metavolcanic and metasedimentary rocks of the Shuksan Metamorphic Suite near Gee Point have been contact metamorphosed by high-temperature emplacement of ultramafic rock. This intrusion occurred at great depth (>25 km) and caused contact temperatures of about 500°C, resulting in epidote-amphibolite facies metamorphism. Minerals of the contact metamorphism are overprinted by mineral assemblages of the regional Shuksan blueschist facies metamorphism. The K/Ar age of the epidote-amphibolites is Jurassic (145-160 m.y.), and thus the age of Shuksan metamorphism is probably younger than Middle Jurassic.

Ultramafic rocks found near Gee Point have been metamorphosed to serpentinites during Shuksan metamorphism and should be …

Coal Petrology Of The Tulameen Coalfield, South Central British Columbia, V. Eileen Williams

WWU Graduate School Collection

The Tulameen Coalfield lies in a small, southeast plunging syncline in the Intermontane Belt of the Canadian Cordillera in south central British Columbia. The coal is interbedded with fluvial and lacustrine sediments of the Eocene Allenby Formation of the Princeton Group. The abundance of tephra and bentonite indicates volcanic activity was contemporaneous with coal and sediment deposition.

Although coal occurs on both sides of the basin, its economic importance is currently restricted to a 15-21 meter thick coal seam on the southwestern limb of the syncline. The coal is predominantly vitrain and clarain composed of greater than 90 percent vitrinite. …

Paleomagnetism And Tectonic Significance Of The Goble Volcanics Of Southern Washington, Cynthia D. Burr

WWU Graduate School Collection

The upper Eocene to lower Oligocene Goble Volcanic series of southwest Washington is a thick sequence of areal to submarine basaltic to andesitic flows, pyroclastics, and minor sediments. Major element geochemical analyses suggest that these rocks may represent early magmatism of the Cascade arc. Paleomagnetic results from 37 sites indicate that the direction of remanent magnetization in the Goble Volcanics has a declination of 18.5°, an inclination of 57.5°, and a circle of 95% confidence (∝ ₉₅)of 4.33°. The expected upper Eocene direction in the sampling area is D = 353.5°; Ī = 61.5°. Thus the Goble Volcanics block …

Stratigraphy And Chronology Of Raised Marine Terraces, Bay View Ridge, Skagit County, Washington, Robert T. Siegfried

WWU Graduate School Collection

The evidence presented suggests that terraces and related features found on Bay View Ridge, Skagit County, Washington are raised marine in origin, and formed 13,000 - 11,000 years before present during the Everson Interstade of the Fraser Glaciation. Methods of investigation included topographic profiling, geologic mapping of surface deposits, identifying primary sedimentary structures, grain-size distribution analyses, identifying textural surface features on quartz grains utilizing the Scanning Electron Microscope and radiocarbon age dating.

Little or no measurable differential vertical tectonic and/or glacio-isostatic relative movement has occurred at Bay View Ridge since the Everson Interstade. Volcanic ash found in two peat bogs …

The Geology Of Southwestern Fidalgo Island, Daryl Gusey

WWU Graduate School Collection

Detailed geologic mapping of rocks in the upper stratigraphic levels of the Fidalgo ophiolite Indicates that keratophyres and spilites are interbedded with tuffaceous sediments, sedimentary breccias, and graywacke. Sedimentary breccias containing plutonlc rock fragments as well as volcanic rock fragments are common. The graywackes were derived from a volcanic source area. Radiolaria In the tuffaceous sediments indicate a depositional age of Lower Kimmeridgian to Upper Valanginian.

Compared to the stratigraphy and petrology of other ophiolites and present-day tectonic environments, the Fidalgo Complex most closely resembles that of ancient and modern island-arc sequences.

Clay Mineralogy And Origin Of The Huntingdon Fire Clays On Canadian Sumas Mountain, South British Columbia, Duane G. Horton

WWU Graduate School Collection

Three fire clay seams occur near the base of the Eocene Huntingdon formation at Canadian Sumas Mountain, southwest British Columbia. The three seams are separated from each other and overlain by coal partings.

The fire clays consist predominately of b-axis disordered kaolinite with minor amounts of quartz, detrital coal and x-ray amorphous iron oxides. They contain scant amounts of anatase, siderite, illite, and expandable clays. Expandable clays are concentrated in the fine clay fractions and illite is concentrated in the coarse clay fractions.

The lowermost fire clay seam contains better ordered kaolinite and fewer non-kaolinitic minerals than do the overlying …

Shoreline Processes And Sediment Responses Related To The Origin Of Beach Cusps On Whidbey And Fidalgo Islands, Washington, John V. Spasari

WWU Graduate School Collection

Beach cusps are rhythmically spaced, crescentic beach features which consist of cusp shaped seaward pointing depositional ridges or mounds, often referred to as horns, separated by concave seaward troughs or bays. They have longshore spacings that vary from a few centimeters up to 25 meters. The purpose of the project was to conduct a field investigation of the shoreline processes and sediment responses associated with beach cusp formation on Whidbey and Fidalgo Islands, Washington. Despite the many theories published in the literature for the origin of beach cusps, many of which are contradictory, there were only two theories proposed that …