7,888 research outputs found
Petrology, petrogenesis, and tectonic setting of Jurassic rocks of the central Cascades, Washington, and western Klamath Mountains, California-Oregon
This dissertation consists of four independent, yet related projects: (1) the petrology, geochemistry, and original tectonic setting of the Galice Formation, Klamath Mountains, Oregon-California; (2) the geochemistry, tectonic setting, and possible regional correlations of the Iron Mountain and Esmeralda Peaks units of the Ingalls ophiolite complex, central Cascades, Washington; (3) the provenance and original tectonic setting of sedimentary serpentinites and ophiolite breccias within the sedimentary rocks of the Ingalls ophiolite complex; and (4) geology, tectonics, and possible regional correlations of pre-Cenozoic rocks, central Cascades, Washington. This research indicates that the Galice Formation represents continuous Late Jurassic deposition (Oxfordian-Kimmeridgian), within the Josephine backarc basin. Source; areas for the Galice Formation included active Jurassic arcs, older Klamath terranes, and the North American craton. The Early Jurassic Iron Mountain unit of the Ingalls ophiolite complex originated as a seamount in close proximity to an oceanic spreading ridge. The Late Jurassic Esmeralda Peaks unit of the Ingalls ophiolite complex originated in a backarc basin that included a fracture zone. The Iron Mountain unit is the rifted basement of the Esmeralda Peaks unit, and both units correlate to similar rocks within the Klamath Mountains. Cr-spinel compositions, geochemistry, and petrography indicate that sedimentary serpentinites and ophiolite breccias within the Ingalls sedimentary rocks were locally derived. These rocks were originally deposited in a Late Jurassic fracture zone. The Manastash inlier consists of the Hereford Meadow amphibolite, Lookout Mountain Formation, Quartz Mountain stock, and Helena-Haystack mélange. Hereford Meadow amphibolite is, in part, a dismembered pre-Jurassic ophiolite that originated in a supra-subduction zone setting. The Lookout Mountain Formation is Late Jurassic in age, had cratonic sources, and was originally located in the Klamath Mountains region, Oregon-California. The Quartz Mountain stock is Late Jurassic in age, and the remnants of an island arc. The Helena-Haystack mélange is a major suture between Cascade terranes, and suggests that ∼98 km of right-lateral displacement has occurred along the Straight Creek fault. The De Roux unit consists of metaigneous and metasedimentary rocks. Metaigneous rocks have calc-alkaline, within-plate, and mid-ocean ridge basalt affinities. The De Roux unit correlates with other Cascade mélanges
Gas Chromatography for the Undergraduate Student
Gas chromatography has attained a position of prominence as a separation technique and as a tool for qualitative identification and quantitative determination. As such, it should rightly be discussed and applied in the undergraduate curriculum. A gas chromatograph suitable for teaching purposes has been designed and constructed in this laboratory. Experimentation applicable to the undergraduate laboratory is presented
On-Chip Cavity Optomechanical Coupling
On-chip cavity optomechanics, in which strong co-localization of light and
mechanical motion is engineered, relies on efficient coupling of light both
into and out of the on-chip optical resonator. Here we detail our particular
style of tapered and dimpled optical fibers, pioneered by the Painter group at
Caltech, which are a versatile and reliable solution to efficient on-chip
coupling. First, a brief overview of tapered, single mode fibers is presented,
in which the single mode cutoff diameter is highlighted. The apparatus used to
create a dimpled tapered fiber is then described, followed by a comprehensive
account of the procedure by which a dimpled tapered fiber is produced and
mounted in our system. The custom-built optical access vacuum chambers in which
our on-chip optomechanical measurements are performed are then discussed.
Finally, the process by which our optomechanical devices are fabricated and the
method by which we explore their optical and mechanical properties is
explained. It is our expectation that this manuscript will enable the novice to
develop advanced optomechanical experiments.Comment: 31 pages, 9 figure
Movement of an Ice-Cored Rock Glacier, Tungsten, N.W.T., Canada, 1963-1980
In August 1963 Dr. H. Gabrielse, of the Geological Survey of Canada, established five lines of marked boulders on what is now believed to be a large ice-cored rock glacier near Tungsten, Northwest Territories. The boulders were aligned with survey targets located on the rock walls of the valley in which the rock glacier is located. The distances from the snout of the rock glacier to eight forest trees along its perimeter were measured and blazed into the trees. In July 1980, we visited the rock glacier and resurveyed the marked boulders and the rock glacier's snout in order to establish the rate and nature of movement of the rock glacier over the past 17 years
Lithics in the West: Using Lithic Analysis to Solve Archeological Problems in Western North America
Lithics in the West seeks to link the rich archaeological lithic data base from the western United States with some of the contemporary theoretical and analytical approaches used in global settings in stone tool and debitage analysis today. The book highlights the role that lithic analysis (in all its forms) plays in solving research problems in the prehistory of western North America. The book covers important archaeological sites and projects in Montana, Wyoming, Idaho, Colorado, and Washington.
Contributors include William Andrefsky, Jr., Robert Kelly, Nicole Waguespack, Pei-Lin Yu, Doug MacDonald, Robert Brunswig, Scott Carpenter, Jackie Cook, David Diggs, Philip Fisher, Katie Harris, Brian Ostahowski, Mary Prasciunas, Ken Reid, and Todd Surovell.https://scholarworks.umt.edu/umpress-oabooks/1000/thumbnail.jp
Uncertainty assessment in river flow projections for Ethiopia’s Upper Awash Basin using multiple GCMs and hydrological models
Uncertainty in climate change impacts on river discharge in the Upper Awash Basin, Ethiopia, is assessed using five MIKE SHE hydrological models, six CMIP5 general circulation models (GCMs) and two representative concentration pathways (RCP) scenarios for the period 2071–2100. Hydrological models vary in their spatial distribution and process representations of unsaturated and saturated zones. Very good performance is achieved for 1975–1999 (NSE: 0.65–0.8; r: 0.79–0.93). GCM-related uncertainty dominates variability in projections of high and mean discharges (mean: –34% to +55% for RCP4.5,–2% to +195% for RCP8.5). Although GCMs dominate uncertainty in projected low flows, inter-hydrological model uncertainty is considerable (RCP4.5: –60% to +228%, RCP8.5: –86% to +337%). Analysis of variance uncertainty attribution reveals that GCM-related uncertainty occupies, on average, 68% of total uncertainty for median and high flows and hydrological models no more than 1%. For low flows, hydrological model uncertainty occupies, on average, 18% of total uncertainty; GCM-related uncertainty remains substantial (average: 28%)
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