Spelling suggestions: "subject:"basalt."" "subject:"nasalt.""
111 |
Volatiles in Subglacially Erupted Basaltic Glasses and Their Use in Reconstructing Paleo-Ice ThicknessesLee, Carver 24 March 2017 (has links)
Volatile concentrations in basaltic tuyas, edifices that form during a subglacial eruption and remain once the ice sheet has retreated, have been used to calculate the thickness of the overlying ice sheet at the onset of the eruption (Tuffen, 2010). However, subglacial eruptions are complex events and this technique does not always provide a clear answer (Schopka et al., 2006; Edwards et al., 2009). The purpose of this research is to evaluate this technique and investigate constraints on the quality of data collected by attempting to calculate the minimum ice thickness under which Hlöðufell, a tuya in south-central Iceland, erupted.
Hlöðufell is a Holocene tuya located in the Western Rift Zone of Iceland, 9 km south from the modern edge of Langjökull ice cap. Dissolved H2O concentrations were measured using Fourier transform infrared spectroscopy (FTIR) and quenching pressures were calculated using the VolatileCalc pressure-solubility model (Newman and Lowenstern, 2002). Overlying ice thickness was calculated by relating quenching pressures, the density of ice, and the elevation of the sample.
Water concentrations range from 0.068 –to 0.478 wt. % H2O, representing pressures ranging from 0.66 to 24.72 bars. These pressures represent ice thicknesses between 0 and 268 m thick. The minimum ice thickness level is represented in the lithofacies of the tuya by the passage zone, the transition between subaerial and subaqueous flows. The minimum ice thickness for Hlöðufell is ~ 500 m, much thicker than this study calculated using water concentrations. This indicates that the volatile concentrations in the basaltic glasses at Hlöðufell do not record the accurate quenching pressure. We interpret the overall low water concentrations to mean that our samples must have degassed at or close to atmospheric pressures at higher elevations, and flowed downslope into areas of thicker ice or deeper melt-water before quenching. These results show that subglacial eruptions and degassing processes are complex and variable and require further investigation.
|
112 |
Effects of Nano Silica and Basalt Fibers on Fly Ash Based Geopolymer ConcreteAbu Bakar, Asif January 2018 (has links)
Emission of carbon dioxide gas has been a source of major concern for the construction industry. To curb this emission, geopolymer concrete has been deemed as a potential alternative in the recent studies. Previous research also indicates that silica and fibers provide strength benefits to ordinary Portland cement concrete OPC. This study was undertaken to recognize the benefits of adding silica and basalt fibers in Class F fly ash based geopolymer concrete and comparing it with OPC concrete. One OPC and four Geopolymer mixtures were prepared. The results show a tremendous potential of using geopolymer concrete in place of OPC concrete with Nano silica proving to be the most advantageous. Nano silica provided 28% increase in compressive strength, 8% increase in resistivity when compared with normal Fly ash based geopolymer concrete. The SEM analysis of geopolymer concrete indicates that nano silica improved the compactness of concrete providing a dense microstructure.
|
113 |
Sustainable Transformation and Recovery of Unconventional Resources in Natural and Waste Systems Utilizing CO2Hsu, Emily January 2020 (has links)
The increasing concentration of CO2 in the atmosphere and the rapidly growing amount of waste (industrial and electronic) are two major environmental challenges faced by humanity today. Carbon capture, storage, and utilization (CCUS) aims to address the CO2 challenge and has been shown to be a promising means of CO2 mitigation. For carbon capture, amine scrubbing is an example of an effective means to separate CO2 from other gases, particularly natural gas and hydrogen. Carbon storage entails the injection of CO2 into natural geologic formations, such as basalt, to form permanent, harmless carbonates. Lastly, carbon utilization involves conversion of carbon to chemicals and fuels through a variety of pathways, such as carbon mineralization. Many large-scale projects on CCUS have been conducted, with ongoing research in the aforementioned areas of CCUS. The first half of this dissertation addresses carbon storage and utilization, specifically focusing on carbon mineralization, in order to evaluate the potential for CO2 storage in basalt and CO2 utilization in the transformation of industrial waste to valuable carbonates.
The mounting amount of electronic waste (e-waste) presents a significant challenge in the flow of valuable elements, especially as it relates to the materials cycle. E-waste contains valuable metals, such as copper, gold, silver, iron, and nickel, and contains much higher amounts of these metals than the amounts found in ores. Thus, the recycling of metals from e-waste is favorable and has gained attention over the last few years. E-waste is a complex mixture of metals, plastics, and refractory materials. The brominated flame retardants in the e-waste are of particular concern as they become hazardous when burned. Lead is also often found in the solder material of e-waste.
The risks associated with the toxic and hazardous components of e-waste, along with the heterogeneity in composition, challenge the development of recycling and processing methods for e-waste. While recent developments, such as hydrometallurgy i.e. chemical leaching, have lessened the hazards during processing, pyrometallurgical techniques, which involve smelting, remain the most commonly used treatment. Metal extraction and recovery processes are multi-step techniques that usually involve energy-intensive mechanical processing, and depending on the type of waste, the selectivity of metal separation processes can be quite low. Specifically, for Lithium-ion batteries (LIB), the majority of recycling techniques cannot recover Co and Ni simultaneously. The latter half of this dissertation explores new, sustainable separation processes for the recovery of metals from e-waste, Printed circuit boards (PCB) and LIB, via morphological changes induced by supercritical CO2 and via electrochemical techniques.
Chapter 2 presents an evaluation of the potential of sub-seafloor basalt in the Cascadia Basin offshore Washington State and British Columbia for CO2 storage. Basalt samples from the Cascadia Basin were tested for the extraction of Ca, Mg, and Fe to assess the ability of the basalt to form carbonates under the experimental conditions of injection with CO2. Combining laboratory results with modeling studies from collaborators, and comparisons to existing data on the reactivity of oceanic basalt demonstrated that the basalt formations in the Cascadia Basin are a feasible option for large-scale, permanent CO2 storage. In Chapter 3, the reaction of CO2 and industrial waste for Ca and Mg extraction, is investigated in greater detail in the tailored synthesis of high purity precipitate calcium carbonate (PCC) from slag. Different ligands were studied for the extraction of Ca and Mg and various experimental conditions, such as heating, controlling the pH, and bubbling with air vs. CO2 were studied for the formation of calcium carbonates from the steel slag. A novel synthesis method involving the dissolution of the slag using ligands, heating, and precipitation via bubbling with air or CO2 using the Ca-rich solution derived from dissolution, was developed. High purity PCC was successfully produced, making the proposed synthesis process a promising pathway for carbon management and sustainable waste transformation.
In Chapter 4, a critical review of current metal extraction and recovery techniques for the treatment and processing of electronic waste is presented. The complexity of e-waste requires the development of new metallurgical processes that can separate and extract metals from unconventional components such as plastics and a wide range of metals. This chapter focuses on the science and engineering of both conventional and innovative separation and recovery technologies for e-waste with special attention given to the overall sustainability. Physical separation processes, including disassembly and magnetic separation, as well as thermal treatment of the polymeric component, such as pyrolysis, are discussed for the separation of metals and non- metals from e-waste. The subsequent metal recovery processes through pyrometallurgy, hydrometallurgy, and biometallurgy are also discussed in depth. Finally, insights on future research towards sustainable treatment and recovery of e-waste are highlighted, including the use of supercritical CO2.
Chapter 5 investigates the use of supercritical CO2 for the extraction of metals from electronic waste, specifically Printed circuit boards (PCB). The complexity of PCB was first simplified by synthesizing laminate polymer and metal “model PCB” samples, where the polymer component was polycarbonate (PC) and the metal component was Cu foil. Through controlled studies of the effect of supercritical CO2 (scCO2) and sulfuric acid on the model PCB samples, a thorough understanding of the role of CO2 in the supercritical CO2/co-solvent system was developed. The scCO2/co-solvent system was found to induce permanent, morphological changes in the samples in just 30 minutes. Building on these results, a two-step metal extraction process for waste PCB was proposed. First, the pre-treatment of small pieces of waste PCB with scCO2 and sulfuric acid, and second, chemical leaching at ambient temperature and pressure in a sulfuric acid and hydrogen peroxide solution. This process was demonstrated to yield ~80% Cu extraction in under four hours, without the need for vigorous and energy-intensive mechanical processing, as the starting materials were small pieces of waste PCB, neither shredded nor crushed.
The final part of the thesis presents a study on the electrochemical recovery of Co and Ni from spent Lithium-ion batteries (LIB). Galvanostatic deposition and stripping of the metals were performed using a sulfuric acid-based electrolyte with concentrations of Co and Ni based upon waste LIB solution. A complexing agent, specifically EDTA, was introduced into the electrolyte to selectively deposit one metal over the other. The concentration of EDTA was maintained at the concentration of Co and Ni in the solution, and the pH values of the solution were varied to study the effect of pH on the ratio of Co/Ni in the deposit. In the presence of EDTA, the pH of the solution had a significant impact on the ratio of Co/Ni, making the electrochemical process presented in this study an effective, sustainable approach to simultaneous and tunable metal recovery from waste LIBs.
|
114 |
Geothermal Alteration of Basaltic Core from the Snake River Plain, IdahoSant, Christopher Joseph 01 May 2012 (has links)
The Snake River Plain is located in the southern part of the state of Idaho. The eastern plain, on which this study focuses, is a trail of volcanics from the Yellowstone hotspot. Three exploratory geothermal wells were drilled on the Snake River Plain. This project analyzes basaltic core from the first well at Kimama, north of Burley, Idaho. The objectives of this project are to establish zones of geothermal alteration and analyze the potential for geothermal power production using sub-aquifer resources on the axial volcanic zone of the Snake River Plain. Thirty samples from 1,912 m of core were sampled and analyzed for clay content and composition using X-ray diffraction. Observations from core samples and geophysical logs are also used to establish alteration zones. Mineralogical data, geophysical log data and physical characteristics of the core suggest that the base of the Snake River Plain aquifer at the axial zone is located 960m below the surface, much deeper than previously suspected. Swelling smectite clay clogs pore spaces and reduces porosity and permeability to create a natural base to the aquifer. Increased temperatures favor the formation of smectite clay and other secondary minerals to the bottom of the hole. Below 960 m the core shows signs of alteration including color change, formation of clay, and filling of other secondary minerals in vesicles and fractured zones of the core. The smectite clay observed is Fe-rich clay that is authigenic in some places. Geothermal power generation may be feasible using a low temperature hot water geothermal system if thermal fluids can be attained near the bottom of the Kimama well. (113 pages)
|
115 |
Geology of the Summer Ranch and North Promontory Mountains, UtahAdams, O. Clair 01 May 1962 (has links)
General Statement
The Summer Ranch and North Promontory Mountains have not been studied in detail geologically, although the surrounding mountains have been extensively investigated. Within the limits of this area, sedimentary rocks of Mississippian through Permian crop out. Sedimentary and volcanic rocks of Tertiary age are also exposed. Extensive Lake Bonneville deposits underlie the valleys and overlap the foothills.
The purposes of this study are: (1) to describe the structure, stratigraphy, and geologic history of the area, (2) to prepare a geologic map of the area, and (3) to relate the stratigraphic features of this area to those of the surrounding region.
Location of Area
The area studied is bordered on the north by the Utah-Idaho state line and on the east by Blue Creek Valley. Utah State Highway 83 and Great Salt Lake form the southern boundary and Curlew Valley, south-southwest from Snowville, Utah, defines the western limit (Figure 1).
The mapped area lies completely .within Box Elder County and covers a total of about 529 square miles. The Utah division of the Thiokol Chemical Corporation is located near the southeast corner of the mapped area.
Field Work
Initial field work was begun in August of 1960. Investigation of the 3 mapped area plus near-by areas was carried on continuously through September of that year and intermittently until June, 1961.
Access roads are mainly unimproved but are passable by passenger car. Water is available at most of the ranches in the adjoining valleys and at several springs in the North Promontory and Summer Ranch Mountains.
Structural and stratigraphic details were plotted on vertical aerial photographs in the field. Information was subsequently transferred to a topographic map at a scale of 1:62, 500, which was enlarged from a U. S. Geological Survey map, then traced on a transparent overlay. Stratigraphic sections were measured with a Brunton compass or with a steel tape.
Previous Investigations
No previous complete geologic investigation has been made of the area covered by this report. Various local features within the mapped area have been studied.
Walter (1934, p. 178-195) describes the structural relations of the Hansel Valley earthquake of 1934. Additional investigation concerning the structure of Hansel Valley was conducted by Adams (1938). Tertiary stratigraphy of Cache Valley was studied by Adamson (1955). Adamson reported the occurrence of tuffaceous rocks, similar to those in Cache Valley, in association with basalt flows near Snowville, Utah. Smith (1953, p. 74) diagrams the southern limit of the Snake River basalt flows and showed that they covered the northern part of the area concerned in the present investigation.
|
116 |
The stratigraphy and structure of the Columbia River basalt in the Clackamas River drainageAnderson, James Lee 01 January 1978 (has links)
The Clackamas River drainage within the western Cascade Range is approximately aligned with a northwest trending lineation defined by the Portland Hills and the Brothers Fault zone. This area is occupied by an extensive Columbia River Basalt sequence that is deeply incised by the Clackamas River and its tributaries. Two major basalt units of the Yakima Basalt Subgroup, including the Grande Ronde Basalt and the Frenchman Springs Member of the Wanapurn Basalt, are distinguishable in a 515 meter to 550 meter accumulation. Of particular interest is the presence of five trending right-lateral strike-slip faults is consistent with a stress model of north-south compression and east-west extension.
|
117 |
Experimental Investigation of the Mechanical and Creep Rupture Properties of Basalt Fiber Reinforced Polymer (BFRP) BarsBanibayat, Pouya 07 December 2011 (has links)
No description available.
|
118 |
The Effects of Corrosion on Reinforced Concrete with Fiber AdditionLewis, Jeremy D. 20 December 2012 (has links)
No description available.
|
119 |
Mafic Alkaline Magmatism in the East Tintic Mountains, West-Central Utah: Implications for a Late Oligocene Transition from Subduction to ExtensionAllen, Tara Laine 08 March 2012 (has links) (PDF)
Voluminous Eocene to Oligocene intermediate to silicic volcanic rocks related to subduction erupted throughout the Great Basin and were supplanted by bimodal eruptions of basalt and rhyolite related to extension in the Miocene. Locally, in the northern East Tintic Mountains of central Utah, this important transition is marked by a distinctive package of mafic alkaline magmas that reveal important details about the nature of this fundamental change. A late Oligocene anorthoclase-bearing shoshonite lava in the Boulter Peak quadrangle contains megacrysts of anorthoclase, with phenocrysts of olivine, clinopyroxene, magnesiohastingsite, magnetite, and apatite. The anorthoclase grains occur as glomerocrysts with irregular, resorbed edges, indicating they are not in equilibrium with the mafic phenocrysts in the shoshonite. They are interpreted to be xenocrysts incorporated into an ascending mafic magma that came into contact with a partially crystallized syenite. The mafic magma involved was probably derived by partial melting of the lithospheric mantle based on its high Mg/Fe ratios, magnesian phenocrysts, high water content, and high ratios of lithophile to high field strength elements. The syenite body likely crystallized from a highly differentiated melt. The 40Ar/39Ar age of the shoshonite is 25.35±0.04 Ma, and appears to represent the transition from subduction before the onset of extension (Christiansen et al., 2007). Other Oligocene mafic units in the area may represent different variations of the mafic alkaline endmember for the mixing process. The Gardison Ridge dike, a potassic alkaline basalt with an 40Ar/39Ar age of 26.3±0.3 Ma, contains olivine and clinopyroxene phenocrysts that are compositionally very similar to those found in the shoshonite. Other mafic dikes have even higher alkalis. All of these dikes have similar trace element patterns, with negative Nb and positive Pb anomalies, and high Ba and K concentrations. The minette of Black Rock Canyon (28.45±0.13 Ma) also contains high alkalis, particularly K, and its trace element pattern shows positive Ba and negative Nb anomalies. The clinopyroxene phenocrysts in the minette are also very similar to those found in the other alkaline rocks. The high water contents of these units are evidenced by amphibole in the shoshonite, phlogopite in the minette, and the lack of plagioclase phenocrysts in the basaltic dikes. The ages, mineral assemblages, and chemical compositions show that these late Oligocene alkaline magmas formed after a shallowly subducting oceanic slab peeled away from the overlying continental lithosphere and rolled back. Hot asthenosphere flowed in to replace the subducting plate and caused partial melting of the variably metasomatized lithospheric mantle. These alkaline magmas include the shoshonite, mafic alkaline dikes, and minette of Boulter Peak; they mark the transition from older subduction-related magmatism to Miocene magmatism caused by lithospheric extension.
|
120 |
The Origin and Tectonic Setting of Tow Hill, Queen Charlotte IslandsTimms, Catherine E. 04 1900 (has links)
<p> Tow Hill is a 109m butte located on the north shore of Graham Island, Queen Charlotte Islands. It is composed of a massive, 105m thick layer of olivine tholeiite, underlain by thin sills of tholeiitic basalt and interbedded sediments of the Skonun Formation. The age of this basalt body has been estimated to be less than 5Ma. Three hypotheses have been proposed as to the origin of Tow Hill: 1. a sill intrusion; 2. hydroclastic material; and 3. a lava flow or flows. Macroscopic features observed on Tow Hill do not indicate an origin and each of the three hypotheses can adequately explain the features. Petrographical studies indicate that the basalt is not fragmental and thus, the second hypothesis can be rejected. Neither of the two remaining hypotheses can be strictly accepted or rejected with petrographical examination. Chemical analyses indicate that Tow Hill is made up of "within plate" basalts which are probably related to activity associated with rifting and/or transtension in a continental environment. This constrains the late Tertiary tectonic history of the Queen Charlotte Islands in that any model of the tectonics of this area must involve rifting and/or transtension.</p> / Thesis / Bachelor of Science (BSc)
|
Page generated in 0.0239 seconds