Geology Commons^™

The Stratigraphy And Structure Of The Columbia River Basalt In The Clackamas River Drainage, James Lee Anderson

Dissertations and Theses

The Clackamas River drainage within the western Cascade Range is approximately aligned with a northwest trending lineation defined by the Portland Hills and the Brothers Fault zone. This area is occupied by an extensive Columbia River Basalt sequence that is deeply incised by the Clackamas River and its tributaries. Two major basalt units of the Yakima Basalt Subgroup, including the Grande Ronde Basalt and the Frenchman Springs Member of the Wanapurn Basalt, are distinguishable in a 515 meter to 550 meter accumulation. Of particular interest is the presence of five trending right-lateral strike-slip faults is consistent with a stress model …

A Study Of Estuarine Sedimentation In South Slough, Coos Bay, Oregon, Charles Allen Baker

Dissertations and Theses

Sediments in the South Slough Estuarine Sanctuary, Coos Bay, Oregon, were sampled and studied in order to determine the sources, dispersal systems and depositional facies of sedimentation. The purpose of the study was to establish baseline measurements and observations on the existing sediment conditions within the relatively undisturbed South Slough Estuarine Sanctuary

Stratigraphy And Petrography Of The Selah Member Of The Ellensburg Formation In South-Central Washington And North-Central Oregon, Mavis Hensley Kent

Dissertations and Theses

The Ellensburg Formation of south-central Washington and north-central Oregon has been described by many workers from the time of the original description by Russell (1893) to recent work by Schmincke (1964). However, detailed information concerning the stratigraphy and petrography of the Ellensburg Formation in south-central Washington and north-central Oregon is not available. This study is among the first detailed studies made for a member of the Ellensburg Formation; it provides a specific comparison with the type Ellensburg of central Washington.

Petrology Of The Bull-Of-The-Woods Intrusive Complex, James Streshley Jackson

Dissertations and Theses

An area of unmapped intrusions lies within the Bull-of-the-Woods Roadless Area of Mount Hood National Forest. A variety of andesites, dacites,and diorites intruding units of tuff and andesite lava flows crop out over.an area of 52 sq km. These intrusions do not appear on the Geologic Map of Oregon West of the 121st Meridian (Hells and Peck, 1961). The purpose of this investigation is to map and describe these intrusions, with attention to the following questions:

What is the petrographic and geochemical nature of these intrusions?

What is the order of emplacement of these intrusions?

What is the probable mechanism …