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Full-Text Articles in Geology

The Structure And Stratigraphy Of The Columbia River Basalt In The Chehalem Mountains, Oregon, Abdul-Rahman Mohammed Al-Eisa Jan 1980

The Structure And Stratigraphy Of The Columbia River Basalt In The Chehalem Mountains, Oregon, Abdul-Rahman Mohammed Al-Eisa

Dissertations and Theses

The Chehalem Mountains area, encompassing 70 square kilometers, is at the western extent of the Columbia River Basalt Group as mapped in western Oregon. The flows in the study area were identified as belonging to subdivisions of the Columbia River Basalt Group on the basis of physical characteristics and trace element geochemistry. The basalt flows are poorly exposed in the area and weathering is deep and extensive where the flows have been exposed. Where erosion has exposed the underlying marine sedimentary rocks, the basalt has failed in landslides.


The Structure And Stratigraphy Of The Columbia River Basalt In The Hood River Valley, Oregon, Susan Timm Jan 1979

The Structure And Stratigraphy Of The Columbia River Basalt In The Hood River Valley, Oregon, Susan Timm

Dissertations and Theses

The Hood River Valley, located 100 kilometers east of Portland, Oregon, is in the transition zone between two geologic provinces--the High Cascades and the Columbia Plateau. The entire valley is probably underlain by Columbia River Basalt, but it crops out only on steep hillsides and in stream valleys. The base of the basalt is not exposed in the thesis area. The basalt is overlain by Pliocene and Quaternary basalt and andesite, volcanic sediments and glacial debris.

The stratigraphy of the Columbia River Basalt is useful in determining the path of the basalt flows into western Oregon, in mapping the structure …


Structural Geology Of The Southeast Quarter Of The Dutchman Butte Quadrangle, Oregon, Gerald Lee Black Jan 1979

Structural Geology Of The Southeast Quarter Of The Dutchman Butte Quadrangle, Oregon, Gerald Lee Black

Dissertations and Theses

Field work in the southeast quarter of the Dutchman ·Butte Quadrangle, which lies within the Klamath Mountains geomorphic province of southwestern Oregon, was completed during the summers of 1973 and 1974. The objectives of the study were fourfold: (1) to produce a geologic map of the southeast quarter of the Dutchman Butte Quadrangle, (2) to determine the nature of the contact between the Dothan and Rogue formations, (3) to construct a stratigraphic column of the Dothan Formation in the area, and (4) to attempt to determine the nature of the deformation occurring in the area.


Stratigraphy And Sedimentary Petrology Of The Northwest Quarter Of The Dutchman Butte Quadrangle, Southwest Oregon, Thomas Edward Koler Jan 1979

Stratigraphy And Sedimentary Petrology Of The Northwest Quarter Of The Dutchman Butte Quadrangle, Southwest Oregon, Thomas Edward Koler

Dissertations and Theses

The study area lies in southwest Douglas County 5 kilometers south from Camas Valley and is accessible by state highway 42. The purpose of the study was to map the geology at a 1:31,250 scale, determine the stratigraphy, study the petrology of the formations, and determine the provenance within a tectonic setting.


The Stratigraphy And Structure Of The Columbia River Basalt In The Clackamas River Drainage, James Lee Anderson Jan 1978

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 …


The Geology Of The Castle Rock Area, Grant, Harney And Malheur Counties, Oregon, John David Wood Apr 1976

The Geology Of The Castle Rock Area, Grant, Harney And Malheur Counties, Oregon, John David Wood

Dissertations and Theses

The geology of the Castle Rock area aids in the understanding of Cenozoic volcanic stratigraphy and structures in an area where these volcanic rocks thin near the margins of the pre-Tertiary basement rocks and structural trends are overlapping. The Castle Rock area is unique in several aspects and is important in understanding and interpreting the geology in adjacent regions which have all been studied, at least on a regional basis. Intrusive ash-flow bodies of the Dinner Creek Ash-Flow Tuff, well-exposed sections of complexly interstratified volcanic rocks and well-exposed faults, and of high amount of erosional relief are features which make …