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Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 45 for “"Stable carbon isotope"”.
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Western South Atlantic holocene and glacial deepwater hydrography derived from benthic foraminiferal Cd/Ca and stable carbon isotope data
Today, deep waters produced in the North Atlantic are exported through the western South Atlantic. Antarctic intermediate water AAJW also enters the Atlantic in this region. Circumpolar deep water (CDW) fills the depths below AAIW and above and below northern source waters. A depth transect of …
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Western South Atlantic holocene and glacial deepwater hydrography derived from benthic foraminiferal Cd/Ca and stable carbon isotope data
Today, deep waters produced in the North Atlantic are exported through the western South Atlantic. Antarctic intermediate water (AAIW) also enters the Atlantic in this region. Circumpolar deep water (CDW) fills the depths below AAIW and above and below northern source waters. A depth transect of …
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The Application of Pedology, Stable Carbon Isotope Analyses and Geographic Information Systems to Ancient Soil Resource Investigations at Piedras Negras, Guatemala
… this Maya mystery. Pedological studies and stable carbon isotope analysis of soil organic matter, combined with Geographic Information Systems (GIS) are three tools that can be used to answer crucial questions as to how the Maya managed their soil resources.</p> <p>GIS maps that indicated …
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Differential Utilization of Allochthonous and Autochthonous Carbon By Aquatic Insects of Two Shrub-Steppe Desert Spring-Streams: A Stable Carbon Isotope Analysis and Critique of the Method
<p>Stable carbon isotope analysis, a technique that measures the ratio of stable carbon-12 to stable carbon-13 in abiotic and biotic components of ecosystems, was used to assess the differential utilization of autochthonous and allochthonous carbon by aquatic insects of two cold desert …
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Climatic reconstruction using wood charcoal from archaeological sites
… Ecologically Diagnostic Xylem Analysis and (iii) stable carbon isotope analysis on wood charcoal. The first is a well established method of environmental reconstruction. This is the first systematic application of Ecologically Diagnostic Analysis and the first application of stable carbon isotope …
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Cyclostratigraphy And Sedimentation Of The Cenomanian-Turonian Tuscaloosa Marine Shale
… and biostratigraphic data and unpublished stable carbon isotope data to determine sedimentation rate, to identify and correlate the cretaceous oceanic anoxic event 2 (OAE 2) recovery period within the studied interval, and to determine the possible mechanisms of orbital forcing. Results …
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Carbon Cycle Trends Recorded By Organic Carbon Stable Isotopes In Paleocene Strata, Benton County, Mississippi: Implications For Chronostratigraphy Of The Porters Creek And Naheola Formations
… maximum (petm) is one of the most studied carbon isotope excursions in earth's history. The petm occurred 55 million years ago when excess isotopically heavy carbon (c13) was added into earth's carbon cycle, resulting in ecological and environmental changes. The petm is marked by a negative …
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Climate change, water stress and agriculture in the Indus Civilisation, 3000-1500 BC
… stress. These techniques are first, oxygen isotope analysis of faunal bones and teeth; and second, stable carbon isotope analysis of crop remains. The oxygen analyses provide detailed records of monsoon intensity at a local, human scale, while the carbon analyses provide an empirical test of …
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A 210,000-year reconstruction of subtropical climates from Fern Gully Lagoon, North Stradbroke Island (Minjerribah), Australia
… of hydroclimate data from 40 Australian marine isotope stage 3 (MIS 3; 57 – 29 ka) records, allowing a continental record of moisture availability to be created, and moisture availability during peak Australian megafauna extinction to be identified (Chapter 2). • A chronology for a new wetland …
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Stable carbon isotopes and prehistoric diets in the Eastern Cape Province, South Africa
… in this thesis involves the measurement of stable carbon isotope ratios in human bone collagen as a means of reconstructing prehistoric diets. The sample population includes 67 skeletons of hunter-gatherers, pastoralists and agriculturalists from the Holocene of the Eastern Cape Province, …
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Growth, water use efficiency and stable carbon isotopes in commercial clones of Eucalyptus
… for improved water use efficiency and harvestable stem production under a limited water supply. This study investigated the effects of soil moisture availability on the growth and water use efficiency of 6 commercial clones of Eucalyptus commonly grown in South Africa with the aim of …
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Distribution, diet and kleptoparasitic behaviour of gulls (Aves: Laridae) in the southwestern Cape Province, South Africa
… and at archaeological sites was estimated using stable carbon isotope analysis of bone collagen. Both gulls are generalist foragers feeding on a wide and diverse range of prey species. The Kelp Gull is able to feed on a wider range of prey species than is Hartlaub's Gull due to its larger size. …
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Advances in the reconstruction of temperature history, physiology and paleoenvironmental change : evidence from light stable isotope chemistry
The rationale of this study is to apply light stable isotope chemistry towards investigations that require temporally high-resolution data. High-resolution (or high sampling frequency) data sets, are critical for testing environmental and/or paleoenvironmental hypotheses that seek to explain …
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Carbon flow and food web structure in the mesopelagic zone of the North Atlantic Ocean
… the deep ocean through food web interactions and carbon flow pathways. In this dissertation, I use carbon compound-specific stable carbon isotope analysis of amino acids (CSIA-AA) and DNA gut metabarcoding methodologies to provide a broad ecological outlook on mesopelagic carbon flow coupled with …
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Carbon flow and food web structure in the mesopelagic zone of the North Atlantic Ocean
… the deep ocean through food web interactions and carbon flow pathways. In this dissertation, I use carbon compound-specific stable carbon isotope analysis of amino acids (CSIA-AA) and DNA gut metabarcoding methodologies to provide a broad ecological outlook on mesopelagic carbon flow coupled with …
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A stable isotope and macro-charcoal sediment record spanning the Pleistocene-Holocene transition from Maple Pond in the southern Shenandoah Valley, Virginia, USA
… from the Late Pleistocene to the present. Stable carbon isotope ratios (δ13C: -29‰ to -27‰) and atomic C:N ratios (11-36) indicate terrestrial C₃ vegetation as the primary source of organic matter during the Late Pleistocene and early Holocene (15,000–8,000 cal yr BP), followed by a …
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HIGH-RESOLUTION RECORDS OF CLIMATE CHANGE FROM LACUSTRINE STABLE ISOTOPES THROUGH THE LAST TWO MILLENNIA IN WESTERN TURKEY
… as water is an important resource. Oxygen isotope records from lakes in the region record changes in water balance and are therefore an important archive for observing natural, and anthropogenicaly forced, variabiUty in hydrology. Full understanding of cUmate proxies requires …
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Resident fish community impacts on stocked rainbow trout ecology in 15 eastern Washington lakes
… and trophic position of stocked rainbow trout. Stable isotope analysis was used to accomplish this goal, with stable carbon isotope ratios indicating the source of carbon, pelagic or littoral, in each species' diet and stable nitrogen isotope ratios determining species' relative trophic …
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Use of carbon isotope and C/N geochemistry in reconstructing vegetation communities: a mid- to late- Holocene palaeoenvironmental investigation from Romney Marsh, Kent, UK
The use of stable carbon isotope geochemistry and C/N ratios for coastal palaeoenvironmental reconstructions is a relatively new and under-researched field. This research seeks to understand the processes which govern the carbon isotope and C/N ratios of past and present vegetation communities, …
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The Spatial Distribution of Terrestrial Stable Carbon Isotopes in North America, and the Impacts of Spatial and Temporal Resolution on Static Ecological Models
… resolution on the modeling of terrestrial stable carbon isotopic landscapes (isoscapes). I model the distribution of leaf stable carbon isotope composition (delta<sup>13</sup>C) for the continent of North America at multiple temporal and spatial resolutions. I generate each …
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