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Articles 31 - 60 of 94

Full-Text Articles in Mineral Physics

Crustal Seismic Anisotropy Of The Ruby Mountains Core Complex And Surrounding Northern Basin And Range, Justin T. Wilgus Oct 2018

Crustal Seismic Anisotropy Of The Ruby Mountains Core Complex And Surrounding Northern Basin And Range, Justin T. Wilgus

Earth and Planetary Sciences ETDs

Metamorphic core complexes (MCC) are distinctive uplifts that expose deeply exhumed and deformed crustal rocks due to localized extensional deformation. Consequently, their detailed structure provide a window into deep crustal mechanics. The North American Cordillera contains numerous MCC, one of which is the Ruby Mountains core complex (RMCC) located in the highly extended northern Basin and Range. To constrain the extent to which anisotropy below the RMCC deviates from the regional Basin and Range average and test the depth dependence of crustal anisotropy we conduct a radial anisotropy investigation below the RMCC and surrounding northern Basin and Range. Data from …


Extremely High Diversity Of Sulfate Minerals In Caves Of The Irazú Volcano (Costa Rica) Related To Crater Lake And Fumarolic Activity, Andrés Ulloa, Fernando Gázquez, Aurelio Sanz-Arranz, Jesús Medina, Fernando Rull, José María Calaforra, Guillermo E. Alvarado, María Martínez, Geoffroy Avard, J. Maarten De Moor, Jo De Waele Jun 2018

Extremely High Diversity Of Sulfate Minerals In Caves Of The Irazú Volcano (Costa Rica) Related To Crater Lake And Fumarolic Activity, Andrés Ulloa, Fernando Gázquez, Aurelio Sanz-Arranz, Jesús Medina, Fernando Rull, José María Calaforra, Guillermo E. Alvarado, María Martínez, Geoffroy Avard, J. Maarten De Moor, Jo De Waele

International Journal of Speleology

The caves of the Irazú volcano (Costa Rica), became accessible after the partial collapse of the NW sector of the Irazú volcano in 1994, offering the opportunity to investigate active minerogenetic processes in volcanic cave environments. We performed a detailed mineralogical and geochemical study of speleothems in the caves Cueva los Minerales and Cueva Los Mucolitos, both located in the northwest foothills of the main crater. Mineralogical analyses included X-ray diffraction (XRD) and Raman spectroscopy, while geochemical characterization used Energy Dispersive X-ray spectroscopy (EDX) coupled to Scanning Electron Microscopy (SEM). In addition, measurements of environmental parameters in the caves, …


Giant Plagioclase In The Steens Basalt, Se Oregon: Cumulate Entrainment Revealed By Textural And In Situ Chemical Analysis, Conner H. Toth Jan 2018

Giant Plagioclase In The Steens Basalt, Se Oregon: Cumulate Entrainment Revealed By Textural And In Situ Chemical Analysis, Conner H. Toth

All Master's Theses

Many of the lava flows comprising the Steens Basalt in SE Oregon, the oldest and most mafic formation of the Columbia River Basalt Group (CRBG), contain exceptionally large (up to 5 cm) and abundant (up to 40 modal %) plagioclase crystals. This thesis presents a model for giant plagioclase formation in a complex system that integrates petrographic and in situ plagioclase compositional analyses with whole-rock data and computational modeling to explain systematic textural and chemical differences between plagioclase of the lower and upper Steens Basalt sub-sections. Lower Steens plagioclase are typically more chemically homogenous than upper Steens plagioclase and exhibit …


De Paepe, Duane - Collector (Mss 625), Manuscripts & Folklife Archives Nov 2017

De Paepe, Duane - Collector (Mss 625), Manuscripts & Folklife Archives

Manuscript Collection Finding Aids

Finding aid only for Manuscripts Collection 625. The Duane De Paepe Kentucky Cave Saltpetre History Research Collection, a collection of historical research, field notes, cave surveys, photographs, maps, reports, and scholarly writing on saltpetre mining in Kentucky, especially at Mammoth Cave. The collection was created under a research program sponsored by the Cave Research Foundation and the National Geographic Society in Kentucky, 1976-1980, and directed by De Paepe.


Faust, Burton Sherwood, 1898-1967 (Mss 620), Manuscripts & Folklife Archives Nov 2017

Faust, Burton Sherwood, 1898-1967 (Mss 620), Manuscripts & Folklife Archives

Manuscript Collection Finding Aids

Finding aid only for Manuscripts Collection 620. Correspondence, research notes, drafts, photographs, reference works and bibliographic material of Burton S. Faust relating to his studies of the chemical, historical and cultural aspects of saltpetre and of spelean saltpetre mining in the United States.


Further Study Of Garnet Xenocrysts In New York City Migmatites, Stanley Schleifer, Nazrul I. Khandaker Oct 2017

Further Study Of Garnet Xenocrysts In New York City Migmatites, Stanley Schleifer, Nazrul I. Khandaker

Publications and Research

The authors have previously published an article at the 2004 Geological Society of America Annual Meeting, Petrogenetic Significance of Garnets in the Bedrock of New York City, in which they suggested that the garnet xenocrysts observed in the quartzofeldspathic zones of the migmatites, so frequently seen both at the surface, and below the surface pursuant to the construction of the Manhattan portion of New york City Water Tunnel #3, were a refractory residue of the anatectic melting of the immediately surrounding schistose bedrock. Although the relatively high melting point temperature of garnet compared to other minerals in the surrounding …


Murray Energy Corporation V. Mccarthy, Sarah M. Danno Feb 2017

Murray Energy Corporation V. Mccarthy, Sarah M. Danno

Public Land & 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 Jan 2017

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, Riley Quine Jun 2016

Quartz Crystal Preferred Orientation And Recrystallization Patterns From Naturally Deformed Rocks Under Constriction, Riley Quine

Materials Engineering

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 that …


The Importance Of Geologic Study For The Application Of Carbon Capture And Storage (Ccs) In Otsego County, Michigan, Matthew Rine Apr 2016

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 …


An Investigation Into Transitions In Clay Mineral Chemistry On Mars, Seth Gainey Aug 2015

An Investigation Into Transitions In Clay Mineral Chemistry On Mars, Seth Gainey

UNLV Theses, Dissertations, Professional Papers, and Capstones

This dissertation is comprised of three studies investigating clay mineralogy on, or near the martian surface, with an introductory chapter, introducing and linking the three studies. Chapter two is on the subject of clay mineral synthesis, including Fe/Mg clay minerals which have been detected at multiple locations across the southern highlands. These Fe/Mg clay minerals have been previously interpreted as forming in anoxic/reducing environments, conducive to the preservation of organic matter. The results of this study suggest that the previous interpretation of Fe/Mg-rich clay as requiring anoxic/reducing conditions may not be accurate, as the minor presence of Mg (below what …


Anomalous Thermal Indicators From Authigenic Minerals In Upper Paleozoic Strata Of The Michigan Basin, Kyle Cox Jun 2015

Anomalous Thermal Indicators From Authigenic Minerals In Upper Paleozoic Strata Of The Michigan Basin, Kyle Cox

Masters Theses

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 …


Holocene Sedimentology And Stratigraphy Of Coastal Sediments In An Arid Climate, Al Qahmah, Southern Red Sea, Saudi Arabia, Abdullah Ibrahim Nabhan Jan 2015

Holocene Sedimentology And Stratigraphy Of Coastal Sediments In An Arid Climate, Al Qahmah, Southern Red Sea, Saudi Arabia, Abdullah Ibrahim Nabhan

Doctoral Dissertations

"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, William Thomas Fischer Dec 2014

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 …


Remote Exploration: Understanding Martian Surface Processes, Sarah M. Bass, Virginia C. Gulick, Natalie Glines, Patrick Freeman Aug 2014

Remote Exploration: Understanding Martian Surface Processes, Sarah M. Bass, Virginia C. Gulick, Natalie Glines, Patrick Freeman

STAR Program Research Presentations

Earth and Mars share many similar physical features, including canyons, valleys, craters, volcanoes, ice, and gullies. My research focuses on two distinct projects. The first concentrates on the formation of gullies, which are channel networks generally formed on mid-latitude crater walls on Mars. Debated gully-forming processes include the melting of snowpacks, sublimation of accumulated carbon dioxide frost, melting of snow-rich dusty mantle material, and groundwater flows. Using High Resolution Imaging Science Experiment (HiRISE) images of gullies and working with Digital Elevation Models (DEMs) in ENVI, we are able to perform detailed studies of gully morphology, including volume calculations using slope, …


Exploring The Link Between Otolith Growth And Function Along The Biological Continuum In The Context Of Ocean Acidification, Eric D. Wilcox Freeburg Jun 2014

Exploring The Link Between Otolith Growth And Function Along The Biological Continuum In The Context Of Ocean Acidification, Eric D. Wilcox Freeburg

Graduate Doctoral Dissertations

Oceans are acidifying as atmospheric CO2 is drawn down. This process, known as ocean acidification (OA), is well known and documented. Over the next 100 years, pH of the surface ocean is projected to decrease by up to 0.35 units. This CO2 draw down has a direct effect on dissolved inorganic carbon (DIC) balance in the ocean. OA is expected to impact calcifying organisms that rely on constituencies of the DIC system, specifically carbonate ion [CO32-]. It is clear that externally calcified structures, such as coral skeletons, bivalve shells, etc., will be significantly affected as pH, …


The Effect Of Single Crystal Elastic And Plastic Anisotropy On Stress And Strain Heterogeneity: Comparison Of Olivine To Other Common Minerals, Christopher Joseph Cline Ii May 2014

The Effect Of Single Crystal Elastic And Plastic Anisotropy On Stress And Strain Heterogeneity: Comparison Of Olivine To Other Common Minerals, Christopher Joseph Cline Ii

UNLV Theses, Dissertations, Professional Papers, and Capstones

In order to investigate the influence of single crystal elastic anisotropy on the heterogeneity of stress distributions during polycrystalline deformation multiple deformed crystalline materials were analyzed using electron backscatter diffraction (EBSD). Deformation experiments were conducted on samples of Solnhofen limestone using a modified Griggs piston cylinder apparatus at UNLV, and also on San Carlos olivine using the D-DIA multi-anvil press at the National Synchrotron Light Source beamline X17B2. Analysis of the mechanical twins in deformed calcite and kink bands in olivine help elucidate deviations in local stress directions away from that of the applied macroscopic stress. Combined calculated compression directions …


Microstructures And Quartz Lattice-Preferred Orientations In The Eclogite-Bearing Migmatitic Gneisses Of The D’Entrecasteaux Islands, Papua New Guinea, T. A. Little, B. R. Hacker, S. J. Brownlee, G. Seward Jun 2013

Microstructures And Quartz Lattice-Preferred Orientations In The Eclogite-Bearing Migmatitic Gneisses Of The D’Entrecasteaux Islands, Papua New Guinea, T. A. Little, B. R. Hacker, S. J. Brownlee, G. Seward

Environmental Science and Geology Faculty Research Publications

Lattice preferred orientations (LPO) of quartz in gneiss domes of the D’Entrecasteaux Islands, Woodlark Rift shed insight into exhumation of the world’s youngest (~5–7Ma) eclogite-bearing terrane at cm/yr rates. We focus on deformation that affected the terrane as it transited between lower crustal depths and the surface, including: (1) grain-scale deformation mechanisms; and (2) style of flow and mode of emplacement of the domes. Electron-backscatter diffraction was used to analyze microstructure and LPOs of 37 quartzofeldspathic gneiss samples that enclose meter-scale mafic blocks preserving original eclogite-facies assemblages. During exhumation of the ultrahigh-pressure (UHP) terrane, gneisses were retrogressed in the amphibolite …


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 …


Raman Mapping Of Mars Relevant Minerals Using Multiple Excitation Wavelenghts, Victoria Campbell, William Abbey Aug 2012

Raman Mapping Of Mars Relevant Minerals Using Multiple Excitation Wavelenghts, Victoria Campbell, William Abbey

STAR Program Research Presentations

The purpose of this project is to map Mars relevant minerals using the Raman instrument Horiba LabRam Raman. The Raman spectrometer is a non-invasive sampling technique used to identify mineral composition of various compositions by measuring the “Raman Shift” of each mineral. This was accomplished by using a green (532nm) laser which acted as a monochromatic light source. This source was absorbed by the sample and reemitted. The frequency of the reemitted photons are then shifted up or down in comparison with original frequency, which is referred to as the ‘Raman Effect’. The samples with shorter wavelengths produced a stronger …


Examination Of Spatial Variations In Recrystallization Mechanisms In Quartz, Emma N. Beck Jan 2012

Examination Of Spatial Variations In Recrystallization Mechanisms In Quartz, Emma N. Beck

Honors Theses

S-C mylonites form as a result of non-coaxial deformation in ductile shear zones. Planes of weakness develop and delineate two domains, the S and the C Each of these domains accommodates variable amounts of strain. Sample WMSZ-188 exhibits subgrain rotation (SGR) recrystallization in the C domains, and grain boundary migration (GBM) recrystallization in the S domains. This partitioning of recrystallization mechanisms indicates either: (1) strain-rate partitioning during a single deformation event; or (2) a second, lower-temperature deformation event that over-printed the C domains. This study tests these two hypotheses. Optical and EBSD analyses were used to look for evidence of …


Documenting Magma Evolution Of The Fossa Delle Felci (Salina Island, South Tyrrhenian Sea) By Integrating In Situ Plagioclase Data With Quantitative Modeling, Aaron Mayfield Jan 2012

Documenting Magma Evolution Of The Fossa Delle Felci (Salina Island, South Tyrrhenian Sea) By Integrating In Situ Plagioclase Data With Quantitative Modeling, Aaron Mayfield

All Master's Theses

Compositional diversity occurs via processes dominated by recharge, assimilation and fractional crystallization (RAFC), quantification of which can provide insights into eruption catalysts, and therefore assist in hazard mitigation. This study evaluates the relative roles of RAFC processes in Fossa delle Felci (Salina Island, Italy) magmas, which span the basalt to dacite range (52-65 wt% SiO2). Integration of petrographic, whole rock, and in situ plagioclase data with quantitative magma chamber models suggests differentiation dominated by fractional crystallization and magma recharge/mixing in reservoirs located at different crustal levels. At ~12 km depth, magma evolved through crystallization of a pyroxene dominated assemblage; plagioclase …


Documenting Magnatic Processes At Filicudi Island, Aeolian Arc, Italy: Integrating Quantitative Modeling And Plagioclase Textural And In Situ Compositional Data, Michelle Harris Jan 2012

Documenting Magnatic Processes At Filicudi Island, Aeolian Arc, Italy: Integrating Quantitative Modeling And Plagioclase Textural And In Situ Compositional Data, Michelle Harris

All Master's Theses

Documenting the physiochemical processes that influence magma composition is critical for forecasting eruption styles and managing volcanic hazards. Compositional diversity of magmas develops through recharge, assimilation, and fractional crystallization (RAFC) within subvolcanic magma reservoirs. Integration of MELTS modeling, whole rock, plagioclase textural and in situ elemental and isotopic data from Filicudi Island, Italy allow documentation of the roles and relative chronology that RAFC played in the magmatic evolution and elucidates aspects of the magma plumbing system structure.

Results indicate a polybaric magma plumbing system with deeper (3.5-4 kilobars) and shallower (0.5-1.2 kilobars) storage regions. Within the deeper system, FC acted …


Documenting The Origin Of Compositional Diversity Of Subduction Zone Magmatism, Alicudi, Aeolian Arc (Southern Tyrrhenian Sea, Italy) Using In Situ Plagioclase Data, Rachel Hunt Jan 2012

Documenting The Origin Of Compositional Diversity Of Subduction Zone Magmatism, Alicudi, Aeolian Arc (Southern Tyrrhenian Sea, Italy) Using In Situ Plagioclase Data, Rachel Hunt

All Master's Theses

Processes that generate magma compositional diversity are important to document because composition affects degree of explosivity, which impacts hazard mitigation. Magnesium to silicon rich magmas are produced by processes such as magma recharge, assimilation, and fractional crystallization (RAFC) that occur in subvolcanic magma chamber(s). This study evaluates how magma chamber processes contribute to compositional diversity at Alicudi Volcano, Italy. Analytical and petrographic data from ten samples that span the subaerial history include whole rock major and trace elements and strontium/neodymium isotopes, and plagioclase textural types, major and trace elements, and strontium isotopes; numerical modeling was also conducted. Integration of these …


Microstructural Characterization Of Kinked Germanate Olivine Grains, Alex Gregory Drue Dec 2011

Microstructural Characterization Of Kinked Germanate Olivine Grains, Alex Gregory Drue

UNLV Theses, Dissertations, Professional Papers, and Capstones

Olivine is the most common and the weakest mineral in the upper mantle. Thus the strength of olivine controls the rheology of the earth's upper mantle. The rheology of olivine in the upper mantle has important implications for mantle flow, mountain building, and rates of isostatic adjustment. Recent experimental measurements of the flow strength of deformed olivine polycrystals have assumed a homogeneous state of stress. X-ray synchrotron diffraction experiments have implied that this assumption is not always valid. Elastic Plastic Self Consistent (EPSC) modeling offers an approach to estimating the flow strength of olivine that does not assume a homogeneous …


Depositional Fluxes And Concentrations Of 7Be And 210Pb In Bulk Precipitation And Aerosols At The Interface Of Atlantic And Mediterranean Coasts In Spain, R. L. Lozano, E. G. San Miguel, J. P. Bolívar, M. Baskaran Sep 2011

Depositional Fluxes And Concentrations Of 7Be And 210Pb In Bulk Precipitation And Aerosols At The Interface Of Atlantic And Mediterranean Coasts In Spain, R. L. Lozano, E. G. San Miguel, J. P. Bolívar, M. Baskaran

Environmental Science and Geology Faculty Research Publications

Bulk depositional fluxes of 7Be and 210Pb in precipitation measured over a period of 16 months (April 2009–July 2010) in Huelva, Spain varied between 5.6 and 186 Bq m−2 month−1 (annual mean: 834 Bq m−2 year−1) and 0.8 and 8.1 Bq m−2 month−1 (annual mean: 59 Bq m−2 year−1), respectively, with the lowest depositional fluxes occurring during dry summer months. Quantitative evaluation of the precipitation-normalized seasonal depositional fluxes of 7Be and 210Pb indicates that the enrichment factor in winter is < 1.0 while in 2010 spring, it is significantly higher than 1, possibly indicating input of air from the stratosphere-troposphere exchange (for 7Be). The specific activities of …


Magnetic Properties Of Ilmenite‐Hematite Single Crystals From The Ecstall Pluton Near Prince Rupert, British Columbia, Sarah J. Brownlee, Joshua M. Feinberg, Takeshi Kasama, Richard J. Harrison, Gary R. Scott, Paul R. Renne Sep 2011

Magnetic Properties Of Ilmenite‐Hematite Single Crystals From The Ecstall Pluton Near Prince Rupert, British Columbia, Sarah J. Brownlee, Joshua M. Feinberg, Takeshi Kasama, Richard J. Harrison, Gary R. Scott, Paul R. Renne

Environmental Science and Geology Faculty Research Publications

Paleomagnetic studies of the 91 Ma Ecstall pluton and other Cretaceous plutons of British Columbia imply large northward tectonic movements (>2000 km) may have occurred during the tectonic evolution of western North America. However, more recent studies have shown that the eastern edge of the Ecstall pluton experienced considerable mineralogical changes as younger Eocene plutons, such as the ∼58 Ma Quottoon Pluton, were emplaced along its margins. We investigated changes in the rock magnetic properties associated with this reheating event by examining isolated grains of intergrown ilmenite and hematite, the primary paleomagnetic recorder in the Ecstall pluton. Measurements of …


Correlation Between Grain Dislocation Density And Orientation For Naturally Deformed Mantle Xenolith From Jagersfontein Mine, Quinton Guerrero, Quinlan Smith Aug 2011

Correlation Between Grain Dislocation Density And Orientation For Naturally Deformed Mantle Xenolith From Jagersfontein Mine, Quinton Guerrero, Quinlan Smith

Undergraduate Research Opportunities Program (UROP)

Determining the reaction of poly-crystalline structures to induced stress is an extremely difficult problem in contemporary engineering and geology. The main challenge lies in the inhomogeneity of the grains inside of the poly-crystalline structures. To predict the response of a certain polycrystalline structure to a specific stress, you must resort to one of two views on grain interaction, an orientation or propagation based model. For every material there may be certain correlations between the prediction model used and the actual deformation that occurred. Our work centers around describing the correlation of these prediction models with a sample of naturally deformed …


Rock Porosity Analysis Using High Resolution X-Ray Tomography, Leo Groner, Dula Parkinson, Katya Bazilevskaya Aug 2011

Rock Porosity Analysis Using High Resolution X-Ray Tomography, Leo Groner, Dula Parkinson, Katya Bazilevskaya

STAR Program Research Presentations

Understanding rock porosity, the fraction of rock volume that is in pores, is a key to modeling weathering and flow of water, petroleum and CO2 through geological structures. Weathering of rocks affects the CO2 cycle, nutrient cycle and soil formation. Rock porosity affects water flow rates and, in turn, affects weathering. Avizo software was used to explore, visualize and measure the reconstructed high-resolution X-ray micro-tomography data collected from scanned rocks. Many Avizo approaches were tried before arriving at an acceptable process to determine their porosity characteristics. Porosity dynamics are affected by weathering and lithification. At micron resolution, the image is …


Secondary Halite Deposits In The Iranian Salt Karst: General Description And Origin, Michal Filippi, Jiří Bruthans, Lukáš Palatinus, Mohammad Zare, Naser Asadi Jan 2011

Secondary Halite Deposits In The Iranian Salt Karst: General Description And Origin, Michal Filippi, Jiří Bruthans, Lukáš Palatinus, Mohammad Zare, Naser Asadi

International Journal of Speleology

This paper summaries 12 years of documentation of secondary halite deposits in the Iranian salt karst.

A variety of secondary halite deposits was distinguished and classified into several groups, on the basis of the site and mechanism of their origin. Deposits formed: i) via crystallization in/on streams and pools, ii) from dripping, splashing and aerosol water, iii) from evaporation of seepage and capillary water, and iv) other types of deposits. The following examples of halite forms were distinguished in each of the above mentioned group: i) euhedral crystals, floating rafts (raft cones), thin brine surface crusts and films; ii) straw …