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2012

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Full-Text Articles in Geology

Theoretical Study Of Physiochemical Properties Of Insulin-Like Growth Factor 1, A Ilkhani Dec 2012

Theoretical Study Of Physiochemical Properties Of Insulin-Like Growth Factor 1, A Ilkhani

Tanzania Journal of Science

The computational approach to studying structural changes in a wide range of physical and biological problems, the empirical force fields, have great difficulty in simulating folding of Insulin-like Growth Factor 1 (IGF-1). In an effort to understand the conformational preferences that may be attributed to stereoelectronic effects, a number of computational studies were carried out. Monte Carlo, Molecular Dynamics and Langevin simulation methods by MM+, AMBER and OPLS force fields of calculations have been performed on IGF-1 as growth factors. The parameters of a minimized structure of IGF-1, calculated potential energy for important dihedral angles and the effect of temperature …


Salt Lakes Of The African Rift System: A Valuable Research Opportunity For Insight Into Nature’S Concenrtated Multi-Electrolyte Science, Jyn Philip, Dms Mosha Dec 2012

Salt Lakes Of The African Rift System: A Valuable Research Opportunity For Insight Into Nature’S Concenrtated Multi-Electrolyte Science, Jyn Philip, Dms Mosha

Tanzania Journal of Science

The Tanzanian rift system salt lakes present significant cultural, ecological, recreational and economical values. Beyond the wealth of minerals, resources of these rift salt lakes include unique wildlife, for instance Lesser Flamingo (Phoenicopterus minor) and Cichlids (Alcolapia spp), which adapted chemically aggressive environments like that of Lake Natron. The general hydrochemical equilibria of these salt lakes is governed by Na+ > K+ >> Ca2+ ~ Mg2+ : (CO32- + HCO3-) > Cl- > SO42-~ F- ionic concentration pattern. Salt accumulation mechanism in these endorheic lakes is considered to base on thermo-mechanical disintegrative stress of the geochemistry sourcing. The rains chemically interact with rift terrains, …


Biorecognition Ability Of Polysaccharides As Piezo Quartz Biosensors, En Kalmykova, Ca Mgina Dec 2012

Biorecognition Ability Of Polysaccharides As Piezo Quartz Biosensors, En Kalmykova, Ca Mgina

Tanzania Journal of Science

Piezoquartz biosensors (PQB) which are analytical devices for recognition of biochemical interactions have recently attracted increasing interest from different researchers such as analysts, immune-chemists, medical doctors, environmentalists, etc. This is due to the advantages of PQB for having high detection sensitivity (at ng and mg level depending on the mass of sorbates or micro-organisms) and the ability to monitor biochemical reactions in turbid or highly coloured liquids (including in biological fluids) in real time. The use of additional markers and preliminary sample preparation are not required in this biorecognition process. This paper reports on the principle of the PQB and …


Geochemical Evidence For Vertical Migration Of Deep Formation Fluids Through The Baton Rouge -Denham Springs Fault System, Lesley C. Prochaska Dec 2012

Geochemical Evidence For Vertical Migration Of Deep Formation Fluids Through The Baton Rouge -Denham Springs Fault System, Lesley C. Prochaska

LSU New Orleans Theses and Dissertations

Accumulations of brackish groundwater exist across south Louisiana within the shallow, south-dipping Pleistocene to Upper Miocene Baton Rouge Aquifer System (BRAS). This research investigates the source of brackish groundwater through geochemical analysis of representative groundwater samples by comparing the following geochemical ratios along with other trace elements. Low Bromide (Br)/Chloride (Cl) and Potassium (K) /Cl ratios, high Sodium (Na) /Cl ratios, trace Magnesium (Mg) concentrations, and low Strontium (Sr) 87/Sr86 in brackish waters from the BRAS are inconsistent with in situ saline water from marine formation fluids of similar age. The ratios are consistent with in situ saline-water …


Geomorphologic Evolution Of A Rapidly Deteriorating Barrier Island System With Multiple Sediment Sources: Eastern Isles Dernieres, Louisiana, 1887 To 2006, Benjamin T. Kirkland Dec 2012

Geomorphologic Evolution Of A Rapidly Deteriorating Barrier Island System With Multiple Sediment Sources: Eastern Isles Dernieres, Louisiana, 1887 To 2006, Benjamin T. Kirkland

LSU New Orleans Theses and Dissertations

Trinity, East, and Wine Islands make up the eastern half of the Isles Dernieres barrier arc in south-central Louisiana. Formed following the abandonment of the Lafourche delta complex, subsidence and storm erosion have led to rapid deterioration of the system. Since 1887, the land area of the islands has decreased seventy-seven percent, and the gulf shoreline has retreated landward more than a kilometer. Wave ravinement on the shoreface of the islands is responsible for the most sediment loss; liberated sediment travels longshore to tidal inlets. The dominant ebb tidal currents then transport the sediment to where it is deposited in …


Characterization Of The Red Bluff Landslide, Greater Cascade Landslide Complex, Columbia River Gorge, Washington, James Robert Randall Dec 2012

Characterization Of The Red Bluff Landslide, Greater Cascade Landslide Complex, Columbia River Gorge, Washington, James Robert Randall

Dissertations and Theses

Located in the Columbia River Gorge, The Red Bluff Landslide (18.8 km2) is one of four large landslides that make up the Cascade Landslide Complex. In its current form, the Red Bluff Landslide is a post-Missoula Flood feature made up of two components: an active upper lobe (8.6 km2) that is translational, creeping to the south at 25 cm/yr and spreading laterally to the east at 6 cm/yr over a semi-fixed portion (10.2 km2) of the Red Bluff Landslide area that has been "smoothed" by Missoula Floods. The upper active lobe is the landslide debris accumulated since Missoula Flood time …


Using Marine Snails To Teach Biogeography And Macroevolution: The Role Of Larvae And Dispersal Ability In The Evolution And Persistence Of Species, Jonathan R. Hendricks Dec 2012

Using Marine Snails To Teach Biogeography And Macroevolution: The Role Of Larvae And Dispersal Ability In The Evolution And Persistence Of Species, Jonathan R. Hendricks

Faculty Publications

While some marine animals are capable of traveling great distances, many have limited mobility as adults and spend the majority of their lifetimes in a small geographical area or may even be cemented to a single place. While it might be expected that species with limited mobility would have small geographic distributions, some nevertheless occur over very large areas. This is the case for some marine snails (gastropods). A key factor that impacts the geographic distribution of marine snails is the type of larvae they have during the phase of their life history that follows hatching from an egg. Because …


Chemical Contaminants As Stratigraphic Markers For The Anthropocene, Michael A. Kruge Dec 2012

Chemical Contaminants As Stratigraphic Markers For The Anthropocene, Michael A. Kruge

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Thousands and even millions of years from now, widespread anthropogenic contaminants in sediments would likely persist, incorporated into the geological record. They would inadvertently preserve evidence of our present era (informally designated as the Anthropocene Epoch) characterized by large human populations engaged in intensive industrial and agricultural activities.

Hypothetical geologists in the distant future would likely find unusually high concentrations of a wide variety of contaminants at stratigraphic levels corresponding to our present time, analogous to the iridium anomaly marking the bolide impact event at the close of the Cretaceous Period. These would include both organic and inorganic substances, such …


Faunal Distribution And Relative Abundance In A Silurian (Wenlock) Pinnacle Reef Complex - Ray Reef, Macomb County, Michigan, Jennifer L. Trout Dec 2012

Faunal Distribution And Relative Abundance In A Silurian (Wenlock) Pinnacle Reef Complex - Ray Reef, Macomb County, Michigan, Jennifer L. Trout

Masters Theses

Niagaran (Silurian) reefs are important sources of hydrocarbons in the Michigan Basin. In addition, some of these reservoirs have been used for gas storage and may be potential CO2 sequestration sites.

Despite extensive research on Niagaran reefs, most studies concerning faunal abundance and distribution have been qualitative studies conducted by paleontologists with an emphasis on taxonomy, paleoecology, and evolution.

This study is the first quantitative study of relative abundance and general distribution of fauna throughout a single Wenlock reef located in the southern trend of the Michigan Basin. This study will build on previous work done by WMU students and …


Determining Temperatures Of Deformation In Mylonites From The Scandinavian Caledonides, With Implications For The Thermal And Kinematic Evolution Of Orogens, Andrea Marilina Wolfowicz Dec 2012

Determining Temperatures Of Deformation In Mylonites From The Scandinavian Caledonides, With Implications For The Thermal And Kinematic Evolution Of Orogens, Andrea Marilina Wolfowicz

Boise State University Theses and Dissertations

The Titanium-in-quartz (TitaniQ) thermobarometer was evaluated in ductilely sheared rocks (mylonites) from the Scandinavian Caledonides in comparison with several other thermometric methods, including: (1) TitaniQ thermometry in cross-cutting quartz veins, (2) garnet-biotite Fe-Mg exchange thermometry, (3) metamorphic phase equilibria, and (4) quartz microstructures as calibrated experimentally and empirically. In all instances, quartz vein temperatures mimic TitaniQ temperatures of the host rocks. Similarly, TitaniQ temperatures of dynamically recrystallized quartz, ranging from ~210°C at the thrust front to 475°C at the deepest structural levels, reflect the best estimate of the final temperature of deformation. Higher temperatures are also preserved locally and more …


Detrital Carbonates In A Sequence Stratigraphic Framework: An Example From The Furongian Slope Environment In The Hot Creek Range Of Central Nevada, Leon Taufani Dec 2012

Detrital Carbonates In A Sequence Stratigraphic Framework: An Example From The Furongian Slope Environment In The Hot Creek Range Of Central Nevada, Leon Taufani

UNLV Theses, Dissertations, Professional Papers, and Capstones

An integrated sedimentological study of detrital carbonates of the late Cambrian (Furongian) Hales Limestone in central Nevada was conducted in order to model facies distribution and controlling mechanisms of carbonate gravity-flow deposits. Seven closely-spaced sections and numerous traceable short sections were measured to investigate temporal and spatial changes of detrital carbonates within a high-resolution stratigraphic framework supported by biostratigraphic and carbon isotope chemostratigraphic constraints and by key physical surfaces. Polished slabs and thin section petrographic analysis were used to identify micro- and macro-scale textures and diagenesis.

Ten lithofacies are identified from the Hales Limestone. Lateral tracing of these facies reveals …


Autumn Migration Of Mississippi Flyway Mallards As Determined By Satellite Telemetry, David George G. Krementz, Kwasi Asante, Luke W. Naylor Dec 2012

Autumn Migration Of Mississippi Flyway Mallards As Determined By Satellite Telemetry, David George G. Krementz, Kwasi Asante, Luke W. Naylor

United States Geological Survey: Staff Publications

We used satellite telemetry to study autumn migration timing, routes, stopover duration, and final destinations of mallards Anas platyrhynchos captured the previous spring in Arkansas from 2004 to 2007. Of those mallards that still had functioning transmitters on September 15 (n = 55), the average date when autumn migration began was October 23 (SE = 2.62 d; range = September 17–December 7). For those mallards that stopped for .1 d during migration, the average stopover length was 15.4 d (SE = 1.47 d). Ten mallards migrated nonstop to wintering sites. The eastern Dakotas were a heavily utilized stopover area. The …


A Study Of The Bioherms Of The Early Ordovician Garden City Formation And A Literature Review Of Early Ordovician Organic Buildups, Heidi Pearce Dec 2012

A Study Of The Bioherms Of The Early Ordovician Garden City Formation And A Literature Review Of Early Ordovician Organic Buildups, Heidi Pearce

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

During the Early Ordovician organic buildups formed in shallow seas across the world. This project contains a literature review on these organic buildups with a focus on those occurring in the warm, shallow seas of North America, but also includes a study on organic buildups formed in the cold water region of Russia. The goal of the study was to characterize these Early Ordovician organic buildups in order to identify similarities and differences in their occurrence. The second part of this project is a preliminary study on organic buildups occurring in the Early Ordovician Garden City Formation in Boss Canyon, …


Ore And Gangue Mineral Paragenesis Of The Cortez Hills Carlin-Type Gold Deposit, Nevada: Evidence For Coincident High-Grade Gold Deposition And Collapse Brecciation, Lindsey R. Clark Dec 2012

Ore And Gangue Mineral Paragenesis Of The Cortez Hills Carlin-Type Gold Deposit, Nevada: Evidence For Coincident High-Grade Gold Deposition And Collapse Brecciation, Lindsey R. Clark

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Cortez Hills Carlin-type gold deposit (CTGD), located on the Battle Mountain-Eureka trend of Northern NV, is hosted in a conical shaped polylithic breccia whose central axis strikes parallel to the imbricate Voodoo fault system. Gold grades at the center of the Cortez Hills Breccia Zone (CHBZ) are locally in excess of an ounce per ton. Gold mineralization within the refractory ore at Cortez Hills shares many characteristics with other well studied CTGDs. However, new observations during this study have recognized 1) fragmented realgar that are rimmed by gold-bearing iron-sulfide minerals in four samples, 2) a Hg- and Tl-rich late-ore …


Petrogenesis Of The East Fork Member Rhyolites, Valles Caldera, New Mexico, Usa, Carla Eichler Dec 2012

Petrogenesis Of The East Fork Member Rhyolites, Valles Caldera, New Mexico, Usa, Carla Eichler

UNLV Theses, Dissertations, Professional Papers, and Capstones

The most recent volcanism in the Valles caldera is represented by the El Cajete Pyroclastic Beds (ECPB), Battleship Rock Ignimbrite (BRI), and Banco Bonito Flow (BBF) as well as the VC-1 rhyolite, which are collectively known as the East Fork Member (EFM) of the Valles Rhyolite. The EFM was erupted at approximately 55 ka and 40 ka after an approximate 460 ka lull in volcanism. Previous studies suggested a mafic intrusion at depth triggered the eruptions. This thesis represents the first detailed study of the EFM.

Crystal assemblages consist of plagioclase, biotite, clinopyroxene, orthopyroxene, amphibole, sanidine, quartz, and oxides. Electron …


Volcanic Evolution Of The Southern Quinn Canyon Range: Implications For Regional Correlation Of Volcanic Units, Christina Emery Dec 2012

Volcanic Evolution Of The Southern Quinn Canyon Range: Implications For Regional Correlation Of Volcanic Units, Christina Emery

UNLV Theses, Dissertations, Professional Papers, and Capstones

The southern Quinn Canyon Range lies in an area of the Great Basin subjected to large-volume Oligocene-Miocene silicic volcanism and smaller volume basaltic volcanism during the Pliocene. Three major ash-flow tuff units were correlated in the southern Quinn Canyon Range (the Pahranagat Tuff, Clifford Spring Tuff, and the Cow Canyon Tuff) with regional units by utilizing U/Pb and 40 Ar/ 39Ar geochronology, geochemical correlation, and field mapping. Isotopic analysis suggests that basalt in the southern Quinn Canyon Range is part of the Death Valley-Pancake Range Basalt Zone and is similar to Reveille Range Episode 1 and 2 basalts. Further comparison …


Integrated Approach For Hydrogeologic Investigations In Africa: Inferences From Space-Borne And Land-Based Gravity, Aeromagnetic, Gis, And Remote Sensing Data, Mohamed El Sayed Ahmed Ahmed Dec 2012

Integrated Approach For Hydrogeologic Investigations In Africa: Inferences From Space-Borne And Land-Based Gravity, Aeromagnetic, Gis, And Remote Sensing Data, Mohamed El Sayed Ahmed Ahmed

Dissertations

An integrated (space-borne and land-based gravity, aeromagnetic, GIS, and remote sensing) approach was developed, tested, and applied to investigate the following on regional scales (Africa) or local scales (El Qaa Plain, Sinai): (1) assess the capability of GRACE data (04/2002 to 08/2011) for monitoring elements of hydrologic systems on the sub-basin level (Task 1); (2) address the nature and the controlling factors (e.g., climatic and/or human pressure-related) affecting the inter-annual GRACE-derived Terrestrial Water Storage (TWS) trends over a large suite of hydrologic systems and domains in (Africa) (Task 2); and (3) identify the structural, geologic and hydrologic settings as well …


Stratigraphic Framework For Deposits Of The Saginaw Lobe, Barry And Calhoun Counties, Michigan, Usa, Stephanie K. Ewald Dec 2012

Stratigraphic Framework For Deposits Of The Saginaw Lobe, Barry And Calhoun Counties, Michigan, Usa, Stephanie K. Ewald

Masters Theses

Between 2006 and 2012, twelve rotasonic borings were drilled in Barry and Calhoun Counties, south central Michigan, as part of several Great Lakes Geological Mapping Coalition projects. Natural gamma ray logs were collected at every location and a detailed description and textural analysis was completed for seven of these cores. Five of the seven analyzed cores reached bedrock. Six of the seven borings were drilled north of the Kalamazoo Moraine of the Saginaw Lobe, which was constructed during retreat of the lobe after the Late Glacial Maximum. Five borings, drilled in tunnel valleys, indicate an increase in depth of tunnel …


Characterizing The Internal Architecture Of Upper Bone Spring Limestone Turbidites And Mass-Transport Deposits (Mtds) Utilizing High-Resolution Image Log Technology, Jason J. Asmus Dec 2012

Characterizing The Internal Architecture Of Upper Bone Spring Limestone Turbidites And Mass-Transport Deposits (Mtds) Utilizing High-Resolution Image Log Technology, Jason J. Asmus

Masters Theses

Characterization of reservoir scale (less than 1 meter thick) turbidites and mass-transport deposits (MTDs) using conventional subsurface data is complex, due to millimeter-centimeter scale architectural heterogeneity exhibited by these deposits.

Limited studies of the Bone Spring carbonate turbidites and MTDs within the Delaware Basin subsurface emphasized the use of conventional wire-line log and seismic data to evaluate reservoir potential of such strata. As a result, limited resolution offered by these data sets do not allow for accurate characterization of reservoir, and sub-reservoir scale, architectural and compositional variations.

The present investigation integrates high-resolution (centimeter scale) electrical borehole image logs with conventional …


Hydromechanical Well Testing Using A 3d Fiber Optic Extensometer, Glenn Skawski Dec 2012

Hydromechanical Well Testing Using A 3d Fiber Optic Extensometer, Glenn Skawski

All Theses

Some fractured rock formations hold important resources, such as water, hydrocarbons or heat, whereas others are good candidates for waste disposal. Hydromechanical well tests have been developed to improve characterization of formation properties and parameter distributions by measuring displacement along with pressure while stressing a well. The displacement that occurs during a well test depends on the geometry of fractures or other sources of permeability, as well as the distribution of compliance or elastic modulus. Current methods of hydromechanical well testing, measures axial displacements along a wellbore, which may cause ambiguity in interpretations when 3-D components of deformation are present. …


An Estimate Of Groundwater Recharge In The Nabogo River Basin, Ghana Using Water Table Fluctuation Method And Chloride Mass Balance, Melanie Lynn Krautstrunk Dec 2012

An Estimate Of Groundwater Recharge In The Nabogo River Basin, Ghana Using Water Table Fluctuation Method And Chloride Mass Balance, Melanie Lynn Krautstrunk

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Cambrian-Precambrian fractured sandstone aquifer in the Nabogo River Basin in the Sahelian Northern Region in Ghana is one of the most important sources for fresh water supply for the local rural communities there. Recent population growth and commercial agricultural interests in this region could have an impact on this critical water resource. Groundwater recharge estimates are determined in this study using the Water Table Fluctuation Method and Chloride Mass Balance and can be applied to future sustainability studies of the region's water resources. Recharge estimates of the Water Table Fluctuation Method are in a range of 10-143 mm/yr or …


The Impact Of Creosote Bush (Larrea Tridentata) And Biological Soil Crust On Ca Distribution In Arid Soils Of The Mojave Desert, Brittany Myers Dec 2012

The Impact Of Creosote Bush (Larrea Tridentata) And Biological Soil Crust On Ca Distribution In Arid Soils Of The Mojave Desert, Brittany Myers

UNLV Theses, Dissertations, Professional Papers, and Capstones

Ca is an important nutrient that plays a role in membrane stability and cell repair in plant life. This study examines the impact of creosote bush (Larrea tridentata) and biological soil crust on calcium cycling and distribution in desert soils in order to explore the use of Ca as a biosignature. Samples of creosote bush, biological soil crust and eolian dust were taken at two field sites in the Mojave Desert. The first site is located in Eldorado Valley, NV, a soil formed on a young (800-1200 years) alluvial fan deposit; the second site is located on a late Holocene-aged …


2000 Year Moisture Source Record From A Central Nevada Speleothem, Paul Pribyl Dec 2012

2000 Year Moisture Source Record From A Central Nevada Speleothem, Paul Pribyl

UNLV Theses, Dissertations, Professional Papers, and Capstones

The goal of this study was to determine the moisture source of winter precipitation in the central Great Basin for the past 2000 years, and to elucidate the role of Pacific Ocean and North American climate variability modes in driving observed droughts of the region around the Medieval Climatic Anomaly (MCA, ~900-1300 CE). Here a high resolution (~2-4 year) precisely dated moisture source reconstruction is presented from the δ18O values of speleothem LC-1 collected from Leviathan Cave in central Nevada, which reveals significant δ18O variability. I attribute the δ18O variability to changes in winter-season moisture circulation over the past 2000 …


Penetration Forces For Subsurface Regolith Probes, Ahmed Elshafie Dec 2012

Penetration Forces For Subsurface Regolith Probes, Ahmed Elshafie

Graduate Theses and Dissertations

Investigating planetary bodies using penetrometers can provide detailed information about its history and evolution. An estimation of subsurface density and porosity can be made from the shape of the penetration curve. Using penetrometers mounted on planetary platforms could be challenging due to the uncertainty of the subsurface composition and since the maximum allowed force for penetration is the weight of the lander or rover on the surface. Estimation of penetration forces can provide a reliable constraint on the maximum reachable depth without endangering the whole mission. Therefore, knowledge of the required penetration force to specific depths can be helpful in …


Diagenesis And Reservoir Characterization Of The Pennsylvanian Middle Atoka Formation, Sebastian And Logan Counties, West-Central Arkansas, Elvis Chekwube Bello Dec 2012

Diagenesis And Reservoir Characterization Of The Pennsylvanian Middle Atoka Formation, Sebastian And Logan Counties, West-Central Arkansas, Elvis Chekwube Bello

Graduate Theses and Dissertations

The Middle Atoka Formation evolved from a stable passive margin during the early Pennsylvanian time to a rapidly subsiding basin, with the sedimentary fill thickening greatly southward during the middle Pennsylvanian time. The basin dips in north-south direction. An east-west anticlines and synclines were observed.

The purpose of this study is to establish the stratigraphic units, reservoir geometry and distribution, and infer the depositional environments and reservoir quality. Well correlation and petrographic studies are used to achieve the goals.

Sandstone Point Count method was used. The Point Counts was divided into five categories. They include the framework grains (quartz, feldspar, …


Stratigraphic Variations In The Carboniferous Section Across The Arkansas-Oklahoma State Line Arch, Tyler Dean Engelhardt Dec 2012

Stratigraphic Variations In The Carboniferous Section Across The Arkansas-Oklahoma State Line Arch, Tyler Dean Engelhardt

Graduate Theses and Dissertations

The State Line Arch is represented by a structural high that trends through the study area in a loose alignment with the Arkansas-Oklahoma state line. Evidence of the arch extending further to the north includes a structural high and stratigraphic variation at an outcrop on Highway 59 near Evansville Mountain in Crawford County, Arkansas. The exact timing of the formation of the arch remains undetermined, but upper Devonian thinning at the top of the arch indicates the structure is pre-Mississippian. The reason for the development of the arch is poorly understood, but evidence linking Mississippian-aged Waulsortian mounds to Precambrian Spavinaw …


Modeling Lithospheric Rheology From Modern Measurements Of Bonneville Shoreline Deformation, Eric P. Beard Dec 2012

Modeling Lithospheric Rheology From Modern Measurements Of Bonneville Shoreline Deformation, Eric P. Beard

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Here I develop a new method for estimating differences in elevation between pairs of paleo-lake shoreline features. This method is applied to Lake Bonneville, a large lake that inundated nearly 1/3 of the state of Utah as well as parts of Nevada and Idaho from 34 to 11.5 thousand years ago. Under the weight of the lake water load, the surface of the Earth was depressed by up to 75 m. This occurred as Earth mantle rock at depth flowed outward in response to the weight of the lake. I use this new methodology to compile here a denser sample …


Inventory And Initiation Zone Characterization Of Debris Flows On Mount St. Helens, Washington Initiated During A Major Storm Event In November, 2006, Keith Vinton Olson Nov 2012

Inventory And Initiation Zone Characterization Of Debris Flows On Mount St. Helens, Washington Initiated During A Major Storm Event In November, 2006, Keith Vinton Olson

Dissertations and Theses

The heavy precipitation event of November 3-8, 2006 dropped over 60 cm of rain onto the bare southern slopes of Mount St. Helens and generated debris flows in eight of the sixteen drainages outside the 1980 debris avalanche zone. Debris flows occurred on the upper catchments of the Muddy River, Shoestring Glacier, Pine Creek, June Lake, Butte Camp Dome, Blue Lake, Sheep Creek, and South Fork Toutle River. Debris flows were clustered on the west and south-east sides of the mountain. Of the eight debris flows, three were initiated by landslides, while five were initiated by headward or channel erosion. …


Temporal And Crustal Effects On Differentiation Of Tholeiite To Calcalkaline And Ferro-Trachytic Suites, High Lava Plains, Oregon, Usa, Martin J. Streck, Anita L. Grunder Nov 2012

Temporal And Crustal Effects On Differentiation Of Tholeiite To Calcalkaline And Ferro-Trachytic Suites, High Lava Plains, Oregon, Usa, Martin J. Streck, Anita L. Grunder

Geology Faculty Publications and Presentations

Strongly bimodal, basalt-rhyolite volcanism of the High Lava Plains Province of Oregon followed the Middle Miocene flood basalts of the Pacific Northwest and extends to recent time. During the 8 m.y. of volcanism recorded in the central High Lava Plains, in western Harney Basin, three distinct mafic magmatic trends originate from primitive high-alumina olivine tholeiites (HAOT); they are tholeiitic, calcalkaline and ferro-trachytic. Tholeiitic basalts occur throughout the history and their compositions are derived by crystal fractionation while traversing the crust and mixing with evolved mafic magmas. Scavenging of apatite from crustal rocks and minor contamination with felsic melts accounts for …


Geochemistry And Geochronology Of The Central Metasedimentary Belt Boundary Thrust Zone Thrust Sheets In Southern Ontario, Grenville Province, Kenjo Agustsson Nov 2012

Geochemistry And Geochronology Of The Central Metasedimentary Belt Boundary Thrust Zone Thrust Sheets In Southern Ontario, Grenville Province, Kenjo Agustsson

Natural Resources Management and Environmental Sciences

Studies of pre-Grenvillian (1.4–1.3 Ga) plutons offer insight into the dynamics of arc amalgamation and backarc rifting prior to continental collision in the Ottawan orogeny. The Central Metasedimentary Belt boundary thrust zone (CMBbtz) is a northeast–southwest trending thrust zone consisting of metaplutonic thrust sheets enveloped in gneissic tectonites and calcitic– dolomitic marbles. Tonalitic CMBbtz thrust sheets (Dysart and Redstone) are made up of upper amphibolite-facies, foliation-concordant metatonalites (+ amphibole ± biotite ± accessory zircon and titanite) and amphibolites (± biotite ± clinopyroxene), and are located in the southern Ontario Grenville Province. These thrust sheets are thought to have formed and …