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1
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.
Анотація:
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.
2
Sare, David T. J., John S. Millar, and Frederick J. Longstaffe. "Tracing dietary protein in red-backed voles (Clethrionomys gapperi) using stable isotopes of nitrogen and carbon." Canadian Journal of Zoology 83, no. 5 (May 1, 2005): 717–25. http://dx.doi.org/10.1139/z05-064.
Анотація:
We examined the stable isotopes of nitrogen and carbon in a small mammal, the red-backed vole (Clethroinomys gapperi (Vigors, 1830)), to determine if isotope signatures reflect diet composition. Nitrogen- and carbon-isotope ratios in tissues from voles maintained on different protein levels in the laboratory were compared with wild-trapped voles. The isotopic fractionation of dietary nitrogen and carbon was also examined as food was digested in the stomach, incorporated into bone collagen, bioapatite, and hair, and excreted as feces. Nitrogen and carbon isotopes were fractionated differently depending on the isotopic composition and protein content of the diet. δ15N and δ13C values appear to be influenced by factors in addition to diet, such as macronutrients metabolized for respiration, metabolic rate, and periods of protein shortage.
3
Gruzdev, D. A., A. V. Zhuravlev, Ya A. Vevel, A. V. Erofeevsky, and I. V. Smoleva. "Famennian negative carbon isotope excursion in the Izyayu River section (Tchernyshev Uplift, Cis-Uralian Foredeep)." LITHOSPHERE (Russia) 23, no. 2 (April 27, 2023): 165–78. http://dx.doi.org/10.24930/1681-9004-2023-23-2-165-178.
Анотація:
Research subject. The article is focused on manifestations of the Early-Middle Famennian negative excursion in carbon isotope composition in the Izyayu River section (south of the Tchernyshev Uplift). Aim. The study is aimed to reconstructing of the probable causes of this isotope excursion. Materials and methods. The article is based on the results of study of the deep-shelf lower-middle Famennian sequence of the Izyayu River section. The carbon isotopic composition was studied for the carbonate samples and conodont elements (32 and 9 samples respectively). Results. The lightening of the carbon isotopic composition of carbonates by 2.5 %, and of the carbon isotopic composition of conodont elements by 4 % were found in the Pal. gracilis gracilis–Pal. marginifera marginifera zonal interval. The difference between the carbon isotopic compositions of carbonates and conodont elements increases in this interval by more than 2.5 %. Possible reasons for the observed variations could be the intensification of terrigenous runoff due to regression, a relatively high content of carbon dioxide in the atmosphere, and, possibly, a local decline in primary bioproductivity. Conclusions. The negative carbon isotope shift spans Pal. gracilis gracilis–Pal. marginifera marginifera zonal interval in the Izyayu River section. The shift corresponds to the global decreasing in the δ13Ccarb values in the early/middle Famennian boundary interval. The increase in supply of the isotopically light carbon with terrigenous runoff and decrease in the primary bioproductivity are considered as probable causes of the carbon isotope excursion.
4
Zhuravlev, A. V., and I. V. Smoleva. "Preliminary results of studying the carbon isotope composition of conodont elements at the border of Devonian and Carboniferous periods (Kamenka river sections, Pechora carbonate platform)." LITHOSPHERE (Russia) 20, no. 6 (December 29, 2020): 829–41. http://dx.doi.org/10.24930/1681-9004-2020-20-6-829-841.
Анотація:
Research subject. Changes in the trophic structure of shallow-water pelagic ecosystems at the Devonian/Carboniferous border were investigated by studying the carbon isotope composition of conodont organic matter.Materials and methods. Two Devonian-Carboniferous shallow-water clayey-carbonate sections located in the southern part of the Pechora-Kozhva Uplift (Pechora Plate) were analysed. The Devonian-Carboniferous boundary was detected by the first occurrences of Siphonodella sulcata, S. semichatovae and Patrognathus crassus, as well as by the last occurrence of Pseudopolygnathus graulichi. The carbon isotope composition was investigated both in whole-rock carbonate samples and the conodont organic matter of two dominant species (Polygnathus parapetus and P. communis communis).Results. The distribution of stable carbon isotopes in the organic matter of conodont elements accompanied by the data on carbonate isotope composition allowed us to suggest changes in the food composition of the dominant taxa during the Late Famennian-Early Tournaisian transition. It was assumed that the latest Famennian representatives of Polygnathus parapetus and P. communis communis consumed largely phyto- and zooplankton, which is characterized by a light isotopic composition of organic carbon. The nutrition based on phyto- and zooplankton with a heavier isotopic composition of organic carbon was suggested for the early Tournaisian representatives of these species.Conclusions. The discovered variations in the carbon isotope composition of conodont organic matter in shallow-water facies may correspond to the change from the eutrophic pelagic ecosystem to the oligotrophic ecosystem, and/or global perturbation of the carbon cycle due to climatic changes. Since the available data is limited to two geological sections, it is impossible to unambiguously interpret the scale (local, regional, global) of these variations and their correlation potential.
5
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.
Анотація:
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.
6
Irei, Satoshi. "Isotopic Characterization of Gaseous Mercury and Particulate Water-Soluble Organic Carbon Emitted from Open Grass Field Burning in Aso, Japan." Applied Sciences 12, no. 1 (December 23, 2021): 109. http://dx.doi.org/10.3390/app12010109.
Анотація:
Biomass burning is one of the major emitters of airborne particulate matter (PM) and gaseous mercury. In order to apply the isotopic fingerprinting method to process identification and source apportionment studies, isotopic characterizations of targeted substances at emission are indispensable. Here, we report the stable isotopic composition of total gaseous mercury (TGM) and the stable and radiocarbon isotopic composition of low-volatile water-soluble nitrogen (LV-WSN) and organic carbon (LV-WSOC) in PM emitted from open grass field burning in the Aso region of Japan. The measurement results showed that TGM concentrations in the air increased during the open field burning events, indicating the presence of TGM emissions. The results of LV-WSN analysis showed very low concentrations; therefore, the stable nitrogen isotope ratios could not be measured. The stable mercury isotope ratios exhibited lighter composition than those observed during non-biomass-burning days. The analysis of LV-WSOC revealed heavy stable carbon isotope ratios (average ± SD, −18 ± 2‰), suggesting a substantial contribution from C4 plant carbon. The 14C analysis showed that more than 98% of the LV-WSOC was modern carbon, indicating the contribution of plant carbon to PM emitted from biomass burning. The findings here provide reference isotope compositions of TGM and particulate LV-WSOC from biomass burning in this region.
7
Evans, JR, TD Sharkey, JA Berry, and GD Farquhar. "Carbon Isotope Discrimination measured Concurrently with Gas Exchange to Investigate CO2 Diffusion in Leaves of Higher Plants." Functional Plant Biology 13, no. 2 (1986): 281. http://dx.doi.org/10.1071/pp9860281.
Анотація:
Conventional gas-exchange techniques that measure the stomatal conductance and rate of CO2 assimilation of leaves were combined with measurements of the carbon isotope composition of CO2 in air passing over a leaf. Isotopic discrimination during uptake was determined from the difference in the carbon isotope composition of air entering and leaving the leaf chamber. Isotopic discrimination measured over the short term correlated strongly with that determined from combusted leaf material. Environmental conditions were manipulated to alter the relative influences of stomatal conductance and carboxylation on the discrimination of carbon isotopes by intact leaves. With C3 plants, discrimination increased as the gradient in partial pressure of CO2 across the stomata decreased. For C4 plants there was little change in discrimination despite substantial changes in the diffusion gradient across the sto- mata. These results are consistent with, and provide the first direct experimental support for, theoretical equations describing discrimination during photosynthesis. Despite uncertainties about various processes affecting carbon isotope composition, the resistance to the transfer of CO2 from the intercellular airspaces to the sites of carboxylation in the mesophyll chloroplasts was estimated using this technique. For wheat the estimated resistance was 1.2-2.4 m2 s bar mol -1.
8
Kennedy, Brenda V., and H. Roy Krouse. "Isotope fractionation by plants and animals: implications for nutrition research." Canadian Journal of Physiology and Pharmacology 68, no. 7 (July 1, 1990): 960–72. http://dx.doi.org/10.1139/y90-146.
Анотація:
The isotopic compositions of animal tissues, minerals, and fluids reflect those of ingested food and water and inhaled gases. This relationship is illustrated by a review of data pertaining to five light elements of biological interest (carbon, nitrogen, hydrogen, oxygen, and sulphur). Processes affecting the isotopic composition of inorganic compounds in reservoirs are summarized, and isotope fractionation during transfer of elements from these inorganic reservoirs through progressive trophic levels of food webs is discussed. Variability of δ values within and among individuals, populations, and species of plants and animals is attributed to at least six factors: locality, dietary selectivity, biochemical composition of food, isotope effects in metabolic processes, turnover rates, and stress. Features of a variety of terrestrial and aquatic ecosystems are used to illustrate basic concepts. Future research should seek to clarify specific mechanisms affecting δ values during the transfer of elements through food webs.Key words: food webs, stable isotopes, isotope fractionation, ecosystems.
9
Benbow, Timothy J., Alan R. Hayman, Robert Van Hale, and Russell Frew. "Preparation of aqueous fatty acids for hydrogen and carbon stable isotope analysis by solid phase extraction." Marine and Freshwater Research 64, no. 4 (2013): 294. http://dx.doi.org/10.1071/mf12192.
Анотація:
Stable isotope analyses of fatty acids in environmental waters provides important information as to their source(s). Analysis is often confounded due to low concentrations of fatty acids and/or a complex sample matrix requiring separation of the target analyte. The purpose of this study was to validate a method to extract fatty acids from natural waters using solid phase extraction (SPE) before compound specific isotope analysis (CSIA). Three SPE cartridges and multiple eluting solvents were tested to determine the efficiency, isotopic fractionation, and reproducibility of each extraction technique. Our results indicated that surface-modified styrene divinylbenzene cartridges, when eluted with methanol, caused negligible fractionation of the hydrogen isotopes and minimal fractionation of the carbon isotopes, but that isotopic fractionation occurred when compounds were only partially eluted from SPE cartridges. Compounds were also extracted from landfill leachate using both SPE and liquid–liquid extraction (LLE). The hydrogen isotope composition (δ2H) of compounds extracted from water using either method were within experimental precision and the carbon isotope composition (δ13C) of all but one fatty acid were within experimental precision. Therefore, these experiments prove the aforementioned SPE methods to be a convenient and precise method to extract fatty acids from natural waters before CSIA.
10
Smith, J. J., J. S. Millar, F. J. Longstaffe, and R. Boonstra. "The effect of metabolic rate on stable carbon and nitrogen isotope compositions in deer mice, Peromyscus maniculatus." Canadian Journal of Zoology 88, no. 1 (January 2010): 36–42. http://dx.doi.org/10.1139/z09-116.
Анотація:
The stable isotopic compositions of nitrogen and carbon in animal tissues reflect diet. However, factors other than diet can also affect these stable isotope ratios, leading to misinterpretations of diet composition. To test the hypothesis that variation in metabolic rate alters the isotopic compositions of tissues, deer mice ( Peromyscus maniculatus (Wagner, 1845)) were kept at three temperatures (thermoneutral (23 °C), cool (5 °C), and cold (–10 °C)) and fed ad libitum. The changes in carbon and nitrogen isotope compositions of liver associated with the thermoneutral versus cool and cold conditions were very small in comparison with those arising from differences in diet. We conclude that temperature-induced variations in metabolic rate are insufficient to produce differences in the stable carbon or nitrogen isotope compositions that could be mistaken for changes in diet.
11
Balcaen, A., E. Claeys, V. Fievez, P. Boeckx, O. van Cleemput, and S. de Smet. "Stable carbon isotope analysis of faecal and blood samples of sheep in relation to the diet." Proceedings of the British Society of Animal Science 2003 (2003): 159. http://dx.doi.org/10.1017/s1752756200013181.
Анотація:
Stable isotopes have been extraordinarily helpful in understanding animal migration, diet, food webs and nutrient flow (Hilderbrand et al., 1996), based on the property that C3 and C4 plants possess distinctly different 13C/12C ratios (δ13C value) due to isotopic fractionation during photosynthetic carbon fixation (Smith & Epstein, 1971). Most woody species and temperate graminoids assimilate carbon via the Calvin cycle (C3), which discriminates stronger against the heavier isotope (13C) than Hatch-Slack (C4) species (tropical and subtropical graminoids and some shrubs). C3 and C4 plant species have mean δ13C values of -27 ‰ and -13 ‰ respectively (O’Leary, 1981). DeNiro & Epstein (1978) were one of the first to show that the isotopic composition of the whole animal body is similar to that of its diet. Other authors have also found relationships between the isotopic composition of animal tissues and the diet (González-Martin et al., 1999; Jones et al., 1979). The aim of this study was to investigate stable carbon isotope composition in sheep fed diets consisting of either C3 or C3+C4 plants.
12
Krasnova, Elizaveta A., Anna Yu Yurchenko, Anton G. Kalmykov, and Maria M. Fomina. "Isotopic-geochemical peculiarities of distribution of gas hydrocarbons in the Bazhenov formation section (South part of the Western Siberia)." Georesursy 21, no. 2 (May 2019): 153–58. http://dx.doi.org/10.18599/grs.2019.2.153-158.
Анотація:
In this work we describe the distribution of stable carbon isotopes in hydrocarbon gases from four wells located in the southern and central parts of the Western Siberia. The main goal was to understand the influence of the lithological composition and geological settings on isotopic composition of gases and their formation. Two genetically different groups of hydrocarbon gases were identified based on the author’s research, as well as analysis of archival and literature materials on the isotope composition of hydrocarbons. We estimated the close relationship between the main factors of the migration, degree of metamorphism of organic matter and the isotope composition of hydrocarbon gases produced by the Bazhenov formation.
13
HUA, ZHONG, and MA YONGSHENG. "Carbon isotope stratigraphy of dolomites in the early Proterozoic succession, north China." Geological Magazine 134, no. 6 (November 1997): 763–70. http://dx.doi.org/10.1017/s0016756897007577.
Анотація:
Four hundred and eighty-four whole rock dolomite samples from early Proterozoic strata have been analysed for carbon isotopes. The carbon isotope composition is strata-specific, but abrupt variations have been observed between the Jianancun and the Daguandong as well as the Daguandong and Huaiyincun formations. The carbon isotope composition of dolomites is believed to reflect δ13C of oceanic total dissolved inorganic carbon during the early Proterozoic and reflect changing rates of organic carbon burial.
14
Cao, Chunhui, Zhongping Li, Liwu Li, and Li Du. "Method for Analyzing the Molecular and Carbon Isotope Composition of Volatile Hydrocarbons (C1–C9) in Natural Gas." Journal of Analytical Methods in Chemistry 2018 (December 18, 2018): 1–9. http://dx.doi.org/10.1155/2018/4512081.
Анотація:
Solid-phase microextraction (SPME) coupled with gas chromatography-isotope ratio mass spectrometry (GC-IRMS) has already been applied to collect and identify volatile light hydrocarbons in oil and source rocks. However, this technology has not yet been used to analyze volatile light hydrocarbons in dry gas (natural gas with C1/C2+> 95%). In this study, we developed a method to measure the molecular and carbon isotope composition of natural gas using divinylbenzene/carboxen/polydimethylsiloxane (DVB/CAR/PDMS) fiber. This fiber proved to be suitable for extracting C1–C9hydrocarbons from natural gas without inducing carbon isotopic fractionation. Notably, the extraction coefficients of the analytes were not the same but rather increased with the increasing carbon number of the hydrocarbons. Nevertheless, we successfully identified 24 hydrocarbons from the in-lab standard natural gas, while also obtaining the carbon isotope composition of C1to C9hydrocarbons with satisfying repeatability. The relative standard deviation (RSD) of the molecular composition data was in the range of 0.06–0.74%, with the RSDs of the carbon isotope composition data not exceeding 1‰. Finally, seven natural gas samples, collected from different sedimentary basins, were successfully analyzed and the stable carbon isotope compositions of C1–C9hydrocarbons present in these were determined through this method. Overall, the new approach provides a simple but useful technique to obtain more geochemical information about the source and evolution of natural gas.
15
Yurchenko, Anna, Andrey Voropaev, Elena Kozlova, Nikita Morozov та 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, № 7 (22 червня 2021): 264. http://dx.doi.org/10.3390/geosciences11070264.
Анотація:
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.
16
Ivanova, Elena Sergeevna, Olga Yurievna Rumiantseva, Anastasia Sergeevna Zavertkina, Anastasia Evgenievna Bueva, and Anna Sergeevna Elizarova. "The isotopic composition of hair among the population in the Vologda Region depending on the conditions of living and nutrition." Samara Journal of Science 10, no. 4 (December 1, 2021): 46–50. http://dx.doi.org/10.17816/snv2021104107.
Анотація:
Isotope mass spectrometry methods are used to study changes in the isotopic composition of organisms in the food chain called trophic fractionation. In particular, with the help of isotope analysis of tissues, it is possible to determine the type of nutrition and possible place of residence of a person, which helps in solving the tasks of forensic examination. In this study, the isotopic composition C and ⁵N in the hair of residents of the industrial city of Cherepovets and the Kirillovsky District of the Vologda Region, remote from industrial sources of pollution, was determined. The determination of the isotopic composition of hair was carried out on an isotope mass spectrometer Thermo-Finnigan Delta V Plus in the Ecological and Analytical Laboratory of Cherepovets State University. The average values of isotopes in the hair of the study participants are 20,86 (C) and 9,98 (⁵N). There are differences in the ratio of carbon and nitrogen isotopes in the hair of residents of Cherepovets and Kirillovsky District. There are not statistically significant differences in the isotopic composition of C and ⁵N in the hair of female and male. There are differences of ⁵N in the hair of people who consume different amounts of fish (people who consume fish more often have a higher ratio of ⁵N).
17
Кулешова, Т. Э., Е. С. Павлова та Н. Р. Галль. "Фракционирование изотопов углерода -=SUP=-13-=/SUP=-С/-=SUP=-12-=/SUP=-С из углекислого газа атмосферы в продукты фотосинтеза в листьях растений в зависимости от спектральных характеристик световой среды". Письма в журнал технической физики 46, № 16 (2020): 19. http://dx.doi.org/10.21883/pjtf.2020.16.49848.18333.
Анотація:
We have studied influence of the light with various spectral characteristics, coming to plants during its growth, on the distribution of carbon isotopes between atmospheric carbon dioxide and the primary products of photosynthesis in plant leaves, using the developed set of methods and laboratory setups. The difference between the carbon isotopic composition in the air near the plants and in their leaves varies from 7 to 19 ‰, increase in the red component of the spectrum resulting in leave enrichment with light carbon isotope 12C. This difference reflects the degree of isotope fractionation during the plant life, characterizes the rate of carbon assimilation due to photosynthetic reactions, and can be used as a phytomonitoring parameter.
18
Kelleway, J. J., S. M. Trevathan-Tackett, J. Baldock, and L. P. Critchley. "Plant litter composition and stable isotope signatures vary during decomposition in blue carbon ecosystems." Biogeochemistry 158, no. 2 (February 1, 2022): 147–65. http://dx.doi.org/10.1007/s10533-022-00890-3.
Анотація:
AbstractThe ratio of isotopes of carbon (13C:12C or δ13C) and nitrogen (15N:14N or δ15N) are common indicators of the flow and storage of organic matter in coastal wetland research. Effective use of these indicators requires quantification and understanding of: (1) the variability of isotope signatures of potential organic matter source materials; and (2) the influence of organic matter decomposition on isotopic signatures. While it is well-established that organic matter characteristics change during the decomposition process, there has been little direct quantification of any concurrent shifts in isotope signatures for coastal detritus. In this study, we addressed this by quantifying: (1) shifts in sample composition using solid-state 13C Nuclear Magnetic Resonance (NMR) spectroscopy; and (2) shifts in δ13C and δ15N signatures of coastal plant tissues from field litterbag experiments. We observed significant shifts in 13C NMR spectra across the course of deployment for all four plant tissues assessed (leaves of mangrove Avicennia marina; branchlets of supratidal tree Casuarina glauca; leaf wrack and roots/rhizomes of the seagrass Zostera muelleri), driven largely by the preferential loss of labile constituents and concentration of more resistant macromolecules, such as lignin and leaf waxes. While there were shifts in isotope ratios for all species, these varied in direction and magnitude among species, tissue type and isotopes. This included δ13C enrichments of up to 3.1‰ and 2.4‰ in leaves of A. marina, and branchlets of C. glauca, respectively, but δ13C depletions of up to 4.0‰ for Z. muelleri. Shifts in δ15N varied among species and tissue types, with few clear temporal patterns. Partial least squares regression analyses showed that some tissue isotope signatures can be reliably predicted on the basis of sample composition (13C NMR spectra), however, multiple inter- and intra-species variations preclude a simple explanation of isotopic signature shifts on the basis of plant-material molecular shifts alone. Further, we cannot preclude the potential influence of microbe-associated organic matter on sample composition or isotopic signatures. Our findings emphasise the importance of considering decomposition effects on stable isotope signatures in blue carbon ecosystems. Isotope approaches will remain a valuable tool in coastal ecosystem research, but require robust experimental approaches (including appropriate use of decomposed end-members or fractionation correction factors; quantification of microbial organic matter) and quantification of decomposition dynamics for specific plant tissues and environmental settings.
19
Gaigalas, Algirdas, and Stanislaw Halas. "Stable Isotopes (H, C, S) and the Origin of Baltic Amber." Geochronometria 33, no. -1 (January 1, 2009): 33–36. http://dx.doi.org/10.2478/v10003-009-0001-9.
Анотація:
Stable Isotopes (H, C, S) and the Origin of Baltic Amber New results of isotope analysis of light elements (H, C and S) of a dozen Baltic amber samples are described and discussed. Carbon isotope composition was nearly constant (ca. -23‰), whereas sulphur and hydrogen varied in their isotope compositions from +4 to -28‰ and from -171 to -213‰, respectively. The formation and subsequent evolution of this material since its origin in Paleogene time until present is outlined.
20
Ghent, Edward D., and James R. O'Neil. "Late Precambrian marbles of unusual carbon-isotope composition, southeastern British Columbia." Canadian Journal of Earth Sciences 22, no. 3 (March 1, 1985): 324–29. http://dx.doi.org/10.1139/e85-032.
Анотація:
Carbon- and oxygen-isotope analyses were made of both carbonates and graphites from several Precambrian metamorphic samples from British Columbia. The carbon-isotope data are unusual in that the δ13C values of many marbles are very high, up to 9.9, and the most positive values occur in the sillimanite-zone rocks. The δ13C values of graphite are also relatively high, and the 13C fractionations between calcite and graphite suggest that (1) the rocks attained and retained carbon-isotope equilibrium during metamorphism, and (2) the temperature of graphite equilibration in marbles from the sillimanite zone is 650–690 °C, in agreement with temperatures estimated from mineralogical phase equilibria.Possible precursor carbonates for the 13C-rich marbles in British Columbia include (1) Precambrian carbonate-secreting organisms such as algae that participate in reactions with large kinetic isotope effects, (2) carbonates that exchanged carbon isotopes with a large reservoir of organic material prior to metamorphism, and (3) travertines.
21
Novikov, Dmitry A., Aleksandr N. Pyrayev, Anastasia A. Maksimova, Fedor F. Dultsev та Anatoly V. Chernykh. "Evolution of the composition of Н, О and C stable isotopes in the groundwaters of oil and gas bearing sediments in the northern regions of West Siberia". Georesursy 25, № 4 (30 грудня 2023): 219–32. http://dx.doi.org/10.18599/grs.2023.4.16.
Анотація:
The results of a study of the isotopic composition of oxygen and hydrogen of groundwater and dissolved inorganic carbon in oil and gas deposits of the northern regions of Western Siberia, covering a wide stratigraphic range – Mesozoic and Paleozoic are presented. The obtained values are very diverse, covering the intervals from –120 to –50‰ (δD) and from –17 to –2‰ (δ18O). Such a variable isotopic composition of waters indicates the absence of a unified mechanism for the accumulation of waters and their transformation during the geological evolution of the West Siberian sedimentary basin. The main feature of most of the studied waters is the pronounced values of oxygen isotope shifts relative to GMWL, which generally increase with the age of water-bearing deposits and reach 9‰, which indicates their ancient sedimentary origin. Variations in the isotopic composition of DIC (from –51.8 to +21.8‰) and its content in waters (from 0.2 to 38.6 mmol/I) indicate a wide range of water burial conditions and processes involved in the conversion of water-soluble carbon dioxide. A general pattern of changes in the isotopic composition of carbon in CO2 with time, expressed in general form by damped oscillations of the “isotope oscillator”, is revealed. A model of transformation of the carbon isotope composition in carbon dioxide in the closed cycle “atmosphere-soils-deep aquifers” for oil and gas deposits of the northern regions of Western Siberia based on the obtained isotope data is proposed.
22
Valentini, R., T. Anfodillo та J. R. Ehleringer. "Water sources and carbon isotope composition (δ13C) of selected tree species of the Italian Alps". Canadian Journal of Forest Research 24, № 8 (1 серпня 1994): 1575–78. http://dx.doi.org/10.1139/x94-205.
Анотація:
Selected species of the Italian Alpine region (Piceaabies (L.) Karst., Pinussylvestris L., Pinuscembra L., and Larixdecidua L.) have been investigated in terms of water-source utilization and carbon fixation estimated by the analysis of hydrogen and carbon stable isotopes composition at two sites of differing altitude (1000 and 1500 m above sea level). Larixdecidua is the species most dependent on groundwater in both sites, while Pinussylvestris utilizes rainwater to a greater extent. Concurrently, Pinussylvestris displayed the highest value of the carbon isotopic ratio (δ13C = −25.9 ± 0.6‰), while Larixdecidua had the most negative one (δ13C = −29.0 ± 0.4‰). A relationship was found between water-source utilization and carbon-isotope discrimination.
23
Novikov, Dmitry A., Aleksandr N. Pyrayev, Fedor F. Dultsev, Anatoliy V. Chernykh, Svetlana V. Bakustina, and Dmitry V. Ulyanov. "FORMATION CONDITIONS OF GROUNDWATER OF THE UPPER JURASSIC OF THE CENTRAL REGIONS OF THE ZAURAL MEGAMONOCLYSIS." Interexpo GEO-Siberia 2, no. 1 (May 21, 2021): 181–90. http://dx.doi.org/10.33764/2618-981x-2021-2-1-181-190.
Анотація:
The article presents the first results of complex isotope-hydrogeochemical studies of reservoir waters of the Upper Jurassic deposits of the central regions of the Zaural megamonoclysis. It was shown that most waters have a narrow distribution of oxygen and hydrogen isotopes (δD from -103.2 to -85.6 ‰ and δO from -15.4 to -12.9 ‰). Some of them have pronounced excursions on the isotopic composition, which indicates a difference in their genesis: from condensate to mixed with ancient infiltrogenic. The isotopic composition of carbon of water-dissolved carbon dioxide (δС from -41.6 to -16.3 ‰) indicates its biogenic origin and the possibility of interstratal flows from overlying horizons.
24
Taylor, Matthew D., and Debashish Mazumder. "Stable isotopes reveal post-release trophodynamic and ontogenetic changes in a released finfish, mulloway (Argyrosomus japonicus)." Marine and Freshwater Research 61, no. 3 (2010): 302. http://dx.doi.org/10.1071/mf09014.
Анотація:
Carbon and nitrogen stable isotope ratios were analysed for hatchery-reared, recaptured and wild mulloway, Argyrosomus japonicus, to investigate temporal and growth-related changes in isotopic composition for stocked fish after release, and to evaluate changes in isotopic composition in terms of ontogenetic dietary switches. δ13C and δ15N values decreased and increased, respectively, after release. The isotope composition of released fish was distinct from wild fish until 200 days after release, but after 200 days post-release fish did not differ significantly from wild fish of similar or greater sizes. Abrupt dietary transitions from crustaceans to teleost fish (>50 cm total length (TL)) were evident in a rapid δ13C and δ15N change in wild mulloway, and δ15N was significantly greater in wild fish >65 cm TL compared with wild fish <50 cm TL. Multivariate carbon and nitrogen isotopic data were suitable for separating stocked and wild fish for up to 200 days after release, but did not separate wild fish grouped according to dietary composition. Carbon and nitrogen isotopic composition closely reflected dietary transitions and rapid adaptation by stocked mulloway to wild diets, which was evident in a high tissue turnover rate of up to 0.017 day–1. Stable isotopes are a useful tool for examining the integration of released fish into stocked ecosystems and can be used to describe convergence in the diets of wild and released fish.
25
Carpenter, Chris. "Chemical and Carbon Isotope Composition Proves Effective as Gas Diagnostic Tool." Journal of Petroleum Technology 75, no. 09 (September 1, 2023): 94–96. http://dx.doi.org/10.2118/0923-0094-jpt.
Анотація:
_ This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 209992, “Gas Chemical and Carbon Isotope Composition as a Diagnostic Tool for Energy,” by Zainab Almubarak, SPE, Mohammad Alrowaie, and Feng Lu, Saudi Aramco, et al. The paper has not been peer reviewed. _ Chemical and carbon isotopic compositions of produced gases are useful tools to monitor gas production and to assess their origin, thermal maturity, and migration. In the complete paper, the authors present different geochemical approaches to assess the origin of gases and thermal maturity and to evaluate the effect of adsorption on shale gas during production. Introduction Carbon isotope type curves constructed for compounds from methane through n-pentane can be used to group gases into distinct families and correlate them to their source rocks. Large variations in carbon isotope ratios exist among the natural gas compounds, which are caused by isotopic fractionation between the sedimentary organic matter (kerogen) and each individual hydrocarbon compound. During the generation of hydrocarbons from kerogen, cracking of 12C-12C bonds requires slightly less energy than 13C-12C bonds. Thus, hydrocarbons will be enriched in 12C relative to the kerogen. Methane, which contains only one carbon atom, shows the greatest fractionation and will have the most negative δ13C value (most enriched in 12C). Ethane through pentane show progressively less fractionation (less negative δ13C values), with the latter usually having a δ13C value close to that of kerogen (and associated oil). The magnitude of the fractionation effect will vary depending on the type of kerogen (i.e., Type I, II, IIS, or III), the temperature during hydrocarbon generation, and the adsorption/desorption effect. Thus, gases generated from different source rocks often have distinctive carbon isotope type curves. In shale gas (unconventional reservoirs), two different types of gases coexist—free gas and adsorbed gas. Free gas occurs in natural fractures and matrix pores, whereas adsorbed gas is noted on the surface of pores. During the early stages of production, free gas accounts for most produced gas. The adsorbed gas starts in mid-late stages but maintains high and stable production. In this study, the authors use carbon isotopic compositions of light hydrocarbons (C1–C5) to assess origin and thermal maturity and to compare different gases derived from unconventional reservoirs. Moreover, carbon isotopes are used to assess migration paths and to monitor gas production in unconventional shale gas reservoirs. The gas samples were collected periodically from the same interval to monitor any isotope variation and evaluate the effect of gas adsorption. Methods Pressurized samples of natural gas were collected from conventional and unconventional reservoirs through production tests, drillstem tests, or downhole samplers and analyzed for chemical composition. For the conventional study, a total of 13 gas samples were collected from different reservoirs (A, B, C, D, and J): four gas samples from Reservoir A, two gas samples from Reservoir B, three gas samples from Reservoir C, three gas samples from Reservoir D, and one gas sample from Reservoir J. Gases derived from Reservoirs A, B, and J are younger and shallower than gases derived from Reservoirs C and D (older and deeper). For the unconventional study, seven gas samples were collected periodically from the same shale interval (Reservoir W) from the same well (Well Y) on different dates to monitor any isotope variation.
26
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.
Анотація:
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.
27
Aravena, Ramon, S. L. Schiff, S. E. Trumbore, P. J. Dillon, and Richard Elgood. "Evaluating Dissolved Inorganic Carbon Cycling in a Forested Lake Watershed Using Carbon Isotopes." Radiocarbon 34, no. 3 (1992): 636–45. http://dx.doi.org/10.1017/s003382220006392x.
Анотація:
Dissolved inorganic carbon (DIC) is the main acid buffer in forested lake watersheds in Canada. We used carbon isotopes (13C, 14C) to evaluate the production and cycling of DIC in an acid-sensitive lake watershed of the Precambrian Shield. Soil CO2, groundwater and stream DIC were characterized chemically and isotopically. Soil CO2 concentration profiles reflect both changes in production and in losses due to diffusion. δ13C soil CO2 profiles (δ13C values of −23‰ in summer, slightly enriched during the fall and −25%‰ during the winter) are a reflection of the isotopic composition of the sources and changes in isotopic fractionation due to diffusion. Carbon isotopic composition (13C, 14C) of the groundwater and stream DIC clearly indicate that weathering of silicates by soil CO2 is the main source of DIC in these watersheds. 14C data show that, in addition to recent groundwater, an older groundwater component with depleted 14C activity is also present in the bedrock. The carbon isotope pattern in the groundwater also implies that, besides the main springtime recharge events, contributions to the groundwater may also occur during late winter/early spring.
28
Khubanova, A. M., V. B. Khubanov, and D. A. Miyagashev. "Zoning of Desert, Steppe, Steppe-Forest and Forest Ecosystems By Carbon And Nitrogen Isotope in Mongolia and Western Transbaikalia." GEOGRAPHY, ENVIRONMENT, SUSTAINABILITY 16, no. 3 (October 8, 2023): 14–31. http://dx.doi.org/10.24057/2071-9388-2023-2720.
Анотація:
The Mongolian–Transbaikalian region of the Central Asia is known for its wide range of intracontinental ecosystems from desert through steppe to taiga forest and mountain tundra. Data on the isotopic composition of carbon and nitrogen in the bone and dental tissues of herbivorous animals inhabiting the desert, steppe, and forest–steppe landscapes of Outer Mongolia and Western Transbaikalia are presented. The maximum values of the carbon isotope ratio are observed in animals from the desert (Gobi Desert) and the semi-desert landscapes, median (mean) δ13C is -17.9‰. The minimum values of δ13C were obtained by herbivorous animals of the forest-steppe and the forest landscapes (Transbaikalia), which median δ13C is -23‰. The fauna of the steppes (median δ13C is -21.7‰) has intermediate values of the carbon isotopic composition. According to the isotope composition of nitrogen, the isotope-geochemical isolation of ecosystems is less pronounced.
29
Stelmach, Wioleta, Paweł Szarlip, and Andrzej Trembaczowski. "Changes of Isotopic Composition in Gases Emitted from Wastewater Treatment Plant - Preliminary Study." Ecological Chemistry and Engineering S 21, no. 2 (July 8, 2014): 245–54. http://dx.doi.org/10.2478/eces-2014-0019.
Анотація:
Abstract Investigations of processes occurring during wastewater treatment have progressed beyond the stage of technology. Currently, great numbers of representatives of diverse specialist research apply increasingly sophisticated measurement methods that have not been employed in this field of science. One of the methods is IRMS (Isotope Ratio Mass Spectrometry). Tracking changes in the ratios of biogenic element isotopes is useful in eg identification and monitoring of investigated processes. Since the IRMS technique has hardly been used for investigations of the wastewater treatment process, pilot research should be instigated to determine the isotope ratios occurring naturally in the process. The aim of the study was to determine changes in carbon and nitrogen isotope ratios at the successive stages of the technological line in wastewater treatment plants. The study material comprised: i) suspensions of raw sewage and mixtures of wastewater and activated sludge; ii) gases sampled from the volume of the suspensions; iii) gases sampled from the air above the suspension surface. The research material originated from the facilities of “Hajdow” municipal wastewater treatment plant in Lublin (SE Poland). The samples were analysed for the carbon and nitrogen isotope ratios, and the concentrations of the gases as well as total organic carbon (TOC), inorganic carbon (IC), Kjeldahl nitrogen (KN), dry weight, pH, and Eh were determined. The results obtained suggest that: i) the IRMS technique can be successfully applied in investigations of processes occurring during wastewater treatment; ii) isotope ratios in the carbon and nitrogen compounds (CO2 and N2) both in the suspensions and gases contained therein and in the air above them differ from each other and change at the different stages of the treatment process; iii) further research is indispensable in order to identify processes responsible for fractionation of carbon and nitrogen isotopes.
30
Ivlev, A. A., and N. P. Goncharov. "Isotopic composition of blood plasma carbon in patients with endocrine diseases." Problems of Endocrinology 39, no. 1 (February 15, 1993): 36–40. http://dx.doi.org/10.14341/probl11906.
Анотація:
Forty-eight patients suffering from diabetes mellitus, obesity, hyper- and hypothyrosis, Icenko-Cushings disease were examined to elucidate the relationship between blood plasma carbon isotopic composition and the type of the endocrine disease. This value varied within the range of 19.7 to 24.7 , the mean value being 5 . Blood plasma carbon in the diabetics is enriched for 12C light isotope (delta-13C from 23.0 to 24.5 ) as against a similar characteristic in obese patients (delta-13C from 20.5 to 21.99 ). Patients with hypo- and hyperthyrosis and the Icenko- Cushings disease have a wider range of delta-13C values that seems to be explained by the Icenko-Cushings disease heterogeneity and the presence of biorhythms. Clear-cut isotopic differences in the blood sera of adults and children were revealed whatever the disease type, these differences indicating the changes in cellular metabolism energy in the ontogenesis. These data can be satisfactorily explained within the frames of the model of cellular division of carbon isotopes, suggested previously.
31
Zhang, Wen, Wenhui Liu, Xiaofeng Wang, Zhengliang Huang, Qingfen Kong, Houyong Luo, Dongdong Zhang, Peng Liu, Xiaoyan Chen, and Zhenghong Cai. "Formation Mechanism of Heavy Hydrocarbon Carbon Isotope Anomalies in Natural Gas from Ordovician Marine Carbonate in the Ordos Basin." Journal of Marine Science and Engineering 11, no. 11 (November 15, 2023): 2176. http://dx.doi.org/10.3390/jmse11112176.
Анотація:
Interactive depositional systems of marine carbonates and gypsum salt rocks are closely related to natural gas reservoirs. Despite continuous progress in the exploration of new areas of marine carbonate genesis within the Ordos Basin, the source and mechanism of “sub-salt” natural gas genesis remains controversial. In this study, we investigated natural gas genesis through geochemical analysis of Lower Paleozoic natural gas samples from the mid-eastern Ordos Basin, obtaining natural gas composition data and carbon/hydrogen isotope compositions. We found evident differences between the geochemical characteristics of “sub-salt” and “post-salt” natural gas; the methane carbon isotope signature of “sub-salt” natural gas was lighter overall than that of “post-salt” natural gas, while the ethane carbon isotope composition of the former was more widely distributed and partially lighter than that of the latter. Combining these data with the regional geological background and existing geochemical data, it is evident that Ordovician “post-salt” natural gas comprises a composite of Upper Paleozoic coal-type gas and Lower Paleozoic oil-type gas, with the oil-type gas accounting for the largest proportion. In contrast, the “sub-salt” natural gas was formed and preserved within the Ordovician marine carbonates or sourced from deeper and more ancient hydrocarbon source rocks. Geochemical anomalies, including light methane carbon isotopes and ethane carbon isotopes with coal-type gas characteristics, are closely related to the prevalence of thermochemical sulfate reduction during hydrocarbon formation and reservoir formation of natural gas in “sub-salt” strata.
32
Cowan, Clinton A., David L. Fox, Anthony C. Runkel, and Matthew R. Saltzman. "Terrestrial-marine carbon cycle coupling in ∼500-m.y.-old phosphatic brachiopods." Geology 33, no. 8 (August 1, 2005): 661–64. http://dx.doi.org/10.1130/g21434ar.1.
Анотація:
Abstract Carbon isotope compositions (δ13C) of inarticulate brachiopod shells from Upper Cambrian sandstone in the cratonic interior of Laurentia record a 5‰ positive excursion that correlates biostratigraphically with the global Steptoean positive isotopic carbon excursion. A consistent 6‰ negative displacement in brachiopod δ13C relative to carbonate values is interpreted to represent an onshore-offshore gradient in the isotopic composition of dissolved inorganic carbon in Cambrian seawater. Thus, these ∼500-m.y.-old chitinophosphatic brachiopod shells preserve evidence for carbon cycle coupling between the ancient atmospheric, oceanic, and terrestrial reservoirs in the time before embryophytic land plants.
33
Overman, Nathanael C., та Donna L. Parrish. "Stable isotope composition of walleye: 15N accumulation with age and area-specific differences in δ13C". Canadian Journal of Fisheries and Aquatic Sciences 58, № 6 (1 червня 2001): 1253–60. http://dx.doi.org/10.1139/f01-072.
Анотація:
Stable nitrogen and carbon isotope ratios were measured for walleye (Stizostedion vitreum) collected across Lake Champlain, Vermont, to determine relationships between isotopic composition and diet, location of capture, length, weight, and age. Variation in δ13C values reflected area-specific differences in isotopic composition of organisms collected across the lake. A critical assumption in the application of isotope techniques is that a predictable relationship exists between the diet and isotopic composition of an organism. Our results indicate that isotopic fractionation factors may not be independent of age as has largely been assumed. By combining stable nitrogen and carbon isotope analysis with conventional stomach content analysis, we documented significant age effects in the δ15N composition of adult walleye that were not attributable to observed changes in diet. Age accounted for 81% of the variation in δ15N values of walleye (ages 227, N = 65, δ15N range = 15.319.2), providing evidence supporting 15N accumulation over the life span of walleye. Therefore, the risk of making faulty inferences of trophic position and food web interactions based on δ15N values may be increased when age is unknown. Our results indicate that metabolic effects associated with age require greater consideration in applications of stable isotope analysis.
34
Sho, Kenjiro, Hiroshi Aoki Takahashi, Hiroshi Miyai, Shuichi Ikebuchi, and Toshio Nakamura. "TREE-RING WIDTH AND STABLE CARBON ISOTOPE COMPOSITION OF JAPANESE CYPRESS IN THE LAKE BIWA AREA, CENTRAL JAPAN, AND THEIR HYDROLOGIC AND CLIMATIC IMPLICATIONS." IAWA Journal 30, no. 4 (2009): 395–406. http://dx.doi.org/10.1163/22941932-90000227.
Анотація:
Chronologies of tree-ring width and stable carbon isotope composition of Japanese cypress were developed to help reconstruct a 300-year record of past hydrologic and climatic environments in the Lake Biwa area, central Japan. Site chronologies were built with 37 trees for ring width and four trees for carbon isotope composition, respectively. Correlation analysis with monthly climatic data revealed that radial growth of the trees is related to temperature in early spring, precipitation (or number of precipitation days) in early summer and precipitation in previous-year summer to autumn. Tree-ring cellulose carbon isotopic composition is correlated most significantly with the number of precipitation days in early summer months. Consequently, a chronology of the number of precipitation days in May was reconstructed by multiple regression analysis with ring-width and carbon-isotope predictors and was validated by comparison with the recent observed record.
35
Kristensen, D. K., E. Kristensen, M. C. Forchhammer, A. Michelsen, and N. M. Schmidt. "Arctic herbivore diet can be inferred from stable carbon and nitrogen isotopes in C3 plants, faeces, and wool." Canadian Journal of Zoology 89, no. 10 (October 2011): 892–99. http://dx.doi.org/10.1139/z11-073.
Анотація:
The use of stable isotopes in diet analysis usually relies on the different photosynthetic pathways of C3 and C4 plants, and the resulting difference in carbon isotope signature. In the Arctic, however, plant species are exclusively C3, and carbon isotopes alone are therefore not suitable for studying arctic herbivore diets. In this study, we examined the potential of both stable carbon and nitrogen isotopes to reconstruct the diet of an arctic herbivore, here the muskox ( Ovibos moschatus (Zimmermann, 1780)), in northeast Greenland. The isotope composition of plant communities and functional plant groups was compared with those of muskox faeces and shed wool, as this is a noninvasive approach to obtain dietary information on different temporal scales. Plants with different root mycorrhizal status were found to have different δ15N values, whereas differences in δ13C, as expected, were less distinct. As a result, our examination mainly relied on stable nitrogen isotopes. The interpretation of stable isotopes from faeces was difficult because of the large uncertainty in diet–faeces fractionation, whereas isotope signatures from wool suggested that the muskox summer diet consists of around 80% graminoids and up to 20% willows. In conclusion, the diet composition of an arctic herbivore can indeed be inferred from stable isotopes in arctic areas, despite the lack of C4 plants.
36
Golyshev, S. I., P. N. Sobolev, N. L. Padalko, S. I. Dykhan, P. F. Yavorov, M. I. Prazdnichnykh, and E. V. Chernikov. "FEATURES OF THE CARBON ISOTOPE COMPOSITION OF ORGANIC MATTER AND CARBON AND OXYGEN CARBONATE CONSTITUENT OF OIL AND GAS PRODUCING DEPOSITS OF THE CAMBRIAN OF THE SIBERIAN PLATFORM." Geology and mineral resources of Siberia, no. 2 (2023): 10–22. http://dx.doi.org/10.20403/2078-0575-2023-2-10-22.
Анотація:
The paper presents data on the carbon (δ13С) and oxygen (δ18О) isotopic composition of the carbonate rock constituent (CRC) and carbon (δ13C) of dispersed organic matter (SOM) of rocks of the Shumnaya, Inikan and Kuonamka Formations of the Lower-Middle Cambrian of the Siberian Platform. Dependence of the carbon and oxygen isotopic composition of CRC on the facies subtype of domanicoid deposits of the Cambrian was revealed. The interrelation of the carbon isotope composition of DOM with depositional conditions of sediments of the Lower and Middle Cambrian was considered. In the south-east of the Siberian Platform, Lower Cambrian carbonate deposits with carbon anomalous isotopic composition of CRC (δ13Сср = 6,6 ‰) and carbon of DOM (δ13С = –36,5 ‰) were found.
37
Hüls, C. M., H. Erlenkeuser, M.-J. Nadeau, P. M. Grootes, and N. Andersen. "Experimental Study on the Origin of Cremated Bone Apatite Carbon." Radiocarbon 52, no. 2 (2010): 587–99. http://dx.doi.org/10.1017/s0033822200045628.
Анотація:
Bones that have undergone burning at high temperatures (i.e. cremation) no longer contain organic carbon. Lanting et al. (2001) proposed that some of the original structural carbonate, formed during bioapatite formation, survives. This view is based on paired radiocarbon dating of cremated bone apatite and contemporary charcoal. However, stable carbon isotope composition of carbonate in cremated bones is consistently light compared to the untreated material and is closer to the δ13C values seen in C3 plant material. This raises the question of the origin of carbonate carbon in cremated bone apatite. That is, does the isotope signal reflect an exchange of carbon with the local cremation atmosphere and thus with carbon from the burning fuel, or is it caused by isotopic fractionation during cremation?To study the changes in carbon isotopes (14C, 13C) of bone apatite during burning up to 800 °, a modern bovine bone was exposed to a continuous flow of an artificial atmosphere (basically a high-purity O2/N2 gas mix) under defined conditions (temperature, gas composition). To simulate the influence of the fuel carbon available under real cremation conditions, fossil CO2 was added at different concentrations. To yield cremated bone apatite properties similar to archaeological cremated bones, in terms of crystallographic criteria, water vapor had to be added to the atmosphere in the oven. Infrared vibrational spectra reveal large increases in crystal size and loss of carbonate upon cremation. The isotope results indicate an effective carbon exchange between bone apatite carbonate and CO2 in the combustion gases depending on temperature and CO2 concentration. 14C dates on archaeological cremated bone apatite may thus suffer from an old-wood effect. Paired 13C and 14C values indicate that in addition to this exchange, isotope fractionation between CO2 and carbonate, and admixture of carbon from other sources such as possibly collagen or atmospheric CO2, may play a role in determining the final composition of the apatite carbonate.
38
Doi, Hideyuki, Eisuke Kikuchi, Shigeto Takagi, and Shuichi Shikano. "Spatio-temporal stable isotope variation of a benthic primary consumer in a simple food web in a strongly acidic lake." PeerJ 7 (October 11, 2019): e7890. http://dx.doi.org/10.7717/peerj.7890.
Анотація:
Analysis of aquatic food webs is typically undertaken using carbon and nitrogen stable isotope composition of consumer and producer species. However, the trophic consequences of spatio-temporal variation in the isotope composition of consumers have not been well evaluated. Lake Katanuma, Japan, is highly acidic and has only one dominant species of benthic alga and one planktonic microalga, making it a prime system for studying trophic relationships between primary consumers and producers. In this simple lake food web, we conducted a field survey to evaluate spatial and temporal variation in the carbon and nitrogen stable isotope composition of a chironomid larvae in association with a single benthic and planktonic alga. We found a significant correlation between carbon stable isotope ratios of the chironomid larvae and the benthic diatom species in the lake. Thus, chironomid larvae may represent a reliable isotopic baseline for estimating isotope values in benthic diatoms. However, although the correlation held in shallow water, at four m depths, there was no significant relationship between the isotope ratios of chironomids and benthic diatoms, probably because deep-water larvae spend part of their life cycle migrating from the lake shore to deeper water. The differing isotope ratios of deeper chironomid tissues likely reflect the feeding history of individuals during this migration.
39
Dobrovolskaya, Maria, Natalia Svirkina, Sergey Yazikov, and Alexey Sviridov. "The Lifestyle of Children and Adults in the Barbarian Environ of Chersonesos (Based on Materials from Frontovoe 3 and Kil-Dere 1 Necropolises)." Stratum plus. Archaeology and Cultural Anthropology, no. 4 (August 29, 2023): 139–54. http://dx.doi.org/10.55086/sp234139154.
Анотація:
The necropolises Frontovoe 3 and Kil-Dere 1 from the environ of Chersonesos are interesting and important for the reconstruction of the cultural and historical situation on the borders of the Roman Empire. Data on the isotopic composition of bone collagen and tooth enamel provide new opportunities to discuss the nutrition, economy, and mobility of societies. The isotope composition of carbon and nitrogen informs about the average dietary intake of an individual over the last few years of life (7—10), while the ratio of strontium isotopes in tooth enamel characterizes the habitat of the child during the formation of the crown of the teeth (in this case, from 1 to 6 years). Thus, we obtain information about local natives and migrants of the first generation, whose childhood, probably, passed outside the environ of Chersonesos. The isotopic composition of carbon and nitrogen in 67 samples of bone tissue and the composition of strontium in 35 samples of tooth enamel were studied. The life support system of these societies was based on the use of local terrestrial food resources. Few individuals have been found who can be named first-generation migrants. The low variability of the isotope ratios of strontium and carbon indicates a clear localization of this population group on the given territory. We also discuss the factors behind the differences in the isotopic markers of groups from Kil-Dere 1 and Frontovoye 3. These can be both environmental factors and cultural differences. The questions addressed here can be answered by studying a broader base of the compared materials.
40
Galimov, E. M. "Carbon isotope composition of Antarctic plants." Geochimica et Cosmochimica Acta 64, no. 10 (May 2000): 1737–39. http://dx.doi.org/10.1016/s0016-7037(99)00328-2.
41
Peck, William H., Erin E. Cummings, and Ellis Van Slyke. "Carbon isotope composition of birch syrup." Journal of Food Composition and Analysis 71 (August 2018): 25–27. http://dx.doi.org/10.1016/j.jfca.2018.04.012.
42
Chernodoubov D. A. and Inyushkin A. V. "SiC thermal conductivity: calculation of the isotope effect from first principles." Physics of the Solid State 65, no. 6 (2023): 1031. http://dx.doi.org/10.21883/pss.2023.06.56120.62.
Анотація:
The thermal conductivity temperature dependence kappa(T) of a hexagonal 2H-SiC silicon carbide crystal was calculated using the first-principle approach for the orientation of the heat flux in the basal plane and along the hexagonal axis c in the temperature range from 100 to 500 K. The effect of silicon and carbon isotopic disorder on thermal conductivity is considered. It was found that, at a temperature of 300 K, the thermal conductivity of isotopically pure 2H-SiC containing 100% 28Si and 100% 12C is higher by 15.2% and 12.4% for directions along and across the basal plane, respectively, than that of crystals with a natural composition of silicon and carbon isotopes. For crystals with a natural mixture of carbon isotopes textnatC, the isotope effect for silicon is 14.5% and 11.9% for these directions. Keywords: single crystal, thermal conductivity, silicon carbide, first principle calculation.
43
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.
Анотація:
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.
44
Krumins, Janis, Maris Klavins, Raimonds Krukovskis, Arturs Viksna, and Lauma Busa. "THE EVALUATION OF STABLE ISOTOPIC RATIOS 13C AND 15N IN HUMIC ACIDS ALONG A FEN PEAT PROFILE." ENVIRONMENT. TECHNOLOGIES. RESOURCES. Proceedings of the International Scientific and Practical Conference 1 (June 20, 2019): 123. http://dx.doi.org/10.17770/etr2019vol1.4127.
Анотація:
Mires are known as consistent environmental archives, but humic acids are the fraction of peat that is most recalcitrant and refractory to organic matter degradation, thus data on environmental changes during mire development can be recorded into them. This work was focused on the studies of stable isotopic ratios delta carbon-13 and delta nitrogen-15, and their distribution in humic acids within fen peat layers of different depths and peat composition. The variations in delta carbon-13 reflect isotopic variations in peat-forming plants over time and can be considered as a function of photosynthetic pathway that is being used to fix carbon dioxide. At the same time, variations in delta nitrogen-15 show nitrogen fixation in peat-forming plants and can be traced along with peat decomposition degree and depth. Properties of humic acids were studied in 2018 at 3 fens located in Latvia and Southern Finland, and comparatively they show properties. The method used for the determination of stable isotopes was the isotope-ratio mass spectrometry that was performed in the Faculty of Chemistry, University of Latvia. Results on delta carbon-13 indicate signal of C3 peat-forming plants, while signal of C4 peat-forming plants is not evident, which can be explained by non-efficient carbon dioxide fixation in fen vegetation. Results on delta nitrogen-15 show variations in nitrogen fixation in fen vegetation. Data show nitrogen fixation in terrestrial plants, however significant shifts in absolute isotope values indicate dependence on variations in peat decomposition degree and botanical composition. Data suggest that differences in peat botanical composition, decomposition degree and site dependent characteristics reflect in differences in delta carbon-13 and delta nitrogen-15 variations
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Zhuravlev, Andrey. "Numerical modelling of primary bioproductivity of the Palaeozoic pelagic ecosystems." Vestnik of geosciences, no. 8 (November 10, 2022): 38–43. http://dx.doi.org/10.19110/geov.2022.8.4.
Анотація:
The article considers an approach to the reconstruction of the bioproductivity of Palaeozoic pelagic ecosystems based on the numeric modelling of the carbon isotope fractionation. The model uses information on the carbon dioxide content in atmosphere, water temperature, and carbon isotopic composition of carbonates and conodont elements. The developed model is tested on the material from the Upper Devonian — Lower Carboniferous of the northern Cis-Urals (successions of carbonate platform and slope of intrashelf depression). It allows reconstructing of the primary productivity of the Palaeozoic pelagic ecosystems and their dynamics on the basis of limited data. The results of the modelling are considered as rather qualitative than quantitative. The carbon isotope composition of total organic carbon was used for controlling the quality of the model.
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Strauss, Harald, Stefan Bengtson, Paul M. Myrow, and Gonzalo Vidal. "Stable isotope geochemistry and palynology of the late Precambrian to Early Cambrian sequence in Newfoundland." Canadian Journal of Earth Sciences 29, no. 8 (August 1, 1992): 1662–73. http://dx.doi.org/10.1139/e92-131.
Анотація:
A sequence of clastic sediments in southeastern Newfoundland straddling the Precambrian–Cambrian boundary has been investigated for its stable isotope geochemistry of carbon and sulfur and acid-resistant organic-walled microfossils. A detailed study of the Chapel Island Formation, which includes the boundary interval, has revealed fluctuations in the isotopic composition of organic carbon. These are largely interpreted as caused by differences in the depositional environments. Highly variable sulfur isotopic compositions indicate bacterial sulfate reduction as a pyrite-forming process, sometimes under sulfate-limited conditions. Palynological results are quite limited with respect to diagnostic microfossils.
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Kelly, Jeffrey F. "Stable isotopes of carbon and nitrogen in the study of avian and mammalian trophic ecology." Canadian Journal of Zoology 78, no. 1 (February 28, 2000): 1–27. http://dx.doi.org/10.1139/z99-165.
Анотація:
Differential fractionation of stable isotopes of carbon during photosynthesis causes C4 plants and C3 plants to have distinct carbon-isotope signatures. In addition, marine C3 plants have stable-isotope ratios of carbon that are intermediate between C4 and terrestrial C3 plants. The direct incorporation of the carbon-isotope ratio (13C/12C) of plants into consumers' tissues makes this ratio useful in studies of animal ecology. The heavy isotope of nitrogen (15N) is preferentially incorporated into the tissues of the consumer from the diet, which results in a systematic enrichment in nitrogen-isotope ratio (15N/14N) with each trophic level. Consequently, stable isotopes of nitrogen have been used primarily to assess position in food chains. The literature pertaining to the use of stable isotopes of carbon and nitrogen in animal trophic ecology was reviewed. Data from 102 studies that reported stable-isotope ratios of carbon and (or) nitrogen of wild birds and (or) mammals were compiled and analyzed relative to diet, latitude, body size, and habitat moisture. These analyses supported the predicted relationships among trophic groups. Carbon-isotope ratios differed among species that relied on C3, C4, and marine food chains. Likewise, nitrogen-isotope ratios were enriched in terrestrial carnivorous mammals relative to terrestrial herbivorous mammals. Also, marine carnivores that ate vertebrates had nitrogen-isotope ratios that were enriched over the ratios of those that ate invertebrates. Data from the literature also indicated that (i) the carbon-isotope ratio of carnivore bone collagen was inversely related to latitude, which was likely the result of an inverse relationship between the proportion of carbon in the food chain that was fixed by C4 plants and latitude; (ii) seabirds and marine mammals from northern oceans had higher nitrogen-isotope ratios than those from southern oceans; (iii) the nitrogen-isotope ratios of terrestrial mammals that used xeric habitats were higher than the ratios of those that used mesic habitats, indicating that water stress can have important effects on the nitrogen-isotope ratio; (iv) there was no relationship between body mass and nitrogen-isotope ratio for either bone collagen or muscle of carnivores; and (v) there was linear covariation between stable-isotope ratios of carbon and nitrogen in marine food chains (but not in terrestrial C3 or C4 food chains), which is likely a product of increases in carbon-isotope ratio with trophic level in marine food chains. Differences in stable-isotope composition among trophic groups were detected despite variation attributable to geographic location, climate, and analytical techniques, indicating that these effects are large and pervasive. Consequently, as knowledge of the distribution of stable isotopes of carbon and nitrogen increases, they will probably become an increasingly important tool in the study of avian and mammalian trophic ecology.
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Colonese, André C., Giovanni Zanchetta, Catherine Perlès, Russell N. Drysdale, Giuseppe Manganelli, Ilaria Baneschi, Elissavet Dotsika та Hélène Valladas. "Deciphering late Quaternary land snail shell δ18O and δ13C from Franchthi Cave (Argolid, Greece)". Quaternary Research 80, № 1 (липень 2013): 66–75. http://dx.doi.org/10.1016/j.yqres.2013.03.006.
Анотація:
This paper investigates the stable isotopic composition from late Pleistocene–Holocene (~ 13 to ~ 10.5 cal ka BP) shells of the land snail Helix figulina, from Franchthi Cave (Greece). It explores the palaeoclimatic and palaeoenvironmental implications of the isotope palaeoecology of archaeological shells at the time of human occupation of the cave. Modern shells from around the cave were also analysed and their isotopic signatures compared with those of the archaeological shells. The carbon isotope composition of modern shells depicts the consumption of C3 vegetation. Shell oxygen isotopic values are consistent with other Mediterranean snail shells from coastal areas. Combining empirical linear regression and an evaporative model, the δ18Os suggest that modern snails in the study area are active during periods of higher relative humidity and lower rainfall δ18O, probably at night. Late glacial and early Holocene δ18Os show lower values compared to modern ones. Early Holocene δ18Os values likely track enhanced moisture and isotopic changes in the precipitation source. By contrast, lower late glacial δ18O could reflect lower temperatures and δ18Op, compared to the present day. Shell carbon isotope values indicate the presence of C3 vegetation as main source of carbon to late glacial and early Holocene snails.
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Hesslein, R. H., K. A. Hallard та P. Ramlal. "Replacement of Sulfur, Carbon, and Nitrogen in Tissue of Growing Broad Whitefish (Coregonus nasus) in Response to a Change in Diet Traced by δ34S, δ13C, and δ15N". Canadian Journal of Fisheries and Aquatic Sciences 50, № 10 (1 жовтня 1993): 2071–76. http://dx.doi.org/10.1139/f93-230.
Анотація:
We monitored the change in the isotope composition of sulfur, carbon, and nitrogen in broad whitefish (Coregonus nasus) tissues in response to a change in the isotope composition of their food. One of two batches of 2.5-yr-old fish raised in the laboratory were given a new food source with different δ34S, δ13C, and δ15N, which were monitored in muscle and liver tissue for 1 yr. A model including change due to tissue accumulation (growth) and metabolic replacement was developed. For all three isotopes, most of the change could be attributed to growth. Metabolic replacement expressed as a turnover rate was only 0.1 −0.2%∙d−1 and was similar for the three isotopes. Although liver tissue was −4.4 and −4.1‰, respectively, for δ34S and δ13C relative to muscle tissue, the response over time to the new food was the same as for muscle. We expect that the complete change in the isotope composition of fish tissue in response to a change in food could take years in slow-growing wild populations. The stable isotope composition would represent a long-term average of the food. In fast-growing fish the rate of change would directly reflect the growth rate.
50
Gromov, S., P. Jöckel, R. Sander, and C. A. M. Brenninkmeijer. "A kinetic chemistry tagging technique and its application to modelling the stable isotopic composition of atmospheric trace gases." Geoscientific Model Development 3, no. 2 (August 10, 2010): 337–64. http://dx.doi.org/10.5194/gmd-3-337-2010.
Анотація:
Abstract. Isotope composition, in many cases, holds unique information on the sources, chemical modification and sinks of atmospheric trace gases. Vital to the interpretation and use of an increasing number of isotope analyses is appropriate modelling. However, the exact implementation of isotopic information in chemistry-climate models is a challenge, and often studies use simplifications which limit their applicability. Here we implement a thorough isotopic extension in MECCA, a comprehensive kinetic chemistry sub-model. To this end, we devise a generic tagging technique for the kinetic chemistry mechanisms implemented as the sub-submodel MECCA-TAG. The technique is diagnostic and numerically efficient and supports the investigation of various aspects of kinetic chemistry schemes. We focus specifically on the application to the modelling of stable isotopic composition. The results of MECCA-TAG are evaluated against the reference sub-submodel MECCA-DBL, which is implicitly full-detailed, but computationally expensive and thus sub-optimal in practical applications. Furthermore, we evaluate the elaborate carbon and oxygen isotopic mechanism by simulating the multi-isotope composition of CO and other trace gases in the CAABA/MECCA box-model. The mechanism realistically simulates the oxygen isotope composition of key species, as well as the carbon isotope signature transfer. The model adequately reproduces the isotope chemistry features for CO, taking into account the limits of the modelling domain. In particular, the mass-independently fractionated (MIF) composition of CO due to reactions of ozone with unsaturated hydrocarbons (a source effect) versus its intrinsic MIF enrichment induced in the removal reaction via oxidation by OH is assessed. The simulated ozone source effect was up to +1‰ in Δ17O(CO). The versatile modelling framework we employ (the Modular Earth Submodel System, MESSy) opens the way for implementation of the novel detailed isotopic chemistry treatment in the three-dimensional atmospheric-chemistry general circulation model EMAC. We therefore also present estimates of the computational gain obtained by the developed optimisations.