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2019

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Articles 1531 - 1560 of 1656

Full-Text Articles in Earth Sciences

Mineralogy And Geochemistry Of Metalliferous Sedimentary Rocks From The Uppercretaceous Vms Deposits Of The Eastern Pontides (Ne Turkey), Mustafa Kemal Revan, Yurdal Genç, Okan Deli̇baş, Valeri̇y V. Maslennikov, Nuri̇ya R. Ayupova, Okan Zi̇mi̇toğlu Jan 2019

Mineralogy And Geochemistry Of Metalliferous Sedimentary Rocks From The Uppercretaceous Vms Deposits Of The Eastern Pontides (Ne Turkey), Mustafa Kemal Revan, Yurdal Genç, Okan Deli̇baş, Valeri̇y V. Maslennikov, Nuri̇ya R. Ayupova, Okan Zi̇mi̇toğlu

Turkish Journal of Earth Sciences

Metalliferous sedimentary rocks, despite being limited in scope, are important stratigraphic horizons within the volcanogenic massive sulfide (VMS) deposits in the Upper Cretaceous volcanic belt of the Eastern Pontides. The metalliferous sedimentary rocks compose a distinctive genetic class. The abundance of such rocks in the Eastern Pontide district provides a basis for study and description that may be more widely applied in other VMS districts. The metalliferous sedimentary rocks generally form layers less than 1.5 m thick above stratiform massive sulfide ores. The metalliferous sediments are largely composed of quartz and hematite. While the Si ± Fe content of sediments …


Application Of Zircon Typology Method To Felsic Rocks (Cappadocia, Central Anatolia, Turkey): A Zircon Crystallization Temperature Perspective, Lütfi̇ye Akin, Erkan Aydar, Axel Karl Schmitt, Hüseyi̇n Evren Çubukçu Jan 2019

Application Of Zircon Typology Method To Felsic Rocks (Cappadocia, Central Anatolia, Turkey): A Zircon Crystallization Temperature Perspective, Lütfi̇ye Akin, Erkan Aydar, Axel Karl Schmitt, Hüseyi̇n Evren Çubukçu

Turkish Journal of Earth Sciences

Zircon typology was developed nearly half a century ago as a tool for constraining the thermochemical conditions in granitic magmas from the morphology of zircon prismatic and pyramidal crystal surfaces. Although the method precedes experimentally constrained zircon-based thermometers (zircon saturation, Ti-in-zircon), the morphology of zircon remains an important criterion for zircon studies commonly relying on visual recognition of crystals during sample purification via hand-picking. This may introduce selection bias if morphologically distinct zircon crystals are present in a population. We conducted a comparison between zircon typology and thermochemical constraints from zircon thermometry and whole rock compositions. Therefore, we focused on …


Diagenesis And Diagenetic Facies Distribution Prediction Of Chang 8 Tight Oil Reservoir In Maling Area, Ordos Basin, Nw China, Meng Wang, Shu Liu, Ming Zeng, Gang Lin, Yulin Cheng, Long Fang, Jiaming Zeng Jan 2019

Diagenesis And Diagenetic Facies Distribution Prediction Of Chang 8 Tight Oil Reservoir In Maling Area, Ordos Basin, Nw China, Meng Wang, Shu Liu, Ming Zeng, Gang Lin, Yulin Cheng, Long Fang, Jiaming Zeng

Turkish Journal of Earth Sciences

In this study, characteristics of Chang 8 tight sandstone pore structure and diagenesis are analyzed. A classification standard for sandstone diagenetic facies is established. Combined with the probabilistic neural network method, logging curves are used to predict the distribution of diagenetic facies. The following results are found: the Chang 8 reservoir has low porosity-low permeability characteristics, and the pore-throat structures have strong microscopic heterogeneity; both compaction and siliceous and carbonate cementation promote reservoir densification; chlorite cement lining, hydrocarbon emplacement, and the dissolution of feldspar and rock fragments have constructive effects on reservoir development; and two favorable diagenetic facies, a weakly …


Estimating The Location Of A Causative Body From A Self-Potential Anomaly Using 2d And3d Normalized Full Gradient And Euler Deconvolution, Petek Sindirgi, Şenol Özyalin Jan 2019

Estimating The Location Of A Causative Body From A Self-Potential Anomaly Using 2d And3d Normalized Full Gradient And Euler Deconvolution, Petek Sindirgi, Şenol Özyalin

Turkish Journal of Earth Sciences

Changes in the size and depth of sources greatly affect self-potential (SP) anomalies. Therefore, it is important to determine the location of the source accurately. In the present study, applications of the normalized full gradient (NFG) method and Euler deconvolution (EUD) were described to determine the location of the sphere-like SP body as complementary approaches to other optimization algorithms. The NFG and EUD methods were tested on synthetic, noise-free, and noisy anomalies caused by sphere-like models in two-dimensional (2D) and three-dimensional (3D) cases. Subsequently, the methods were applied to real field data. The importance of the present study lies in …


Spatial Estimation Of Hydraulic Properties In Structured Soils At The Field Scale, Xi Zhang Jan 2019

Spatial Estimation Of Hydraulic Properties In Structured Soils At The Field Scale, Xi Zhang

Theses and Dissertations--Plant and Soil Sciences

Improving agricultural water management is important for conserving water during dry seasons, using limited water resources in the most efficient way, and minimizing environmental risks (e.g., leaching, surface runoff). The understanding of water movement in different zones of agricultural production fields is crucial to developing an effective irrigation strategy. This work centered on optimizing field water management by characterizing the spatial patterns of soil hydraulic properties. Soil hydraulic conductivity was measured across different zones in a farmer’s field, and its spatial variability was investigated by using geostatistical techniques. Since direct measurement of hydraulic conductivity is time-consuming and arduous, pedo-transfer functions …


Exploring The Northwest Margin Of The High Plains Aquifer: Structure, Depositional History And Hydrogeology, Nebraska Geological Society Field Trip, Doug Hallum, Dennis O. Terry, Jr., Michael Leite, Jennifer Balmat Jan 2019

Exploring The Northwest Margin Of The High Plains Aquifer: Structure, Depositional History And Hydrogeology, Nebraska Geological Society Field Trip, Doug Hallum, Dennis O. Terry, Jr., Michael Leite, Jennifer Balmat

Conservation and Survey Division: Faculty and Staff Publications

The northwest portion of the High Plains Aquifer in Nebraska corresponds with the western Sandhills, Box Butte, Sioux and Dawes County tablelands, and the Nebraska Pine Ridge in northwest Nebraska. This field excursion will travel beyond the margins of the High Plains aquifer into the White River valley and onto the Oglala National Grasslands. These areas are not only rich in natural resources, but rich in history as well. While this excursion will explore earth history, depositional environments and a portion of the High Plains Aquifer, the authors encourage all attendees to take additional time to explore the cultural, military …


Radar Quantification, Temporal Analysis And Influence Of Atmospheric Conditions On A Roost Of American Robins (Turdus Migratorius) In Oklahoma, Matthew S. Van Den Broeke Jan 2019

Radar Quantification, Temporal Analysis And Influence Of Atmospheric Conditions On A Roost Of American Robins (Turdus Migratorius) In Oklahoma, Matthew S. Van Den Broeke

Department of Earth and Atmospheric Sciences: Faculty Publications

Radar observations present a way to monitor large, mobile populations across long temporal scales, and are especially valuable when individual scatterers are challenging to count visually. The focus of this study is a large and relatively homogeneous wintertime roost of American Robins (Turdus migratorius) in central Oklahoma. Radar observations are used to estimate the roost population through winter 2010–2011, and the population time series is related to weather variables and radar beam propagation. Radar-estimated roost population gradually increased to an estimated peak of 1.5–2 million individuals from November 2010 to January 2011, and then decreased in a more …


Rinded, Iron-Oxide Concretions In Navajo Sandstone Along The Trail To Upper Calf Creek Falls, Garfield County, David Loope, Richard Kettler Jan 2019

Rinded, Iron-Oxide Concretions In Navajo Sandstone Along The Trail To Upper Calf Creek Falls, Garfield County, David Loope, Richard Kettler

Department of Earth and Atmospheric Sciences: Faculty Publications

Concretions are hard rock masses, usually spheroidal, but commonly oblate or discoidal, that are formed by strongly localized precipitation of minerals in the pores of an otherwise weaker sedimentary rock (see Bates and Jackson, 1980, for a more extensive definition). The iron-oxide-rich concretions in the Jurassic Navajo Sandstone in southern Utah are unusual in two fundamental ways. First, they are cemented by iron oxide (Fe2O3, or Fe(OH)3); most other concretions are cemented by silica (SiO2), calcite (CaCO3), dolomite (CaMg(CO3)2), or siderite (FeCO3). Second, unlike other concretions, they are not strongly cemented throughout, but instead, the iron oxide is concentrated in …


Plant Root Systems Preserved In The Permian Cedar Mesa Sandstone At Moki Dugway, Southeastern Utah, David Loope Jan 2019

Plant Root Systems Preserved In The Permian Cedar Mesa Sandstone At Moki Dugway, Southeastern Utah, David Loope

Department of Earth and Atmospheric Sciences: Faculty Publications

Rooted green plants represent the base of the food chain for most terrestrial ecosystems, but, compared to animal burrows, root systems are relatively rarely recognized in ancient sedimentary rocks. Plant roots that penetrate unconsolidated sand dunes, especially those containing not only quartz grains, but also abundant grains of calcite (CaCO3), are commonly replaced by fine crystals of calcite (Klappa, 1980). These structures (known by geologists as rhizoliths from the Greek for “root rock”) are one form of calcite cemented soil and sediment called caliche (figure 1). Caliche crystallizes well above the water table and its calcite crystals are …


Variations Of Stomatal Frequency In Taxodium And Metasequoia Populations At The Mid-Miocene Clarkia Lake Deposits: Implications For Atmospheric Co2 Reconstruction, Meng-Xiao Wu, Qin Leng, Hong Yang, Daianne F. Hofig, Yi-Ge Zhang Jan 2019

Variations Of Stomatal Frequency In Taxodium And Metasequoia Populations At The Mid-Miocene Clarkia Lake Deposits: Implications For Atmospheric Co2 Reconstruction, Meng-Xiao Wu, Qin Leng, Hong Yang, Daianne F. Hofig, Yi-Ge Zhang

Science and Technology Department Faculty Conference Proceedings

Stomatal frequency (such as stomatal index-SI and stomatal density-SD) has been widely used to reconstruct atmospheric CO2 levels in geological history as it is one of the most reliable proxies of paleo-CO2 that predate the oldest icecore records. However, living plants show large variations on stomatal frequency within the same species, potentially generating large error margins for estimated paleo-CO2 levels using limited fossil specimen(s). The extraordinarily wellpreserved and abundant fossil leaves from the mid-Miocene (~15Ma) Clarkia Lake deposits in northern Idaho, the USA, allow us to test variations within a population of a fossil species and to compare that cross …


Modeled And Measured Ecosystem Respiration In Maize–Soybean Systems Over 10 Years, Ming Zhan, Adam Liska, Anthony Nguy-Robertson, Andrew E. Suyker, Matthew P. Pelton, Haishun Yang Jan 2019

Modeled And Measured Ecosystem Respiration In Maize–Soybean Systems Over 10 Years, Ming Zhan, Adam Liska, Anthony Nguy-Robertson, Andrew E. Suyker, Matthew P. Pelton, Haishun Yang

Adam Liska Papers

Crop residue is an abundant resource for the potential production of biofuels, but a better understanding of its use on net carbon emissions must be developed to mitigate climate change. This analysis combines two established crop growth models (Hybrid-Maize and SoySim) with a simple soil and crop residue respiration model to estimate daily ecosystem respiration (ERe) from maize and soybean; ERe was estimated to be the sum of CO2 emissions from the oxidation of the growing crop, crop residue, and soil organic carbon (SOC). Model-estimated CO2 fluxes from irrigated continuous maize and irrigated maize–soybean cropping systems in eastern …


Using Paleolimnology To Establish Baseline Conditions For Metal Contaminants In Advance Of Proposed Mining To Inform A Northern Community-Led Aquatic Monitoring Program, Tłı̨Chǫ Lands, Northwest Territories, Canada., James Telford Jan 2019

Using Paleolimnology To Establish Baseline Conditions For Metal Contaminants In Advance Of Proposed Mining To Inform A Northern Community-Led Aquatic Monitoring Program, Tłı̨Chǫ Lands, Northwest Territories, Canada., James Telford

Theses and Dissertations (Comprehensive)

The Marian Watershed Stewardship Program (MWSP), a community-driven aquatic ecosystem monitoring program, was developed by the Tłı̨chǫ Government to address concerns regarding the cumulative impacts of multiple potential stressors. In particular, the MWSP aims to develop methods that will be effective for detecting potential pollution from the proposed cobalt-gold-copper-bismuth NICO mine within Tłı̨chǫ Lands. In collaboration with the MWSP, paleolimnological methods and geochemical normalization are used to establish pre-mine baselines of lake sediment metals concentrations in the Marian River watershed prior to mine development. This baseline framework can be used to assess for pollution from surficial sediment once the mine …


Biogeochemical And Hydrological Impacts Of A Low-Severity Wildfire In The Wetland-Dominated Zone Of Discontinuous Permafrost, Caren J. Ackley Jan 2019

Biogeochemical And Hydrological Impacts Of A Low-Severity Wildfire In The Wetland-Dominated Zone Of Discontinuous Permafrost, Caren J. Ackley

Theses and Dissertations (Comprehensive)

Northern regions are experiencing rapid climate warming. As these regions warm, the occurrences of naturally ignited wildfires are increasing in frequency, severity and area burned, calling for a more thorough understanding of post-fire eco-hydrological impacts. Changes in runoff chemistry, and soil moisture and thermal regimes, have been attributed to the significant loss of organic matter (OM) and exposure of deeper soils, leading to enhanced permafrost degradation, ground surface subsidence and the conversion of peat landscapes from long-term C sinks to sources. However, low-severity wildfires often result in minor OM loss. Due to the significant and immediate threats posed to the …


Development And Application Of Hydrological And Limnological Monitoring In Lake-Rich Landscapes Of Canada’S Subarctic National Parks, Hilary Emma White Jan 2019

Development And Application Of Hydrological And Limnological Monitoring In Lake-Rich Landscapes Of Canada’S Subarctic National Parks, Hilary Emma White

Theses and Dissertations (Comprehensive)

Arctic and subarctic environments are being adversely influenced by human-caused climate change across our entire planet. Canada’s northern freshwater ecosystems are influenced by a variety of environmental stressors and are particularly sensitive to climate change, since small shifts in climate have the potential to substantially alter their hydrological, limnological, and biogeochemical conditions. Some other indirect effects on northern freshwater landscapes are the expansion of vegetation as well as changes in wildlife and waterfowl populations and distribution. It is, therefore, critical to understand the observed and predicted influences of climate change and other environmental stressors on these northern freshwater environments dominant …


Influence Of Ligand Complexation On Nickel Toxicity, Speciation And Bioavailability In Marine Waters, Samantha Sherman Jan 2019

Influence Of Ligand Complexation On Nickel Toxicity, Speciation And Bioavailability In Marine Waters, Samantha Sherman

Theses and Dissertations (Comprehensive)

Currently there are no site-specific bioavailability-based prediction models for assessing the impacts of nickel (Ni) in marine environments although there are indications that these may be warranted. The aim of this research was to characterize the complexation of Ni in relation to toxicity and speciation. Various complexing ligands were used, and it was predicted that the binding affinity (logKf) of ligands would be inversely correlated to toxicity based on dissolved Ni concentrations ([NiD]) but that on a free ion concentration ([Ni2+]) basis, toxicity would not vary. A two-phased approach was used; the first was a proof of principle where synthetic …


Bridge Deck Deterioration Assessment By Nondestructive Testing Methods, Thanop Siriwattananuruk Jan 2019

Bridge Deck Deterioration Assessment By Nondestructive Testing Methods, Thanop Siriwattananuruk

Chulalongkorn University Theses and Dissertations (Chula ETD)

In general, the inspection of the damage on concrete bridge deck is usually done by visual inspection and coring test together with simple survey such as chain drag and hammer sounding. These methods may not be able to verify damage condition correctly. However, at present, there are many nondestructive testing methods which is used to investigate the damage on concrete bridge deck together with simple testing methods. For this study, ground penetrating radar, half-cell potential and impact echo test were selected to evaluate damage condition of concrete bridge deck. The results from simple methods can be detect only damage on …


Pressure, Temperature, And Stress Conditions Of Southern Alpine Fault (New Zealand) Mylonites, Jake T. Reitman Jan 2019

Pressure, Temperature, And Stress Conditions Of Southern Alpine Fault (New Zealand) Mylonites, Jake T. Reitman

Dissertations and Theses

The Alpine Fault, New Zealand, provides a unique window into the rheologic history of a seismically-active continental plate boundary. Due to lower exhumation rates along southern portions of the fault relative to the well-studied central Alpine Fault, deformation ages vary along strike by ~15 m.y.. Mylonites collected from two southern creeks near Haast, NZ, display a uniform recrystallized grain size of ~11 𝜇m in mylonitic quartz indicating differential stress values in the south of ~100 MPa, roughly twice the stress values observed in the central Alpine Fault. Constraints from Ti-in-quartz thermobarometry and Raman Spectroscopy of Carbonaceous Material (RSCM) indicate mylonitization …


Snowmelt Detection On Alpine Glaciers Using Synthetic Aperture Radar Time Series, Corey Scher Jan 2019

Snowmelt Detection On Alpine Glaciers Using Synthetic Aperture Radar Time Series, Corey Scher

Dissertations and Theses

Hindu Kush Himalayan (HKH) glaciers serve as some of the most sensitive indicators of changes in global climate. These glaciers shape the hydrologic dynamics of river systems supplying freshwater to over 2 billion people throughout Asia and regulate the geochemistry of sensitive aquatic alpine ecosystems. As snowmelt onsets sooner, lasts longer, and snowfields retreat due to increases in global temperature, the hydrologic dynamics of catchments draining HKH threaten to change the availability of surface freshwater resources for nearly one fifth of the global population, disturb sensitive aquatic habitat, and precipitate hazards associated with glacier wasting. Informed planning and decision-making around …


Carbonatites As A Record Of The Carbon Isotope Composition Of Large Igneous Province Outgassing, Ellen Gales Jan 2019

Carbonatites As A Record Of The Carbon Isotope Composition Of Large Igneous Province Outgassing, Ellen Gales

Dissertations and Theses

Large igneous province (LIP) eruptions have been linked in some cases to major perturbations of Earth’s carbon cycle. However, few observations directly constrain the isotopic composition of carbon released by LIP magmas because carbon isotopes fractionate during degassing, which hampers understanding of the relative roles of mantle versus crustal carbon reservoirs. Carbonatite magmatism associated with LIPs provides a unique window into the isotopic systematics of LIP carbon because the majority of carbon in carbonatites crystalizes rather than degassing. Here, we present new δ13C data for the Guli carbonatites in the Siberian Traps. In addition, we compile ~260 published …


Hydroclimate Drivers And Atmospheric Dynamics Of Floods, Nasser Najibi Jan 2019

Hydroclimate Drivers And Atmospheric Dynamics Of Floods, Nasser Najibi

Dissertations and Theses

Our preliminary survey showed that most of the recent flood-related studies did not formally explain the physical mechanisms of long-duration and large-peak flood events that can evoke substantial damages to properties and infrastructure systems. These studies also fell short of fully assessing the interactions of coupled ocean-atmosphere and land dynamics which are capable of forcing substantial changes to the flood attributes by governing the exceeding surface flow regimes and moisture source-sink relationships at the spatiotemporal scales important for risk management. This dissertation advances the understanding of the variability in flood duration, peak, volume, and timing at the regional to the …


Complete Mitochondrial Genome Of Callogorgia Cf. Gracilis (Octocorallia: Calcaxonia: Primnoidae), Erin E. Easton, David Hicks Jan 2019

Complete Mitochondrial Genome Of Callogorgia Cf. Gracilis (Octocorallia: Calcaxonia: Primnoidae), Erin E. Easton, David Hicks

School of Earth, Environmental, & Marine Sciences Faculty Publications

We report the first complete mitochondrial genome of Callogorgia. Callogorgia cf. gracilis isolate DFH32_518B was collected by a remotely operated vehicle at 98 m on McGrail Bank (27.9840725°N, 92.604242°W). The complete mitogenome is 18,937 bp (27.8% A, 18.3% C, 19.8% G, and 34.1% T) and has the ancestral octocoral gene order for its 14 protein-coding genes, two rRNA genes, and one tRNA gene. It is sister to and ∼96.6% similar (uncorrected) to Narella hawaiiensis, the only other complete mitogenome reported for Primnoidae. The cox1 + igr1 + mtMutS region differs by two base pairs (0.12%) from the only reported …


A High-Latitude, Mesophotic Cycloseris Field At 85 M Depth Off Rapa Nui (Easter Island), Bert W. Hoeksema, Javier Sellanes, Erin E. Easton Jan 2019

A High-Latitude, Mesophotic Cycloseris Field At 85 M Depth Off Rapa Nui (Easter Island), Bert W. Hoeksema, Javier Sellanes, Erin E. Easton

School of Earth, Environmental, & Marine Sciences Faculty Publications

Published records of mesophotic zooxanthellate corals from Rapa Nui (Easter Island) are rare and so far based only on dredged specimens and observations during scuba dives (Wells 1972, Glynn et al. 2003, 2007). During recent remotely operated vehicle (ROV) surveys off Rapa Nui (March 2016), a large and dense aggregation of zooxanthellate Cycloseris corals (Scleractinia: Fungiidae) with a density of approximately 500 ind m−2 was discovered (27°08΄55˝S, 109°26΄46˝W) on black sand in a depth range of approximately 79–85 m (Panels A, B). A few corals were overturned, exposing their white (azooxanthellate) undersides and sutures along which self-fragmentation took place (Panel …


Past, Present, And Future Perspectives Of Environmental Dna (Edna) Metabarcoding: A Systematic Review In Methods, Monitoring, And Applications Of Global Edna, Krista M. Ruppert, Richard J. Kline, Md. Saydur Rahman Jan 2019

Past, Present, And Future Perspectives Of Environmental Dna (Edna) Metabarcoding: A Systematic Review In Methods, Monitoring, And Applications Of Global Edna, Krista M. Ruppert, Richard J. Kline, Md. Saydur Rahman

School of Earth, Environmental, & Marine Sciences Faculty Publications

Environmental DNA (eDNA) metabarcoding is a novel method of assessing biodiversity wherein samples are taken from the environment via water, sediment or air from which DNA is extracted, and then amplified using general or universal primers in polymerase chain reaction and sequenced using next-generation sequencing to generate thousands to millions of reads. From this data, species presence can be determined, and overall biodiversity assessed. It is an interdisciplinary method that brings together traditional fieldbased ecology with in-depth molecular methods and advanced computational tools. As an emerging monitoring method, there are many pitfalls and roadblocks to be considered and avoided, but …


Continued Eastward Range Expansion Of Black Phoebes (Sayornis Nigricans) In Southernmost Texas, Samuel G. Ortiz, Christopher A. Gabler, Timothy Brush Jan 2019

Continued Eastward Range Expansion Of Black Phoebes (Sayornis Nigricans) In Southernmost Texas, Samuel G. Ortiz, Christopher A. Gabler, Timothy Brush

School of Earth, Environmental, & Marine Sciences Faculty Publications

ABSTRACT—We observed black phoebe (Sayornis nigricans) nests, breeding pairs, and juveniles in Cameron County, Texas, in 2017. Our first confirmed nesting records in Cameron County document a continued eastward range expansion by black phoebes.

RESUMEN—En el 2017, observamos nidos, parejas reproductoras y juveniles del pajaro mosquero negro (Sayornis nigricans) en el condado de Cameron, Texas. Los primeros registros confirmados de reproducci ´on en el condado de Cameron son evidencia de una continua expansion hacia el este de la distribuci ´on geogr´afica del mosquero negro.


Sweet Potato: A Potentially Profitable Summer Crop For South Texas Organic Farmers To Enhance Soil Biological Activity And Nutrient Release, Jahdiel Salazar, Josabeth Navarro, James Jihoon Kang, Engil Isadora Pujol Pereira Jan 2019

Sweet Potato: A Potentially Profitable Summer Crop For South Texas Organic Farmers To Enhance Soil Biological Activity And Nutrient Release, Jahdiel Salazar, Josabeth Navarro, James Jihoon Kang, Engil Isadora Pujol Pereira

School of Earth, Environmental, & Marine Sciences Faculty Publications

No abstract provided.


Volatiles And Trace Element Contents In Melt Inclusions From The Zoned Green Tuff Ignimbrite (Pantelleria, Sicily): Petrological Inferences., Pierangelo Romano, John C. White, Alessandro Ciulla, Ida Di Carlo, Claudia D'Oriano, Patrizia Landi, Silvio G. Rotolo Jan 2019

Volatiles And Trace Element Contents In Melt Inclusions From The Zoned Green Tuff Ignimbrite (Pantelleria, Sicily): Petrological Inferences., Pierangelo Romano, John C. White, Alessandro Ciulla, Ida Di Carlo, Claudia D'Oriano, Patrizia Landi, Silvio G. Rotolo

EKU Faculty and Staff Scholarship

The island of Pantelleria is one of the best known localities of bimodal mafic-felsic magmatism (alkali basalt and trachyte-pantellerite). Among the felsic rocks, the coexistence in a single eruption of products of both trachyte and pantellerite compositions is limited to few occurrences, the Green Tuff (GT) ignimbrite being one of these. The GT is compositionally zoned from pantellerite (70.1 wt% SiO2, mol Na+K/Al = 1.86, 1871 ppm Zr) at the base to crystal-rich (>30 vol%) comenditic trachyte (63.4 wt% SiO2, mol Na+K/Al = 1.10, 265 ppm Zr) at the top, although the pantellertic compositions dominate the erupted volume. We …


Manufactured By Nature: Growing Generatively Designed Products, Mohammad Jawad Jan 2019

Manufactured By Nature: Growing Generatively Designed Products, Mohammad Jawad

Theses and Dissertations

Mass production and assembly lines are yesterday’s manufacturing methods. They have exhausted Earth’s resources and limited the possibilities of design in terms of both form and material, prompting designers to search for new processes. A new generation of making includes biomimicry-inspired technologies such as 3D printing and parametric simulation, which have transformed the production paradigm. Utilizing nature as industry, this thesis explores the possibility of “growing” designed objects by employing nature’s own processes and resources. It integrates bio materials, generative design and additive manufacturing to produce objects for a post-industrial world. The project outcomes employ natural minerals, crystallization and 3D …


Quantifying Magma Recharge At Parinacota Volcano, Northern Chile (52 Ka - Recent): Insight From The Magma Chamber Simulator, Jennifer Mcleod Jan 2019

Quantifying Magma Recharge At Parinacota Volcano, Northern Chile (52 Ka - Recent): Insight From The Magma Chamber Simulator, Jennifer Mcleod

All Master's Theses

The Magma Chamber Simulator (MCS; Bohrson et al., 2014) was used to produce new thermodynamic models that constrain and quantify recharge and fractional crystallization (RFC) processes for the Old Cone (OC; 52-20 ka; 56-66 wt.% SiO2) and Healing Flows (HF; >8 ka-recent; 58-64 wt.% SiO2) eruptive stages of Parinacota volcano, northern Chile. Using the MCS, over 200 RFC models were produced that constrain host magma initial conditions, including pressure, fO2 and H2O, and host and recharge magma masses, temperatures and compositions. A Rhyolite Domes (RD; 47-40 ka; 74 wt.% SiO2) …


Utilizing Radiolarian Assemblages To Track Changes In The Agulhas Current Through The Mid-Pleistocene Transition: Iodp Site U1479, William Alberto Bugbee Jan 2019

Utilizing Radiolarian Assemblages To Track Changes In The Agulhas Current Through The Mid-Pleistocene Transition: Iodp Site U1479, William Alberto Bugbee

Graduate Research Theses & Dissertations

The objective of this study was to assess the radiolarian assemblage of the Agulhas Current at International Ocean Discovery Program Expedition 361, Site U1479 (the most westward site), through the Mid-Pleistocene Transition (MPT). Samples between 1,000 to 777ka were utilized to (1) characterize the radiolarian assemblage, (2) observe whether the radiolarian assemblage is sufficiently distinctive to help discern the occurrence of the MPT in the Southern Ocean, and (3) determine whether changes in the radiolarian assemblage reflect a change or changes in ocean currents that may have occurred during the MPT.

Over 300 radiolarian species from 15 different families were …


Conservation Agriculture In The Heartland: Farmer Perceptions Of Soil Health And The Adoption Of Cover Crops, Lillian Clarissa Cobo Jan 2019

Conservation Agriculture In The Heartland: Farmer Perceptions Of Soil Health And The Adoption Of Cover Crops, Lillian Clarissa Cobo

Graduate Research Theses & Dissertations

The benefits of cover crops are widely recognized by those interested in conservation agriculture and soil health. These benefits include soil erosion control, nutrient loss reduction, and overall improvement of soil health. However, while these benefits are well-documented, the adoption rate of cover crops in the American Heartland remains astoundingly low. While some studies have attempted to determine the reasons for this low adoption rate, the information relating to how farmer perceptions of soil health impact cover crop adoption is almost nonexistent. Furthermore, there is a clear absence of mixed method studies in the literature relating to this subject. This …