Open Access. Powered by Scholars. Published by Universities.®
- Discipline
-
- Geology (264)
- Geochemistry (107)
- Hydrology (105)
- Environmental Sciences (102)
- Life Sciences (69)
-
- Geophysics and Seismology (63)
- Oceanography and Atmospheric Sciences and Meteorology (54)
- Engineering (50)
- Soil Science (47)
- Tectonics and Structure (46)
- Ecology and Evolutionary Biology (41)
- Environmental Monitoring (40)
- Mineral Physics (35)
- Civil and Environmental Engineering (33)
- Volcanology (33)
- Water Resource Management (32)
- Chemistry (27)
- Desert Ecology (26)
- Sedimentology (26)
- Climate (25)
- Fresh Water Studies (22)
- Social and Behavioral Sciences (22)
- Environmental Indicators and Impact Assessment (21)
- Paleontology (19)
- Physics (19)
- Stratigraphy (18)
- Astrophysics and Astronomy (15)
- Environmental Chemistry (13)
- Keyword
-
- Nevada – Yucca Mountain (69)
- Groundwater (25)
- Geochemistry (19)
- Tuff (18)
- Nevada (17)
-
- Volcanic ash (16)
- Earthquake hazard analysis (14)
- Geology (14)
- Groundwater flow (12)
- Faults (Geology) (11)
- Mars (11)
- Etc. (10)
- Radioactive waste repositories (10)
- Seismic networks (10)
- Water chemistry (10)
- Climatic changes (9)
- Earth sciences (9)
- Earthquakes (9)
- Mineralogy (9)
- Igneous rocks (8)
- Rock mechanics (8)
- Fluid inclusions (7)
- Hydrology (7)
- Magmas (7)
- Mars sample return (7)
- Planetary geoscience (7)
- Planetary science (7)
- Planetary surfaces (7)
- Seismological stations (7)
- Space Science and Research (7)
- Publication Year
- Publication
-
- UNLV Theses, Dissertations, Professional Papers, and Capstones (245)
- Geoscience Faculty Research (74)
- Publications (YM) (74)
- Undergraduate Research Opportunities Program (UROP) (19)
- Publications (WR) (16)
-
- Civil and Environmental Engineering and Construction Faculty Research (13)
- Public Policy and Leadership Faculty Research (13)
- Life Sciences Faculty Research (8)
- Undergraduate Research Symposium Posters (7)
- Festival of Communities: UG Symposium (Posters) (6)
- Physics & Astronomy Faculty Research (6)
- UNLV Magazine (4)
- 2010 Annual Nevada NSF EPSCoR Climate Change Conference (3)
- Anthropology Faculty Research (3)
- Chemistry and Biochemistry Faculty Research (3)
- McNair Journal (3)
- Calvert Undergraduate Research Awards (2)
- Curriculum materials (FE) (2)
- Environment (2)
- Limnological Studies (2)
- Mechanical Engineering Faculty Research (2)
- NSTec UNLV Symposium (2)
- Climate Change Seminar Series (NNE) (1)
- College of Engineering: Graduate Celebration Programs (1)
- Inside UNLV (1)
- LSAMP Poster Presentations (1)
- McNair Poster Presentations (1)
- Nevada Renewable Energy Consortium Meeting (1)
- Oliver Ranch Project (1)
- Publications (HRC) (1)
- Publication Type
Articles 121 - 150 of 521
Full-Text Articles in Earth Sciences
Structure-Strength Relations Of Distinct Mon Phases From First-Principles Calculations, Cheng Lu, Changfeng Chen
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, Cheng Lu, Changfeng Chen
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 …
High‐Pressure Carbonaceous Phases As Minerals, Oliver Tschauner
High‐Pressure Carbonaceous Phases As Minerals, Oliver Tschauner
Geoscience Faculty Research
High‐pressure carbonaceous minerals establish a link between one of the most abundant chemical elements and processes that occur at high pressures, either in the interior of the Earth or during shock‐metamorphosis in space or on Earth. Diamonds from the Earth's mantle carry inclusions of carbides, carbonates, methane, and carbon‐dioxide. These inclusions elucidate diamond formation and the carbon recycling in the mantle. This chapter focuses on these inclusion minerals themselves, the means of detection, and the reconstruction of pressure‐temperature conditions of their formation in the mantle.
Critical Knowledge Gaps In The Martian Geological Record: A Rationale For Regional-Scale In Situ Exploration By Rotorcraft Mid-Air Deployment, William Rapin Sorbonne Université, A. Fraeman California Institute Of Technology, B. L. Ehlmann California Institute Of Technology, A. Mittelholz University Of British Columbia, B. Langlais, R. Lillis, V. Sautter, D. Baratoux, V. Payré, Arya Udry, B. Horgan, J. Flahaut, G. Dromart, C. Quantin-Nataf, N. Mangold, S. Maurice, J. T. Keane, J. Bapst
Critical Knowledge Gaps In The Martian Geological Record: A Rationale For Regional-Scale In Situ Exploration By Rotorcraft Mid-Air Deployment, William Rapin Sorbonne Université, A. Fraeman California Institute Of Technology, B. L. Ehlmann California Institute Of Technology, A. Mittelholz University Of British Columbia, B. Langlais, R. Lillis, V. Sautter, D. Baratoux, V. Payré, Arya Udry, B. Horgan, J. Flahaut, G. Dromart, C. Quantin-Nataf, N. Mangold, S. Maurice, J. T. Keane, J. Bapst
Geoscience Faculty Research
Mars oldest terrains hold the answers to key science questions, yet remain largely unexplored. In situ exploration by mid-air deployed rotorcrafts can uniquely answer these questions in the near future due to their unique ability to access the ancient southern highlands and perform in situ analyses at regional-scale, at breakthrough costs.
Thermal Analysis, Compressibility, And Decomposition Of Synthetic Bastnäsite-(La) To Lanthanum Oxyfluoride, Richard L. Rowland, Barbara Lavina, Kathleen E. Vander Kadeen, Lisa R. Danielson, Pamela C. Burnely
Thermal Analysis, Compressibility, And Decomposition Of Synthetic Bastnäsite-(La) To Lanthanum Oxyfluoride, Richard L. Rowland, Barbara Lavina, Kathleen E. Vander Kadeen, Lisa R. Danielson, Pamela C. Burnely
Geoscience Faculty Research
Understanding basic material properties of rare earth element (REE) bearing minerals such as their phase stability and equations of state can assist in understanding how economically viable deposits might form. Bastnäsite is the most commonly mined REE bearing mineral. We synthesized the lanthanum-fluoride end member, bastnäsite-(La) (LaCO3F), and investigated its thermal behavior and decomposition products from 298 K to 1173 K under ambient pressure conditions through thermogravimetric analysis, differential scanning calorimetry, evolved gas analysis, and high temperature powder X-ray diffraction. We also investigated the compressibility of bastnäsite-(La) via single crystal X-ray diffraction in diamond anvil cells at an ambient temperature …
Initiation Of A Stable Convective Hydroclimatic Regime In Central America Circa 9000 Years Bp, Amos Winter, Davide Zanchettin, Matthew Lachniet, Rolf Vieten, Francesco S. R. Pausata, Fredrik Charpentier Ljungqvist, Hai Cheng, R. Lawrence Edwards, Thomas Miller, Sara Rubinetti, Angelo Rubino, Carla Taricco
Initiation Of A Stable Convective Hydroclimatic Regime In Central America Circa 9000 Years Bp, Amos Winter, Davide Zanchettin, Matthew Lachniet, Rolf Vieten, Francesco S. R. Pausata, Fredrik Charpentier Ljungqvist, Hai Cheng, R. Lawrence Edwards, Thomas Miller, Sara Rubinetti, Angelo Rubino, Carla Taricco
Geoscience Faculty Research
Many Holocene hydroclimate records show rainfall changes that vary with local orbital insolation. However, some tropical regions display rainfall evolution that differs from gradual precessional pacing, suggesting that direct rainfall forcing effects were predominantly driven by sea-surface temperature thresholds or inter-ocean temperature gradients. Here we present a 12,000 yr continuous U/Th-dated precipitation record from a Guatemalan speleothem showing that Central American rainfall increased within a 2000 yr period from a persistently dry state to an active convective regime at 9000 yr BP and has remained strong thereafter. Our data suggest that the Holocene evolution of Central American rainfall was driven …
The Impact Of Advanced Treatment Technologies On The Engery Use In Satellite Water Reuse Plants, Jonathan R. Bailey, Sajjad Ahmad, Jacimaria Batista
The Impact Of Advanced Treatment Technologies On The Engery Use In Satellite Water Reuse Plants, Jonathan R. Bailey, Sajjad Ahmad, Jacimaria Batista
Civil and Environmental Engineering and Construction Faculty Research
With an ever-increasing world population and the resulting increase in industrialization and agricultural practices, depletion of one of the world’s most important natural resources, water, is inevitable. Water reclamation and reuse is the key to protecting this natural resource. Water reclamation using smaller decentralized wastewater treatment plants, known as satellite water reuse plants (WRP), has become popular in the last decade. Reuse plants have stricter standards for effluent quality and require a smaller land footprint (i.e., real estate area). They also require additional treatment processes and advanced treatment technologies. This greatly increases the energy consumption of an already energy intensive …
Riesite, A New High Pressure Polymorph Of Tio2 From The Ries Impact Structure, Tschauner, Chi Ma, Antonio Lanzirotti, Matthew G. Newville
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.
Mildly Hydrophobic Biobased Mulch: A Sustainable Approach To Controlling Bare Soil Evaporation, Jesse Lee Barnes, Michael John Nicholl
Mildly Hydrophobic Biobased Mulch: A Sustainable Approach To Controlling Bare Soil Evaporation, Jesse Lee Barnes, Michael John Nicholl
Geoscience Faculty Research
© 2020 The Authors. Vadose Zone Journal published by Wiley Periodicals LLC on behalf of Soil Science Society of America Mulching with polyethylene film is the conventional approach to decrease evaporative water loss from agricultural soils, but it is not environmentally sustainable. In this study, a laboratory experiment was conducted to test the potential utility of partially polymerized soybean oil (PSO) coated sands as a surface treatment to reduce bare soil evaporation. Evaporation was tracked for 23.8 d from saturated sand columns treated with a surface layer (1 or 2 cm) of either coated medium sand (MS-PSO) or coated coarse …
Subglacial Meltwater Supported Aerobic Marine Habitats During Snowball Earth, Maxwell A. Lechte, Malcolm W. Wallace, Ashleig Van Smeerdijk Hooda, Weiqiang Li, Ganqing Jiang, Galen P. Halverson, Dan Asael, Stephanie L. Mccoll, Noah J. Planavsky
Subglacial Meltwater Supported Aerobic Marine Habitats During Snowball Earth, Maxwell A. Lechte, Malcolm W. Wallace, Ashleig Van Smeerdijk Hooda, Weiqiang Li, Ganqing Jiang, Galen P. Halverson, Dan Asael, Stephanie L. Mccoll, Noah J. Planavsky
Geoscience Faculty Research
The Earth’s most severe ice ages interrupted a crucial interval in eukaryotic evolution with widespread ice coverage during the Cryogenian Period (720 to 635 Ma). Aerobic eukaryotes must have survived the “Snowball Earth” glaciations, requiring the persistence of oxygenated marine habitats, yet evidence for these environments is lacking. We examine iron formations within globally distributed Cryogenian glacial successions to reconstruct the redox state of the synglacial oceans. Iron isotope ratios and cerium anomalies from a range of glaciomarine environments reveal pervasive anoxia in the ice-covered oceans but increasing oxidation with proximity to the ice shelf grounding line. We propose that …
Examination Of Maskelynite Through Static Recompression And Dynamic Compression, Justin James Reppart
Examination Of Maskelynite Through Static Recompression And Dynamic Compression, Justin James Reppart
UNLV Theses, Dissertations, Professional Papers, and Capstones
This is an experimental study that aims to clarify the possible formation mechanisms of maskelynite. Maskelynite is a diaplectic glass, that forms during shock compression of feldspar far below the melting point, and without fusion. Maskelynite also paramorphises precursor feldspar grains. Maskelynite is an important probe of shock-pressures at terrestrial impact sites and in many meteorites. Two mechanisms of formation of maskelynite are examined here: 1) maskelynite is result of a pressure-induced amorphization of feldspar compressed beyond its mechanical stability where the formation of thermodynamically stable phases is kinetically inhibited [1, 2]. 2) Feldspar transforms upon dynamic compression into a …
Moisture Dynamics Of A Near-Surface Desert Soil, Yuan Luo
Moisture Dynamics Of A Near-Surface Desert Soil, Yuan Luo
UNLV Theses, Dissertations, Professional Papers, and Capstones
Desert soils cover about one third of the Earth’s land surface. Despite their large extent, however, our understanding of desert soil hydraulic processes and properties is still rather limited. In particularly with respect to the near-surface (top centimeters) of the soil profile, which play a critical role for infiltration, redistribution and evapotranspiration of rainwater, the limiting resource for life in desert environments, but also hosts most of the biologic activity and controls runoff, erosion as well as the emission of dust (Nannipieri et al.,2003; Bradford et al.,1987). Additionally, deserts are ideal locations for electricity generation with solar energy using large-scale …
Utility Of Bench Scale Sand Tank Experiments At Assessing Permeable Reactive Barrier Design, Brandon Meier
Utility Of Bench Scale Sand Tank Experiments At Assessing Permeable Reactive Barrier Design, Brandon Meier
UNLV Theses, Dissertations, Professional Papers, and Capstones
The objective of this work was to evaluate the utility of bench scale sand tank experiments at assessing permeable reactive barrier (PRB) design. Our criteria for meeting this goal was that differences between PRB designs could be identified solely by measuring concentration in outflow from the sand tank models. For our PRB designs (funnel-and-gate, staggered wells, and parallel bars), numerical simulations clearly showed that PRB design had a quantifiable effect on outflow concentration, provided that the solute reacted with the PRB materials. Conversely, use of a conservative (non-reactive) solute did not allow us to discern between PRB design alternatives. Employing …
Bringing Statistical Learning Machines Together For Hydro-Climatological Predictions - Case Study For Sacramento San Joaquin River Basin, California, Balbhadra Thakur, Ajay Kalra, Sajjad Ahmad, Kenneth W. Lamb, Venkat Lakshmi
Bringing Statistical Learning Machines Together For Hydro-Climatological Predictions - Case Study For Sacramento San Joaquin River Basin, California, Balbhadra Thakur, Ajay Kalra, Sajjad Ahmad, Kenneth W. Lamb, Venkat Lakshmi
Civil and Environmental Engineering and Construction Faculty Research
Study region: Sacramento San Joaquin River Basin, California Study focus: The study forecasts the streamflow at a regional scale within SSJ river basin with largescale climate variables. The proposed approach eliminates the bias resulting from predefined indices at regional scale. The study was performed for eight unimpaired streamflow stations from 1962–2016. First, the Singular Valued Decomposition (SVD) teleconnections of the streamflow corresponding to 500 mbar geopotential height, sea surface temperature, 500 mbar specific humidity (SHUM500), and 500 mbar U-wind (U500) were obtained. Second, the skillful SVD teleconnections were screened non-parametrically. Finally, the screened teleconnections were used as the streamflow predictors …
Chemostratigraphic Correlations Across The First Major Trilobite Extinction And Faunal Turnovers Between Laurentia And South China, Jih-Pai Lin, Frederick A. Sunberg, Ganqing Jiang, Isabel P. Montanez, Thomas Wotte
Chemostratigraphic Correlations Across The First Major Trilobite Extinction And Faunal Turnovers Between Laurentia And South China, Jih-Pai Lin, Frederick A. Sunberg, Ganqing Jiang, Isabel P. Montanez, Thomas Wotte
Geoscience Faculty Research
During Cambrian Stage 4 (~514 Ma) the oceans were widely populated with endemic trilobites and three major faunas can be distinguished: olenellids, redlichiids, and paradoxidids. The lower–middle Cambrian boundary in Laurentia was based on the first major trilobite extinction event that is known as the Olenellid Biomere boundary. However, international correlation across this boundary (the Cambrian Series 2–Series 3 boundary) has been a challenge since the formal proposal of a four-series subdivision of the Cambrian System in 2005. Recently, the base of the international Cambrian Series 3 and of Stage 5 has been named as the base of the Miaolingian …
Comparison Of Extraction Methods For Recovering Ancient Microbial Dna From Paleofeces, Richard W. Hagan, Courtney A. Hofman, Alexander Hübner, Karl Reinhard, Stephanie Schnorr, Cecil M. Lewis Jr., Krithivasan Sankaranarayanan, Christina G. Warinner
Comparison Of Extraction Methods For Recovering Ancient Microbial Dna From Paleofeces, Richard W. Hagan, Courtney A. Hofman, Alexander Hübner, Karl Reinhard, Stephanie Schnorr, Cecil M. Lewis Jr., Krithivasan Sankaranarayanan, Christina G. Warinner
Anthropology Faculty Research
Objectives Paleofeces are valuable to archeologists and evolutionary biologists for their potential to yield health, dietary, and host information. As a rich source of preserved biomolecules from host‐associated microorganisms, they can also provide insights into the recent evolution and changing ecology of the gut microbiome. However, there is currently no standard method for DNA extraction from paleofeces, which combine the dual challenges of complex biological composition and degraded DNA. Due to the scarcity and relatively poor preservation of paleofeces when compared with other archeological remains, it is important to use efficient methods that maximize ancient DNA (aDNA) recovery while also …
Magnetite Magnetosome Biomineralization In Magnetospirillum Magneticum Strain Amb-1: A Time Course Study, Lucas Le Nagard, Xiaohui Zhu, Hao Yuan, Karim Benzerara, Dennis A. Bazylinski, Cécile Fradin, Adrien Besson, Sufal Swaraj, Stefan Stanescu, Rachid Belkhou, Adam P. Hitchcock
Magnetite Magnetosome Biomineralization In Magnetospirillum Magneticum Strain Amb-1: A Time Course Study, Lucas Le Nagard, Xiaohui Zhu, Hao Yuan, Karim Benzerara, Dennis A. Bazylinski, Cécile Fradin, Adrien Besson, Sufal Swaraj, Stefan Stanescu, Rachid Belkhou, Adam P. Hitchcock
Life Sciences Faculty Research
Magnetotactic bacteria are a highly studied group of diverse prokaryotes that biomineralize chains of magnetosomes, single domain, single crystal magnetic nanoparticles of magnetite or greigite, enclosed by a lipid bilayer membrane whose synthesis is under strict genetic control.
Spread Of Domestic Animals Across Neolithic Western Anatolia: New Stable Isotope Evidence From Ugurlu Höyük, The Island Of Gökçeada, Turkey, Suzanne E. Pilaar Birch, Levent Atici, Burcin Erdogu
Spread Of Domestic Animals Across Neolithic Western Anatolia: New Stable Isotope Evidence From Ugurlu Höyük, The Island Of Gökçeada, Turkey, Suzanne E. Pilaar Birch, Levent Atici, Burcin Erdogu
Anthropology Faculty Research
The origins of agriculture in Southwest Asia over 10,000 years ago and its subsequent spread into Europe during the Neolithic have been the focus of much archaeological research over the past several decades. Increasingly more sophisticated analytical techniques have allowed for better understanding of the complex interactions that occurred amongst humans, animals, and their environments during this transition. The Aegean Islands are critically situated where Anatolia and the mainland Greece meet, making the region pivotal for understanding the movement of the Neolithic into Europe. Located on the largest Turkish Aegean island of Gökçeada, the site of Uğurlu Höyük dates to …
Reproduction And Dispersal Of Biological Soil Crust Organisms, Steven D. Warren, Larry L. St. Clair, Lloyd R. Stark, Louise A. Lewis, Nuttapon Pombubpa, Tania Kurbessoian, Jason E. Stajich, Zachary T. Aanderud
Reproduction And Dispersal Of Biological Soil Crust Organisms, Steven D. Warren, Larry L. St. Clair, Lloyd R. Stark, Louise A. Lewis, Nuttapon Pombubpa, Tania Kurbessoian, Jason E. Stajich, Zachary T. Aanderud
Life Sciences Faculty Research
Biological soil crusts (BSCs) consist of a diverse and highly integrated community of organisms that effectively colonize and collectively stabilize soil surfaces. BSCs vary in terms of soil chemistry and texture as well as the environmental parameters that combine to support unique combinations of organisms—including cyanobacteria dominated, lichen-dominated, and bryophyte-dominated crusts. The list of organismal groups that make up BSC communities in various and unique combinations include—free living, lichenized, and mycorrhizal fungi, chemoheterotrophic bacteria, cyanobacteria, diazotrophic bacteria and archaea, eukaryotic algae, and bryophytes. The various BSC organismal groups demonstrate several common characteristics including—desiccation and extreme temperature tolerance, production of various …
Numerical Simulation Based Targeting Of The Magushan Skarn Cu-Mo Deposit, Middle-Lower Yangtze Metallogenic Belt, China, Xunyu Hu, Xiaohui Li, Feng Yuan, Alison Ord, Simon M. Jowitt, Yue Li, Wenqiang Dai, Rui Ye, Taofa Zhou
Numerical Simulation Based Targeting Of The Magushan Skarn Cu-Mo Deposit, Middle-Lower Yangtze Metallogenic Belt, China, Xunyu Hu, Xiaohui Li, Feng Yuan, Alison Ord, Simon M. Jowitt, Yue Li, Wenqiang Dai, Rui Ye, Taofa Zhou
Geoscience Faculty Research
The Magushan Cu–Mo deposit is a skarn deposit within the Nanling–Xuancheng mining district of the Middle-Lower Yangtze River Metallogenic Belt (MLYRMB), China. This study presents the results of a new numerical simulation that models the ore-forming processes that generated the Magushan deposit and enables the identification of unexplored areas that have significant exploration potential under areas covered by thick sedimentary sequences that cannot be easily explored using traditional methods. This study outlines the practical value of numerical simulation in determining the processes that operate during mineral deposit formation and how this knowledge can be used to enhance exploration targeting in …
Literature Review: Biocement For Stabilization Of Expansive Soils In Las Vegas, Nevada, Silva Topchyan, Moses Karakouzian
Literature Review: Biocement For Stabilization Of Expansive Soils In Las Vegas, Nevada, Silva Topchyan, Moses Karakouzian
LSAMP Poster Presentations
The aim of this study was to present a possibility for the use of biocementon expansive clay. Expansive soil is a type of clay when exposed to water and moisture changes its volume. Due to the clays swelling and shrinkage behavior itsdifficult to use it in engineering and construction projects, therefore costly and unhealthy techniques have been used to stabiliseexpansive soil in order to address the problem [12]. A possible healthy and environmentally friendly solution is Biocement which uses microbial induced calcite precipitation (MICP) in order to help aggregate soil to form a stable cementitiousmaterial. MICP isdependent on the innate …
A Nanoscale Investigation Of Carlin-Type Gold Deposits: An Atom-Scale Elemental And Isotopic Perspective, Philippe Gopon, James O. Douglas, Maria A. Auger, Lars Hansen, Jon Wade, Jean S. Cline, Laurence J. Robb, Michael P. Moody
A Nanoscale Investigation Of Carlin-Type Gold Deposits: An Atom-Scale Elemental And Isotopic Perspective, Philippe Gopon, James O. Douglas, Maria A. Auger, Lars Hansen, Jon Wade, Jean S. Cline, Laurence J. Robb, Michael P. Moody
Geoscience Faculty Research
Carlin-type gold deposits are one of the most important gold mineralization styles in the world. Despite their economic importance and the large volume of work that has been published, there remain crucial questions regarding their metallogenesis. Much of this uncertainty is due to the cryptic nature of the gold occurrence, with gold occurring as dispersed nanoscale inclusions within host pyrite rims that formed on earlier formed barren pyrite cores. The small size of the gold inclusions has made determining their nature within the host sulfides and the mechanisms by which they precipitated from the ore fluids particularly problematic. This study …
Evaluating The Sustainability Of Indirect Potable Reuse And Direct Potable Reuse: A Southern Nevada Case Study, Sajjad Ahmad, Cory Dow, Krystyna Stave, Daniel Gerrity
Evaluating The Sustainability Of Indirect Potable Reuse And Direct Potable Reuse: A Southern Nevada Case Study, Sajjad Ahmad, Cory Dow, Krystyna Stave, Daniel Gerrity
Civil and Environmental Engineering and Construction Faculty Research
This case study presents a framework for evaluating the sustainability of indirect potable reuse (IPR) and direct potable reuse (DPR) in Las Vegas, Nevada. A system dynamics model was developed to simulate population growth, water supply, water quality, energy costs, net present worth (NPW), and greenhouse gas (GHG) emissions. The model confirmed that DPR could achieve a net reduction in energy costs of up to US$250 million while still ensuring an adequate water supply. However, the high NPW of DPR ($1.0–$4.0 billion) relative to the status quo IPR approach ($0.6 billion) represents a significant economic hurdle, although future monetization of …
Application Of Semi-Hydrophobic Layers To Decrease Bare Soil Evaporation, Jesse Lee Barnes
Application Of Semi-Hydrophobic Layers To Decrease Bare Soil Evaporation, Jesse Lee Barnes
UNLV Theses, Dissertations, Professional Papers, and Capstones
Evaporative water loss from bare agricultural soils is a primary area of water conservation research. Mulching is the commonly utilized method to decrease evaporative water loss. The most commonly utilized mulch is nonbiodegradable polyethylene sheeting because it tends to decrease evaporative water loss and increase crop yields more than environmentally friendly mulches. This study aimed to test the utility of sand coated with polymerized soybean oil (i.e., hydrophobic sand) as a treatment to reduce bare soil evaporation and an alternative to current practices. Evaporation rates were measured in laboratory soil columns containing both treated and untreated soils. Treatment parameters were …
Fault Slip And Exhumation History Of The Willard Thrust Sheet, Sevier Fold‐Thrust Belt, Utah: Relations To Wedge Propagation, Hinterland Uplift, And Foreland Basin Sedimentation, W. A. Yonkee, Bryan Eleogram, Michael L. Wells, Daniel F. Stockli, Shari Kelley, D. E. Barber
Fault Slip And Exhumation History Of The Willard Thrust Sheet, Sevier Fold‐Thrust Belt, Utah: Relations To Wedge Propagation, Hinterland Uplift, And Foreland Basin Sedimentation, W. A. Yonkee, Bryan Eleogram, Michael L. Wells, Daniel F. Stockli, Shari Kelley, D. E. Barber
Geoscience Faculty Research
Zircon (U‐Th)/He (ZHe) and zircon fission track thermochronometric data for 47 samples spanning the areally extensive Willard thrust sheet within the western part of the Sevier fold‐thrust belt record enhanced cooling and exhumation during major thrust slip spanning approximately 125–90 Ma. ZHe and zircon fission track age‐paleodepth patterns along structural transects and age‐distance relations along stratigraphic‐parallel traverses, combined with thermo‐kinematic modeling, constrain the fault slip history, with estimated slip rates of ~1 km/Myr from 125 to 105 Ma, increasing to ~3 km/Myr from 105 to 92 Ma, and then decreasing as major slip was transferred onto eastern thrusts. Exhumation was …
A New Plumbing System Framework For Mantle Plume-Related Continental Large Igneous Provinces And Their Mafic-Ultramafic Intrusions, Richard E. Ernst, Dustin A. Liikane, Simon M. Jowitt, K. L. Buchan, J. A. Blanchard
A New Plumbing System Framework For Mantle Plume-Related Continental Large Igneous Provinces And Their Mafic-Ultramafic Intrusions, Richard E. Ernst, Dustin A. Liikane, Simon M. Jowitt, K. L. Buchan, J. A. Blanchard
Geoscience Faculty Research
The magmatic components of continental Large Igneous Provinces (LIPs) include flood basalts and their plumbing system of giant mafic dyke swarms (radiating, linear, and the recently discovered circumferential type), mafic sill provinces, a lower crustal magmatic underplate, mafic-ultramafic (M–UM) intrusions, associated silicic magmatism, and associated carbonatites and kimberlites. This paper proposes a new plumbing system framework for mantle plume-related continental LIPs that incorporates all of these components, and provides a context for addressing key thematic aspects such as tracking magma batches “upstream” and “downstream” and their geochemical evolution, assessing the setting of M-UM intrusions and their economic potential, interpreting deep …
A Vacancy-Rich, Partially Inverted Spinelloid Silicate, (Mg,Fe,Si)(2)(Si,)O-4, As A Major Matrix Phase In Shock Melt Veins Of The Tenham And Suizhou L6 Chondrites, Oliver Tschauner, Chi Ma, Luca Bindi, John R. Beckett, Xiande Xie
A Vacancy-Rich, Partially Inverted Spinelloid Silicate, (Mg,Fe,Si)(2)(Si,)O-4, As A Major Matrix Phase In Shock Melt Veins Of The Tenham And Suizhou L6 Chondrites, Oliver Tschauner, Chi Ma, Luca Bindi, John R. Beckett, Xiande Xie
Geoscience Faculty Research
A new high‐pressure silicate, (Mg,Fe,Si)2(Si,□)O4 with a tetragonal spinelloid structure, was discovered within shock melt veins in the Tenham and Suizhou meteorites, two highly shocked L6 ordinary chondrites. Relative to ringwoodite, this phase exhibits an inversion of Si coupled with intrinsic vacancies and a consequent reduction of symmetry. Most notably, the spinelloid makes up about 30–40 vol% of the matrix of shock veins with the remainder composed of a vitrified (Mg,Fe)SiO3 phase (in Tenham) or (Mg,Fe)SiO3‐rich clinopyroxene (in Suizhou); these phase assemblages constitute the bulk of the matrix in the shock veins. Previous assessments of the melt matrices concluded that …
Twenty-Three Unsolved Problems In Hydrology (Uph) -- A Community Perspective, Günter Blöschl, Marc F.P. Bierkens, Antonio Chambel, Christophe Cudennec, Georgia Destouni, Aldo Fiori, James W. Kirchner, Jeffrey J. Mcdonnell, Hubert H.G. Savenjie, Murugesu Sivapalan, Christine Stumpp, Elena Toth, Elena Volpi, Gemma Carr, Claire Lupton, Jose Salinas, Borbala Szeles, Alberto Viglione, Hafzullah Aksoy, Scott T. Allen, Anam Amin, Vazken Andreassian, Berit Arheimer, Santosh K. Aryal, Victor Baker, Earl Bardsley, Marlies H. Barendrecht, Alena Bartosova, Okke Batelaan, Wouter R. Berghuijs, Keith Beven
Twenty-Three Unsolved Problems In Hydrology (Uph) -- A Community Perspective, Günter Blöschl, Marc F.P. Bierkens, Antonio Chambel, Christophe Cudennec, Georgia Destouni, Aldo Fiori, James W. Kirchner, Jeffrey J. Mcdonnell, Hubert H.G. Savenjie, Murugesu Sivapalan, Christine Stumpp, Elena Toth, Elena Volpi, Gemma Carr, Claire Lupton, Jose Salinas, Borbala Szeles, Alberto Viglione, Hafzullah Aksoy, Scott T. Allen, Anam Amin, Vazken Andreassian, Berit Arheimer, Santosh K. Aryal, Victor Baker, Earl Bardsley, Marlies H. Barendrecht, Alena Bartosova, Okke Batelaan, Wouter R. Berghuijs, Keith Beven
Geoscience Faculty Research
This paper is the outcome of a community initiative to identify major unsolved scientific problems in hydrology motivated by a need for stronger harmonisation of research efforts. The procedure involved a public consultation through online media, followed by two workshops through which a large number of potential science questions were collated, prioritised, and synthesised. In spite of the diversity of the participants (230 scientists in total), the process revealed much about community priorities and the state of our science: a preference for continuity in research questions rather than radical departures or redirections from past and current work. Questions remain focused …
Cave Temperature And Management Implications In Lehman Caves, Great Basin National Park, Usa, Stanka Šebela, Gretchen Baker, Barbara Luke
Cave Temperature And Management Implications In Lehman Caves, Great Basin National Park, Usa, Stanka Šebela, Gretchen Baker, Barbara Luke
Civil and Environmental Engineering and Construction Faculty Research
Cave air temperature was measured at six locations in Lehman Caves (USA) for one year at hourly intervals. Lehman is a show cave in a national park, treasured for its geological and biological resources. The two monitoring locations that are off of the tour route and, also, relatively distant from the cave’s entrances displayed nearly constant air temperature during the year. The other four sites, along the tour route, show daily temperature variation as well as annual fluctuation. After visitation levels decreased in the autumn, cave temperatures lagged but eventually reached an equilibrium which demonstrates recovery in the quiet winter. …
Pressure-Induced Phase Transition In 1,3,5-Triamino-2,4,6-Trinitrobenzene (Tatb), Brad A. Steele, Samantha M. Clarke, Matthew P. Kroonblawd, I-Feng W. Kuo, Philip F. Pagoria, Sergey N. Tkachev, Jesse S. Smith, Sorin Bastea, Laurence E. Fried, Joseph M. Zaug, Elissaios Stavrou, Oliver Tschauner
Pressure-Induced Phase Transition In 1,3,5-Triamino-2,4,6-Trinitrobenzene (Tatb), Brad A. Steele, Samantha M. Clarke, Matthew P. Kroonblawd, I-Feng W. Kuo, Philip F. Pagoria, Sergey N. Tkachev, Jesse S. Smith, Sorin Bastea, Laurence E. Fried, Joseph M. Zaug, Elissaios Stavrou, Oliver Tschauner
Geoscience Faculty Research
Determining the unreacted equation of state of 1,3, 5-triamino-2,4,6-trinitrobenzene (TATB) is challenging because it exhibits low crystal symmetry and low X-ray scattering strength. Here, we present the first high-pressure single-crystal X-ray diffraction (SXD) study of this material. Our SXD results reveal a previously unknown transition to a monoclinic phase above 4 GPa. No abrupt change of the volume occurs but the compressibility changes. Concomitant first principles evolutionary crystal structure prediction USPEX calculations confirm this transition and show that it involves a pressure-induced in-plane shift of the layers of TATB molecules with respect to the ambient-pressure phase.