Physical Sciences and Mathematics Commons^™

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 …