Measurement Of Luminescent Banding In Speleothems: Some Techniques And Limitations, 2012 Meiser & Earl, Inc.
Measurement Of Luminescent Banding In Speleothems: Some Techniques And Limitations, Bryan E. Crowell, William B. White
International Journal of Speleology
Speleothems, especially flowstone and cylindrical stalagmites, exhibit phosphorescence which is often banded on the scale of a few tens of micrometers. The luminescence bands are paleoclimatic records with a very high temporal resolution. A technique has been developed using a laser source and a high resolution Raman spectrometer with microscope and computer-controlled translation stage for both luminescence profiles and luminescence spectroscopy. Luminescence intensity could be measured as a function of traverse distance with a spatial resolution of 2 – 3 μm. Potential sources of error include loss of intensity due to radiation damage by the laser beam, irregularities, cracks, and …
Examination Of Spatial Variations In Recrystallization Mechanisms In Quartz, 2012 Colby College
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 Magnatic Processes At Filicudi Island, Aeolian Arc, Italy: Integrating Quantitative Modeling And Plagioclase Textural And In Situ Compositional Data, 2012 Central Washington University
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 …
Mineralogical, Petrographical And Geochemical Characteristics Of Eldivan Ophiolite (Çankiri) Harzburgitic Tectonites, 2011 Bulletin of the Mineral Research and Exploration
Mineralogical, Petrographical And Geochemical Characteristics Of Eldivan Ophiolite (Çankiri) Harzburgitic Tectonites, Tijen Üner, Üner Çakir
Bulletin of the Mineral Research and Exploration
The Eldivan Ophiolite is located at the central part of the Ýzmir-Ankara-Erzincan Ophiolitic Belt and between Þabanözü, Eldivan and Korgun towns. Ophiolite consists of volcanic-sedimentary series, metamorphic series, tectonites, cumulates and sheeted dikes from bottom to top. Tectonites, which are the main subject of the study, are generally represented by harzburgites and occassionally include dunite, pyroxenolite and chromitite levels. Harzburgites display of traces of plastic deformation (foliation, lineasyon, fold) A clear orientation in minerals can be observed as a result of in the tectonic sequence and grinding mechanisms. The degree of deformation decreases upwards. Harzburgites are generally composed of olivine …
Microstructural Characterization Of Kinked Germanate Olivine Grains, 2011 University of Nevada, Las Vegas
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, 2011 University of Huelva
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, 2011 University of California - Berkeley
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, 2011 Monmouth College
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 …
High Pressure Structural Studies On Baco3 Up To 20 Gpa, 2011 Colorado College
High Pressure Structural Studies On Baco3 Up To 20 Gpa, Justine Carryer, Ravhi S. Kumar
Undergraduate Research Opportunities Program (UROP)
Carbonate compounds are thought to make up a minor portion of the Earth's upper mantel. Shock heating of the surfaces of carbonate rocks, as in the instance of a meteor impact, has the potential to affect CO2 concentrations in the Earth's atmosphere. The bulkmodulus of carbonate materials is directly proportional to the rate of devolatilization under these conditions [1]. The interest in Barium Carbonate (BaCO3) specifically is motivated by its structural proximity to aragonite carbonates. Crystalline phase transitions occur in aragonite under extreme conditions that are difficult to maintain in a laboratory; BaC03 is isostructural with aragonite and therefore is …
Investigation Of Raman Active Modes Of Mgxzn1-Xcr2o4, 2011 Loyola University Chicago
Investigation Of Raman Active Modes Of Mgxzn1-Xcr2o4, Nichollas Macholl, Tyler Mosher
Undergraduate Research Opportunities Program (UROP)
Using Raman spectroscopy, vibrational modes of the spinel structure MgxZn1-xCr2O4 were experimentally examined. The spinel compounds were synthesized by producing solid solutions via combustion method, of MgxZn1-xCr2O4 in the range x=0 to x=1 in 0.1 intervals. The purpose of which was to experimentally verify gradual shifts of Raman peaks as the samples transitioned between the two different compounds and gain information about the dependencies of the lattice vibrations on the tetrahedral and octahedral cations. X-ray diffraction was also used to verify spinel structure, and track the changes in lattice parameter of the samples.
Rock Porosity Analysis Using High Resolution X-Ray Tomography, 2011 lgroner@gmail.com
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 …
Raman Spectroscopic Study Of Solid Solution Spinel Oxides, 2011 University of Nevada, Las Vegas
Raman Spectroscopic Study Of Solid Solution Spinel Oxides, Brian D. Hosterman
UNLV Theses, Dissertations, Professional Papers, and Capstones
Solid solution spinel oxides of composition MgxNi1−xCr2O4, NiFexCr2−xO4, and FexCr3−xO4 were synthesized and characterized using x-ray diffraction and Raman spectroscopy. Frequencies of the Raman-active modes are tracked as the metal cations within the spinel lattice are exchanged. This gives information about the dependence of the lattice vibrations on the tetrahedral and octahedral cations. The highest-frequency Raman-active mode, A1g, is unaffected by substitution of the divalent tetrahedral cation, whereas the lower frequency vibrations are more strongly affected by substitution of the tetrahedral cation. The change in wavenumber of many phonons is nonlinear upon cation exchange. All detected modes of MgxNi1−xCr2O4 and …
Elastic Plastic Self Consistent (Epsc) Modeling Of Plastic Deformation In Fayalite Olivine, 2011 University of Nevada, Las Vegas
Elastic Plastic Self Consistent (Epsc) Modeling Of Plastic Deformation In Fayalite Olivine, Christopher J. Cline Ii, Pamela Burnley
Festival of Communities: UG Symposium (Posters)
We are using an Elastic Plastic Self Consistent Model (a type of numerical simulation) to study deformation of olivine. Olivine is one of the major constituents of the Earth’s upper mantle and its deformation properties have an important influence on how the Earth’s crust deforms. For example, the flow strength of olivine limits the size of the largest earthquakes and the heights of the tallest mountains on Earth. By comparing the results of our simulations with data from olivine deformation experiments we are able to better interpret the experimental data.
Trace Element And Stable Isotope Data From A Flowstone In A Natural Cave Of The Mining District Of Sw Sardinia (Italy): Evidence For Zn²⁺-Induced Aragonite Precipitation In Comparatively Wet Climatic Conditions, 2011 Dipartimento di Scienze della Terra, Via Trentino 51 – 09127 Cagliari (Italy) (e-mail: g.caddeo@unica.it)
Trace Element And Stable Isotope Data From A Flowstone In A Natural Cave Of The Mining District Of Sw Sardinia (Italy): Evidence For Zn²⁺-Induced Aragonite Precipitation In Comparatively Wet Climatic Conditions, Guglielmo Angelo Caddeo, Jo De Waele, Franco Frau, Loren Bruce Railsback
International Journal of Speleology
A speleothem from Crovassa Azzurra, a mine cave in SW Sardinia (Italy), has been analysed for mineralogy, minor and trace elements and stable isotopes. It is composed of layers of primary calcite and aragonite, with a region of secondary calcite. The primary carbonate is strikingly rich in Zn and Pb, presumably as the result of transport in solution from overlying Pb-Zn deposits. Immediately below the transition between calcite and aragonite, concentrations of Zn, Cd and P increase. At the transition between aragonite and Pb-rich aragonite, concentrations of Pb and P increase. Stable isotopes indicate an evolution toward more humid periods …
The First Cave Occurrence Of Orpiment (As₂S₃) From The Sulfuric Acid Caves Of Aghia Paraskevi (Kassandra Peninsula, N. Greece), 2011 Department of Geology, Aristotle University of Thessaloniki, Thessaloniki, GR-54124, Greece
The First Cave Occurrence Of Orpiment (As₂S₃) From The Sulfuric Acid Caves Of Aghia Paraskevi (Kassandra Peninsula, N. Greece), Georgios Lazaridis, Vasilios Melfos, Lambrini Papadopoulou
International Journal of Speleology
Orpiment, tamarugite and pickeringite occur in close association above the surface of thermal water cave pools in the active sulfuric acid caves of Aghia Paraskevi on the Kassandra peninsula, northern Greece. Gypsum also occurs as small interstitial crystals or encrustations. Orpiment is of high significance since it has not previously been reported as a cave mineral. In addition, tamarugite and pickeringite rarely occur in karst caves. Water from a borehole and a spring is of Na-Cl type and contains traces of CO2 and H2S. The B/Cl ratios indicate seawater participation with a possible mixing with geothermal water …
Secondary Halite Deposits In The Iranian Salt Karst: General Description And Origin, 2011 Institute of Geology, Academy of Science of the Czech Republic, Rozvojova 269, 165 00 Prague 6, Czech Republic
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 …
Revisiting Three Minerals From Cioclovina Cave (Romania), 2011 University of South Florida
Revisiting Three Minerals From Cioclovina Cave (Romania), Bogdan P. Onac, Herta S. Effenberger, Nathan C. Collins, Joe B. Kearns, Radu C. Breban
International Journal of Speleology
Cioclovina Cave in Romania’s Southern Carpathians is a world-renowned cave site for its paleontological, anthropological, and mineralogical (type locality of ardealite) findings. To date, over 25 mineral species have been documented, some unusual for a cave environment. This paper presents details on the occurrence of collinsite [Ca2(Mg,Fe2+)(PO4)2·2H2O], atacamite [Cu22+Cl(OH)3], and kröhnkite [Na2Cu2+(SO4)2·2H2O] based on single-crystal X-ray diffraction, electron microprobe, stable isotope analyses, and scanning electron microscope imaging. This is the first reported occurrence of kröhnkite …
2,2′,5,5′-TetraChloroBenzidine, 2010 University of Missouri–St. Louis
2,2′,5,5′-TetraChloroBenzidine, Onome Ugono, Marcel Douglas, Nigam Rath, Alicia Beatty
Chemistry & Biochemistry Faculty Works
In the crystal structure of the title compound, C12H8Cl4N2, molecules lie on crystallographic twofold axes at the centre of the C-C bonds linking the benzene rings, such that the asymmetric unit consists of a half-molecule. The individual molecules participate in intermolecular N-H...N, N-H...Cl, C-H...Cl and Cl...Cl [3.4503 (3) Å] interactions.
2,2′,5,5′-TetraChloroBenzidine, 2010 University of Missouri–St. Louis
2,2′,5,5′-TetraChloroBenzidine, Onome Ugono, Marcel Douglas, Nigam P. Rath, Alicia M. Beatty
Nigam Rath
2,2′,5,5′-TetraChloroBenzidine, 2010 University of Missouri–St. Louis