Geology Commons^™

Dynamics Of Intermediate-Size Stream Outlets, Northern Oregon Coast, Ellen Eberhardt

Dissertations and Theses

This study measured and evaluated the relation of coastal foredune morphology to stream beach outlets, and investigated the processes associated with the stream outlet. Intermediate-size streams were studied, and defined as those that flow across the beach most of the year but have no tidal influence. Fifty-four of these streams were found along the northern Oregon coast between the Columbia River and Yaquina Bay. Crescent Lake Outlet, Saltair Creek and Daley Lake Outlet were chosen as study streams for further investigation.

Rock Slope Stability Studies In Siskiyou National Forest, Greg Visconty

Dissertations and Theses

The line mapping method of Piteau and Martin (1977) was tested on two different rock type road cuts in the Siskiyou National Forest, and was found to be an efficient means of collecting geological data for rock slope stability analysis. The unbiased approach of this method calls for close scrutiny of the outcrops in question, covering more ground than other methods in less time. In turn, this close attention to every crack in the outcrop reveals more about the stability of the slope, and can reveal hidden hazards of rock fall.

The supportive systems for analyzing the data - stereonets …

Geochemical Stratigraphy Of The Dooley Rhyolite Breccia And Tertiary Basalts In The Dooley Mountain Quadrangle, Oregon, David Neale Whitson

Dissertations and Theses

The Dooley Rhyolite Breccia in northeast Oregon was erupted between 12 and 16 million years ago, from central vents and linear feeder dikes within the Dooley Mountain quadrangle. The peraluminous, high-silica rhyolites of the formation were erupted over an irregular highland of eroded pre-Tertiary metamorphic rocks locally overlain by intracanyon, Eocene Clarno-type basalt flow(s) . The Dooley Rhyolite Braccia is exposed in a tectonically disrupted, north-south trending graben across the Elkhorn Range. The formation is variable in thickness with maximum thickness exceeding 660 meters in the south and 600 meters in the north half of the quadrangle. Volumetrically the formation …

A Geochemical Study Of The Eagle Creek Formation In The Columbia River Gorge, Oregon, Rachel Ann Carlin

Dissertations and Theses

The Early Miocene Eagle Creek Formation, a series of volcanic mudflows and debris flows, is exposed in the Columbia River Gorge about 64 kilometers east of Portland, Oregon. Eighty-seven samples were analyzed using instrumental neutron activation analysis for trace element concentrations. Eleven samples were analyzed by Dr. Peter Hooper at Washington State University using X-ray Fluorescence for major element chemistry. These data were used to determine that the Eagle Creek Formation compositionally ranges from andesite to dacite.

Metasomatism Between Amphibolite And Metaultramafic Rocks During Upper Amphibolite Facies Metamorphism, Tobacco Root Mountains, Southwest Montana, William Robert Mcculloch

Dissertations and Theses

The purpose of this study is to characterize the metasomatism that has taken place as a result of the chemical incompatibility between mafic and metaultramafic bulk compositions during high-grade regional metamorphism in the Tobacco Root Mountains, southwest Montana. Metasomatism of these rocks took place by both diffusionand infiltration-dominated processes. The result of these processes are characterized mineralogically and geochemically in the rocks.