Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons™

Open Access. Powered by Scholars. Published by Universities.®

Stable isotopes

2021

Discipline
Institution
Publication
Publication Type

Articles 1 - 16 of 16

Full-Text Articles in Physical Sciences and Mathematics

The Hera Orebody: A Complex Distal (Au–Zn–Pb–Ag–Cu) Skarn In The Cobar Basin Of Central New South Wales, Australia, Corey Wall Oct 2021

The Hera Orebody: A Complex Distal (Au–Zn–Pb–Ag–Cu) Skarn In The Cobar Basin Of Central New South Wales, Australia, Corey Wall

Geosciences Faculty Publications and Presentations

The Hera Au–Pb–Zn–Ag deposit in the southeastern Cobar Basin of central New South Wales preserves calc-silicate veins and remnant sandstone/carbonate-hosted skarn within a reduced anchizonal Siluro-Devonian turbidite sequence. The skarn orebody distribution is controlled by a long-lived, basin margin fault system, that has intersected a sedimentary horizon dominated by siliciclastic turbidite, with lesser gritstone and thick sandstone intervals, and rare carbonate-bearing stratigraphy. Foliation (S1) envelopes the orebody and is crosscut by a series of late-stage east–west and north–south trending faults. Skarn at Hera displays mineralogical zonation along strike, from southern spessartine–grossular–biotite–actinolite-rich associations, to central diopside-rich–zoisite–actinolite/tremolite–grossular-bearing associations, through to the northern …

Go to article

Stable Isotopes Used To Infer Trophic Position Of Green Turtles (Chelonia Mydas) From Dry Tortugas National Park, Gulf Of Mexico, United States, David C. Roche, Michael S. Cherkiss, Brian J. Smith, Derek A. Burkholder, Kristen M. Hart Sep 2021

Stable Isotopes Used To Infer Trophic Position Of Green Turtles (Chelonia Mydas) From Dry Tortugas National Park, Gulf Of Mexico, United States, David C. Roche, Michael S. Cherkiss, Brian J. Smith, Derek A. Burkholder, Kristen M. Hart

Marine & Environmental Sciences Faculty Articles

Evaluating resource use patterns for imperiled species is critical for understanding what supports their populations. Here we established stable isotope (δ13C, δ15N) values for the endangered green sea turtle (Chelonia mydas) population found within the boundaries of Dry Tortugas National Park (DRTO), south Florida, USA. There is little gene flow between turtles sampled at DRTO and in other rookeries in Florida, underscoring the need to study this distinct population. Between 2008 and 2015 we collected multiple sample types (skin [homogenized epidermis/dermis], whole blood, red blood cells, plasma, carapace) from 151 unique green turtles, including …

Go to article

Spatiotemporal Variability Of Soil Water Δ18o And Δ2h Reveals Hydrological Processes In Two Floodplain Soils, Amanda Ceming-Barbato Sep 2021

Spatiotemporal Variability Of Soil Water Δ18o And Δ2h Reveals Hydrological Processes In Two Floodplain Soils, Amanda Ceming-Barbato

LSU Master's Theses

The movement of water through soil is preferential and heterogeneous. Subsurface interactions between mobile flows and the soil matrix are not uniform and are therefore difficult to predict through time and space. The use of stable isotopes of hydrogen (2H) and oxygen (18O) as conservative tracers of water movement is improving understanding of soil hydrological processes, yet field-scale observations of isotopic variability remain scarce despite implications for identifying dominant hydrologic processes. We sampled two adjacent soils at a ridge-swale topography floodplain forest to determine soil water isotopic variability at a 20 cm depth resolution in soils …

Go to article

Effect Of The Hierarchical Position Of Individuals In A Medicago Sativa Stand On Shoot Respiration, M. Lötscher, Hans Schnyder Aug 2021

Effect Of The Hierarchical Position Of Individuals In A Medicago Sativa Stand On Shoot Respiration, M. Lötscher, Hans Schnyder

IGC Proceedings (1997-2023)

The influence of the hierarchical position on the relationship between C gains and C losses (respiration) of individuals was investigated in a alfalfa (Medicago sativa) stand. The hierarchical position that an individual occupied was defined by its height relative to the stand height. Stands were established by arranging potted individual plants at a density of 400 plants m-2. Stands were grown in growth cabinets. 13C steady-state labelling was used to assess C fixation (Cnew) by individuals during a photoperiod of 16 h. Respiration of shoots was measured during the following 8 h dark …

Go to article

Stable Hydrogen Isotopes Of Aquatic-Emergent Versus Terrestrial Insects In Southern Ontario, Celina Y. Tang Aug 2021

Stable Hydrogen Isotopes Of Aquatic-Emergent Versus Terrestrial Insects In Southern Ontario, Celina Y. Tang

Undergraduate Student Research Internships Conference

Aquatic-emergent insects are vectors of both contaminants and nutrients, linking the aquatic system to the terrestrial system. Aquatic-emergent insects are high in omega-3 fatty acids that benefit terrestrial aerial insectivores, such as bats and birds. With aerial insectivores on a decline, a contributing factor could be a decrease in the quality of insects. We collected insects from lakeshore and inland locations in Southern Ontario. Insects sampled included bees, wasps, ants, beetles, caddisflies, craneflies, dragonflies, marchflies, mayflies, midges, other flies, and true bugs. Insects’ wings and powdered bodies were then analyzed for stable hydrogen isotopes (d2H) in order …

Go to article

A Study Of Stable Isotopes In Snow On Mt. Hood, Oregon, Maya Felix Jun 2021

A Study Of Stable Isotopes In Snow On Mt. Hood, Oregon, Maya Felix

University Honors Theses

Over the 2020-2021 Winter, event-based and end-of-season snow samples were collected on Mt. Hood near Government Camp, OR and analyzed for their stable isotopic compositions of 18O and 2H. It was found that surficial snow collected through the winter had higher variation in isotopic values than samples from a snow pit collected in spring. This suggests homogenization occurred in the snowpack over the season from snow metamorphism, sublimation, and/or melting. Homogenization of the snowpack will likely become more pronounced as temperatures increase and rain falls more often than snow due to climate change. Research that utilizes the snowpack …

Go to article

Mosquito Distribution And Stoichiometric Analysis Between Open And Closed Canopies In New Orleans Cemeteries, Rachel Rogers May 2021

Mosquito Distribution And Stoichiometric Analysis Between Open And Closed Canopies In New Orleans Cemeteries, Rachel Rogers

LSU Master's Theses

Cemetery vases represent an important container habitat for mosquito larvae. Some species, like, Aedes albopictus and Aedes aegypti, prefer container habitats, whereas others, like Culex quinquefasciatus, will opportunistically use containers. In New Orleans, these three medically important vector species (Ae. albopictus Ae. aegypti, and Cx. quinquefasciatus) co-occur, despite a demonstrated competitive advantage of Ae. albopictus to the other two. Here we test the hypothesis that canopy cover from trees could be a mediating factor in driving mosquito assemblages in New Orleans, by influencing food sources, and the microclimate experienced by mosquito larvae. Samples from seven …

Go to article

Identifying Nitrogen Source And Seasonal Variation In A Black Mangrove (Avicennia Germinans) Communityof The South Texas Coast, Ashley Elizabeth Murphy, Carlos E. Cintra-Buenrostro, Alejandro Fierro-Cabo Feb 2021

Identifying Nitrogen Source And Seasonal Variation In A Black Mangrove (Avicennia Germinans) Communityof The South Texas Coast, Ashley Elizabeth Murphy, Carlos E. Cintra-Buenrostro, Alejandro Fierro-Cabo

School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations

Black mangrove (Avicennia germinans) stands in south Texas grow in association with other autotrophic organisms including herbaceous halophytes and cyanobacterial mats. Despite the relevant ecosystem services provided by this coastal plant community, limited information exists on its functioning, in particular as it pertains to nutrient dynamics, namely nitrogen (N). Nitrogen stable isotopes were used to assess potential N sources for plant growth in this community. Plant tissue (leaves), cyanobacteria, and sediment were sampled once every season for one year. Total N in A. germinans (2.6 %) and associated saltwort (Batis maritima) (2.1 %) was higher than in cyanobacteria (0.6 %), …

Go to article

Organic-Input Impacts On Soil Carbon Flux, Storage, And Budget In Conservation Agricultural Soils, Central Washington, Usa, Jessica Hartman Jan 2021

Organic-Input Impacts On Soil Carbon Flux, Storage, And Budget In Conservation Agricultural Soils, Central Washington, Usa, Jessica Hartman

All Master's Theses

The increase in global atmospheric CO2 over the last 200 years has generated an urgent need for strategies for sequestering carbon (C). Soil C, which has been depleted by land use change and agricultural practices, is a prime target for C storage. Land management practices, including no-till, cover cropping and crop rotation, and the application of C amendments such as compost and biochar, are suggested to increase C in the soil. Spoon Full Farm, near Thorp, WA, was a conventional hay farm until 2016, when management practices changed to implement some of these C sequestration strategies. A prior CWU …

Go to article

The Multidisciplinary Approaches On Facies Developments And Depositional Systems Of The Bahçecik Travertines, Gümüşhane, Ne-Turkey, Rai̇f Kandemi̇r, Ezher Tagli̇asacchi̇, Mi̇ne Sezgül Kayseri̇ Özer, Di̇lek Şaffak, Fati̇h Köroğlu, Hsun-Ming Hu, Chuan-Chou Shen Jan 2021

The Multidisciplinary Approaches On Facies Developments And Depositional Systems Of The Bahçecik Travertines, Gümüşhane, Ne-Turkey, Rai̇f Kandemi̇r, Ezher Tagli̇asacchi̇, Mi̇ne Sezgül Kayseri̇ Özer, Di̇lek Şaffak, Fati̇h Köroğlu, Hsun-Ming Hu, Chuan-Chou Shen

Turkish Journal of Earth Sciences

The Bahçecik travertines, located in Gümüşhane (NE-Turkey) have been investigated for the first time using a multidisciplinary approach, which included sedimentological (lithofacies, depositional system), petrographic, radiometric 230Th dating, geochemical analysis (stable isotopes), palynomorphs and geophysics (GPR). A carbonate build-up, 12 m thick, was formed with some interruptions, through the middle Pleistocene period. For this study, two travertine sections (F and D) were extensively used to figure out palaeoenvironmental and palaeoclimatic proxies. The main precipitation cycles, separated by palaeosol levels, have been described and interpreted from a sedimentological perspective. The carbonate deposits consist of shrubs, crystalline crust, reed, laminated (micritic), pisoids, …

Go to article

Can Stable Isotopes From Tree Rings Improve Our Understanding Of Past Variability In The Southern Annular Mode?, Zachary Grzywacz Jan 2021

Can Stable Isotopes From Tree Rings Improve Our Understanding Of Past Variability In The Southern Annular Mode?, Zachary Grzywacz

Graduate Theses, Dissertations, and Problem Reports

Few annually dated stable isotope records exist across Oceania. In mid- to high-latitude locations in South America, tree-ring stable isotopes provide information about past climate dynamics such as the Southern Annular Mode (SAM). The SAM drives latitudinal shifts in Southern Hemisphere westerly winds, influencing temperature and moisture delivery across the mid- to high-latitudes, including Tasmania. Combinations of paleoclimate proxies from across the Southern Ocean might provide insight into dynamic processes like the SAM that are difficult to measure with a single proxy. Measuring stable carbon and oxygen isotope ratios from tree rings in Tasmania could provide complementary data to contribute …

Go to article

Multiple Fluid-Mineral Equilibria Approach To Constrain The Evolution Of Thermal Watersin The Hisaralan Geothermal Field, Simav Graben, Western Turkey, Ali̇ Gökgöz, Hali̇m Mutlu, Mehmet Özkul, Ali̇ Kami̇l Yüksel Jan 2021

Multiple Fluid-Mineral Equilibria Approach To Constrain The Evolution Of Thermal Watersin The Hisaralan Geothermal Field, Simav Graben, Western Turkey, Ali̇ Gökgöz, Hali̇m Mutlu, Mehmet Özkul, Ali̇ Kami̇l Yüksel

Turkish Journal of Earth Sciences

In this study seasonal changes in the geochemical and stable isotope compositions of Hisaralan thermal waters in Simav Graben, western Turkey, were investigated with regards to a variety of mineral-water interactions and mixing processes. The Hisaralan and Emendere geothermal waters, with temperatures of up to 99 °C, were mostly of Na-HCO3 and Ca-HCO3 types. The δ18O and δ2H values of the Hisaralan waters ranged from -9.32‰ to -8.73‰ and -65.02‰ to -61.10‰, with maximum seasonal differences of 0.3‰ and 1.8‰. The Emendere waters were represented by a more positive range of δ2H values (-54.95‰ to -54.61‰), while their δ18O compositions …

Go to article

Stable Isotopes Of Water Reveal Differences In Plant – Soil Water Relationships Across Northern Environments, Matthew J. Kohn, James P. Mcnamara Jan 2021

Stable Isotopes Of Water Reveal Differences In Plant – Soil Water Relationships Across Northern Environments, Matthew J. Kohn, James P. Mcnamara

Geosciences Faculty Publications and Presentations

We compared stable isotopes of water in plant stem (xylem) water and soil collected over a complete growing season from five well‐known long‐term study sites in northern/cold regions. These spanned a decreasing temperature gradient from Bruntland Burn (Scotland), Dorset (Canadian Shield), Dry Creek (USA), Krycklan (Sweden), to Wolf Creek (northern Canada). Xylem water was isotopically depleted compared to soil waters, most notably for deuterium. The degree to which potential soil water sources could explain the isotopic composition of xylem water was assessed quantitatively using overlapping polygons to enclose respective data sets when plotted in dual isotope space. At most sites …

Go to article

Triple Oxygen Isotope Measurements (Δ'17O) Of Body Water Reflect Water Intake, Metabolism, And Δ18O Of Ingested Water In Passerines, Pablo Sabat, Seth D. Newsome, Stephanie Pinochet, Roberto Nespolo, Juan Carlos Sanchez-Hernandez, Karen Maldonado, Alexander R. Gerson, Zachary D. Sharp, John P. Whiteman Jan 2021

Triple Oxygen Isotope Measurements (Δ'17O) Of Body Water Reflect Water Intake, Metabolism, And Δ18O Of Ingested Water In Passerines, Pablo Sabat, Seth D. Newsome, Stephanie Pinochet, Roberto Nespolo, Juan Carlos Sanchez-Hernandez, Karen Maldonado, Alexander R. Gerson, Zachary D. Sharp, John P. Whiteman

Biological Sciences Faculty Publications

Understanding physiological traits and ecological conditions that influence a species reliance on metabolic water is critical to creating accurate physiological models that can assess their ability to adapt to environmental perturbations (e.g., drought) that impact water availability. However, relatively few studies have examined variation in the sources of water animals use to maintain water balance, and even fewer have focused on the role of metabolic water. A key reason is methodological limitations. Here, we applied a new method that measures the triple oxygen isotopic composition of a single blood sample to estimate the contribution of metabolic water to the body …

Go to article

Diversity And Function Of Algal Biofilms In The Laurentian Great Lakes, Leon R. Katona Jan 2021

Diversity And Function Of Algal Biofilms In The Laurentian Great Lakes, Leon R. Katona

Browse all Theses and Dissertations

Attached algae are ubiquitous components of lake benthic habitats wherever sufficient light reaches submerged surfaces. Attached algae interact with heterotrophic bacteria and fungi to form complex biofilms (“periphyton”) that provide a nutritious food source for consumers and influence biogeochemical cycling by regulating redox potential at the sediment-water interface. Despite their ecological importance, there are limited data on the role of periphyton in the Laurentian Great Lakes. I quantified wave exposure and light availability in rocky nearshore habitats in Lake Erie and Lake Huron. Periphyton biomass and productivity in nearshore Lake Erie was very high while algal biomass and productivity in …

Go to article

Factors Determining Seagrass Blue Carbon Across Bioregions And Geomorphologies, Ines Mazarrasa, Paul Lavery, Carlos M. Duarte, Anna Lafratta, Catherine E. Lovelock, Peter I. Macreadie, Jimena Samper-Villarreal, Cristian Salinas, Christian J. Sanders, Stacey Trevathan-Tackett, Mary Young, Andy Steven, Oscar Serrano Jan 2021

Factors Determining Seagrass Blue Carbon Across Bioregions And Geomorphologies, Ines Mazarrasa, Paul Lavery, Carlos M. Duarte, Anna Lafratta, Catherine E. Lovelock, Peter I. Macreadie, Jimena Samper-Villarreal, Cristian Salinas, Christian J. Sanders, Stacey Trevathan-Tackett, Mary Young, Andy Steven, Oscar Serrano

Research outputs 2014 to 2021

Seagrass meadows rank among the most significant organic carbon (Corg) sinks on earth. We examined the variability in seagrass soil Corg stocks and composition across Australia and identified the main drivers of variability, applying a spatially hierarchical approach that incorporates bioregions and geomorphic settings. Top 30 cm soil Corg stocks were similar across bioregions and geomorphic settings (min-max: 20–26 Mg Corg ha−1), but meadows formed by large species (i.e., Amphibolis spp. and Posidonia spp.) showed higher stocks (24–29 Mg Corg ha−1) than those formed by smaller species (e.g., Halodule, Halophila, …

Go to article