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Full-Text Articles in Physical Sciences and Mathematics
Application Of Agisoft Photoscan And Sediment Transport Modeling For The Analysis Of Sediment Wave Propagation Succeeding Gravel Augmentation, Oak Grove Fork Of The Clackamas River, Oregon, Mindi Lea Curran
Cal Poly Humboldt theses and projects
Application of agisoft photoscan and sediment transport modeling for the analysis of sediment wave propagation succeeding gravel augmentation, oak grove fork of the clackamas river, oregon
Mindi Lea Curran
Physical features in alluvial rivers such as riffles, gravel bars, pools, and side channels provide refugia, nutrients, and spawning and rearing habitat for anadromous fish and other aquatic organisms. The downstream transport of gravels that continuously replenish these features is prevented by dams, and often leads to a coarsened channel bed condition and other geomorphic changes that have negative impacts on aquatic organisms. Geomorphic change in rivers can be challenging to …
Reconstructing Late Pleistocene And Holocene Paleoenvironments Using Playa-Lunette System Sediments Within The Harney Basin Of Southeastern Oregon, Usa, Joe Collins
Open Access Theses & Dissertations
Paleoenvironmental investigations of the Late Pleistocene and Early Holocene in the Harney Basin of eastern Oregon have been limited to date. This Dissertation investigates and links the stratigraphy of Rimrock Draw Rockshelter (35HA3855) (RDR) and two surrounding playas, Rimrock Lake and Hay Lake, located on the western margin of the Harney Basin, in order to identify paleoenvironmental shifts during the last ~20 kyr. An emphasis also is given to demonstrating the potential for playas in the Harney Basin to record changes in paleoclimate, as well as the application of multivariate statistics to interpret paleoenvironments from sedimentary grain size data. Stratigraphy …
Petrogenetic Relationship Of The Postcaldera Eruptions Of Mount Mazama, Crater Lake, Oregon; Evolution Of A Sub-Volcanic Magma Chamber Following A Large Silicic Eruption, Michelle Leanna Tebbe
Petrogenetic Relationship Of The Postcaldera Eruptions Of Mount Mazama, Crater Lake, Oregon; Evolution Of A Sub-Volcanic Magma Chamber Following A Large Silicic Eruption, Michelle Leanna Tebbe
All Master's Theses
Mount Mazama is the volcanic edifice that cataclysmically erupted ~503 km of relatively homogeneous rhyodacite lava ~ 7,700 years ago, forming the caldera known as Crater Lake. Within a few hundred years, andesitic eruptions built three distinct volcanic edifices on the floor of Crater Lake; ~ 3000 years later, rhyodacite eruptions formed a dome (Bacon et al., 2002). How magmatic systems evolve following a shallow, relatively large silicic eruption is the focus of this study. In situ geochemical analysis coupled with high-resolution textural images of plagioclase crystals in the four postcaldera volcanic edifices were used to identify distinct crystal populations …
Lacustrine Sediment Record Of Multiple Quaternary Lava Dams On The Owyhee River, Southeastern Oregon, Caitlin Anne Orem
Lacustrine Sediment Record Of Multiple Quaternary Lava Dams On The Owyhee River, Southeastern Oregon, Caitlin Anne Orem
All Master's Theses
Multiple lava dams and correlating lakes impacted the Quaternary evolution of the Owyhee River. Sediment records from lava-dammed lakes were investigated to understand effects of the West Crater (WC) lava dam (~70 ka), the Saddle Butte 2 lava dam (~144 ka), and the Bogus Rim lava dam (~1.9 Ma). Evidence from the WC lava dam and related features indicates that dam duration consisted of five stages (1) dam and lake formation at ~70 ka; (2) dam overflow and lake sedimentation from ~70–46 ka; (3) removal of lava dam and lake termination from ~46 ka to at least 36 ka; (4) …
Petrogenetic Processes Characterizing The Mount Bachelor, Oregon Magmatic System: Open- Versus Closed-System Processes, Sara Elizabeth Johnson
Petrogenetic Processes Characterizing The Mount Bachelor, Oregon Magmatic System: Open- Versus Closed-System Processes, Sara Elizabeth Johnson
All Master's Theses
Mount Bachelor volcanic chain (MBVC), located in central Oregon, is one of the larger basalt and basaltic-andesite edifices in central Oregon. Preliminary studies have defined how eruptions have changed composition with time, but a detailed assessment of magma chamber processes has not been conducted. To gain a more thorough understanding of the magmatic processes that have contributed to the observed compositional evolution, this study focuses on one of four eruptive episodes, specifically episode III, the most voluminous episode of the four. Magmatic processes are assessed by focusing on both whole-rock and single crystal data.
The geochemistry and textural diversity of …
Comparison Of Landslides And Their Related Outburst Flood Deposits, Owyhee River, Southeastern Oregon, Shannon Marian Othus
Comparison Of Landslides And Their Related Outburst Flood Deposits, Owyhee River, Southeastern Oregon, Shannon Marian Othus
All Master's Theses
Numerous landslides have entered the Owyhee River canyon north of Rome, Oregon. As the river flows through different lithologic units, the style of mass wasting changes from large slump events and small rock falls to large earthflows. The change in mechanism of mass wasting from upstream to downstream seems to depend on several factors: (1) the ratio of the basalt cap to the exposed underlying sediments, (2) the composition of underlying sediments, (3) the canyon geometry, and (4) the extent and frequency of mass wasting. All three mechanisms of mass wasting have the ability to block the river channel and …
Paleoflood Record Reconstruction At An Archaeological Site On The Owyhee River, Southeastern Oregon, Stephanie Louise Vandal
Paleoflood Record Reconstruction At An Archaeological Site On The Owyhee River, Southeastern Oregon, Stephanie Louise Vandal
All Master's Theses
The magnitude and frequency of late Holocene floods on the Owyhee River in southeastern Oregon were reconstructed from fine-grained flood deposits at three sites in the river canyon. The stratigraphy at the Birch Creek study site (BCSS) preserves a record of seven to nine large floods from the last 2800 years. Two additional study sites, the Iron Gate and Waterwheel, within a 5-km reach of the BCSS, showed 18-26 floods from the late Holocene to 1993 A.D. and 17-22 floods from 8600 B.P. to 1993 A.D., respectively. Hydrologic Engineering Center-River Analysis System modeling of the 1993 flood and several paleofloods …
Fluvial Response To Intra-Canyon Lava Flows, Owyhee River, Southeastern Oregon, Cooper Cooke Brossy
Fluvial Response To Intra-Canyon Lava Flows, Owyhee River, Southeastern Oregon, Cooper Cooke Brossy
All Master's Theses
At least six lava flows have entered the Owyhee River Canyon north of Rome, Oregon, since the Pliocene and directly impacted the Owyhee River. The effects on the river of the two youngest lava flows, the West Crater (60–80 ka) and Saddle Butte (> 60–90 ka), are readily apparent. These two lava flows entered a paleo-Owyhee Canyon several kilometers wide via three different tributary drainages. The flows dammed the Owyhee River, created lakes, and effectively confined the river to the opposite side of the valley from the flows’ entrance. Lava from these flows filled a paleo-Owyhee Canyon to depths of …
A Small Look At The Big Picture: Linking Geopotential Height Anomalies To Paleofloods On The Snake River, Idaho And Oregon, Gwendolyn Bernitha Rhodes
A Small Look At The Big Picture: Linking Geopotential Height Anomalies To Paleofloods On The Snake River, Idaho And Oregon, Gwendolyn Bernitha Rhodes
All Master's Theses
A combined paleoflood and flood hydroclimatology study on the Snake River in Idaho and Oregon suggests a link between floods and patters of geopotential height anomalies over the North Pacific Ocean. Examination of the paleoflood record in two 4-m (12 ft) tall terraces along the Hells Canyon reach of the Snake River in Idaho and Oregon shows evidence of at least twenty-two late-Holocene extreme floods that occurred approximately 5,000 years. The ages of paleoflood deposits at these sites fall into two time periods, from 5130 ± 40 to 1960 ± 40 yr BP and from 320 ± 40 yr BP …