Physical Sciences and Mathematics Commons^™

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 …

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 …

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.

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 …

Petrology And Major Element Geochemistry Of Albite Granite Near Sparta, Oregon, Robert Brayton Almy Iii

WWU Graduate School Collection

Albite granite near Sparta, Oregon occurs in an igneous complex containing serpentinite, gabbro, diorite, tonalite and granite with overlying keratophyric and spilitic volcanic rocks. This igneous suite is overlain by Triassic limestones of reef origin. In all the igneous rocks primary hypidiomorphic and porphyritic textures predominate but a metamorphic overprint of the prehnite-pumpellyite facies is widespread. Whole rock chemical analyses show that albite granite has relatively high Si0₂ (69-81%) and Na₂0 (4-7%) and low K₂O (0.1-1%). Rare plagioclase potassium-feldspar granite contains up to 3.6% K₂O.

Although local isochemical alteration is demonstrable and local …

Geology And Mineral Deposits Of The Southwest Quarter Of The Tanacross D-1 Quadrangle, Alaska, Roger Douglas Gill

WWU Graduate School Collection

The study area is in the northeast corner of the Tanacross quadrangle, east-central Alaska. Known as the Interior Porphyry belt, it lies between the Tintina fault to the north and the Denali fault to the south. Seven major porphyry copper-type deposits have been found within the belt since I969. Because much of the belt was unglaciated during Pleistocene time, the probability of finding a zone of supergene enrichment is enhanced. In Alaska a porphyry copper-type deposit with a supergene zone may improve the current economic status by helping to facilitate amortization of production capital costs.

The rocks within the study …

Petrology Of The Crystalline Rocks Of Vedder Mountain, British Columbia, Mitchell L. Bernardi

WWU Graduate School Collection

Vedder Mountain lies in Washington state and British Columbia on the western flank of the North Cascades. Metamorphic rocks, which comprise most of the western half of the mountain, can be divided into two separate and distinct units. The southern unit is composed of foliated and non-foliated hornblende-plagioclase gabbro with minor serpentinite and pyroxenite. Most of the gabbroic rocks are sheared and altered and exhibit a lower greenschist facies metamorphism overprinted by a subsequent prehnite-pumpellyite facies metamorphism. Whole-rock chemical analyses of the gabbros plot in and near the fields defined by oceanic gabbro (Engel and Fisher, 1969; Miyashiro et al, …

Volcanology And Geochemistry Of The South Flank Of Mount Baker, Cascade Range, Washington, Douglas Mckeever

WWU Graduate School Collection

Major element chemical analysis of 97 rocks from the south side of Mount Baker was performed by energy dispersive x-ray fluorescence. Conclusions based on chemistry are:

1) Variation diagrams based on a large number of samples show that variation is not continuous nor, in general, smooth. Rocks from two major stratigraphic positions exhibit compositional coherency within each group and are interpreted as eruptive groups which were extruded over time intervals which were short compared to the lifetime of the volcanic center. The older of the two groups is called the Park Butte phase, and the younger is the Koma Kulshan …

Paleomagnetism Of The San Juan Volcanic Field, Southwestern Colorado, Steven Douglas Sheriff

WWU Graduate School Collection

Geologic Setting

The San Juan volcanic field of southwestern Colorado consists of 2.5 X 10⁴ km² of volcanic rocks ranging in age from early Oligocene to Pliocene. Major volcanic activity in the San Juan field began about 35 million years ago with widespread eruption of rhyodacitic to andesitic lavas from scattered volcanic centers (Lipman and others, 1970). This type of volcanism peaked about 33 million years ago and then began to decline. About 30 million years ago, volcanic activity once again increased in the area. This time the eruptions were ash flows of intermediate to felsic composition. The …

Geology Of The Older Precambrian Rocks In The Vicinity Of Clear Creek And Zoroaster Canyon, Grand Canyon, Arizona, William S. Lingley Jr.

WWU Graduate School Collection

The Clear Creek-Zoroaster Canyon area is located in the east- central section of the Bright Angel Quadrangle (Maxson, 1968) roughly seven miles east northeast of Grand Canyon Village, Arizona. The boundaries of the present study area are shown in Figure 1. The study area extends from Mile 83.7 to Mile 86 on the Colorado River below Lee's Ferry, Arizona.

Older Precambrian rocks are exposed along the Inner Gorge of the Colorado River. They also crop out at Zoroaster Canyon, Clear Creek, and Cremation Creek. There are over 450 m of vertical exposure. Many outcrops are inaccessible due to steepness of …

Paleomagnetism Of Late Pleistocene Sediments, Puget Lowland, Washington, Kurt L. Othberg

WWU Graduate School Collection

Establishment of late Pleistocene geomagnetic polarity events would provide useful time indices for regional and interregional stratigraphic correlations. Development of a geomagnetic polarity scale tied to radiocarbon dating for the Puget Lowland helps to elucidate the possible occurrence of world-wide (dipole) reversed events during the last 50,000 years. Stability and reliability tests indicate that late Pleistocene sediments exposed in the Puget Lowland record valid paleomagnetic directions. Puget Lowland geomagnetic polarity for the interval 11,000 years to 30,000 years BP was normal except for a short reversed period between 20,000 years and 15,000 years BP. In addition to sampling errors and …

Petrogenesis Of The Granitic Rocks Of Part Of The Upper Granite Gorge, Grand Canyon, Arizona, Michael B. Walen

WWU Graduate School Collection

The study area extends from Phantom Creek to Crystal Creek, a distance of approximately 10 miles along the Colorado River. The units exposed are the Precambrian Vishnu Schist granitic to granodioritic units in Phantom Canyon, Trinity Canyon, and near Crystal Creek, and pegmatites and aplites. The Vishnu Schist is composed mostly of quartzo-feldspathic schists. The assemblage quartz-oligoclase-muscovite-biotite-sillimanite-K-feldspar indicates metamorphic conditions in the upper amphibolite facies between Phantom Creek and Mile 95. Between Mile 95 and Crystal Creek, assemblages indicate lower amphibolite to greenschist facies conditions.

The Phantom Granitic Complex consists of granodioritic and quartz monzonitic units. The presence of a …

A Paleomagnetic Reconnaissance Of The Platoro Caldera, Southeastern San Juan Mountains, Colorado, Jimmy F. Diehl

WWU Graduate School Collection

Paleomagnetic results have been obtained from twenty-five sites in intrusive and extrusive units of Oligocene age from the Platoro caldera, southwestern Colorado, All specimens from each site were subjected to af demagnetization, and the reliability of each site thereby determined. Eighteen sites gave reliable results. Because six sites from the La Jara Canyon tuff appear to have become magnetized during the same small interval of geologic time, their results were combined and their mean pole and direction used in the final calculations. The thirteen remaining reliable sites yielded a paleomagnetic pole at 84.5°N and 306.5°E (o< = 12.9°, k = 11.2). Site-mean directions have an angular standard deviation of 18°, which is considerably greater than the dispersion predicted by models based on the present geomagnetic field but consistent with results from Late Tertiary and Quaternary studies. Because site-mean directions and site poles both have Fisherian distribution, it is not possible to determine whether dipole wobble or random fluctuation caused by a changing non-dipole field could be the cause of the geomagnetic secular variation during the Oligocene; probably both contribute. Interpretations based on mid-Tertiary paleomagnetic poles are consistent with those derived from sea-floor magnetic anomaly patterns, and possibly indicate that some true polar wandering has occurred since the mid-Tertiary, Due to lack of resolution in potassium-argon dating, the polarity time-scale constructed from the Platoro caldera units can only be used as a guide for future paleomagnetic work and geological mapping in the area.

Paleomagnetism Of The Snoqualmie Batholith Central Cascades, Washington, Suzanne J. Beske

WWU Graduate School Collection

Paleomagnetic results have been obtained from eight sites in the Miocene (15-18 m.y.) Snoqualmie batholith, Central Cascades, Washington. After ac magnetic cleaning, four magnetically stable sites remained, yielding a pole at 221.0°E, 84.5°N, (δ_p = 7.9, δ_m = 9.3, k = 286.4). A stability test was formulated based on the ratio of the intensity of natural remanent magnetism, NRM, (after ac demagnetization) to the weak field susceptibility. This ratio, Q_d proved effective in determining magnetically stable samples from samples showing a wide spectrum of stability from within the Snoqualmie batholith, and therefore, was strictly applied to all …

A Sedimentary Core Analysis Of Late Pleistocene To Recent Sediments In A Portion Of Bellingham Bay, Washington, James T. Lowe

WWU Graduate School Collection

Sub-bottom profiles and core sampling indicate that a trough-like depression below the bay near South Bellingham is a Pleistocene erosional paleotopographic surface sloping bayward from the uplandds to the east. A series of Late Pleistocene glacial till and glaciomarine deposits overlie the erosional surface and fill the depression. The glacial deposits are overlain by Recent sand and mud deposits which are rich in wood fragments and shell materials.

Bellingham Bay is basin-shaped with a deep narrow trough to the west. The Pleistocene basement is generally structureless and conforms to the bay bottom. Several trough shaped depressions which are overlain by …

Clay Mineralogy Of Late Pleistocene Sequences In Northwestern Washington And Southwestern British Columbia, Michael Arthur Hepp

WWU Graduate School Collection

Pleistocene clay-bearing sediments of parts of northwestern Wash­ington and southwestern British Coliambia were studied in an attempt to determine the clay mineral composition of these units; the origin of these clay minerals; and any correlation between clay mineral composi­tion, sediment type, location, or probable geologic history of the sediments. The Pleistocene stratigraphy of the area is fairly well known, although in some specific locations the stratigraphy has not been determined. Recorded work in the region dates back to Dawson (1887). The units studied range in age from the greater than 50,000 year old Double Bluff Drift to Holocene (Recent) river …

Biostratigraphy Of The Bilk Limestone (Permian), Northwestern Nevada, Erich Thomas

WWU Graduate School Collection

The Bilk Limestone (new manuscript name) described in this report is a carbonate sequence located in the Bilk Creek Mountains at the southernmost end of the Kings River Range (fig. 1), about 30 miles south of the town Denio in north-central Humboldt County, Nevada. This study investigates the biostratigraphy and general paleoecology of about 2900 feet of limestone of early to middle Permian (middle Wolfcampian to middle Leonardian) age. The limestone is interbedded with nodular chert and is considerably altered by faulting and fracturing with associated epigenetic dolomitization. The fossil content is varied, and in this report stress is placed …