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Geochemical Controls On Arsenic Mobilization, Speciation, And Distribution In Alluvial Aquifer Deposits Of The Nawalparasi District, Nepal, Jasmine Diwakar 2017 Southern Cross University

Geochemical Controls On Arsenic Mobilization, Speciation, And Distribution In Alluvial Aquifer Deposits Of The Nawalparasi District, Nepal, Jasmine Diwakar

Theses

Considerable effort have been put into understanding As release mechanism into groundwater of the Upper Gangetic floodplain (the Terai), yet remain poorly understood. We examined aqueous and mineralogical characteristics of the Nawalparasi aquifer system. Hydrogeochemical data revealed that microbially mediated reductive processes are important for mobilizing As in the aquifer. Coupling of As(s) and Fe(s) were observed within the alluvial landscape’s redox cycle. The absence of Fe(III) oxides in sediments at tube-well screen-depth suggested that the As(III)aq was mobilised by either downward transportor desorption of As(III) species. Fine-grained sediments controlled the mobility of ...


Spatial Patterns Of Sea Level Variability Associated With Natural Internal Climate Modes, Weiqing Han, Gerald A. Meehl, Detlef Stammer, Aixue Hu, Benjamin Hamlington, Jessica Kenigson, Hindumathi Palanisamy, Philip Thompson 2017 Old Dominion University

Spatial Patterns Of Sea Level Variability Associated With Natural Internal Climate Modes, Weiqing Han, Gerald A. Meehl, Detlef Stammer, Aixue Hu, Benjamin Hamlington, Jessica Kenigson, Hindumathi Palanisamy, Philip Thompson

OEAS Faculty Publications

Sea level rise (SLR) can exert significant stress on highly populated coastal societies and low-lying island countries around the world. Because of this, there is huge societal demand for improved decadal predictions and future projections of SLR, particularly on a local scale along coastlines. Regionally, sea level variations can deviate considerably from the global mean due to various geophysical processes. These include changes of ocean circulations, which partially can be attributed to natural, internal modes of variability in the complex Earth's climate system. Anthropogenic influence may also contribute to regional sea level variations. Separating the effects of natural climate ...


New And Improved Infra-Red Absorption Cross Sections And Ace-Fts Retrievals Of Carbon Tetrachloride (Ccl4), Jeremy J. Harrison, Christopher D. Boone, Peter F. Bernath 2017 Old Dominion University

New And Improved Infra-Red Absorption Cross Sections And Ace-Fts Retrievals Of Carbon Tetrachloride (Ccl4), Jeremy J. Harrison, Christopher D. Boone, Peter F. Bernath

Chemistry & Biochemistry Faculty Publications

Carbon tetrachloride (CCl4) is one of the species regulated by the Montreal Protocol on account of its ability to deplete stratospheric ozone. As such, the inconsistency between observations of its abundance and estimated sources and sinks is an important problem requiring urgent attention (Carpenter et al., 2014) [5]. Satellite remote-sensing has a role to play, particularly limb sounders which can provide vertical profiles into the stratosphere and therefore validate stratospheric loss rates in atmospheric models. This work is in two parts. The first describes new and improved high-resolution infra-red absorption cross sections of carbon tetrachloride/dry synthetic air over ...


Dynamics Of Solute Transport And Rare Earth Element Behavior In Acid Mine Drainage Impacted Alpine Rivers, Snake River Co, Jordan Elizabeth Carroll 2017 University of Colorado at Boulder

Dynamics Of Solute Transport And Rare Earth Element Behavior In Acid Mine Drainage Impacted Alpine Rivers, Snake River Co, Jordan Elizabeth Carroll

Civil Engineering Graduate Theses & Dissertations

Quantifying and understanding the transport of rare earth elements (REEs) in relation to heavy metals within acidic alpine rivers is relatively understudied. However, employing solute transport models, specifically One-Dimensional Transport with Inflow and Storage (OTIS) can provide insight on the reactivity and transport of REEs. The Snake River is located along the Colorado Mineral Belt in Summit County, Colorado and drains into metropolitan Denver’s drinking water source – Dillon Reservoir. The Snake River is of particular interest due to its hydrological and geochemical similarity to other alpine streams impacted by acid mine drainage throughout Colorado.

In previous studies, most REEs ...


Using Strontium Isotopes In Conjunction With Major, And Trace Elements To Identify Water/Rock Interaction In The Upper Kittitas County, Washington, James Patterson, Carey Gazis 2017 Central Washington University

Using Strontium Isotopes In Conjunction With Major, And Trace Elements To Identify Water/Rock Interaction In The Upper Kittitas County, Washington, James Patterson, Carey Gazis

All Master's Theses

The complex bedrock lithologies in the Upper Kittitas County provide an ideal setting for developing isotopic methodology to identify groundwater sources and track flow paths through water-rock interaction. A wide range of 87Sr/86Sr (0.7040 to 0.7068) in surface waters, springs, and groundwater from wells was found, allowing for identification of the individual signatures of lithologic units. Rock leachates from different lithology were compared to water samples to determine a general 87Sr/86Sr signature of the water-rock interaction for that lithology. The signatures identified were systematically lower than their associated waters, but similar enough to identify the expected ...


Acid Sulfate Soil Resistance Of Mortar And Concretes Using Modified Bauxite Refinery Residue, Rumia Tasmim 2017 Southern Cross University

Acid Sulfate Soil Resistance Of Mortar And Concretes Using Modified Bauxite Refinery Residue, Rumia Tasmim

Theses

Acid sulfate soils (ASS) occur naturally and are soils and sediments containing commonly iron sulfides, mostly pyrite. ASS occur mostly, but not always in low-lying coastal areas (≤5m of sea level) where significant concrete infrastructure such as bridges, roads and port facilities exists. The sulfates produced (particularly sulphuric acid) as disturbed ASS oxidise on from air exposure, reacts with concrete often causing premature failures and reduced service life through chemical expansion, fracturing and spalling. In this study Modified Bauxite Refinery Residue (MBRR) are proposed as a part natural sand replacement in mortar and concrete mixes to improve acid sulfate resistance ...


An Evaluation Of The Lithologies And Geochemistry Of The Upper Beaver Deposit Of The Kirkland Lake Area, Katherine E. Feick 2016 The University of Western Ontario

An Evaluation Of The Lithologies And Geochemistry Of The Upper Beaver Deposit Of The Kirkland Lake Area, Katherine E. Feick

Electronic Thesis and Dissertation Repository

The Upper Beaver Cu-Au deposit contains a unique style of mineralization in the Larder Lake and Kirkland Lake areas in terms of mineralization, alteration style, and age. This study aims to use company-provided data, supplemented with focused data collection, to evaluate what information can be attained from company-provided geochemical data. The evaluation uses a combination of hand sample, petrographic, geochemical, statistical, and microprobe analytical methods.

Lithogeochemical analyses indicated that the altered igneous host rock is calc-alkaline in composition and is most likely part of the diorite-monzonite suite. Further, exploratory data analysis of Au and Cu mineralization identified that there are ...


Annually Resolved North Atlantic Marine Climate Over The Last Millennium, D. J. Reynolds, J. D. Scourse, P. R. Halloran, A. J. Nederbragt, Alan D. Wanamaker, P. G. Butler, C. A. Richardson, J. Heinemeier, J. Eiriksson, K. L. Knudsen, I. R. Hall 2016 Cardiff University

Annually Resolved North Atlantic Marine Climate Over The Last Millennium, D. J. Reynolds, J. D. Scourse, P. R. Halloran, A. J. Nederbragt, Alan D. Wanamaker, P. G. Butler, C. A. Richardson, J. Heinemeier, J. Eiriksson, K. L. Knudsen, I. R. Hall

Geological and Atmospheric Sciences Publications

Owing to the lack of absolutely dated oceanographic information before the modern instrumental period, there is currently significant debate as to the role played by North Atlantic Ocean dynamics in previous climate transitions (for example, Medieval Climate Anomaly-Little Ice Age, MCA-LIA). Here we present analyses of a millennial-length, annually resolved and absolutely dated marine δ18O archive. We interpret our record of oxygen isotope ratios from the shells of the long-lived marine bivalve Arctica islandica18O-shell), from the North Icelandic shelf, in relation to seawater density variability and demonstrate that solar and volcanic forcing coupled with ocean ...


Sedimentology And Geochemistry Of The Mixed Carbonate-Siliciclastic Espanola Formation, Paleoproterozoic Huronian Supergroup, Bruce Mines-Elliot Lake Area, Ontario, Canada, Mansour H. Al-Hashim 2016 The University of Western Ontario

Sedimentology And Geochemistry Of The Mixed Carbonate-Siliciclastic Espanola Formation, Paleoproterozoic Huronian Supergroup, Bruce Mines-Elliot Lake Area, Ontario, Canada, Mansour H. Al-Hashim

Electronic Thesis and Dissertation Repository

The Espanola Formation of the Paleoproterozoic Huronian Supergroup is a mixed carbonate-siliciclastic succession. Detailed sedimentological analysis of the formation in the Bruce Mines-Elliot Lake region reveals 17 sedimentary lithofacies, which comprise three distinct lithofacies associations. The lithofacies associations represent, in ascending order, shoreface, offshore, and nearshore (or lagoon) depositional environments along a wave- and storm-dominated shallow siliciclastic marine shelf. Major, trace, and rare earth element analyses of the siliciclastic component indicate derivation from a mainly granodioritic Archean upper continental crust with some contributions from mafic volcanic and/or sedimentary rocks. The results show that the source rocks were subjected to ...


Characterizing Crystal Populations For The Petrogenesis Of The Post-Collapse Rhyolites In The Long Valley Caldera, California, William Joseph 2016 University of Nevada, Las Vegas

Characterizing Crystal Populations For The Petrogenesis Of The Post-Collapse Rhyolites In The Long Valley Caldera, California, William Joseph

UNLV Theses, Dissertations, Professional Papers, and Capstones

Post-collapse rhyolites of the Long Valley in eastern California are the product of remelting of crystal mush bodies via mafic rejuvenation following the eruption of the Bishop Tuff. This is supported by mineral textures and major element geochemistry from the Resurgent Dome rhyolite, the Moat rhyolite, the Hot Creek Flow, and the Deer Mountain rhyolite. New 40Ar/39Ar eruptive ages are reported for the Moat rhyolites (525 ka, 333 ka, 118 – 94 ka), Hot Creek Flow (312 – 295 ka), and the Deer Mountain rhyolite (65 ka). The initial post-collapse eruptions, resulting in the Resurgent Dome rhyolite, appear to be derived ...


Temporal Co2 Variations And The Influence Of Bat Colonies In Speleogenesis: Continuous Co2 Monitoring In War Eagle Cavern, Arkansas, Ginny Sue Holcomb 2016 University of Arkansas, Fayetteville

Temporal Co2 Variations And The Influence Of Bat Colonies In Speleogenesis: Continuous Co2 Monitoring In War Eagle Cavern, Arkansas, Ginny Sue Holcomb

Theses and Dissertations

Dissolved concentrations of CO2 in a karst aquifer are a major control on calcite dissolutional processes, as CO2 combines chemically with water to form carbonic acid. As increasing amounts of CO2 are added to the system, greater resultant water aggressivity generates greater rates of dissolution. Spatial and temporal variations in carbon flux through the system may occur over a range of time scales, and high-resolution data collection is needed to truly understand and characterize such variability. Continuous CO2 monitoring in War Eagle Cavern, Arkansas, will suggest a number of influential parameters with varying degrees of importance throughout an annual cycle ...


Abrupt Ocean Anoxia During The Late Ordovician Mass Extinction Detected Using Uranium Isotopes Of Marine Carbonates, Rickey Bartlett, Maya Elrick, Yemane Asmerom, Viorel Atudorei 2016 University of New Mexico

Abrupt Ocean Anoxia During The Late Ordovician Mass Extinction Detected Using Uranium Isotopes Of Marine Carbonates, Rickey Bartlett, Maya Elrick, Yemane Asmerom, Viorel Atudorei

Earth and Planetary Sciences ETDs

The Ordovician witnessed an explosion in marine biodiversity punctuated by the first of the ‘big-5’ Phanerozoic mass extinctions, the Late Ordovician mass extinction (LOME). The LOME consists of two discrete pulses occurring at the beginning and end of the Hirnantian. Lithologic and geochemical evidence suggests widespread marine anoxia triggered the second LOME pulse; however, most of these redox proxies record local bottom water or porewater conditions rather than global seawater conditions. To evaluate global redox trends, we utilize uranium (U) isotopes and trace element geochemistry of marine carbonates as a global marine redox proxy.

Bulk carbonate samples were collected from ...


Geochemical Constraints Of The Gold Mineralization Sources From The South Mine Complex And The Main/’04 Breaks, Macassa Mine, Kirkland Lake, Ontario, Liana K.T. Stammers 2016 The University of Western Ontario

Geochemical Constraints Of The Gold Mineralization Sources From The South Mine Complex And The Main/’04 Breaks, Macassa Mine, Kirkland Lake, Ontario, Liana K.T. Stammers

Electronic Thesis and Dissertation Repository

Kirkland Lake Gold’s Macassa Mine is a lode gold deposit in the Abitibi Greenstone. It has two systems of mineralization: the Main/’04 Breaks, and the South Mine Complex (SMC). The objective of this work was to constrain mineralization sources between these systems using geochemical signatures. The SMC has different structure, mineralogy, alteration, trace- and major-elements composition, and δ18O values. The Main/’04 is a series of faults with thin alteration dipping south 60-85º. The SMC is a series of structurally controlled zones dipping southeast 25-50° with wide alteration. It is interpreted to be a Riedel Shear ...


A Stable Isotope Investigation Of Pollen From Pinery Provincial Park, Southwestern Ontario, Canada, Deana M. Schwarz 2016 The University of Western Ontario

A Stable Isotope Investigation Of Pollen From Pinery Provincial Park, Southwestern Ontario, Canada, Deana M. Schwarz

Electronic Thesis and Dissertation Repository

Pollen is a useful proxy for reconstructing paleoclimate; however, the relationship between its stable isotopic composition and the environment in which it forms is still poorly understood. We examine the stable oxygen, carbon, and nitrogen isotope compositions of pollen from tree (coniferous and deciduous), grass (C3 and C4), and marsh species from Pinery Provincial Park, Ontario, and its environs, and maple and oak tree species from eight localities across the United States of America, to (i) determine the major environmental influences on pollen δ18O, δ13C, and δ15N values, (ii) examine the causes ...


Abundance Of Archaias Angulatus On The West Florida Coast Indicates The Influence Of Carbonate Alkalinity Over Salinity, Sean Thomas Beckwith 2016 University of South Florida

Abundance Of Archaias Angulatus On The West Florida Coast Indicates The Influence Of Carbonate Alkalinity Over Salinity, Sean Thomas Beckwith

Graduate Theses and Dissertations

Archaias angulatus, a large symbiont-bearing foraminifer (Order Miliolida) that produces a Mg-calcite shell, is common throughout the Caribbean and warm western Atlantic region. This species lives abundantly in seagrass beds along the Springs Coast of northwest Florida (up to 4 adults per gram of sediment) where spring-fed rivers emerge from a limestone aquifer, and in Florida Bay to the southeast (25 adults/g) where the sediment is primarily biogenic carbonate. In contrast, live specimens are seldom found in the seagrass beds along the central-west coast of Florida, where barrier islands are dominated by quartz sand. My working hypothesis is that ...


The Character And Distribution Of Cu-Pge Mineralization At The Geordie Lake Deposit Within The Coldwell Complex, Ontario, Imran Meghji 2016 The University of Western Ontario

The Character And Distribution Of Cu-Pge Mineralization At The Geordie Lake Deposit Within The Coldwell Complex, Ontario, Imran Meghji

Electronic Thesis and Dissertation Repository

Cu-PGE mineralization at the Geordie Lake Deposit (GLD) is spatially associated with weak to intense actinolite and albite alteration within gabbro and troctolite. Previous studies have determined a magmatic, and magmatic-hydrothermal origin of the deposit. The most significant Cu-PGE occurrence in the GLD is dominantly stratiform, and in contact with a basal syenite. Similar patterns of REE with progressive enrichment from troctolite, to gabbro, and basal syenite indicate that these lithologies are genetically linked. Major element geochemistry shows no discernable variation between the altered and unaltered samples. Whole rock δ18O analyses were conducted in equal intervals down the ...


Surficial Geology Of York College Campus (Queens) And Montauk Point (Long Island): An Open Access To Geoscience Education, Nazrul I. Khandaker, Stanley Schleifer, Krishna Mahabir, Erik Menjivar, Ality Aghedo, Dennis Baidoo, Tenzin Choeying, Vanessa Erwin, Jonathan Xavier, Laboni Molla, Akeed Alrubay 2016 CUNY York College

Surficial Geology Of York College Campus (Queens) And Montauk Point (Long Island): An Open Access To Geoscience Education, Nazrul I. Khandaker, Stanley Schleifer, Krishna Mahabir, Erik Menjivar, Ality Aghedo, Dennis Baidoo, Tenzin Choeying, Vanessa Erwin, Jonathan Xavier, Laboni Molla, Akeed Alrubay

Publications and Research

To evaluate compositional and textural differences among the samples collected from York College (YC) campus (Queens), Montauk Point (MP) and Hither Hills (HH), Long Island, emphasis is given to the general geologic setting, overall grain size distribution, and relative abundances of light and heavy mineral assemblages. Geologic setting encompasses outwash plains (York College), fluvioglacial and glacial (Montauk Point) and beach and dune complex (Hither Hills). YC samples were collected from depth ranging 40 cm to 250 cm and are mostly an assortment of medium to coarse sand, granule to cobble sized, minor silt, and clay. Presence of low angle cross ...


Convergence In Nitrogen Deposition And Cryptic Isotopic Variation Across Urban And Agricultural Valleys In Northern Utah, Steven J. Hall, E. M. Ogata, S. R. Weintraub, M. A. Baker, J. R. Ehleringer, C. I. Czimczik, D. R. Bowling 2016 Iowa State University

Convergence In Nitrogen Deposition And Cryptic Isotopic Variation Across Urban And Agricultural Valleys In Northern Utah, Steven J. Hall, E. M. Ogata, S. R. Weintraub, M. A. Baker, J. R. Ehleringer, C. I. Czimczik, D. R. Bowling

Ecology, Evolution and Organismal Biology Publications

The extent to which atmospheric nitrogen (N) deposition reflects land use differences and biogenic versus fossil fuel reactive N sources remains unclear yet represents a critical uncertainty in ecosystem N budgets. We compared N concentrations and isotopes in precipitation-event bulk (wet + dry) deposition across nearby valleys in northern Utah with contrasting land use (highly urban versus intensive agriculture/low-density urban). We predicted greater nitrate (NO3−) versus ammonium (NH4+) and higher δ15N of NO3− and NH4+ in urban valley sites. Contrary to expectations, annual N deposition (3.5–5.1 kg N ha−1 yr−1) and inorganic N concentrations were ...


Emplacement Of The Foy, Hess And Pele Offset Dykes At The Sudbury Impact Structure, Canada, Eric A. Pilles 2016 The University of Western Ontario

Emplacement Of The Foy, Hess And Pele Offset Dykes At The Sudbury Impact Structure, Canada, Eric A. Pilles

Electronic Thesis and Dissertation Repository

The 1.85 Ga Sudbury impact structure is the remnant of what is generally considered to have been an ~150–200 km diameter impact basin in central Ontario, Canada. The so-called Offset Dykes are impact melt dykes that are found concentrically around – and extending radially outward from – the Sudbury Igneous Complex (SIC), a ~3 km thick differentiated impact melt sheet. The dykes are typically composed of two main phases of granodiorite: an inclusion- and sulfide-rich granodiorite in the centre of the dyke, and an inclusion- and sulfide-poor granodiorite along the margins of the dyke. This study uses a combination of ...


Data-Driven Diagnostics Of Terrestrial Carbon Dynamics Over North America, Jingfeng Xiao, Scott V. Ollinger, Steve Frolking, George Hurtt, David Y. Hollinger, Kenneth J. Davis, Yude Pan, Xiaoyang Zhang, Feng Deng, Jiquan Chen, Dennis D. Baldocchi, Beverly E. Law, M. Altaf Arain, Ankur R. Desai, Andrew D. Richardson, Ge Sun, Brian Amiro, Hank Margolis, Lianhong Gu, Russell L. Scott, Peter D. Blanken, Andrew E. Suyker 2016 University of New Hampshire, Durham

Data-Driven Diagnostics Of Terrestrial Carbon Dynamics Over North America, Jingfeng Xiao, Scott V. Ollinger, Steve Frolking, George Hurtt, David Y. Hollinger, Kenneth J. Davis, Yude Pan, Xiaoyang Zhang, Feng Deng, Jiquan Chen, Dennis D. Baldocchi, Beverly E. Law, M. Altaf Arain, Ankur R. Desai, Andrew D. Richardson, Ge Sun, Brian Amiro, Hank Margolis, Lianhong Gu, Russell L. Scott, Peter D. Blanken, Andrew E. Suyker

Xiaoyang Zhang

The exchange of carbon dioxide is a key measure of ecosystem metabolism and a critical intersection between the terrestrial biosphere and the Earth’s climate. Despite the general agreement that the terrestrial ecosystems in North America provide a sizeable carbon sink, the size and distribution of the sink remain uncertain. We use a data-driven approach to upscale eddy covariance flux observations from towers to the continental scale by integrating flux observations, meteorology, stand age,aboveground biomass, and a proxy for canopy nitrogen concentrations from AmeriFlux and Fluxnet-Canada Research Network as well as a variety of satellite data streams from the ...


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