Portland State University. Department of Earth Sciences
Marvin H. Beeson
Date of Award
Master of Science (M.S.) in Geology
1 online resource (77 p.)
Basalt -- Oregon -- Chehalem Mountains, Geology -- Oregon -- Chehalem Mountains, Stratigraphic geology
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.
Al-Eisa, Abdul-Rahman Mohammed, "The structure and stratigraphy of the Columbia River basalt in the Chehalem Mountains, Oregon" (1980). Dissertations and Theses. Paper 3200.