Physical Sciences and Mathematics Commons^™

A Paleomagnetic Age Investigation Of Pre-Salmon Springs Drift Pleistocene Deposits In The Southern Puget Lowland, Washington, John L. (John Leo) Roland

WWU Graduate School Collection

The Pleistocene history of the southern Puget Lowland is marked by repeated invasions by the Puget Lobe of the Cordilleran ice sheet. The present stratigraphic sequence is represented by four glaciations (Orting, Stuck, Salmon Springs, and Fraser) of northern provenance, separated by unconformities and two nonglacial formations (Alderton and Puyallup) of central Cascade and Mount Rainier provenances. Paleomagnetic work conducted on pre-Salmon Springs sediments at their type localities and correlative exposures in the Puyallup Valley provide evidence for the ages of the Orting Drift, Alderton Formation, Stuck Drift, and Puyallup Formation.

The silts sampled demonstrate an array of soft (unconsolidated) …

Net Shore-Drift Of Thurston County, Washington, David M. Hatfield Jr.

WWU Graduate School Collection

Geomorphic and sedimentologic variations in coastal landforms were used to determine the direction of net shore-drift and delineate the boundaries of drift cells along 178 kilometers of the southern Puget Sound coast fronting Thurston County, Washington. The net shore-drift indicators used along the Thurston County coast were, in descending order of observed frequency, gradation in mean sediment size, beach width, foreshore offsets at drift obstructions, spit development, bluff morphology, beach slope, diversion of stream mouth outlets, plan view of deltas or intertidal fans, oblique bars, beach pads, and identifiable sediment.

Wind from the south-southwest prevails over Thurston County. Fetch is …

Temporal Trends In The Geochemistry And Petrology Of The 1980 Mount St. Helens Pyroclastic Flow Deposits, Robert L. Logan

WWU Graduate School Collection

Petrographic and geochemical analyses were performed on pumice from the May 18, June 12, July 22, August 7, and October 16-18 pyroclastic flow deposits. The pumice is dacitic and contains, in order of decreasing abundance, the minerals plagioclase An_30-57, hypersthene, hornblende, magnetite-illmenite, ± augite, ± apatite, in a groundmass of highly vesiculated glass and plagioclase microlites. Vesiculation occurred over a period of about one second, but at times during the eruption probably within a zone in the vent rather than at the atmosphere-magma interface.

An increase with time in the crystal to glass ratio indicates continued cooling of …

Genesis Of Gold Deposits At The Little Squaw Mines, Chandalar Mining District, Alaska, Kathryn King Ashworth

WWU Graduate School Collection

The Little Squaw gold mines are located in the Chandalar Mining District, which is in the Brooks Range, 200 miles north of Fairbanks, Alaska. Country rock in the Little Squaw area consists of Devonian clastic and volcanic rocks which were subjected to two periods of upper greenschist facies metamorphism during the Cretaceous. A penetrative schistosity developed during the first metamorphic event, and thrust faulting and the development of a non-penetrative cleavage occurred during the second.

Gold-bearing quartz veins in the Little Squaw area crystallized along high angle normal faults which post date thrust faulting and cross-cut the non-penetrative cleavage. Data …

Net Shore-Drift Of Mason County, Washington, Dana G. (Dana Genre) Blankenship

WWU Graduate School Collection

Winds from various directions cause waves which transport sediment along the shore. Over a relatively long time interval, sediment is moved in one predominant direction, which is the direction of net shore-drift. Variations in shoreline orientation cause shore drift to occur in discrete, essentially independent, drift cells.

By the specific identification of a number of established geomorphic and sedimentological shore drift indicators, drift cell boundaries can be delineated and the directions of net shore-drift determined. These indicators include changes in bluff morphology, beach width and slope, sediment-size gradation, identifiable sediment, deposition and/or erosion at shore drift obstructions, direction of spit …

Net Shore-Drift Of Pierce County, Washington, Brad D. Harp

WWU Graduate School Collection

The coastline of Pierce County, Washington, lies along the glacially scoured channels of Puget Sound. The highly crenelated coastline totals 373 km in length, with approximately 80 km contributed by five major islands and five minor islands. This study was conducted to determine the long-term net shore-drift along the Pierce County coast. Geomorphic and sedimentologic indicators were used to determine drift directions. These indicators include: direction of spit growth, change in bluff morphology and beach profile, stream diversion, sediment-size gradation, identifiable sediments (sediments from an identifiable source), and nearshore sand bar orientation. Sediment supplied to the foreshore is derived primarily …

Diatoms And Magnetic Anisotropy As Means Of Distinguishing Glacial Till From Glaciomarine Drift, Robert Crandall

WWU Graduate School Collection

Fossil diatom occurrence and anistropy of magnetic susceptibility are evaluated for their usefulness in differentiating glaclomarlne drift from till.

Fossil diatoms in Everson glaciomarine drift occur abundantly enough to be of paleoenvironmental significance only in association with in situ Serpula vermlcularia (Linne). Diatoms are generally a poor discriminator between till and glaciomarine drift. Paleoecological data suggest that, berg ice in marine water was the dominant agent of transportation for clastic particlesin Everson glaciomarine drift.

Anisotropy of magnetic susceptibility investigations generated a characteristic magnetic signature for each diamicton, demonstrating intrinsic differences in the petrofabrics of the two sediment types.

Geology Of The Park Butte-Loomis Mountain Area, Washington (Eastern Margin Of The Twin Sisters Dunite), David L. (David Lewis) Blackwell

WWU Graduate School Collection

Mappable units in the Park Butte-Loomis Mountain area of northwestern Washington are distinguished on the basis of age, lithologic association, structural position, and metamorphic recrystallization. There are four volcanic/volcaniclastic units: the Chilliwack Group, the Cultus Formation, the Elbow Lake-Haystack Mountain unit, and the Nooksack Group: and at least three allocthonous crystalline units: ultramafic rock (including the Twin Sisters and Goat Mountain dunite bodies), the Yellow Aster Complex, and the Vedder Complex. All units occur as tectonic fragments (fault bounded blocks) which are juxtaposed along anastomosing, horizontal to low angle, west dipping faults.

The upper Paleozoic Chilliwack Group is represented by …