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Full-Text Articles in Physical Sciences and Mathematics
Structure And Influence Of The Tillamook Uplift On The Stratigraphy Of The Mist Area, Oregon, Moinoddin Murtuzamiya Kadri
Structure And Influence Of The Tillamook Uplift On The Stratigraphy Of The Mist Area, Oregon, Moinoddin Murtuzamiya Kadri
Dissertations and Theses
Fifty three sedimentary samples were analyzed for their minor and trace element concentrations utilizing instrumental neutron activation analysis. Concentrations of Na, K, La, Sm and Sc, and their ratios appear to establish significant trends. The data suggest a major break from a granitic-metamorphic provenance and a volcanic component dominated provenance between the Cowlitz and Keasey Formations respectively. The provenance of the Astoria Formation indicates the presence of flood basalts.
A Preliminary Investigation Of The Lithological Characteristics Of The Troutdale Formation In Portions Of The Camas, Sandy, Washougal, And Bridal Veil Quadrangles, David Lee Cole
Dissertations and Theses
The study area encompasses a region of about 80 square kilometers, centered about Corbett, Oregon. Sieve analyses suggest that the Troutdale Formation is composed of a conglomerate, a coarse-grained sandstone, and a siltstone lithofacies. Measured sections data show that 56 to 60 percent of the Troutdale Formation's exposures are composed of the conglomerate lithofacies. The coarsegrained sandstone lithofacies makes up 34 to 38 percent, while the siltstone lithofacies makes up only 4 to 8 percent. Pebble count data show that the representation of basalt varies from 69 to 100 percent, with an average of 85 percent, while quartzite varies from …
The Geology Of The Floras Creek Area, Curry County, Oregon, Jon Dudley Bounds
The Geology Of The Floras Creek Area, Curry County, Oregon, Jon Dudley Bounds
Dissertations and Theses
The Floras Creek area, east of the town of Langlois, near the southwest Oregon coast, includes Colebrooke Schist (a klippe of metamorphosed pelitic sediments of Jurassic age), Jurassic Otter Point Formation (a melange complex), and lower the middle Eocene Roseburg and Lookingglass Formations, part of a sandstone-shale sequence occurring more extensively in other areas. The Colebrooke Schist occurs in the south-central part of the area, bounded on the Otter Point and Roseburg. The Lookingglass is exposed as a small (1.5 sq. km) block in the north-north-west part of the area. Two major structural trends are found in the Floras Creek …
Stratigraphy And Sedimentation Of The Spencer Formation In Yamhill And Washington Counties, Oregon, Fathi Ayoub Al-Azzaby
Stratigraphy And Sedimentation Of The Spencer Formation In Yamhill And Washington Counties, Oregon, Fathi Ayoub Al-Azzaby
Dissertations and Theses
The Spencer Formation in Yamhill and Washington Counties, Oregon, is exposed in a narrow belt 27 km long, from 1/4 to 3 km wide and with a maximum thickness of about 400 m. The formation is composed entirely of sandstone with interbedded thin layers of mudstone in the uppermost member. The sedimentary structure and paleoecology indicate a shallow marine depositional environment. The upper member of the Spencer Formation contains more quartz, plagioclase, and hornblende than does the lower member, but K-feldspar is less than that of the lower member. Shallower water conditions for the deposition of the upper member are …