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The Stratigraphy And Structure Of The Columbia River Basalt Group In The Salmon River Area, Oregon, Martin S. Burck

Dissertations and Theses

Approximately 16 km of Columbia River basalt are exposed in the Salmon River area to the south and to the west of Mount Hood, Oregon. A maximum composite basalt section composed of 15 flows and totaling 461 m is exposed in discontinuous areas of outcrop.

The Columbia River basalt in the Salmon River area belongs to the Grande Ronde Basalt and the Frenchman Springs Member of the Wanapum Basalt. The Grande Ronde Basalt section (6 flows) was mapped as two chemically distinct units referred to as low-M_gO (older) and high-M_gO (younger) Grande Ronde Basalt. At least …

Stratigraphic Relationships Of The Tillamook Volcanics And The Cowlitz Formation In The Upper Nehalem River-Wolf Creek Area, Northwestern Oregon, Michael Keith Jackson

Dissertations and Theses

The upper Nehalem River-Wolf Creek area is located on the northeastern flank of the Tillamook Highlands in the northern Oregon Coast Range. Three rock stratigraphic units underlie the thesis area, and these units range from late Eocene to Oligocene in age.