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- Stratigraphic geology (3)
- Stratigraphic geology -- Eocene (2)
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- Basalt -- Oregon -- Salmon River Region (1)
- Fossil foraminifera -- Oregon -- Nehalem River Watershed (1)
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- Geochemistry -- Oregon -- Sandy River Mudstone (1)
- Geochemistry -- Oregon -- Troutdale Formation (1)
- Geology -- Oregon -- Columbia County (1)
- Geology -- Oregon -- Nehalem River Watershed (1)
- Geology -- Oregon -- Salmon River Region (1)
- Geology -- Oregon -- Sandy River Mudston (1)
- Geology -- Oregon -- Troutdale Formation (1)
- Petrology -- Oregon (1)
- Sandstone -- Oregon (1)
- Stratigraphic Geology -- Eocene (1)
- Stratigraphic geology -- Miocene (1)
- Structural geology (1)
- Volcanic ash -- Washington (State) -- Chumstick Formation (1)
Articles 1 - 6 of 6
Full-Text Articles in Geology
Tephrostratigraphy Of The Middle Eocene Chumstick Formation, Cascade Range, Douglas County, Washington, Matthew John Mcclincy
Tephrostratigraphy Of The Middle Eocene Chumstick Formation, Cascade Range, Douglas County, Washington, Matthew John Mcclincy
Dissertations and Theses
This study outlines the ash (tuff) bed stratigraphy (tephrostratigraphy) in the middle Eocene Chumstick Formation of central Washington. The tuff beds provide local marker beds enabling interpretation of the stratigraphy and structure of the formation. The chemical signature of these units provides the basis on which the units can be traced over broad areas in the basin of deposition. Correlations of tuff beds were obtained over distances of 41 km.
The tephrostratigraphy of the Chumstick Formation consists of nineteen tuff marker beds. Seventeen of these units are chemically characterized in this study. Ten elements were used to fingerprint these tuff …
Biostratigraphy Of The Cowlitz Formation In The Upper Nehalem River Basin, Northwest Oregon, Neil B. Shaw
Biostratigraphy Of The Cowlitz Formation In The Upper Nehalem River Basin, Northwest Oregon, Neil B. Shaw
Dissertations and Theses
Examination of stream and roadcut exposures of the Cowlitz Formation allows the selection of measured representative sections, and collection of fossils, from an area roughly defined by the intersection of the boundaries of Clatsop, Columbia, Tillamook and Washington counties in Oregon. The study defines the features of the local environment of deposition, correlates sections to derive a composite columnar section, and develops a checklist of species for both microfossils and megafossils of the Cowlitz Formation.
A Stratigraphic-Geochemical Study Of The Troutdale Formation And Sandy River Mudstone In The Portland Basin And Lower Columbia River Gorge, Rodney Duane Swanson
A Stratigraphic-Geochemical Study Of The Troutdale Formation And Sandy River Mudstone In The Portland Basin And Lower Columbia River Gorge, Rodney Duane Swanson
Dissertations and Theses
Hyaloclastic sediment forms an identifiable stratigraphic interval within the Troutdale Formation that can be traced from the Bridal Veil channel to the Portland basin. Hyaloclastic sediment composed chiefly vitric sands is found interbedded with muds, sandy muds and gravels penetrated by wells in northeast Portland are correlated with the upper member of the Troutdale Formation. These beds are characteristic of the informal upper member of the Troutdale Formation in the Bridal Veil channel of the ancestral Columbia River (Tolan and Beeson, 1984) and the type area of the Troutdale Formation exposed along the Sandy River (Trimble, 1963). Fluvially deposited hyaloclastic …
Stratigraphic And Petrologic Analysis Of Trends Within The Spencer Formation Sandstones : From Corvallis, Benton County, To Henry Hagg Lake, Yamhill And Washington Counties, Oregon, Brent Joseph Cunderla
Stratigraphic And Petrologic Analysis Of Trends Within The Spencer Formation Sandstones : From Corvallis, Benton County, To Henry Hagg Lake, Yamhill And Washington Counties, Oregon, Brent Joseph Cunderla
Dissertations and Theses
Within the thesis study area Spencer Formation arkosic/arkosic lithic sandstone lithofacies of Narizian age crop out in a sinuous north-northwesterly band from the Corvallis area into the Henry Hagg Lake vicinity ten kilometers southwest of Forest Grove, Oregon.
The Stratigraphy And Structure Of The Columbia River Basalt Group In The Salmon River Area, Oregon, Martin S. Burck
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-MgO (older) and high-MgO (younger) Grande Ronde Basalt. At least …
The Stratigraphy Of The Scappoose Formation, The Astoria Formation, And The Columbia River Basalt Group In Northwestern Columbia County, Oregon, Nancy Tompkins Ketrenos
The Stratigraphy Of The Scappoose Formation, The Astoria Formation, And The Columbia River Basalt Group In Northwestern Columbia County, Oregon, Nancy Tompkins Ketrenos
Dissertations and Theses
The study area is located in northwestern Columbia County, and covers an area of approximately 70 square kilometers. The purpose of the study was to investigate the possible correlation of the Scappoose and Astoria Formations and determine their stratigraphic relationship to the Columbia River Basalt Group through mapping, geochemistry and petrography.