Stick-Slip And Creep Behavior In Lubricated Granular Material: Insights Into The Brittle-Ductile Transition, 2017 Iowa State University
Stick-Slip And Creep Behavior In Lubricated Granular Material: Insights Into The Brittle-Ductile Transition, Jacqueline E. Reber, Nicholas W. Hayman, Luc L. Lavier
Crustal deformation can occur via stick-slip events, viscous creep, or strain transients at variable rates. Here we explore such strain transients with physical experiments comprising a quasi-two-dimensional shear zone with elastic, acrylic discs and interstitial viscous silicone. Experiments of solely elastic discs produce stick-slip events and an overall (constant volume) strengthening. The addition of the viscous silicone enhances localization but does not greatly change the overall pattern of strengthening. It does, however, damp the stick-slip events, leading to transient, creep-like behavior that approaches the behavior of a Maxwell body. There is no gradual transition from frictional to viscous deformation with ...
Experimental Studies Of Electrical Resistivity Behavior Of Cu, Zn And Co Along Their Melting Boundaries: Implications For Heat Flux At Earth’S Inner Core Boundary, 2017 The University of Western Ontario
Experimental Studies Of Electrical Resistivity Behavior Of Cu, Zn And Co Along Their Melting Boundaries: Implications For Heat Flux At Earth’S Inner Core Boundary, Innocent Chinweikpe Ezenwa
Electronic Thesis and Dissertation Repository
The electrical resistivity of high purity Cu, Zn and Co has been measured at pressures (P) up to 5GPa and at temperatures (T) in the liquid phase. The electrical resistivity of solid state Nb was also measured up to 5GPa and ~1900K. All measurements were made in a large volume cubic anvil press. Using two thermocouples placed at opposite ends of the sample wire, serving as temperature probes as well as resistance leads, a four-wire technique resistivity measurement was employed along with a polarity switch. Post-experiment compositional analyses were carried out on an electron microprobe.
The expected resistivity decrease ...
Bat Urea-Derived Minerals In Arid Environment. First Identification Of Allantoin, C4H6N4O3, In Kahf Kharrat Najem Cave, United Arab Emirates, 2017 University of Nice Sophia-Antipolis
Bat Urea-Derived Minerals In Arid Environment. First Identification Of Allantoin, C4H6N4O3, In Kahf Kharrat Najem Cave, United Arab Emirates, Philippe Audra, Pavel Bosák, Fernando Gázquez, Didier Cailhol, Roman Skála, Lenka Lisá, Šárka Jonášová, Amos Frumkin, Martin Knez, Tadej Slabe, Nadja Zupan Hajna, Asma Al-Farraj
International Journal of Speleology
Kahf Kharrat Najem Cave is a small cave in United Arab Emirates (UAE) that hosts a bat colony which is the source of guano deposits and peculiar centimeter-long yellowish stalactites. The mineralogy and geochemistry of these deposits were analyzed using powder X-ray diffraction (XRD), energy dispersive X-ray spectroscopic microanalysis (EDX), scanning electron microscope (SEM), and stable isotope composition (δ13C and δ15N). Urea CO(NH2)2 was found to be the main compound of these stalactites, while allantoin C4H6N4O3 was found to be an accessory urea byproduct. This paper ...
Murray Energy Corporation V. Mccarthy, 2017 University of Montana School of Law
Murray Energy Corporation V. Mccarthy, Sarah M. Danno
Public Land and Resources Law Review
Holding that the widespread effects of environmental regulation on the coal industry constituted sufficient importance, the Northern District of West Virginia ordered the Environmental Protection Agency to conduct analysis on employment loss and plant reduction resulting from regulatory effects. In admonishing the EPA’s inaction, the court ruled that the Agency had a non-discretionary duty to evaluate employment and plant reduction. Furthermore, the court held that the EPA’s attempt to put forth general reports in place of required evaluations was an invalid attempt to circumvent its statutory duty.
Secondary Minerals From Salt Caves In The Atacama Desert (Chile): A Hyperarid And Hypersaline Environment With Potential Analogies To The Martian Subsurface, Jo De Waele, Cristina Carbone, Laura Sanna, Marco Vattano, Ermanno Galli, Francesco Sauro, Paolo Forti
International Journal of Speleology
Over the past 15 years several expeditions by French, American and especially Italian cavers have unveiled over 50 caves in the Cordillera de la Sal (Atacama Desert, Northern Chile). Many of these caves contain a variety of speleothems and minerals, some of which have rarely been observed within karst systems. Most of the secondary deposits in these caves are composed of halite, but also other halide, carbonate, sulphate, nitrate, phosphate, and silicate minerals have been found. Among the sixteen cave mineral species recognized, atacamite, darapskite, blödite, leonite, anhydrite, and especially antarcticite are worth mentioning. In one of the samples an ...
Quartz Crystal Preferred Orientation And Recrystallization Patterns From Naturally Deformed Rocks Under Constriction, 2016 California Polytechnic State University, San Luis Obispo
Quartz Crystal Preferred Orientation And Recrystallization Patterns From Naturally Deformed Rocks Under Constriction, Riley Quine
This study analyzes crystal preferred orientation (CPO) patterns within constrictional quartz-rich gneisses. Quartz deformation and CPO patterns are an area of interest because quartz is one of the most prevalent minerals in earth's crust. Understanding the typical way that quartz crystals reorient under different states of strain can provide geologists with an additional tool for understanding paleo-strain. Temperature and strain geometry are two dominant factors that control the orientation of quartz crystals within a rock. Temperature determines which slip planes are active and slip planes typically reorient so that they are perpendicular to maximum stress. Previous workers have suggested ...
Investigating Mineral Stability Under Venus Conditions: A Focus On The Venus Radar Anomalies, 2016 University of Arkansas, Fayetteville
Investigating Mineral Stability Under Venus Conditions: A Focus On The Venus Radar Anomalies, Erika Kohler
Theses and Dissertations
Radar studies of the surface of Venus have identified regions with high radar reflectivity concentrated in the Venusian highlands: between 2.5 and 4.75 km above a planetary radius of 6051 km, though it varies with latitude. Previous research has proposed several theories on the source of these anomalies, including increased surface roughness, metallic materials with higher dielectric constants, or ferroelectric materials. Prior work suggests several processes that could be the origin of these anomalies, such as surface-atmospheric interactions or low lying clouds or fog. Alternatively, these anomalies could result from a semi-metallic compound trapped at the cooler conditions ...
Growth Of Synthetic Silver Wires From Natural Acanthite, 2016 Cedarville University
Growth Of Synthetic Silver Wires From Natural Acanthite, Calvin J. Anderson
The Research and Scholarship Symposium
Wire silver is an unusual crystal habit of native silver which is intimately associated with acanthite (Ag2S). These delicate wires have been collected for several centuries, but much remains unknown regarding their growth mechanism and crystal structure. This study has successfully produced synthetic silver wires from natural acanthite in order to investigate the nature of their crystallinity.
Chunks of crude acanthite crystals from the Hongda mine, Shanxi Province, China, were trimmed into roughly 1 cm chunks for growth experiments. Preexisting silver wires, which appeared to be natural, were avoided.
Several techniques were explored with varying degrees of success. Attempts using ...
The Importance Of Geologic Study For The Application Of Carbon Capture And Storage (Ccs) In Otsego County, Michigan, 2016 Western Michigan University
The Importance Of Geologic Study For The Application Of Carbon Capture And Storage (Ccs) In Otsego County, Michigan, Matthew Rine
Research and Creative Activities Poster Day
The most recent Paris climate talks emphasized the importance of reducing carbon dioxide pollution associated with burning fossil fuels. In an attempt to mitigate CO2 emissions, carbon capture and storage (CCS), which is a process by which CO2 is pulled from a smokestack before it is released into our atmosphere and buried deep underground, is currently underway in Otsego County, Michigan. In order to safely and effectively store CO2 into deep geologic formations, it is critical to gain a better understanding for the geologic “storage tank” in which these fluids will be stored. As part of this ...
Precipitation And Growth Of Barite Within Hydrothermal Vent Deposits From The Endeavour Segment, Juan De Fuca Ridge, 2016 GEOMAR – Helmholtz Centre for Ocean Research Kiel
Precipitation And Growth Of Barite Within Hydrothermal Vent Deposits From The Endeavour Segment, Juan De Fuca Ridge, John William Jamieson, Mark D. Hannington, Margaret K. Tivey, Thor Hansteen, Nicole M.-B. Williamson, Margaret Stewart, Jan Fietzke, David Butterfield, Matthias Frische, Leigh Allen, Brian Cousens, Julia Langer
Publications, Agencies and Staff of the U.S. Department of Commerce
Hydrothermal vent deposits form on the seafloor as a result of cooling and mixing of hot hydrothermal fluids with cold seawater. Amongst the major sulfide and sulfate minerals that are preserved at vent sites, barite (BaSO4) is unique because it requires the direct mixing of Ba-rich hydrothermal fluid with sulfate-rich seawater in order for precipitation to occur. Because of its extremely low solubility, barite crystals preserve geochemical fingerprints associated with conditions of formation. Here, we present data from petrographic and geochemical analyses of hydrothermal barite from the Endeavour Segment of the Juan de Fuca Ridge, northeast Pacific Ocean, in ...
Evaluating Mineralogy At Terrestrial Analogs For Early Mars: Detection And Characterization Of Clays With Xrd And Investigation Of Iron Substitution In Natroalunite, 2016 University of Colorado at Boulder
Evaluating Mineralogy At Terrestrial Analogs For Early Mars: Detection And Characterization Of Clays With Xrd And Investigation Of Iron Substitution In Natroalunite, Laura Grace Beckerman
Geological Sciences Graduate Theses & Dissertations
The Mars Science Laboratory (MSL) Curiosity rover is equipped with CheMin, the first x-ray diffraction (XRD) instrument on Mars, for in situ mineralogy as part of its mission to seek evidence of past habitability at Gale Crater. Detection and characterization of hydrated minerals like clays and sulfates provides crucial insight into Mars’ early geochemistry. For example, clays are often interpreted as having formed in lacustrine environments at neutral pHs, while sulfates such as jarosite are evidence of acid sulfate alteration.
However, CheMin’s inability to remove non-clay minerals and to preferentially orient samples may pose significant challenges to clay detection ...
The Role Of The State, Multinational Oil Companies, International Law & The International Community: Intersection Of Human Rights & Environmental Degradation Climate Change In The 21st Century Caused By Traditional Extractive Practices, The Amazon Rainforest, Indigenous People And Universal Jurisdiction To Resolve The Accountability Issue, 2015 University of San Francisco
The Role Of The State, Multinational Oil Companies, International Law & The International Community: Intersection Of Human Rights & Environmental Degradation Climate Change In The 21st Century Caused By Traditional Extractive Practices, The Amazon Rainforest, Indigenous People And Universal Jurisdiction To Resolve The Accountability Issue, Marcela Cabrera Luna
Local, national and international conventions that protect indigenous sovereignty and their territories, where many of the resources are extracted from by multinational corporations (MNCs) particularly oil, the number one commodity of the world and cause of climate change, continue to be jeopardized because of the lack of a clear international legal framework that can protect them and potentially hold multinationals accountable for their actions. These practices are causing not only environmental issues to the indigenous and surrounding communities, but climate change is in fact, the real human rights issue of the 21st century and it affects everyone. By using ...
Strength Study Of Zircon Under High Pressure, 2015 The University of Western Ontario
Strength Study Of Zircon Under High Pressure, Ievgeniia Morozova
Electronic Thesis and Dissertation Repository
Zircon (ZrSiO4) is a strong accessory mineral that can retain U, Th and Hf within its structure. This makes zircon an important material in geochemical and geochronological studies. In addition, the strong thermal shock resistance of zircon allows for dating the formations of melt and impact events and to separate shocked and potentially shocked country rocks. However, the deformation mechanism and microstructure behavior of zircon at high pressure is poorly understood. Therefore, this work aims to study the deformation and texture of zircon in situ at high pressure and room temperature, and also to examine the microstructure of samples ...
Serpentinization, Carbon, And Deep Life, 2015 University of South Carolina - Columbia
Serpentinization, Carbon, And Deep Life, M. Schrenk, W. Brazelton, Susan Lang
Susan Q. Lang
No abstract provided.
Anomalous Thermal Indicators From Authigenic Minerals In Upper Paleozoic Strata Of The Michigan Basin, 2015 Western Michigan University
Anomalous Thermal Indicators From Authigenic Minerals In Upper Paleozoic Strata Of The Michigan Basin, Kyle Cox
Indications of anomalous paleo-temperatures exist in strata of the Michigan basin, USA. The thermal history of the basin was investigated through identification and analysis of authigenic components in two Upper Paleozoic strata, the Devonian Dundee Formation and Mississippian Marshall Sandstone. Formation conditions for diagenetic phases in both units were estimated through a variety of means and compared to conditions expected for a simple burial model. Authigenic clays identified in the Marshall via X-ray diffraction are expected to have formed at temperatures above what would have been produced by burial alone. Stable isotope and fluid inclusion analysis indicate the same for ...
Hydrothermal Acid-Sulfate Alteration At Krafla And Námafjall, Ne Iceland: Implications For Gusev Crater And Meridiani Planum, Mars, 2015 University of Wisconsin-Milwaukee
Hydrothermal Acid-Sulfate Alteration At Krafla And Námafjall, Ne Iceland: Implications For Gusev Crater And Meridiani Planum, Mars, George L. Carson
Theses and Dissertations
Opaline silica, sulfate, and phyllosilicate-bearing deposits have been detected on Mars from both obiters and rovers, indicating extensive aqueous alteration of the basaltic surface, some of which likely occurred under hydrothermal conditions. Ongoing hydrothermal acid-sulfate alteration of Mars-like high-Fe (15.48-16.27 wt. % Fe2O3T) basalts and hyaloclastites in northeastern Iceland was studied to help interpret the products of alteration in analogous environments on ancient Mars. The Krafla and Námafjall areas feature intense surface alteration in gas- (fumarole) and fluid- (hot spring/mud pot) dominated settings. Influx of H2S gas (H2S + 2O2 = H2SO4) produced steam-derived acid-sulfate waters with pH values 1 ...
Holocene Sedimentology And Stratigraphy Of Coastal Sediments In An Arid Climate, Al Qahmah, Southern Red Sea, Saudi Arabia, 2015 Missouri University of Science and Technology
Holocene Sedimentology And Stratigraphy Of Coastal Sediments In An Arid Climate, Al Qahmah, Southern Red Sea, Saudi Arabia, Abdullah Ibrahim Nabhan
"Holocene sedimentary deposits in Al Qahmah coast, southern Red Sea, in Saudi Arabia have been accumulated on an arid siliciclastic coast in a rift tectonic setting. This study provides a detail interpretation and analysis of sedimentary facies, stratigraphy, depositional environment, and major geological processes. Two studies have been undertaken. First, petrological study of composition and texture of modern sediments and facies mapping delineate facies distribution and mechanisms of sediment transport and deposition. A unique suite of complex riverine, wave, tidal, wind, and chemical and biological processes affect the composition, texture, and distribution of the facies. Second, the depositional environments of ...
Ore Classification And Breccia Formation In The 144 Zone Gold Deposit: A Chemical Replacement Model, Bare Mountain Range, Nevada, 2014 University of Nevada, Las Vegas
Ore Classification And Breccia Formation In The 144 Zone Gold Deposit: A Chemical Replacement Model, Bare Mountain Range, Nevada, William Thomas Fischer
UNLV Theses, Dissertations, Professional Papers, and Capstones
The 144 Zone is an oxidized, breccia-hosted, disseminated gold deposit that formed along the contact between Early Cambrian Carrara Formation limestone and overlying Bonanza King Formation dolomite within the Bare Mountain range in southern Nevada. Gold mineralization occurs within a breccia body that contains a variety of breccia types. Research goals of this project included classifying clay, oxide and other minerals as well as breccia types to identify the habits of gold mineralization and the minerals associated with gold. Research was also aimed at determining the paragenesis of Au mineralization and brecciation in the 144 Zone. Underground mapping provided spatial ...
Microstratigraphic Logging Of Calcite Fabrics In Speleothems As Tool For Palaeoclimate Studies, 2014 The University of Newcastle, Callaghan, Australia
Microstratigraphic Logging Of Calcite Fabrics In Speleothems As Tool For Palaeoclimate Studies, Silvia Frisia
International Journal of Speleology
The systematic documentation of calcite fabrics in stalagmites and flowstones provides robustness to palaeoclimate interpretation based on geochemical proxies, but it has been neglected because it is difficult to transform crystal morphologies into numerical values, and construct fabric time series. Here, general criteria that allow for coding fabrics of calcite composing stalagmites and flowstones is provided. Being based on known models of fabric development, the coding ascribes sequential numbers to each fabric, which reflect climate-related parameters, such as changes in drip rate variability, bio-mediation or diagenetic modifications. Acronyms are proposed for Columnar types, Dendritic, Micrite, Microsparite and Mosaic fabrics, whose ...
The Role Of Th-U Minerals In Assessing The Performance Of Nuclear Waste Forms, 2014 University of Pennsylvania
The Role Of Th-U Minerals In Assessing The Performance Of Nuclear Waste Forms, Gregory R. Lumpkin, Yan Gao, Reto Gieré, C T. Williams, Anthony Mariano, Thorsten Geisler
Departmental Papers (EES)
Materials designed for nuclear waste disposal include a range of ceramics, glass ceramics and glass waste forms. Those with crystalline phases have provided the momentum for studies of minerals as a means to understand aspects of waste-form crystal chemistry, behaviour in aqueous systems and radiation damage over geological periods of time. Although the utility of natural analogue studies varies, depending upon the degree of analogy to the proposed geological repository and other factors such as chemical composition, the available data suggest that Th-U host phases such as brannerite, monazite, pyrochlore, zircon and zirconolite are resistant generally to dissolution in aqueous ...