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Physical Sciences and Mathematics Commons™

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

2017

Earth Sciences

Western University

Series

Articles 1 - 5 of 5

Full-Text Articles in Physical Sciences and Mathematics

Nitrogen And Carbon Isotopic Dynamics Of Subarctic Soils And Plants In Southern Yukon Territory And Its Implications For Paleoecological And Paleodietary Studies, Farnoush Tahmesabi, Fred J. Longstaffe, Grant Zazula, Bruce Bennett Aug 2017

Nitrogen And Carbon Isotopic Dynamics Of Subarctic Soils And Plants In Southern Yukon Territory And Its Implications For Paleoecological And Paleodietary Studies, Farnoush Tahmesabi, Fred J. Longstaffe, Grant Zazula, Bruce Bennett

Earth Sciences Publications

We examine here the carbon and nitrogen isotopic compositions of bulk soils (8 topsoil and 7 subsoils, including two soil profiles) and five different plant parts of 79 C3 plants from two main functional groups: herbs and shrubs/subshrubs, from 18 different locations in grasslands of southern Yukon Territory, Canada (eastern shoreline of Kluane Lake and Whitehorse area). The Kluane Lake region in particular has been identified previously as an analogue for Late Pleistocene eastern Beringia. All topsoils have higher average total nitrogen δ15N and organic carbon δ13C than plants from the same sites with a …

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New Biotite And Muscovite Isotopic Reference Materials, Usgs57 And Usgs58, For Δ2h Measurements–A Replacement For Nbs 30, Haiping Qi, Tyler B. Coplen, Matthias Gehre, Torsten W. Vennemann, Willi A. Brand, Heike Geilmann, Gerald Olack, Ilya N. Bindeman, Jim Palandri, Li Huang, Fred J. Longstaffe Jul 2017

New Biotite And Muscovite Isotopic Reference Materials, Usgs57 And Usgs58, For Δ2h Measurements–A Replacement For Nbs 30, Haiping Qi, Tyler B. Coplen, Matthias Gehre, Torsten W. Vennemann, Willi A. Brand, Heike Geilmann, Gerald Olack, Ilya N. Bindeman, Jim Palandri, Li Huang, Fred J. Longstaffe

Earth Sciences Publications

The advent of continuous-flow isotope-ratio mass spectrometry (CF-IRMS) coupled with a high temperature conversion (HTC) system enabled faster, more cost effective, and more precise δ2H analysis of hydrogen-bearing solids. Accurate hydrogen isotopic analysis by on-line or off-line techniques requires appropriate isotopic reference materials (RMs). A strategy of two-point calibrations spanning δ2H range of the unknowns using two RMs is recommended. Unfortunately, the supply of the previously widely used isotopic RM, NBS 30 biotite, is exhausted. In addition, recent measurements have shown that the determination of δ2H values of NBS 30 biotite on the VSMOW-SLAP …

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Morpho-Sedimentary Characteristics Of Proximal Gravel Braided River Deposits In A Froude-Scaled Physical Model, Peter Ashmore, Tobias Gardner, Pauline Leduc Jan 2017

Morpho-Sedimentary Characteristics Of Proximal Gravel Braided River Deposits In A Froude-Scaled Physical Model, Peter Ashmore, Tobias Gardner, Pauline Leduc

Geography & Environment Publications

A Froude‐scaled physical model of a proximal gravel‐bed braided river was used to connect the river morphological characteristics, and sedimentary processes and forms, to deposit geometry. High resolution continuous three‐dimensional topographic data were acquired from sequential photogrammetric digital elevation models paired with grain‐size surface maps derived from image analysis of textural properties of the surface. From these data, the full three‐dimensional development of the braided river deposit and grain‐size sorting patterns was compiled over an experimental time period of 41 h during which the model river reworked a large portion of the braided channel. The minimum surface of the deposit …

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Origin Of Graphite In The Southwestern Grenville Province, Mehmet F. Taner, Cameron Drever, Chris Yakymhuk, Fred Longstaffe Jan 2017

Origin Of Graphite In The Southwestern Grenville Province, Mehmet F. Taner, Cameron Drever, Chris Yakymhuk, Fred Longstaffe

Earth Sciences Publications

Two graphite deposits in the southwestern Grenville Province are investigated to evaluate the origin of graphitic carbon and to test if the graphite mineralization is syngenetic or epigenetic. Graphite mineralization in the Bissett Creek deposit is characterized by homogeneously distributed and disseminated graphite flakes (approximately 1 to 5 mm in size and 2 to 10 vol.%) within graphitic gneisses. The graphite flakes are intergrown with metamorphic minerals, most notably biotite. The Montpellier graphite showing in Qu´ebec contains graphite concentrations of up to 20 vol.%. In contrast to the disseminated and homogenously distributed graphite in the Bissett Creek deposit, graphite mineralization …

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Stable Isotope Investigation Of The Migratory Behavior Of Silverhaired Bats (Lasionycteris Noctivagans) In Eastern North America, Erin E. Fraser, Darin Brooks, Fred J. Longstaffe Jan 2017

Stable Isotope Investigation Of The Migratory Behavior Of Silverhaired Bats (Lasionycteris Noctivagans) In Eastern North America, Erin E. Fraser, Darin Brooks, Fred J. Longstaffe

Earth Sciences Publications

We investigated the migratory movements of silver-haired bats (Lasionycteris noctivagans) across the eastern extent of the species’ range. We conducted stable hydrogen isotope analysis of fur samples (δ2Hfur) from museum specimens collected across latitudes and at all times of the year. We first used these data to estimate the timing of fur replacement and to develop a model associating δ2Hfur with that of local precipitation (δ2Hprecip) at the location where fur replacement occurred. We then used this model to 1) identify individuals that had migrated …

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