Chemical Mapping To Evaluate Post-Depositional Diagenesis Among The Earliest Ceramics In The Teotihuacan Valley, Mexico,
2021
University of Arkansas, Fayetteville
Chemical Mapping To Evaluate Post-Depositional Diagenesis Among The Earliest Ceramics In The Teotihuacan Valley, Mexico, Wesley D. Stoner, Barry J. Shaulis
Anthropology Faculty Publications and Presentations
Chemical and mineral sourcing techniques are commonly employed in archaeology to reconstruct patterns of ceramic exchange and raw material procurement practices for the past, but the effects of post-depositional diagenesis are still often ignored despite a number of key studies warning that the composition of ceramics from archaeological deposits often diverges greatly from their original composition at the time of production. This current study on diagenesis derives from a large chemical and petrographic analysis of some of the earliest ceramics (1500-100 cal Before Common Era [BCE]) in the Basin of Mexico at a time when the development of ceramic trade …
Microstructural Characteristics Of Deformed Quartz Under Non-Steady-State Conditions,
2021
CUNY Graduate Center
Microstructural Characteristics Of Deformed Quartz Under Non-Steady-State Conditions, Hamidreza Soleymani
Dissertations, Theses, and Capstone Projects
Because of the long timescale of many geological processes (millions of years), it has been traditionally assumed that the existing forces acting on the rocks at deep crustal levels are in equilibrium (i.e., steady-state). An alternative assumption, however, suggests that rocks in the lower crust and upper mantle are continuously evolving and exchanging energy at various time scales. Under the latter assumption (i.e., non-steady-state), certain geologic systems may never attain equilibrium regardless of the length and the time scale of operating geologic events. These two “endpoint” assumptions suggest there is a wide range of geologically reasonable conditions under which rocks …
Frozen In Time: A Numerical Modeling Approach To The Study Of Ice Bearing Planetesimals Through Carbonaceous Chondrites,
2021
CUNY Graduate Center
Frozen In Time: A Numerical Modeling Approach To The Study Of Ice Bearing Planetesimals Through Carbonaceous Chondrites, Jasmine M. Bayron
Dissertations, Theses, and Capstone Projects
Icy planetesimals are significant objects of study for meteoritics, planetary science, and astrobiology due to their connections to the origins of life and liquid water on Earth. An existing closed system aqueous alteration model was adapted to simulate several scenarios involving early Solar System geologic processes occurring in an icy planetesimal interior. The model described in this work has been developed not only to test the validity of constraints currently thought to apply to CM1 parent bodies, but to directly compare the implications of these constraints for the isotopic composition and the modal mineralogy of carbonaceous chondrites. Isotopic ratios of …
Microstructural And Microchemical Studies Of Fluid–Chondrule Interactions In A Pristine Cr Carbonaceous Chondrite And Apatite In Martian Nakhlites,
2021
University of New Mexico
Microstructural And Microchemical Studies Of Fluid–Chondrule Interactions In A Pristine Cr Carbonaceous Chondrite And Apatite In Martian Nakhlites, Marina Martínez
Earth and Planetary Sciences ETDs
PROJECT 1: Chondrites are the most primitive objects in the solar system, aggregates of the material that formed in the solar protoplanetary disk during the first 1-5 million years of its formation. However, petrographic observations indicate that most chondrites have been modified by secondary processes, including aqueous alteration, thermal metamorphism, and shock. Fortunately, a few chondrites largely escaped these processes and are considered pristine, such as the CR carbonaceous chondrite Queen Alexandra Range (QUE) 99177. QUE 99177 is an excellent sample for deciphering information about the reactions that took place between unaltered anhydrous solar nebular components and water under highly …
Ultralow Velocities Of Caco3 And The Origin Of Seismic Anomalies In The Earth's Upper Mantle,
2021
University of New Mexico
Ultralow Velocities Of Caco3 And The Origin Of Seismic Anomalies In The Earth's Upper Mantle, Mingqiang Hou, Ming Hao, Jin Liu, Xiaowan Su, Wen-Yi Zhou, Jin S. Zhang, Rostislav Hrubiak
Earth and Planetary Sciences Faculty and Staff Publications
Calcium carbonate (CaCO3) is a major mineral host for CO2 in deep Earth. The physical and chemical properties of CaCO3 at extreme pressure-temperature (P-T) conditions are important for understanding the CO2 circulation between the Earth's surface and interior primarily via volcanism and subduction. Using the pulse-echo-overlap method combined with Paris-Edinburgh (PE) press, we measured velocities of CaCO3 under upper mantle conditions and observed an anomalous velocity drop associated with the amorphization of aragonite. The compressional (VP) and shear (VS) wave velocities of the partially amorphized CaCO …
The Effects Of Heterogeneities And Syn-Deformational Partial Melting On Rock Strength Evolution And Melt Migration,
2021
The University of Akron
The Effects Of Heterogeneities And Syn-Deformational Partial Melting On Rock Strength Evolution And Melt Migration, Nicole Wagner
Williams Honors College, Honors Research Projects
In nature, the segregation of granitic melts at the source may be controlled by fabric and compositional heterogeneities in the source rock, such as foliation and lineation. To investigate the influence of foliation/lineation orientation and composition on rock strength and melt interconnectivity, I performed a series of experiments on cores of a fine-grained gneiss (Gneiss Minuti) and a fine-grained muscovite-bearing quartzite (Moine Thrust quartzite). These rocks were cored at six primary orientations parallel, 45 degrees, and perpendicular to the foliation and lineation and were deformed at a constant temperature of 900°C, pressure of ~2 GPa, and strain rate of ~10-6/s …
Analysis Of Water Concentration Formed Within Deformed Synthetic Quartz Crystals,
2021
The University of Akron
Analysis Of Water Concentration Formed Within Deformed Synthetic Quartz Crystals, Andrew Steward
Williams Honors College, Honors Research Projects
Analyzing the strength of synthetic quartz is essential to understanding the strength of natural milky quartz, which likely controls the strength of Earth’s continental crust. Synthetic quartz is sometimes used for deformation experiments because it has a homogenous water distribution unlike natural milky quartz. The purpose of this study is to determine if annealing synthetic quartz at T = 600°C will convert the water in synthetic quartz to free water, like milky quartz, but with little water loss. Following two annealing experiments at Texas A&M University, I performed four annealing experiments to measure the water content of five synthetic quartz …
Alteration Reactions In A Hornblende-Biotite-Anthophyllite-Fluid System: Implications For Cu-Au Ore Deposits,
2021
Northern Illinois University
Alteration Reactions In A Hornblende-Biotite-Anthophyllite-Fluid System: Implications For Cu-Au Ore Deposits, James Mitchell Lightner
Graduate Research Theses & Dissertations
High-grade porphyry Cu-Au ore deposits are typically contained in the potassic alteration zone, which forms through the alteration of preexisting country rock by a magmatic volatile phase (MVP) exsolved from an igneous intrusion. The MVP is a H2O dominant phase that contains high concentrations of NaCl, KCl, FeCl2, HCl, sulfur (as H2S or SO2) and minor concentrations of metals. The minerals in the potassic alteration zone are predominantly K-feldspar and biotite with a shreddy texture. Shreddy biotite forms from the replacement of prismatic-tabular shaped hornblende crystals, resulting in a characteristic shreddy texture. The alteration of hornblende to biotite can neutralize …
Optimizing Raman Spectral Collection For Quartz And Zircon Crystals For Elastic Geothermobarometry,
2020
Boise State University
Optimizing Raman Spectral Collection For Quartz And Zircon Crystals For Elastic Geothermobarometry, Mayara F. Cizina
Boise State University Theses and Dissertations
Raman microspectroscopy is widely used to identify and characterize organic and inorganic compounds. In the geosciences, Raman microspectroscopy has been used to identify mineral and fluid inclusions in host crystals, as well as to calculate pressure-temperature (P-T) conditions using mineral inclusions in host crystals, such as quartz-in-garnet barometry (QuiG). For thermobarometric applications, the reproducibility of Raman peak position measurements is crucial to obtain accurate P-T estimates. In this study, we explored how to optimize Raman spectral collection of quartz and zircon inclusions and reference crystals by monitoring machine stability and by varying spectral parameters. We also monitored a reference Hg …
Structure Analysis Of Natural Wangdaodeite—Linbo3-Type Fetio3,
2020
University of Nevada, Las Vegas
Structure Analysis Of Natural Wangdaodeite—Linbo3-Type Fetio3, Oliver Tschauner, Chi Ma, Matthew G. Newville, Antonio Lanzirotti
Geoscience Faculty Research
© 2020 by the authors. Licensee MDPI, Basel, Switzerland. This paper reports the first structure refinement of natural wangdaodeite, LiNbO3-type FeTiO3 from the Ries impact structure. Wangdaodeite occurs together with recrystallized ilmenite clasts in shock melt veins which have experienced peak shock pressures of between 17 and 22 GPa. Comparison of natural and synthetic wangdaodeite points toward a correlation between the distortion of ferrate-and titanate-polyhedra and the c/a ratio of the unit cell. The Raman spectrum of wangdaodeite is calculated based on the refined structure. Comparison to the reported spectrum of the type-material shows that the Raman peak at 738–740 …
Framework Grain Composition And Texture Of The Wedington Sandstone Member, Fayetteville Shale, As A Provenance And Sediment Dispersal Indicator For Clastic Depositional Systems Across The Northern Arkansas Structural Platform During The Late Mississippian,
2020
University of Arkansas, Fayetteville
Framework Grain Composition And Texture Of The Wedington Sandstone Member, Fayetteville Shale, As A Provenance And Sediment Dispersal Indicator For Clastic Depositional Systems Across The Northern Arkansas Structural Platform During The Late Mississippian, Tanner Wayne Corbin
Graduate Theses and Dissertations
The Wedington Sandstone Member of the Fayetteville Shale is a constructive delta complex in the Chesterian section of the Late Mississippian record in Northwest Arkansas. A comparative analysis of framework grain composition between the Wedington and two other stratigraphically proximal Carboniferous sandstones: the Batesville Sandstone (older) and the Basal Atoka-Spiro Sandstone (younger) has addressed three questions: 1) Is there similarity in sediment provenance for the three sandstones? 2) Do these three sandstone units have a similar sediment dispersal vector? 3) What are likely sediment source terrains for the Wedington Sandstone? Wedington samples overwhelmingly plot as quartzarenites with fewer samples plotting …
Foliar Application Of Low Concentrations Of Titanium Dioxide And Zinc Oxide Nanoparticles To The Common Sunflower Under Field Conditions,
2020
Slovak University of Agriculture in Nitra
Foliar Application Of Low Concentrations Of Titanium Dioxide And Zinc Oxide Nanoparticles To The Common Sunflower Under Field Conditions, Marek Kolenčík, Dávid Ernst, Martin Urík, Ľuba Ďurišová, Marek Bujdoš, Martin Šebesta, Edmund Dobročka, Samuel Kšiňan, Ramakanth Illa, Qian Yu, Huan Feng, Ivan Černý, Veronika Holišová, Gabriela Kratošová
Department of Earth and Environmental Studies Faculty Scholarship and Creative Works
Nano-fertilisers have only recently been introduced to intensify plant production, and there still remains inadequate scientific knowledge on their plant-related effects. This paper therefore compares the effects of two nano-fertilisers on common sunflower production under field conditions. The benefits arising from the foliar application of micronutrient-based zinc oxide fertiliser were compared with those from the titanium dioxide plant-growth enhancer. Both the zinc oxide (ZnO) and titanium dioxide (TiO2) were delivered by foliar application in nano-size at a concentration of 2.6 mg·L−1. The foliar-applied nanoparticles (NPs) had good crystallinity and a mean size distribution under 30 nm. …
Storm Surges In The Bohai Sea: The Role Of Waves And Tides,
2020
Chinese Research Academy of Environmental Sciences
Storm Surges In The Bohai Sea: The Role Of Waves And Tides, Yuanyi Li, Huan Feng, Guillaume Vigouroux, Dekui Yuan, Guangyu Zhang, Xiaodi Ma, Kun Lei
Department of Earth and Environmental Studies Faculty Scholarship and Creative Works
A storm surge is a complex phenomenon in which waves, tide and current interact. Even though wind is the predominant force driving the surge, waves and tidal phase are also important factors that influence the mass and momentum transport during the surge. Devastating storm surges often occur in the Bohai Sea, a semi-enclosed shallow sea in North China, due to extreme storms. However, the effects of waves on storm surges in the Bohai Sea have not been quantified and the mechanisms responsible for the higher surges that affect part of the Bohai Sea have not been thoroughly studied. In this …
Comparative Geochemical Analysis Of Ordovician And Mississippian Cherts In Relation To The Northern Arkansas And The Tri-State Mississippi Valley-Type Ore Districts,
2020
University of Arkansas, Fayetteville
Comparative Geochemical Analysis Of Ordovician And Mississippian Cherts In Relation To The Northern Arkansas And The Tri-State Mississippi Valley-Type Ore Districts, Jonathan T. Chick
Graduate Theses and Dissertations
It has been hypothesized that Ordovician, Mississippian, and younger carbonate and clastic formations found within the Ouachita Basin of west-central Arkansas and northward onto the Ozark Dome have experienced interaction with hydrothermal fluids due to tectonic forces produced by the Ouachita Orogeny. Lead (Pb) isotope analyses and resulting values produced through previous and concurrent geochemical studies of several formations indicate that the Mississippi Valley-type (MVT) ores were produced from a mixing and cooling of these sedimentary basinal brines by meteoric or connate waters. Reduction of sulfate to sulfide is one of the possible mechanisms by which MVT ore precipitation may …
Structure-Strength Relations Of Distinct Mon Phases From First-Principles Calculations,
2020
China University of Geosciences
Structure-Strength Relations Of Distinct Mon Phases From First-Principles Calculations, Cheng Lu, Changfeng Chen
Physics & Astronomy Faculty Research
Molybdenum mononitrides (MoN) exhibit superior strength and hardness among the large class of transition-metal light-element compounds, but the underlying atomistic mechanisms for their outstanding mechanical properties and the variations of those properties among various MoN phases adopting different crystal structures remain largely unexplored and require further investigation. Here we report first-principles calculations that examine the stress-strain relations of these materials, and systematically compare results under pure and indentation shear deformations. In particular, we examine the distinct bonding structures and the associated mechanical properties in four different crystal phases of MoN that have been experimentally synthesized and stabilized under various physical …
Indentation-Strain Stiffening In Tungsten Nitrides: Mechanisms And Implications,
2020
China University of Geosciences
Indentation-Strain Stiffening In Tungsten Nitrides: Mechanisms And Implications, Cheng Lu, Changfeng Chen
Physics & Astronomy Faculty Research
We report on a systematic computational study of ideal strengths, i.e., the lowest stresses needed to destabilize a perfect crystal under a variety of loading conditions for six stable and metastable tungsten nitrides identified by advanced crystal structure search algorithms. We employ first-principles calculations to determine stress-strain relations and examine the corresponding atomistic bonding changes for a microscopic understanding of the structural deformation modes. The obtained results show that, in stark contrast to many previously studied transition-metal borides, carbides, and also most nitrides, the tungsten nitrides exhibit surprisingly broad and common patterns of strain-stiffening effects under indentation strains. These extraordinary …
Riesite, A New High Pressure Polymorph Of Tio2 From The Ries Impact Structure,
2020
University of Nevada, Las Vegas
Riesite, A New High Pressure Polymorph Of Tio2 From The Ries Impact Structure, Tschauner, Chi Ma, Antonio Lanzirotti, Matthew G. Newville
Geoscience Faculty Research
This paper describes riesite, a new high-pressure polymorph of TiO2 from the Ries impact structure, Germany. Riesite occurs in shock-induced melt veins within xenoliths of bedrock in suevite. It is structurally closely related to srilankite from which it differs by having two distinct cation sites rather than one and through its monoclinic symmetry. It is indicative that riesite forms only upon release from the shock state upon back transformation from akaogiite.
Statistical Analysis Of Nutrient Loads From The Mississippi-Atchafalaya River Basin (Marb) To The Gulf Of Mexico,
2020
Southern University and A & M College
Statistical Analysis Of Nutrient Loads From The Mississippi-Atchafalaya River Basin (Marb) To The Gulf Of Mexico, Phyllis Okwan, Yi Zhen, Huan Feng, Shinjae Yoo, Murty S. Kambhampati, Abreione Walker, Shayne Boykin, Joe Omojola, Noel Blackburn
Department of Earth and Environmental Studies Faculty Scholarship and Creative Works
This study investigated the annual and seasonal variations in nutrient loads (NO2− + NO3− and orthophosphate) delivered to the Gulf of Mexico from the Mississippi-Atchafalaya River Basin (MARB) and examined the water quality variations. The results indicate that (1) annually, the mean NO2− + NO3− and orthophosphate loads showed a steady increase during 1996–1999, a persistent level during 2000–2007, and a moderate increase during 2008–2016; (2) seasonally, NO2− + NO3− and orthophosphate in MARB in spring and summer were higher than those in autumn and winter. Analysis of …
Seismic Visibility Of Eclogite In The Earth’S Upper Mantle – Implications From High Pressure-Temperature Single-Crystal Elastic Properties Of Omphacite,
2020
University of New Mexico
Seismic Visibility Of Eclogite In The Earth’S Upper Mantle – Implications From High Pressure-Temperature Single-Crystal Elastic Properties Of Omphacite, Ming Hao, Jin S. Zhang, Wen-Yi Zhou, Qin Wang
Earth and Planetary Sciences Faculty and Staff Publications
Eclogite, constituting the subducted crust, is one of the most important geochemical and geophysical heterogeneities in the Earth’s mantle. As the dominant anisotropic phase in eclogite, precise high pressure-temperature single-crystal elastic properties of omphacite provides the basis for detecting eclogite in the Earth’s upper mantle. In this study, we measured the single-crystal elastic moduli of omphacite up to 18 GPa and 700 K using Brillouin spectroscopy. A least-squares fit to a third-order finite strain equation of state yields KS0’=4.5(1), G0’=1.53(5), ∂KS0/∂T=-0.029(5) GPa/K, ∂G0/∂T=-0.013(5) GPa/K, with ρ0=3.34(1) g/cm3, K …
Analysis Of Deformation Mechanisms That Formed The Shear Zones Found In The Scituate Granite, Rhode Island, Usa,
2020
The University of Akron
Analysis Of Deformation Mechanisms That Formed The Shear Zones Found In The Scituate Granite, Rhode Island, Usa, Jacob Waller
Williams Honors College, Honors Research Projects
The rheology of the ductile middle and lower crust affects the rate and intensity of aftershocks following major seismic events. This ductile deformation in the middle crust is commonly localized in narrow shear zones, which requires a process that causes strain weakening to operate in order to form these shear zones. In order to determine the mechanisms that cause strain localization in a common crustal rock, microstructures were analyzed in and around a shear zone found in a granite, Scituate, RI, deformed during the Alleghenian orogeny. Evolution of shear zone growth was observed through optical and scanning electron microscope (SEM) …
