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1
Treydte, Kerstin, Jan Esper, and Holger Gärtner. "Stabile Isotope in der Dendroklimatologie | Stable isotopes and dendroclimatology." Schweizerische Zeitschrift fur Forstwesen 155, no. 6 (June 1, 2004): 222–32. http://dx.doi.org/10.3188/szf.2004.0222.
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This paper expounds the basics of isotope fixation in tree rings and relevant field and laboratory procedures. Examples from high mountain regions show both the potential and limits of employing these methods in dendroclimatological studies. Carbon isotopes yield seasonally resolved information on temperature,precipitation and relative humidity, whilst oxygen isotopes provide information on the isotope values of the source water,and thus, on precipitation. Inter-annual and decadal variations, in particular, reflect a strong common climatic signal that extends across a wide range of site ecologies. However, low frequency trends are masked by a non-climatic, human induced long-term trend, especially where carbon isotopes are concerned. At present,detrending methods are of a provisional nature and set a limit to stable isotopes for paleoclimatic questions. Highly resolved plant physiological and biochemical investigations should provide more insight into these unsolved problems.
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DeSantis, L. R. G., and C. Hedberg. "Stable isotope ecology of the koala (Phascolarctos cinereus)." Australian Journal of Zoology 64, no. 5 (2016): 353. http://dx.doi.org/10.1071/zo16057.
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Australia has undergone significant climate change, both today and in the past. Koalas, due to their restricted diet of predominantly eucalyptus leaves and limited drinking behaviour may serve as model organisms for assessing past climate change via stable isotopes of tooth enamel. Here, we assess whether stable carbon and oxygen isotopes from tooth enamel record known climate variables, including proxies of relative aridity (e.g. mean annual precipitation, mean annual maximum temperature, and relative humidity). The results demonstrate significant negative relationships between oxygen isotope values and both relative humidity and mean annual precipitation, proxies for relative aridity. The best model for predicting enamel oxygen isotope values incorporates mean annual precipitation and modelled oxygen isotope values of local precipitation. These data and the absence of any relationship between modelled oxygen isotope precipitation values, independently, suggest that koalas do not track local precipitation values but instead record relative aridity. The lack of significant relationships between carbon isotopes and climate variables suggests that koalas may instead be tracking the density of forests and/or their location in the canopy. Collectively, these data suggest that koalas are model organisms for assessing relative aridity over time – much like kangaroos.
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Swart, Peter K., and Jim J. Leder. "The utility of stable isotopic signatures in coral skeletons." Paleontological Society Papers 1 (October 1996): 249–91. http://dx.doi.org/10.1017/s1089332600000127.
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There is a fundamental ecologic differentiation between zooxanthellate and non-zooxanthellate corals. This paper reviews factors which govern the stable carbon and oxygen isotopic composition of these groups of corals. Although the stable carbon and oxygen isotope compositions of coral skeletons are strongly influenced by environmental and physiological factors, the precise mechanisms remain a matter of debate. In particular the oxygen isotopic composition is known to be governed by the temperature and the oxygen isotopic composition of the water and perhaps also by kinetic factors. In contrast the carbon isotopic composition is controlled by a combination of photosynthesis, respiration, autotrophy, heterotrophy, and the isotopic composition of dissolved inorganic carbon. Using a combination of carbon and oxygen isotopes it is possible to distinguish zooxanthellate from non-zooxanthellate corals.
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Passey, Benjamin H. "Reconstructing Terrestrial Environments Using Stable Isotopes in Fossil Teeth and Paleosol Carbonates." Paleontological Society Papers 18 (November 2012): 167–94. http://dx.doi.org/10.1017/s1089332600002606.
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Carbon isotopes in Neogene-age fossil teeth and paleosol carbonates are commonly interpreted in the context of past distributions of C3 and C4 vegetation. These two plant types have very different distributions in relation to climate and ecology, and provide a robust basis for reconstructing terrestrial paleoclimates and paleoenvironments during the Neogene. Carbon isotopes in pre-Neogene fossil teeth are usually interpreted in the context of changes in the δ13C value of atmospheric CO2, and variable climate-dependent carbon-isotope discrimination in C3 plants. Carbon isotopes in pre-Neogene soil carbonates can be used to estimate past levels of atmospheric CO2. Oxygen isotopes in fossil teeth and paleosol carbonates primarily are influenced by the oxygen isotopic compositions of ancient rainfall and surface waters. The oxygen isotopic composition of rainfall is has a complex, but tractable, relationship with climate, and variably relates to temperature, elevation, precipitation amount, and other factors. Mammal species that rely on moisture in dietary plant tissues to satisfy their water requirements (rather than surface drinking water) may have oxygen isotopic compositions that track aridity. Thus, oxygen isotopes of fossil mammals can place broad constraints on paleoaridity. Carbonate clumped isotope thermometry allows for reconstruction of soil temperatures at the time of pedogenic carbonate mineralization. The method is unique because it is the only thermodynamically based isotopic paleothermometer that does not require assumptions about the isotopic composition of the fluid in which the archive mineral formed. Soil temperature reflects a complex interplay of air temperature, solar radiative heating, latent heat effects, soil thermal diffusivity, and seasonal variations of these parameters. Because plants and most animals live in and/or near the soil, soil temperature is an important aspect of terrestrial (paleo)climate.
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Kakareka, S. V., T. I. Kukharchyk, A. A. Ekaykin, and Yu G. Giginyak. "Stable isotopes in the snow of the coastal areas of Antarctica." Doklady of the National Academy of Sciences of Belarus 65, no. 4 (September 2, 2021): 495–502. http://dx.doi.org/10.29235/1561-8323-2021-65-4-495-502.
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The first results of study of stable isotopes of oxygen (δ18O) and hydrogen (δD) in the snow samples taken on the islands of Marguerite Bay (Antarctic Peninsula), in the Vecherny Oasis (Enderby Land), and Larsemann Hills (Princess Elizabeth Land) by the participants of the 12th Belarusian Antarctic Expedition (January–March 2020) are presented. The concentration of water isotopes: deuterium (D) and oxygen-18 (18O) in the samples was determined using a laser isotope composition analyzer Picarro L2130. A total of 32 snow samples were analyzed. The statistical parameters of the isotopic composition of snow were estimated, and the main differences in the content of δ18O and δD between the study areas were shown. A decrease in the content of heavy oxygen and hydrogen isotopes in the newly fallen snow to the old snow of the surface horizons is shown. The maximum values of δ18O and δD are typical for the Maritime Antarctica, decreasing towards the coastal zone and further – towards its continental part. The possible factors affecting the isotope content are described. It is shown that the monitoring of the isotope composition can be an integral part of the monitoring of climatic changes within the area of operation of the Belarusian Antarctic Expedition. The study of the isotopic composition of surface snow is important for the reconstruction of the paleoclimate of the marginal zone of the Antarctic ice sheet based on the ice cores study.
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Li, Xiangnan, Baisha Weng, Denghua Yan, Tianling Qin, Kun Wang, Wuxia Bi, Zhilei Yu, and Batsuren Dorjsuren. "Anthropogenic Effects on Hydrogen and Oxygen Isotopes of River Water in Cities." International Journal of Environmental Research and Public Health 16, no. 22 (November 12, 2019): 4429. http://dx.doi.org/10.3390/ijerph16224429.
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Stable hydrogen and oxygen isotopes are important indicators for studying water cycles. The isotopes are not only affected by climate, but are also disturbed by human activities. Urban construction has changed the natural attributes and underlying surface characteristics of river basins, thus affecting the isotopic composition of river water. We collected urban river water isotope data from the Global Network for Isotopes in Rivers (GNIR) database and the literature, and collected river water samples from the Naqu basin and Huangshui River basin on the Tibetan Plateau to measure hydrogen and oxygen isotopes. Based on 13 pairs of urban area and non-urban area water samples from these data, the relationship between the isotopic values of river water and the artificial surface area of cities around rivers was analyzed. The results have shown that the hydrogen and oxygen isotope (δD and δ18O) values of river water in urban areas were significantly higher than those in non-urban areas. The isotopic variability of urban and non-urban water was positively correlated with the artificial surface area around the rivers. In addition, based on the analysis of isotope data from 21 rivers, we found that the cumulative effects of cities on hydrogen and oxygen isotopes have led to differences in surface water line equations for cities with different levels of development. The combined effects of climate and human factors were the important reasons for the variation of isotope characteristics in river water in cities. Stable isotopes can not only be used to study the effects of climate on water cycles, but also serve as an important indicator for studying the degree of river development and utilization.
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Alderton, David H. M. "Oxygen isotope fractionation between cassiterite and water." Mineralogical Magazine 53, no. 371 (June 1989): 373–76. http://dx.doi.org/10.1180/minmag.1989.053.371.13.
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Analysis of stable isotopes in coexisting minerals has found wide application in the study of hydrothermal mineral deposits, particularly for elucidating the temperature and source of the fluid phase involved in mineralisation. For these purposes the temperature dependence of isotopic fractionation in several mineral-water systems has already been established (e.g. Friedman and O'Neil, 1977; O'Neil, 1986). Unfortunately, the oxygen isotope fractionation between cassiterite (SnO2) and water has not been adequately characterized, and this has hindered a full utilization of oxygen isotope data derived from studies of tin deposits (e.g. Harzer, 1970; Patterson et al., 1981; Kelly and Rye, 1979). Because of this situation, an attempt is made here to derive a relationship between temperature and the fractionation of oxygen isotopes (Δ) between quartz and cassiterite, based on the fractionations observed in naturally-occurring assemblages and independent temperature estimates.
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Jung, Hyejung, Dong-Chan Koh, Yun Kim, Sung-Wook Jeen, and Jeonghoon Lee. "Stable Isotopes of Water and Nitrate for the Identification of Groundwater Flowpaths: A Review." Water 12, no. 1 (January 1, 2020): 138. http://dx.doi.org/10.3390/w12010138.
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Nitrate contamination in stream water and groundwater is a serious environmental problem that arises in areas of high agricultural activities or high population density. It is therefore important to identify the source and flowpath of nitrate in water bodies. In recent decades, the dual isotope analysis (δ15N and δ18O) of nitrate has been widely applied to track contamination sources by taking advantage of the difference in nitrogen and oxygen isotope ratios for different sources. However, transformation processes of nitrogen compounds can change the isotopic composition of nitrate due to the various redox processes in the environment, which often makes it difficult to identify contaminant sources. To compensate for this, the stable water isotope of the H2O itself can be used to interpret the complex hydrological and hydrochemical processes for the movement of nitrate contaminants. Therefore, the present study aims at understanding the fundamental background of stable water and nitrate isotope analysis, including isotope fractionation, analytical methods such as nitrate concentration from samples, instrumentation, and the typical ranges of δ15N and δ18O from various nitrate sources. In addition, we discuss hydrograph separation using the oxygen and hydrogen isotopes of water in combination with the nitrogen and oxygen isotopes of nitrate to understand the relative contributions of precipitation and groundwater to stream water. This study will assist in understanding the groundwater flowpaths as well as tracking the sources of nitrate contamination using the stable isotope analysis in combination with nitrate and water.
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Hamzić Gregorčič, Staša, Doris Potočnik, Federica Camin, and Nives Ogrinc. "Milk Authentication: Stable Isotope Composition of Hydrogen and Oxygen in Milks and Their Constituents." Molecules 25, no. 17 (September 2, 2020): 4000. http://dx.doi.org/10.3390/molecules25174000.
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This paper summarises the isotopic characteristics, i.e., oxygen and hydrogen isotopes, of Slovenian milk and its major constituents: water, casein, and lactose. In parallel, the stable oxygen isotope ratios of cow, sheep, and goat’s milk were compared. Oxygen stable isotope ratios in milk water show seasonal variability and are also 18O enriched in relation to animal drinking water. The δ18Owater values were higher in sheep and goat’s milk when compared to cow milk, reflecting the isotopic composition of drinking water source and the effect of differences in the animal’s thermoregulatory physiologies. The relationship between δ18Omilk and δ18Olactose is an indication that even at lower amounts (>7%) of added water to milk can be determined. This procedure once validated on an international scale could become a reference method for the determination of milk adulteration with water.
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Reyes-García, Casandra, and José Luis Andrade. "Los isótopos estables del hidrógeno y el oxígeno en los estudios ecofisiológicos de plantas." Botanical Sciences, no. 80 (June 3, 2017): 19. http://dx.doi.org/10.17129/botsci.1742.
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Stable isotope studies of elements in biological organisms have become a useful tool to assess the exchange of molecules in the biosphere. Since water is one of the most abundant molecules in such an exchange, studies on stable isotopes of hydrogen and oxygen have become a fundamental component of many plant ecophysiological studies, from the leaf level to the reconstruction of past climates. In this review, we mention the most common methodologies, general notation and the most relevant research on hydrogen and oxygen stable isotopes. Also, we discuss studies on plant water sources, leaf isotopic enrichment due to transpiration, the relationship between environment and oxygen stable isotopes in organic matter, and present studies that propose some plant species as environmental indicators in a globally changing world.
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Høie, Hans, Erling Otterlei, and Arild Folkvord. "Temperature-dependent fractionation of stable oxygen isotopes in otoliths of juvenile cod (Gadus morhua L.)." ICES Journal of Marine Science 61, no. 2 (January 1, 2004): 243–51. http://dx.doi.org/10.1016/j.icesjms.2003.11.006.
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Abstract Analysis of stable oxygen isotopes in otoliths is a promising technique for estimating the ambient temperature experienced by fish, but consistent equations relating temperature and fractionation of stable oxygen isotopes in otoliths among different fish species are lacking. Juvenile cod were reared at constant temperatures from 6 to 20°C and the sagittal otoliths were analysed for oxygen isotope values. We determined that temperature-dependent fractionation of oxygen isotopes in the otoliths was close to that reported for inorganic aragonite at low temperatures, but there were deviations from oxygen isotope fractionation equations for otoliths of other species. The linear relationship between oxygen isotope value in the cod otoliths and temperature was determined to be: 1000 Ln α = 16.75(103 TK−1) − 27.09. Temperature estimates with 1°C precision at the 95% probability level require a sample size of ≥5 otoliths. Only an insignificant amount of the variance in the data was due to variance between left and right otolith, and due to repeated measurements of otolith subsamples. This study confirms that stable isotope values of cod otoliths can give precise and accurate estimates of the ambient temperature experienced by fish.
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Lisowska-Gaczorek, Aleksandra, Beata Cienkosz-Stepańczak, and Krzysztof Szostek. "Oxygen stable isotopes variation in water precipitation in Poland – anthropological applications." Anthropological Review 80, no. 1 (March 1, 2017): 57–70. http://dx.doi.org/10.1515/anre-2017-0005.
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Abstract The main objective of oxygen isotope analysis is to determine the probable place of origin of an individual or the reconstruction of migration paths. The research are methodologically based on referencing oxygen isotope ratios of apatite phosphates (δ18Op) to the range of environmental background δ18O, most frequently determined on the basis of precipitation. The present work is a response to the need for providing background for oxygen isotope studies on skeletons excavated in Poland. Currently there no monitoring of the isotope composition of precipitation water in Poland is conducted. For this reason, based on the data generated in the Online Isotopes In Precipitation Calculator (OIPC), a database was developed, containing δ18O levels in precipitation for locations in which exploration work was carried out in the archaeological fields from Poland. In total, 279 locations were analysed. The result of the data analysis was a complete isotope composition map for Poland with four zones distinguished by δ18Ow values. The observable differences in oxygen isotope composition of precipitation in Poland are sufficient to trace migrations of individuals and populations, although accurate only at the level of macroregions.
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Barbour, Margaret M. "Stable oxygen isotope composition of plant tissue: a review." Functional Plant Biology 34, no. 2 (2007): 83. http://dx.doi.org/10.1071/fp06228.
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With the development of rapid measurement techniques, stable oxygen isotope analysis of plant tissue is poised to become an important tool in plant physiological, ecological, paleoclimatic and forensic studies. Recent advances in mechanistic understanding have led to the improvement of process-based models that accurately predict variability in the oxygen isotope composition of plant organic material (δ18Op). δ18Op has been shown to reflect the isotope composition of soil water, evaporative enrichment in transpiring leaves, and isotopic exchange between oxygen atoms in organic molecules and local water in the cells in which organic molecules are formed. This review presents current theoretical models describing the influences on δ18Op, using recently published experimental work to outline strengths and weaknesses in the models. The potential and realised applications of the technique are described.
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Fricke, Henry C., Raymond R. Rogers, and Terry A. Gates. "Hadrosaurid migration: inferences based on stable isotope comparisons among Late Cretaceous dinosaur localities." Paleobiology 35, no. 2 (2009): 270–88. http://dx.doi.org/10.1666/08025.1.
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Stable carbon and oxygen isotope ratios were measured for carbonate in samples of hadrosaurid tooth enamel and dentine, and gar scale ganoine and dentine from five geologically “contemporaneous“ (two-million-year resolution) and geographically distant late Campanian formations (Two Medicine, Dinosaur Park, Judith River, Kaiparowits, and Fruitland) in the Western Interior Basin. In all cases, isotopic offsets were observed between enamel and dentine from the same teeth, with dentine being characterized by higher and more variable carbon and oxygen isotope ratios. Isotopic offsets were also observed between gar ganoine and hadrosaur enamel in all sites analyzed. Both of these observations indicate that diagenetic overprinting of enamel isotope ratios did not entirely obfuscate primary signals. Decreases in carbon and oxygen isotope ratios were observed in hadrosaur enamel from east to west, and overlap in isotope ratios occurred only between two of the sampled sites (Dinosaur Park and Judith River Formations).The lack of isotopic overlap for enamel among localities could be due to diagenetic resetting of isotope ratios such that they reflect local groundwater effects rather than primary biogenic inputs. However, the large range in carbon isotope ratios, the consistent taxonomic offsets for enamel/ganoine data, and comparisons of enamel-dentine data from the same teeth all suggest that diagenesis is not the lone driver of the signal. In the absence of major alteration, the mostly likely explanation for the isotopic patterns observed is that hadrosaurids from the targeted formations were eating plants and drinking waters with distinct isotopic ratios. One implication of this reconstruction is that hadrosaurids in the Late Cretaceous of the Western Interior did not migrate to an extent that would obscure local isotopic signatures.
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Clay, A., C. Bradley, A. J. Gerrard, and M. J. Leng. "Using stable isotopes of water to infer wetland hydrological dynamics." Hydrology and Earth System Sciences 8, no. 6 (December 31, 2004): 1164–73. http://dx.doi.org/10.5194/hess-8-1164-2004.
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Abstract. This paper considers the potential of oxygen and hydrogen isotope ratios to identify spatial and temporal changes in the water source of a lowland headwater wetland situated adjacent to the River Tern in Shropshire, UK. Stable isotope composition (d18O) of end-members varied between –7.5 and –8.0‰ for groundwater, –7.3 and –8.5‰ for river-water and –4.5 and –8.0‰ for precipitation. Water samples were extracted from six nests each comprising three porous cup samplers at depths of 0.2 m, 0.5 m and 1.0 m between June 2000 and October 2001, and their isotope compositions determined. Groundwater appears to be the main source of water to the wetland, but stable isotope ratios enable seasonal variations in the contribution of precipitation to be determined, and indicate the extent of precipitation storage within the wetland. Keywords: oxygen and hydrogen isotopes, water source, hydrodynamics, lowland wetland
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Holzkämper, Steffen, Päivi Kaislahti Tillman, Peter Kuhry, and Jan Esper. "Comparison of stable carbon and oxygen isotopes in Picea glauca tree rings and Sphagnum fuscum moss remains from subarctic Canada." Quaternary Research 78, no. 2 (June 20, 2012): 295–302. http://dx.doi.org/10.1016/j.yqres.2012.05.014.
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AbstractStable isotope ratios from tree rings and peatland mosses have become important proxies of past climate variations. We here compare recent stable carbon and oxygen isotope ratios in cellulose of tree rings from white spruce (Picea glauca), growing near the arctic tree line; and cellulose of Sphagnum fuscum stems, growing in a hummock of a subarctic peatland, in west-central Canada. Results show that carbon isotopes in S. fuscum correlate significantly with July temperatures over the past ~20 yr. The oxygen isotopes correlate with both summer temperature and precipitation. Analyses of the tree-ring isotopes revealed summer temperatures to be the main controlling factor for carbon isotope variations, whereas tree-ring oxygen isotope ratios are controlled by a combination of spring temperatures and precipitation totals. We also explore the potential of combining high-frequency (annual) climate signals derived from long tree-ring series with low-frequency (decadal to centennial) climate signals derived from the moss remains in peat deposits. This cross-archive comparison revealed no association between the oxygen isotopes, which likely results from the varying sensitivity of the archives to different seasons. For the carbon isotopes, common variance could be achieved through adjustments of the Sphagnum age model within dating error.
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Watkinson, Charles J., Peter Gasson, Gareth O. Rees, and Markus Boner. "The Development and Use of Isoscapes to Determine the Geographical Origin of Quercus spp. in the United States." Forests 11, no. 8 (August 7, 2020): 862. http://dx.doi.org/10.3390/f11080862.
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The stable isotope ratios of oxygen, hydrogen, carbon and sulfur from extracted wood of 87 samples of oaks from the United States were analysed. Relationships with climate variables and the stable isotope ratios of the 69 training dataset samples were investigated to a monthly resolution using long-term monthly mean climate data from NASA and the University of East Anglia’s Climate Research Unit, in conjunction with forecast data for hydrogen and oxygen isotope ratios in precipitation. These relationships were used to construct model isoscapes for oxygen, hydrogen, carbon and sulfur for US oak with the aim of using them to forecast isotopic patterns in areas that were not sampled and predict values in samples not used to construct the models. The leading predictors for isoscape generation were oxygen isotope ratios in January precipitation for oak oxygen isotope ratios, hydrogen isotope ratios in July precipitation for oak hydrogen isotope ratios, water vapour in April for carbon isotope ratios, and reflected shortwave radiation in March in combination with sulfate concentration in May for oak sulfur isotopes. The generated isoscapes can be used to show regions an unknown sample may have originated from with a resolution dependent on the rarity of the stable isotope signature within the United States. The models were assessed using the data of 18 samples of georeferenced oak. The assessment found that 100% of oxygen, 94% of hydrogen, 78% of carbon, and 94% of sulfur isotope ratios in the 18 test dataset samples fell within two standard deviations of the isoscape models. Using the results of the isoscapes in combination found that there were 4/18 test samples which did not fall within two standard deviations of the four models, this is largely attributed to the lower predictive power of the carbon isoscape model in conjunction with high local variability in carbon isotope ratios in both the test and training data. The method by which this geographic origin method has been developed will be useful to combat illegal logging and to validate legal supply chains for the purpose of good practice due diligence.
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Abiye, Tamiru A., Molla B. Demlie, and Haile Mengistu. "An Overview of Aquifer Physiognomies and the δ18O and δ2H Distribution in the South African Groundwaters." Hydrology 8, no. 2 (April 19, 2021): 68. http://dx.doi.org/10.3390/hydrology8020068.
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A comprehensive assessment of the stable isotope distribution in the groundwater systems of South Africa was conducted in relation to the diversity in the aquifer lithology and corresponding hydraulic characteristics. The stable isotopes of oxygen (18O) and hydrogen (2H) in groundwater show distinct spatial variation owing to the recharge source and possibly mixing effect in the aquifers with the existing water, where aquifers are characterized by diverse hydraulic conductivity and transmissivity values. When the shallow aquifer that receives direct recharge from rainfall shows a similar isotopic signature, it implies less mixing effect, while in the case of deep groundwater interaction between recharging water and the resident water intensifies, which could change the isotope signature. As aquifer depth increases the effect of mixing tends to be minimal. In most cases, the isotopic composition of recharging water shows depletion in the interior areas and western arid zones which is attributed to the depleted isotopic composition of the moisture source. The variations in the stable isotope composition of groundwater in the region are primarily controlled by the isotope composition of the rainfall, which shows variable isotope composition as it was observed from the local meteoric water lines, in addition to the evaporation, recharge and mixing effects.
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Humphrey, John D., and C. Reid Ferring. "Stable Isotopic Evidence for Latest Pleistocene and Holocene Climatic Change in North-Central Texas." Quaternary Research 41, no. 2 (March 1994): 200–213. http://dx.doi.org/10.1006/qres.1994.1022.
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AbstractA paleoclimatic record for a southern Great Plains locality (the Aubrey Clovis site in north-central Texas) has been established using stable carbon and oxygen isotopes. Detailed composite stratigraphic sections, constrained by 14 C ages, place the age of these deposits between 14,200 and 1600 yr B.P. Calcium carbonate samples of lacustrine and pedogenic origin were analyzed. Oxygen isotopic compositions of most of these in situ carbonates reflect equilibrium precipitation from local meteoric waters. Oxygen isotope values reflect changes in the composition of meteoric waters tied to changes in the isotopic composition of moisture derived from the Gulf of Mexico. Oxygen isotopic variability at the Aubrey site is coincident with marine isotopic records from the gulf that vary due to changes in Laurentide ice sheet volume and meltwater influx. The stable carbon isotopic record, reflecting changing biomass through time, corroborates humid versus arid interpretations based on sedimentology and rates of alluviation. A middle Holocene arid period was in contrast to moist early and late Holocene climate, affirming interpretations of other workers studying southern Great Plains Holocene climate history.
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Cullen, T. M., F. J. Longstaffe, U. G. Wortmann, M. B. Goodwin, L. Huang, and D. C. Evans. "Stable isotopic characterization of a coastal floodplain forest community: a case study for isotopic reconstruction of Mesozoic vertebrate assemblages." Royal Society Open Science 6, no. 2 (February 2019): 181210. http://dx.doi.org/10.1098/rsos.181210.
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Stable isotopes are powerful tools for elucidating ecological trends in extant vertebrate communities, though their application to Mesozoic ecosystems is complicated by a lack of extant isotope data from comparable environments/ecosystems (e.g. coastal floodplain forest environments, lacking significant C 4 plant components). We sampled 20 taxa across a broad phylogenetic, body size, and physiological scope from the Atchafalaya River Basin of Louisiana as an environmental analogue to the Late Cretaceous coastal floodplains of North America. Samples were analysed for stable carbon, oxygen and nitrogen isotope compositions from bioapatite and keratin tissues to test the degree of ecological resolution that can be determined in a system with similar environmental conditions, and using similar constraints, as those in many Mesozoic assemblages. Isotopic results suggest a broad overlap in resource use among taxa and considerable terrestrial–aquatic interchange, highlighting the challenges of ecological interpretation in C 3 systems, particularly when lacking observational data for comparison. We also propose a modified oxygen isotope-temperature equation that uses mean endotherm and mean ectotherm isotope data to more precisely predict temperature when compared with measured Atchafalaya River water data. These results provide a critical isotopic baseline for coastal floodplain forests, and act as a framework for future studies of Mesozoic palaeoecology.
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Wommack, Elizabeth A., Lisa C. Marrack, Stefania Mambelli, Joshua M. Hull, and Todd E. Dawson. "Using oxygen and hydrogen stable isotopes to track the migratory movement of Sharp-shinned Hawks (Accipiter striatus) along Western Flyways of North America." PLOS ONE 15, no. 11 (November 17, 2020): e0226318. http://dx.doi.org/10.1371/journal.pone.0226318.
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The large-scale patterns of movement for the Sharp-shinned Hawk (Accipiter striatus), a small forest hawk found throughout western North America, are largely unknown. However, based on field observations we set out to test the hypothesis that juvenile migratory A. striatus caught along two distinct migration routes on opposite sides of the Sierra Nevada Mountains of North America (Pacific Coast and Intermountain Migratory Flyways) come from geographically different natal populations. We applied stable isotope analysis of hydrogen (H) and oxygen (O) of feathers, and large scale models of spatial isotopic variation (isoscapes) to formulate spatially explicit predictions of the origin of the migrant birds. Novel relationships were assessed between the measured hydrogen and oxygen isotope values of feathers from A. striatus museum specimens of known origin and the isoscape modeled hydrogen and oxygen isotope values of precipitation at those known locations. We used these relationships to predict the origin regions for birds migrating along the two flyways from the measured isotope values of migrant’s feathers and the associated hydrogen and oxygen isotopic composition of precipitation where these feathers were formed. The birds from the two migration routes had overlap in their natal/breeding origins and did not differentiate into fully separate migratory populations, with birds from the Pacific Coast Migratory Flyway showing broader natal geographic origins than those from the Intermountain Flyway. The methodology based on oxygen isotopes had, in general, less predictive power than the one based on hydrogen. There was broad agreement between the two isotope approaches in the geographic assignment of the origins of birds migrating along the Pacific Coast Flyway, but not for those migrating along the Intermountain Migratory Flyway. These results are discussed in terms of their implications for conservation efforts of A. striatus in western North America, and the use of combined hydrogen and oxygen stable isotope analysis to track the movement of birds of prey on continental scales.
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Botsyun, Svetlana, Pierre Sepulchre, Yannick Donnadieu, Camille Risi, Alexis Licht, and Jeremy K. Caves Rugenstein. "Revised paleoaltimetry data show low Tibetan Plateau elevation during the Eocene." Science 363, no. 6430 (February 28, 2019): eaaq1436. http://dx.doi.org/10.1126/science.aaq1436.
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Paleotopographic reconstructions of the Tibetan Plateau based on stable isotope paleoaltimetry methods conclude that most of the Plateau’s current elevation was already reached by the Eocene, ~40 million years ago. However, changes in atmospheric and hydrological dynamics affect oxygen stable isotopes in precipitation and may thus bias such reconstructions. We used an isotope-equipped general circulation model to assess the influence of changing Eocene paleogeography and climate on paleoelevation estimates. Our simulations indicate that stable isotope paleoaltimetry methods are not applicable in Eocene Asia because of a combination of increased convective precipitation, mixture of air masses, and widespread aridity. Rather, a model-data comparison suggests that the Tibetan Plateau only reached low to moderate (less than 3000 meters) elevations during the Eocene, reconciling oxygen isotope data with other proxies.
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Guo, Rong, Shengjie Wang, Mingjun Zhang, Athanassios A. Argiriou, Xuemei Liu, Bo Su, Xue Qiu, et al. "Stable Hydrogen and Oxygen Isotope Characteristics of Bottled Water in China: A Consideration of Water Source." Water 11, no. 5 (May 22, 2019): 1065. http://dx.doi.org/10.3390/w11051065.
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The origin of bottled water can be identified via its stable isotope signature because of the spatial variation of the stable isotope composition of natural waters. In this paper, the spatial pattern of δ2H and δ18O values were analyzed for a total of 242 bottled water samples produced at 137 sites across China that were randomly purchased during 2014–2015. The isotopic ratios of bottled water vary between −166‰ and −19‰ for δ2H, and between −21.6‰ and −2.1‰ for δ18O. Based on multiple regression analyses using meteorological and geographical parameters, an isoscape of Chinese bottled water was created. The results showed that altitude among spatial parameters and precipitation amount and air temperature among meteorological parameters were major natural factors determining the isotopic variation of bottled water. Our findings indicate the potential and the significance of the use of stable isotopes for the source identification of bottled water. An analysis of different origin types (spring, glacier and unmarked) and several different brands of bottled water in the same location reflected different production processes and source signatures.
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Hendry, K. R., G. E. A. Swann, M. J. Leng, H. J. Sloane, C. Goodwin, J. Berman, and M. Maldonado. "Technical Note: Silica stable isotopes and silicification in a carnivorous sponge \\textit{Asbestopluma} sp." Biogeosciences Discussions 11, no. 12 (December 2, 2014): 16573–97. http://dx.doi.org/10.5194/bgd-11-16573-2014.
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Abstract. The stable isotope composition of benthic sponge spicule silica is a potential source of palaeoceanographic information about past deep seawater chemistry. The silicon isotopic composition of spicules has been shown to relate to the silicic acid concentration of ambient water, although existing calibrations do exhibit a degree of scatter in the relationship. Less is known about how the oxygen isotope composition of sponge spicule silica relates to environmental conditions during growth. Here, we investigate the biological vital effects on silica silicon and oxygen isotope composition in a carnivorous sponge, Asbestopluma sp., from the Southern Ocean. We find significant variations in silicon and oxygen isotopic composition within the specimen that appear related to unusual spicule silicification. The largest variation in both isotope systems was associated to the differential distribution of an unconventional, hypersilicified spicule type (desma) along the sponge body. The absence of an internal canal in the desmas suggests an unconventional silicification pattern leading to an unusually heavy isotopic signature. Additional internal variability derives from a systematic offset between the peripheral skeleton of the body having systematically a higher isotopic composition than the internal skeleton. A simplified silicon isotope fractionation model, in which desmas were excluded, suggests that the lack of a system for seawater pumping in carnivorous sponges favours a low replenishment of dissolved silicon within the internal tissues, causing kinetic fractionation during silicification that impacts the isotopic signature of the internal skeleton. Analysis of multiple spicules should be carried out to "average out" any artefacts in order to produce more robust downcore measurements.
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Marentes, E., R. A. Vanderpool, and B. J. Shelp. "Boron-isotope fractionation in plants." Canadian Journal of Plant Science 77, no. 4 (October 1, 1997): 627–29. http://dx.doi.org/10.4141/p97-010.
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Naturally-occurring variations in the abundance of stable isotopes of carbon, nitrogen, oxygen, and other elements in plants have been reported and are now used to understand various physiological processes in plants. Boron (B) isotopic variation in several plant species has been documented, but no determination as to whether plants fractionate the stable isotopes of boron, 11B and 10B, has been made. Here, we report that plants with differing B requirements (wheat, corn and broccoli) fractionated boron. The whole plant was enriched in 11B relative to the nutrient solution, and the leaves were enriched in 10B and the stem in 11B relative to the xylem sap. Although at present, a mechanistic role for boron in plants is uncertain, potential fractionating mechanisms are discussed. Key words: Brassica oleracea var. italica Plenck (broccoli), Triticum aestivum L. (wheat), Zea mays L. (corn), boron, isotope fractionation
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Gennett, Judith A., and Ethan L. Grossman. "Oxygen and Carbon Isotope Trends in a Late Glacial-Holocene Pollen Site in Wyoming, U.S.A." Géographie physique et Quaternaire 40, no. 2 (December 4, 2007): 161–69. http://dx.doi.org/10.7202/032636ar.
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ABSTRACT Stable isotope studies of North American Late Glacial and Holocene lake sediments are few. Previous studies of pollen sites in Indiana, South Dakota, and the Great Lakes area show low δ18O values during deglaciation, rising to a Hypsithermal peak, and provide paleoenvironmental reconstructions similar to those obtained from pollen studies. Blacktail Pond, located in Douglas fir steppe in northern Yellowstone National Park, Wyoming, is one of the highest elevation lakes (2018 m) yet studied with both pollen and stable isotopes. Analyses of marls yield low oxygen and carbon isotope values at the base of the core probably due to meltwater influx at 12,500 to 14,000 BP. Tundra vegetation persisted for about an additional 1,500 years following the end of meltwater input. Later, more enriched isotope values fluctuate due to the high sensitivity of Blacktail Pond to evaporation and CO2 exchange because of its shallow depth. These processes result in a covariance between δ13C and δ18O related to the residence time of water in the pond; they exert a primary control on the isotopic composition of the Holocene marl. It may be possible to filter the data for residence time effects and extract additional paleoenvironmental information based on the offsets of isotopic data from the δ13C-δ18O trend for a particular pollen zone.
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Lewicka-Szczebak, Dominika, Jens Dyckmans, Jan Kaiser, Alina Marca, Jürgen Augustin, and Reinhard Well. "Oxygen isotope fractionation during N<sub>2</sub>O production by soil denitrification." Biogeosciences 13, no. 4 (February 24, 2016): 1129–44. http://dx.doi.org/10.5194/bg-13-1129-2016.
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Abstract. The isotopic composition of soil-derived N2O can help differentiate between N2O production pathways and estimate the fraction of N2O reduced to N2. Until now, δ18O of N2O has been rarely used in the interpretation of N2O isotopic signatures because of the rather complex oxygen isotope fractionations during N2O production by denitrification. The latter process involves nitrate reduction mediated through the following three enzymes: nitrate reductase (NAR), nitrite reductase (NIR) and nitric oxide reductase (NOR). Each step removes one oxygen atom as water (H2O), which gives rise to a branching isotope effect. Moreover, denitrification intermediates may partially or fully exchange oxygen isotopes with ambient water, which is associated with an exchange isotope effect. The main objective of this study was to decipher the mechanism of oxygen isotope fractionation during N2O production by soil denitrification and, in particular, to investigate the relationship between the extent of oxygen isotope exchange with soil water and the δ18O values of the produced N2O. In our soil incubation experiments Δ17O isotope tracing was applied for the first time to simultaneously determine the extent of oxygen isotope exchange and any associated oxygen isotope effect. We found that N2O formation in static anoxic incubation experiments was typically associated with oxygen isotope exchange close to 100 % and a stable difference between the 18O ∕ 16O ratio of soil water and the N2O product of δ18O(N2O ∕ H2O) = (17.5 ± 1.2) ‰. However, flow-through experiments gave lower oxygen isotope exchange down to 56 % and a higher δ18O(N2O ∕ H2O) of up to 37 ‰. The extent of isotope exchange and δ18O(N2O ∕ H2O) showed a significant correlation (R2 = 0.70, p < 0.00001). We hypothesize that this observation was due to the contribution of N2O from another production process, most probably fungal denitrification. An oxygen isotope fractionation model was used to test various scenarios with different magnitudes of branching isotope effects at different steps in the reduction process. The results suggest that during denitrification, isotope exchange occurs prior to isotope branching and that this exchange is mostly associated with the enzymatic nitrite reduction mediated by NIR. For bacterial denitrification, the branching isotope effect can be surprisingly low, about (0.0 ± 0.9) ‰, in contrast to fungal denitrification where higher values of up to 30 ‰ have been reported previously. This suggests that δ18O might be used as a tracer for differentiation between bacterial and fungal denitrification, due to their different magnitudes of branching isotope effects.
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Lewicka-Szczebak, D., J. Dyckmans, J. Kaiser, A. Marca, J. Augustin, and R. Well. "The mechanism of oxygen isotope fractionation during N<sub>2</sub>O production by denitrification." Biogeosciences Discussions 12, no. 20 (October 22, 2015): 17009–49. http://dx.doi.org/10.5194/bgd-12-17009-2015.
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Abstract. The isotopic composition of soil-derived N2O can help differentiate between N2O production pathways and estimate the fraction of N2O reduced to N2. Until now, δ18O of N2O has been rarely used in the interpretation of N2O isotopic signatures because of the rather complex oxygen isotope fractionations during N2O production by denitrification. The latter process involves nitrate reduction mediated through the following three enzymes: nitrate reductase (NAR), nitrite reductase (NIR) and nitric oxide reductase (NOR). Each step removes one oxygen atom as water (H2O), which gives rise to a branching isotope effect. Moreover, denitrification intermediates may partially or fully exchange oxygen isotopes with ambient water, which is associated with an exchange isotope effect. The main objective of this study was to decipher the mechanism of oxygen isotope fractionation during N2O production by denitrification and, in particular, to investigate the relationship between the extent of oxygen isotope exchange with soil water and the δ18O values of the produced N2O. We performed several soil incubation experiments. For the first time, Δ17O isotope tracing was applied to simultaneously determine the extent of oxygen isotope exchange and any associated oxygen isotope effect. We found bacterial denitrification to be typically associated with almost complete oxygen isotope exchange and a stable difference in δ18O between soil water and the produced N2O of δ18O(N2O / H2O) = (17.5 ± 1.2) ‰. However, some experimental setups yielded oxygen isotope exchange as low as 56 % and a higher δ18O(N2O / H2O) of up to 37 ‰. The extent of isotope exchange and δ18O(N2O / H2O) showed a very significant correlation (R2 = 0.70, p < 0.00001). We hypothesise that this observation was due to the contribution of N2O from another production process, most probably fungal denitrification. An oxygen isotope fractionation model was used to test various scenarios with different magnitudes of branching isotope effects at different steps in the reduction process. The results suggest that during denitrification the isotope exchange occurs prior to the isotope branching and that the mechanism of this exchange is mostly associated with the enzymatic nitrite reduction mediated by NIR. For bacterial denitrification, the branching isotope effect can be surprisingly low, about (0.0 ± 0.9) ‰; in contrast to fungal denitrification where higher values of up to 30 ‰ have been reported previously. This suggests that δ18O might be used as a tracer for differentiation between bacterial and fungal denitrification, due to their different magnitudes of branching isotope effects.
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Kämpf, Lucas, Birgit Plessen, Stefan Lauterbach, Carla Nantke, Hanno Meyer, Bernhard Chapligin, and Achim Brauer. "Stable oxygen and carbon isotopes of carbonates in lake sediments as a paleoflood proxy." Geology 48, no. 1 (October 16, 2019): 3–7. http://dx.doi.org/10.1130/g46593.1.
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Abstract Lake sediments are increasingly explored as reliable paleoflood archives. In addition to established flood proxies including detrital layer thickness, chemical composition, and grain size, we explore stable oxygen and carbon isotope data as paleoflood proxies for lakes in catchments with carbonate bedrock geology. In a case study from Lake Mondsee (Austria), we integrate high-resolution sediment trapping at a proximal and a distal location and stable isotope analyses of varved lake sediments to investigate flood-triggered detrital sediment flux. First, we demonstrate a relation between runoff, detrital sediment flux, and isotope values in the sediment trap record covering the period 2011–2013 CE including 22 events with daily (hourly) peak runoff ranging from 10 (24) m3 s−1 to 79 (110) m3 s−1. The three- to ten-fold lower flood-triggered detrital sediment deposition in the distal trap is well reflected by attenuated peaks in the stable isotope values of trapped sediments. Next, we show that all nine flood-triggered detrital layers deposited in a sediment record from 1988 to 2013 have elevated isotope values compared with endogenic calcite. In addition, even two runoff events that did not cause the deposition of visible detrital layers are distinguished by higher isotope values. Empirical thresholds in the isotope data allow estimation of magnitudes of the majority of floods, although in some cases flood magnitudes are overestimated because local effects can result in too-high isotope values. Hence we present a proof of concept for stable isotopes as reliable tool for reconstructing flood frequency and, although with some limitations, even for flood magnitudes.
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Krigbaum, John, Michael H. Berger, David J. Daegling, and W. Scott McGraw. "Stable isotope canopy effects for sympatric monkeys at Taï Forest, Côte d'Ivoire." Biology Letters 9, no. 4 (August 23, 2013): 20130466. http://dx.doi.org/10.1098/rsbl.2013.0466.
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This study tests the hypothesis that vertical habitat preferences of different monkey species inhabiting closed canopy rainforest are reflected in oxygen isotopes. We sampled bone from seven sympatric cercopithecid species in the Taï forest, Côte d'Ivoire, where long-term study has established taxon-specific patterns of habitat use and diet. Modern rib samples ( n = 34) were examined for oxygen ( δ 18 O ap ) and carbon ( δ 13 C ap ) from bone apatite (‘bioapatite’), and carbon ( δ 13 C co ) and nitrogen ( δ 15 N co ) from bone collagen. Results are consistent for C 3 feeders in a closed canopy habitat. Low irradiance and evapotranspiration, coupled with high relative humidity and recycled CO 2 in forest understory, contribute to observed isotopic variability. Both δ 13 C co and δ 13 C ap results reflect diet; however, δ 13 C values are not correlated with species preference for canopy height. By contrast, δ 18 O ap results are correlated with mean observed height and show significant vertical partitioning between taxa feeding at ground, lower and upper canopy levels. This oxygen isotope canopy effect has important palaeobiological implications for reconstructing vertical partitioning among sympatric primates and other species in tropical forests.
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Wang, Yong Sen, Zheng He Xu, and Si Fang Dong. "An Oxygen Isotope Study of Seasonal Trends in Jinxiuchuan River of Jinan South Mountain." Applied Mechanics and Materials 522-524 (February 2014): 954–57. http://dx.doi.org/10.4028/www.scientific.net/amm.522-524.954.
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The stable isotope composition of river water contains some information of water cycle and climatic factors, such as precipitation, evaporation and temperature. Oxygen isotopes in river water were monitored at one site in Jinxiuchuang basin of Jinan southern mountain.δ18O values of river water show a variation from-7.82 on July 6 to-9.98 on June 6. The result reveals that the river water was mainly supplied by the precipitation. The isotopic variations at Jinxiuchuan river have strong precipitation patterns owning to different rainfall in summer.
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Yurchenko, Anna, Andrey Voropaev, Elena Kozlova, Nikita Morozov, and Mikhail Spasennykh. "Application of the Data on δ13C and δ18O of Carbonates for the Study of Unconventional Reservoirs on the Example of the Bazhenov Source Rocks, Western Siberia, Russia." Geosciences 11, no. 7 (June 22, 2021): 264. http://dx.doi.org/10.3390/geosciences11070264.
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This paper addresses potential application of data on stable carbon and oxygen isotope composition of carbonates for study of organic rich source rocks on the example of the Late Jurassic–Early Cretaceous Bazhenov Formation (West Siberian petroleum basin, Russia). Geochemical studies were conducted for sections located in central (most productive) and peripheral (northern and southern) regions of the Bazhenov Formation distribution area, containing deposits formed under different conditions. We identified key factors impacting stable isotope composition of carbonate minerals and established relation of their isotope composition to the formation conditions. Using a thermodynamic model of carbon and oxygen isotope exchange in the carbonate–water–carbon dioxide system, it is shown that variations in the isotope composition of secondary carbonates are affected by isotopic composition of primary carbonates in sediments and by the isotope exchange reactions with water and carbon dioxide, generated during the source rocks transformation. Our results demonstrate that stable isotope data for carbonates in the Bazhenov Formation together with standard geochemical methods can be efficiently applied to determine sedimentation conditions and secondary alteration processes of oil source rocks.
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VOIGT, SILKE. "Stable oxygen and carbon isotopes from brachiopods of southern England and northwestern Germany: estimation of Upper Turonian palaeotemperatures." Geological Magazine 137, no. 6 (November 2000): 687–703. http://dx.doi.org/10.1017/s0016756800004696.
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More than 190 articulate brachiopods from Turonian sections in northwestern Germany and southern England were studied for their stable carbon and oxygen isotopic composition, and some of them for their elemental composition. Most of the brachiopod shells are well preserved, and oxygen isotope composition reflects the temperate conditions of the European epicontinental sea. Upper Turonian mean δ18O values from Lower Saxony and southern England show bottom-water temperatures in the range of 14.2 to 18.2 °C (δ18Ow = −1.5‰ SMOW for an ice-free world). The relative trend of mean brachiopod oxygen and carbon isotopes shows a short-term (200 k.y.) increase in the mid-Upper Turonian horizons that confirms the climate cooling (∼ 2 °C) observed in bulk-rock samples at different sites in Europe. Interbasinal comparisons between England and Germany show similar δ13C values in both basins, whereas oxygen isotopes are heavier in northwestern Germany than in England, suggesting a cool-water influence from the North Sea basin and temperate conditions in the Anglo-Paris basin.
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Pollard, A. M. "Isotopes and impact: a cautionary tale." Antiquity 85, no. 328 (May 2011): 631–38. http://dx.doi.org/10.1017/s0003598x00068034.
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There can be no doubt that isotopic studies have made a huge contribution to archaeology in recent years, so much so that isotope archaeology is now seen as an essential subdiscipline of archaeology in much the same way as isotope geochemistry is a key subdiscipline of geochemistry. Ignoring for current purposes the contribution made by the measurement of a particular radioactive isotope of carbon (14C) since 1950, we can date the beginnings of isotope archaeology to the mid 1960s with the first measurements of lead isotopes in archaeological metals and slags by Brill and Wampler (1965, 1967). This was followed by carbon stable isotopes in human bone collagen in the late 1970s, building on previous work measuring σ13C in archaeological bone for radiocarbon determinations (Vogel & Van der Merwe 1977; Van der Merwe & Vogel 1978). Other isotopes followed rapidly, such as nitrogen, oxygen, sulphur and hydrogen for archaeological, palaeoecological or palaeoclimatological purposes and, more recently, the heavier radiogenic isotopes of strontium and neodymium for determining the provenance of organic and inorganic materials (Pollard & Heron 2008).
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Wang, Yong Sen, and Zheng He Xu. "Analysis of Water Movement through an Unsaturated Soil Zone in Jinan Southern Mountain Using Stable Oxygen and Hydrogen Isotopes." Applied Mechanics and Materials 522-524 (February 2014): 958–62. http://dx.doi.org/10.4028/www.scientific.net/amm.522-524.958.
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The stable isotope compositions of soil water from the profiles at Jinan southern mountain reveal information about the mechanism of soil movement. The stable isotopes in soil water have a wide range from-8.92 to-5.95 forδ18O and-50.01 to-79.44 forδD . The mean isotope values is-7.75 forδ18O and 65.84 forδD. The low-δD of shallow (<5cm) soil water is due to the precipitation infiltration. And deep soil water (>5cm) is enrichment, which indicates the soil water is evaporated before recharging. The stable oxygen and hydrogen isotope are plotted near the meteoric water line. The trend line for the relationship between δ18O and δD of soil water is given.
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Zhang, Qian, Wen Hui Huang, and Ya Mei Zhang. "Characteristics and its Environment Implications of Carbon and Oxygen Isotopic of Ordovician Carbonate Rock in Yubei Area." Advanced Materials Research 1092-1093 (March 2015): 1375–78. http://dx.doi.org/10.4028/www.scientific.net/amr.1092-1093.1375.
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Based on a large number of carbon and oxygen stable isotope data, researched environment characteristics of Ordovician carbonate rocks in Yubei area, Tarim Basin. According to carbon, oxygen stable isotopes (&13C, &18O) data, combining the diagenetic environment characteristics studied all kinds of geochemical characteristics of rocks in Yubei area. The research results show that: Paleosalinity feature of Ordovician carbonate rocks in this area reflected the carbonate rocks is formed in the stability of the marine environment and basically kept the composition of carbon and oxygen isotopic of the original environment. the paleo temperature characteristics indicate that the diagenetic burial depth was increased first and then decreased, the sea level characteristics indicate that the sedimentary strata by Yingshan period to Lianglitage period corresponds with a rise in sea level.
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Smith, Abigail M., and Marcus M. Key. "Controls, variation, and a record of climate change in detailed stable isotope record in a single bryozoan skeleton." Quaternary Research 61, no. 2 (March 2004): 123–33. http://dx.doi.org/10.1016/j.yqres.2003.11.001.
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The long-lived (about 20 yr) bryozoan Adeonellopsis sp. from Doubtful Sound, New Zealand, precipitates aragonite in isotopic equilibrium with seawater, exerting no metabolic or kinetic effects. Oxygen isotope ratios (δ18O) in 61 subsamples (along three branches of a single unaltered colony) range from −0.09 to +0.68‰ PDB (mean = +0.36‰ PDB). Carbon isotope ratios (δ13C) range from +0.84 to +2.18‰ PDB (mean = +1.69‰ PDB). Typical of cool-water carbonates, δ18O-derived water temperatures range from 14.2 to 17.5 °C. Adeonellopsis has a minimum temperature growth threshold of 14 °C, recording only a partial record of environmental variation. By correlating seawater temperatures derived from δ18O with the Southern Oscillation Index, however, we were able to detect major events such as the 1983 El Niño. Interannual climatic variation can be recorded in skeletal carbonate isotopes. The range of within-colony isotopic variability found in this study (0.77‰ in δ18O and 1.34 in δ13C) means that among-colony variation must be treated cautiously. Temperate bryozoan isotopes have been tested in less than 2% of described extant species — this highly variable phylum is not yet fully understood.
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Hendry, K. R., G. E. A. Swann, M. J. Leng, H. J. Sloane, C. Goodwin, J. Berman, and M. Maldonado. "Technical Note: Silica stable isotopes and silicification in a carnivorous sponge <i>Asbestopluma</i> sp." Biogeosciences 12, no. 11 (June 5, 2015): 3489–98. http://dx.doi.org/10.5194/bg-12-3489-2015.
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Abstract. The stable isotope composition of benthic sponge spicule silica is a potential source of palaeoceanographic information about past deep seawater chemistry. The silicon isotope composition of spicules has been shown to relate to the silicic acid concentration of ambient water, although existing calibrations do exhibit a degree of scatter in the relationship. Less is known about how the oxygen isotope composition of sponge spicule silica relates to environmental conditions during growth. Here, we investigate the vital effects on silica, silicon and oxygen isotope composition in a carnivorous sponge, Asbestopluma sp., from the Southern Ocean. We find significant variations in silicon and oxygen isotopic composition within the specimen that are related to unusual spicule silicification. The largest variation in both isotope systems was associated with the differential distribution of an unconventional, hypersilicified spicule type (desma) along the sponge body. The absence an internal canal in the desmas suggests an unconventional silicification pattern leading to an unusually heavy isotope signature. Additional internal variability derives from a systematic offset between the peripheral skeleton of the body having systematically a higher isotopic composition than the internal skeleton. A simplified silicon isotope fractionation model, in which desmas were excluded, suggests that the lack of a system for seawater pumping in carnivorous sponges favours a low replenishment of dissolved silicon within the internal tissues, causing kinetic fractionation during silicification that impacts the isotope signature of the internal skeleton. Analysis of multiple spicules should be carried out to "average out" any artefacts in order to produce more robust downcore measurements.
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Ford, William, Mark R. Williams, Megan B. Young, Kevin W. King, and Eric Fischer. "Assessing Intra-Event Phosphorus Dynamics in Drainage Water Using Phosphate Stable Oxygen Isotopes." Transactions of the ASABE 61, no. 4 (2018): 1379–92. http://dx.doi.org/10.13031/trans.12804.
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Abstract. Quantifying fluxes and pathways of dissolved reactive phosphorus (DRP) in tile-drained landscapes has been hampered by a lack of measurements that are sensitive to P fate and transport processes. One potential tool to help understand these dynamics is the oxygen isotope signature of phosphate (d18OPO4); however, its potential benefits and limitations are not well understood for intra-event dynamics at the field scale. The objectives of this study were to quantify intra-event variability of d18OPO4 signatures in tile drainage water and assess the efficacy of d18OPO4 to elucidate mechanisms and flow pathways controlling DRP transport to tile drains. We collected water samples during a summer storm event from a subsurface (tile)-drained field located in west-central Ohio and analyzed for d18OPO4 of DRP. Supplementary water quality measurements, hydrologic modeling, and soil temperature data were used to help understand intra-event d18OPO4 dynamics. Results of the soil extraction analysis from our study site highlight that the soil water-extractable P (WEP) pool was not in equilibrium with long-term, temperature-dependent water isotope values. This result suggests that P-rich soils may, at least partially, retain their original source signature, which has significant implications for identifying hotspots of P delivery in watershed-scale applications. Results of the storm event analysis highlight that equilibration of leached DRP in soil water creates a gradient between isotopic compositions of pre-event shallow subsurface sources, pre-event deep subsurface sources, and the WEP tied up in surface soils. The current study represents the first intra-event analysis of d18OPO4 and highlights the potential for phosphate oxygen isotopes as a novel tool to improve understanding of P fate and transport in artificially drained agroecosystems. Keywords: Agriculture, Edge-of-field, Macropores, Phosphate oxygen isotopes, Tile-drainage.
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Hu, Yue, Guo-dong Liu, and Cheng-cheng Xia. "Multi-time scale analysis of hydrogen and oxygen isotope characteristics and influence factors in precipitation in Vienna." MATEC Web of Conferences 246 (2018): 02011. http://dx.doi.org/10.1051/matecconf/201824602011.
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Based on isotope and meteorology data at Vienna station from 1972 to 2014 provided by GNIP, the average monthly and annual hydrogen and oxygen stable isotopic compositions and main factors were analyzed by using various trend analysis, periodic analysis and correlation analysis methods. The monthly mean isotopic compositions change slightly, reflecting the fact that although Vienna is affected by the maritime climate and the continental climate, the former impact is more significant. The slope and intercept of the LMWL in Vienna changed significantly from October to March, indicating that it was affected by alternating effects of the two climates. The annual mean isotopes show a trend of enrichment, and it has an obvious temperature effect, but the rainfall amount effect does not exist, and no simple linear relationship was found between isotopes and vapor pressure. The annual mean isotopes also show the periodic variation characteristics with scales such as 9-16 years and 18~29 years, and it is concluded that the isotope values will be enriched after 2011 at the scale 22 years. The multivariate regression relationship established by δD and δ18O with three climate parameters of temperature, precipitation and vapor pressure can quantitatively estimate the missing value in isotopic data.
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Miljević, Nada, and Dušan Golobočanin. "Potential Use of Environmental Isotopes in Pollutant Migration Studies." Archives of Industrial Hygiene and Toxicology 58, no. 2 (June 1, 2007): 251–62. http://dx.doi.org/10.2478/v10004-007-0015-5.
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Potential Use of Environmental Isotopes in Pollutant Migration StudiesThis article presents the use of natural abundance stable isotope (hydrogen, carbon, nitrogen, oxygen, chlorine) analysis data as a tool for providing important information about the origin of contaminants, the contribution of different sources to a multi-source plume, characterisation of their complex transport (rate and mechanisms) and for evaluating the success of contaminated site remediation. Isotopic signatures of contaminants are useful tracers of their sources, while isotopic fractionation can be used to quantitatively assess the progress of an environmental process such as biodegradation. This new isotopic approach is reliable and can offer more information than traditional techniques in pollutant migration studies, particularly after waste disposal. During biological degradation of any organic compound, molecules containing lighter isotopes are degraded, and the portion of heavier isotopes in the substrate is increased, identifying specific microbial roles in biogeochemical cycling. Since isotopic fractionation is proportional to degradation, depending on the type of contamination, a microbial degradation of 50% to 99% of the initial concentration can be quantified using isotope ratio measurements.
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Linge, Henriette, Stein-Erik Lauritzen, and Joyce Lundberg. "Stable Isotope Stratigraphy of a Late Last Interglacial Speleothem from Rana, Northern Norway." Quaternary Research 56, no. 2 (September 2001): 155–64. http://dx.doi.org/10.1006/qres.2001.2254.
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AbstractA stalagmite from Rana, northern Norway, dated by the TIMS uranium-series technique, yields records of stable oxygen and carbon isotopes covering the period from late marine oxygen isotope substages (MIS) 5e to 5a, that is, 123,350 to 73,300 yr ago. Rapid growth (∼46 μm/yr) between 123,350 and 119,500 yr ago reflects climatic conditions favorable for speleothem growth. This period is characterized by century- to millennial-scale oscillations in both stable isotope records, where both the absolute values and the isotope ranges are similar to Holocene and older samples from the region. From 119,500 to 107,700 yr ago, speleothem growth was slow (∼0.7 μm/yr), and between 107,700 and 73,300 yr ago growth is barely noticeable (0.07 μm/yr). During the period of slow growth the stable isotope records show an overall enrichment trend. The transition between rapid and slow growth rate occurring sometime between 119,500 and 107,700 yr ago is believed to reflect the termination of interglacial climate in this region. The absence of detritus and corrosion features in the slowly deposited calcite suggests that the valley outside the cave remained sufficiently ice free for speleothem growth to occur until at least 73,300 yr ago.
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Hu, Happy, Annie Bourbonnais, Jennifer Larkum, Hermann W. Bange, and Mark A. Altabet. "Nitrogen cycling in shallow low-oxygen coastal waters off Peru from nitrite and nitrate nitrogen and oxygen isotopes." Biogeosciences 13, no. 5 (March 9, 2016): 1453–68. http://dx.doi.org/10.5194/bg-13-1453-2016.
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Abstract. O2 deficient zones (ODZs) of the world's oceans are important locations for microbial dissimilatory nitrate (NO3−) reduction and subsequent loss of combined nitrogen (N) to biogenic N2 gas. ODZs are generally coupled to regions of high productivity leading to high rates of N-loss as found in the coastal upwelling region off Peru. Stable N and O isotope ratios can be used as natural tracers of ODZ N-cycling because of distinct kinetic isotope effects associated with microbially mediated N-cycle transformations. Here we present NO3− and nitrite (NO2−) stable isotope data from the nearshore upwelling region off Callao, Peru. Subsurface oxygen was generally depleted below about 30 m depth with concentrations less than 10 µM, while NO2− concentrations were high, ranging from 6 to 10 µM, and NO3− was in places strongly depleted to near 0 µM. We observed for the first time a positive linear relationship between NO2−δ15N and δ18O at our coastal stations, analogous to that of NO3− N and O isotopes during NO3− uptake and dissimilatory reduction. This relationship is likely the result of rapid NO2− turnover due to higher organic matter flux in these coastal upwelling waters. No such relationship was observed at offshore stations where slower turnover of NO2− facilitates dominance of isotope exchange with water. We also evaluate the overall isotope fractionation effect for N-loss in this system using several approaches that vary in their underlying assumptions. While there are differences in apparent fractionation factor (ε) for N-loss as calculated from the δ15N of NO3−, dissolved inorganic N, or biogenic N2, values for ε are generally much lower than previously reported, reaching as low as 6.5 ‰. A possible explanation is the influence of sedimentary N-loss at our inshore stations which incurs highly suppressed isotope fractionation.
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Hu, H., A. Bourbonnais, J. Larkum, H. W. Bange, and M. A. Altabet. "Nitrogen cycling in shallow low oxygen coastal waters off Peru from nitrite and nitrate nitrogen and oxygen isotopes." Biogeosciences Discussions 12, no. 10 (May 18, 2015): 7257–99. http://dx.doi.org/10.5194/bgd-12-7257-2015.
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Abstract. O2 minimum zones (OMZ) of the world's oceans are important locations for microbial dissimilatory NO3- reduction and subsequent loss of combined nitrogen (N) to biogenic N2 gas. This is particularly so when the OMZ is coupled to a region of high productivity leading to high rates of N-loss as found in the coastal upwelling region off Peru. Stable N isotope ratios (and O in the case of NO3- and NO2-) can be used as natural tracers of OMZ N-cycling because of distinct kinetic isotope effects associated with microbially-mediated N-cycle transformations. Here we present NO2- and NO3- stable isotope data from the nearshore upwelling region off Callao, Peru. Subsurface O2 was generally depleted below about 30 m depth with O2 less than 10 μM, while NO2- concentrations were high, ranging from 6 to 10 μM and NO3- was in places strongly depleted to near 0 μM. We observed for the first time, a positive linear relationship between NO2- δ15N and δ18O at our coastal stations, analogous to that of NO3- N and O isotopes during assimilatory and dissimilatory reduction. This relationship is likely the result of rapid NO2- turnover due to higher organic matter flux in these coastal upwelling waters. No such relationship was observed at offshore stations where slower turnover of NO2- facilitates dominance of isotope exchange with water. We also evaluate the overall isotope fractionation effect for N-loss in this system using several approaches that vary in their underlying assumptions. While there are differences in apparent fractionation factor (ε) for N-loss as calculated from the δ15N of [NO3-], DIN, or biogenic N2, values for ε are generally much lower than previously reported, reaching as low as 6.5‰. A possible explanation is the influence of sedimentary N-loss at our inshore stations which incurs highly suppressed isotope fractionation.
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Detjen, M., E. Sterling, and A. Gómez. "Stable isotopes in barnacles as a tool to understand green sea turtle (<i>Chelonia mydas</i>) regional movement patterns." Biogeosciences 12, no. 23 (December 8, 2015): 7081–86. http://dx.doi.org/10.5194/bg-12-7081-2015.
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Abstract. Sea turtles are migratory animals that travel long distances between their feeding and breeding grounds. Traditional methods for researching sea turtle migratory behavior have important disadvantages, and the development of alternatives would enhance our ability to monitor and manage these globally endangered species. Here we report on the isotope signatures in green sea-turtle (Chelonia mydas) barnacles (Platylepas sp.) and discuss their potential relevance as tools with which to study green sea turtle migration and habitat use patterns. We analyzed oxygen (δ18O) and carbon (δ13C) isotope ratios in barnacle calcite layers from specimens collected from green turtles captured at the Palmyra Atoll National Wildlife Refuge (PANWR) in the central Pacific. Carbon isotopes were not informative in this study. However, the oxygen isotope results suggest likely regional movement patterns when mapped onto a predictive oxygen isotope map of the Pacific. Barnacle proxies could therefore complement other methods in understanding regional movement patterns, informing more effective conservation policy that takes into account connectivity between populations.
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Detjen, M., E. Sterling, and A. Gómez. "Stable isotopes in barnacles as a tool to understand green sea turtle (<i>Chelonia mydas</i>) regional movement patterns." Biogeosciences Discussions 12, no. 6 (March 23, 2015): 4655–69. http://dx.doi.org/10.5194/bgd-12-4655-2015.
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Abstract. Sea turtles are migratory animals that travel long distances between their feeding and breeding grounds. Traditional methods for researching sea turtle migratory behavior have important disadvantages, and the development of alternatives would enhance our ability to monitor and manage these globally endangered species. Here we report on the isotope signatures in green sea turtle (Chelonia mydas) barnacles (Platylepas sp.) and discuss their potential relevance as tools with which to study green sea turtle migration and habitat use patterns. We analyzed oxygen (δ18O) and carbon (δ13C) isotope ratios in barnacle calcite layers from specimens collected from green turtles captured at the Palmyra Atoll National Wildlife Refuge (PANWR) in the Central Pacific. Carbon isotopes were not informative in this study. However, the oxygen isotope results suggest likely regional movement patterns when mapped onto a predictive oxygen isotope map of the Pacific. Barnacle proxies could therefore complement other methods in understanding regional movement patterns, informing more effective conservation policy that takes into account connectivity between populations.
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Sehrawat, Jagmahender Singh, and Jaspreet Kaur. "Role of stable isotope analyses in reconstructing past life-histories and the provenancing human skeletal remains: a review." Anthropological Review 80, no. 3 (September 1, 2017): 243–58. http://dx.doi.org/10.1515/anre-2017-0017.
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AbstractThis article reviews the present scenario of use of stable isotopes (mainly δ13C, δ15N, δ18O,87Sr) to trace past life behaviours like breast feeding and weaning practices, the geographic origin, migration history, paleodiet and subsistence patterns of past populations from the chemical signatures of isotopes imprinted in human skeletal remains. This approach is based on the state that food-web isotopic signatures are seen in the human bones and teeth and such signatures can change parallely with a variety of biogeochemical processes. By measuring δ13C and δ15N isotopic values of subadult tissues of different ages, the level of breast milk ingestion at particular ages and the components of the complementary foods can be assessed. Strontium and oxygen isotopic analyses have been used for determining the geographic origins and reconstructing the way of life of past populations as these isotopes can map the isotopic outline of the area from where the person acquired water and food during initial lifetime. The isotopic values of strontium and oxygen values are considered specific to geographical areas and serve as reliable chemical signatures of migration history of past human populations (local or non-local to the site). Previous isotopic studies show that the subsistence patterns of the past human populations underwent extensive changes from nomadic to complete agricultural dependence strategies. The carbon and nitrogen isotopic values of local fauna of any archaeological site can be used to elucidate the prominence of freshwater resources in the diet of the past human populations found near the site. More extensive research covering isotopic descriptions of various prehistoric, historic and modern populations is needed to explore the role of stable isotope analysis for provenancing human skeletal remains and assessing human migration patterns/routes, geographic origins, paleodiet and subsistence practices of past populations.
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Völpel, Rike, André Paul, Annegret Krandick, Stefan Mulitza, and Michael Schulz. "Stable water isotopes in the MITgcm." Geoscientific Model Development 10, no. 8 (August 25, 2017): 3125–44. http://dx.doi.org/10.5194/gmd-10-3125-2017.
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Abstract. We present the first results of the implementation of stable water isotopes in the Massachusetts Institute of Technology general circulation model (MITgcm). The model is forced with the isotopic content of precipitation and water vapor from an atmospheric general circulation model (NCAR IsoCAM), while the fractionation during evaporation is treated explicitly in the MITgcm. Results of the equilibrium simulation under pre-industrial conditions are compared to observational data and measurements of plankton tow records (the oxygen isotopic composition of planktic foraminiferal calcite). The broad patterns and magnitude of the stable water isotopes in annual mean seawater are well captured in the model, both at the sea surface as well as in the deep ocean. However, the surface water in the Arctic Ocean is not depleted enough, due to the absence of highly depleted precipitation and snowfall. A model–data mismatch is also recognizable in the isotopic composition of the seawater–salinity relationship in midlatitudes that is mainly caused by the coarse grid resolution. Deep-ocean characteristics of the vertical water mass distribution in the Atlantic Ocean closely resemble observational data. The reconstructed δ18Oc at the sea surface shows a good agreement with measurements. However, the model–data fit is weaker when individual species are considered and deviations are most likely attributable to the habitat depth of the foraminifera. Overall, the newly developed stable water isotope package opens wide prospects for long-term simulations in a paleoclimatic context.
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Hamilton, Marian I., B. Lee Drake, W. H. Wills, Emily Lena Jones, Cyler Conrad, and Patricia L. Crown. "STABLE OXYGEN ISOTOPE SOURCING OF ARCHAEOLOGICAL FAUNA FROM CHACO CANYON, NEW MEXICO." American Antiquity 83, no. 1 (November 16, 2017): 163–75. http://dx.doi.org/10.1017/aaq.2017.61.
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Modern datasets provide the context necessary for accurate interpretations of isotopic data from archaeological faunal assemblages. In this study, we use the oxygen isotope ratios (δ18O) of modern small mammals from Chaco Canyon, New Mexico, to quantify expected isotopic variation in a local population. The δ18O values of local, modern small mammals encompass a broad range (−6.0‰ to 4.8‰ VPDB), which is expected given the extreme seasonal variation in the δ18O of precipitation on the Colorado Plateau (−11‰ to −3‰ VPDB). Isotopic ratios of small mammals obtained from excavated archaeological sites in Chaco Canyon (ca. AD 800 to 1200) show no significant differences with their modern counterparts, suggesting that there is no difference in the origins of the archaeological small-mammal collection and the modern, local Chaco Canyon small-mammal collection. In contrast, δ18O values of large mammals from Chaco archaeological sites are significantly different from those of modern specimens, reflecting a nonlocal, but also nonspecific, source in the past.
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Barford, Carol C., Joseph P. Montoya, Mark A. Altabet, and Ralph Mitchell. "Steady-State Nitrogen Isotope Effects of N2 and N2O Production in Paracoccus denitrificans." Applied and Environmental Microbiology 65, no. 3 (March 1, 1999): 989–94. http://dx.doi.org/10.1128/aem.65.3.989-994.1999.
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ABSTRACT Nitrogen stable-isotope compositions (δ15N) can help track denitrification and N2O production in the environment, as can knowledge of the isotopic discrimination, or isotope effect, inherent to denitrification. However, the isotope effects associated with denitrification as a function of dissolved-oxygen concentration and their influence on the isotopic composition of N2O are not known. We developed a simple steady-state reactor to allow the measurement of denitrification isotope effects in Paracoccus denitrificans. With [dO2] between 0 and 1.2 μM, the N stable-isotope effects of NO3 − and N2O reduction were constant at 28.6‰ ± 1.9‰ and 12.9‰ ± 2.6‰, respectively (mean ± standard error,n = 5). This estimate of the isotope effect of N2O reduction is the first in an axenic denitrifying culture and places the δ15N of denitrification-produced N2O midway between those of the nitrogenous oxide substrates and the product N2 in steady-state systems. Application of both isotope effects to N2O cycling studies is discussed.