Isotopic values of oxygen oxygen or carbon isotopes. Medical search. Frequent questions

collected from nonpolluted northwest coast was higher as compared to the average δ15N contents (8.0‰ air) of Ulva from the Manora Channel, suggesting that nitrogen isotopic ratios of Ulva spp. (intechopen.com)
δ 15 N values and C/N ratios did not change in Symbiodinium and host tissue along the p CO 2 gradient. (nature.com)
Tree -ring carbon and oxygen isotope ratios from live and recently dead trees may reveal important mechanisms of tree mortality . (bvsalud.org)
A new study comparing the stable oxygen and carbon isotope ratios of giant land snails in New Zealand and New Caledonia found a surprising result. (massey.ac.nz)
New Zealand snails had, on average, higher oxygen isotope ratios values than their counterparts in New Caledonia, counter to the relative isotopic composition of rainwater between these two regions. (massey.ac.nz)
Most interesting are the dramatic drops in oxygen isotope ratios that seem to correspond to heavy rainfall - suggesting an opportunity to dig into the past to compare past precipitation with current frequency of wet weather events in New Zealand. (massey.ac.nz)
Very heavy rainfall events produce lower stable oxygen isotope ratios incorporated into the shells of the living-growing land snails. (massey.ac.nz)
We present the petrographic and chemical compositions of rocks and minerals of igneous rocks, the δ 13 С values of graphites and calcitites, the δ 18 O values of carbonates, the δ 34 S values of sulfides, and the 87 Sr/ 86 Sr and 87 Rb/ 86 Sr ratios in calcitites and microdolerite injections. (geoscienceworld.org)
In order to gain the best possible insight into the origins and formation of the niche in which we live, it is therefore important to determine such isotopic abundance ratios in as many members of the solar family as possible. (eso.org)
Measurements of isotopic ratios is an especially daunting undertaking, mainly because of the extreme weakness of the spectral signatures (emissions) of the less abundant species like carbon-13, nitrogen-15, etc. (eso.org)
Chemical separation and MC-ICPMS analysis of U, Th, Pa and Ra isotope ratios of carbonates. (uni-mainz.de)
The carbon you eat goes into your hair, so hair is a record of carbon ratios. (pnnl.gov)
This laboratory contains air flasks waiting to be sampled, a wall lined with tanks of standards, large metal containers of liquid nitrogen, and computers showing graphs of carbon isotope ratios. (noaa.gov)
Analysis of stable isotope ratios from mineralised tissue has been widely used for dietary reconstruction. (springer.com)

By making measurements of the volume, lattice spacing (how far the atoms are apart) and the isotopic composition of the silicon (which types of silicon atoms make up the crystal), the mass of the sphere can be determined and used to define the SI unit of mass. (npl.co.uk)
The carbon isotopic composition of carbonates from both sites shows an unusually wide variation, ranging from +9.7 ‰ to -55.9 ‰, which indicates a complex carbon source from both a 13 C-depleted and a residual, 13 C-enriched, carbon pool. (searchanddiscovery.com)
Reexamination of modern bryozoan isotopic composition shows that skeletons of Adeonellopsis spp. (tamu.edu)
The oxygen and hydrogen isotopic composition δ 2 H and δ 18 O of leaf and lake water reflects the isotopic composition of source water/precipitation modified by evapo(transpi)rative enrichment. (copernicus.org)
Oxygen and carbon isotopic composition of bulk carbonates were measured in sections at Kőris-hegy (Bakony Mts. (lu.se)
Concretions of authigenic minerals formed in the near sub-bottom sediments of the Paola Ridge were investigated for their geochemical and isotopic composition. (ac.bw)
In this study, we used stable isotopes (carbon and oxygen) of carbonates coupled with rare earth element (REE) composition of different carbonate and non-carbonate phases for tracing fluid composition and early diagenesis of authigenic precipitates. (ac.bw)
Authigenic calcite/aragonite concretions, from surficial sediments on diapiric structures, have depleted 13 C isotopic composition and slightly positive δ 18 O values. (ac.bw)
In 2009, the Commission on Isotopic Abundances and Atomic Weights (CIAAW) of the International Union of Pure and Applied Chemistry (IUPAC) introduced the interval notation to express the standard atomic weights of elements whose isotopic composition varies significantly in nature. (degruyter.com)
In the absence of detailed knowledge about the isotopic composition of a material, or when such details may safely be ignored, the probability distribution assigned to the standard atomic weight intervals may be taken as rectangular (or, uniform). (degruyter.com)
When information about the provenance of the material, or other information about the isotopic composition needs to be taken into account, then this distribution may be non-uniform. (degruyter.com)
Concerning the provision that the isotopic composition of a "normal" material should not have been modified significantly in a geologically brief period, John Böhlke (2015, personal communication) has pointed out that "high and low atomic weight values of light elements commonly are due to isotopic fractionation processes that are happening every day," as arise in respiration, evaporation, and dissolution. (degruyter.com)
The 2009 recommendation to use interval notation did achieve the valuable educational goal of drawing attention to the fact that isotopic composition can vary among natural materials, hence so do the atomic weights [ 8 ]. (degruyter.com)
Ideally, this proxy correlates with and only with the growth temperature of the crystal and does not require knowing the isotopic composition of the growth medium. (timescavengers.blog)
The isotopic composition of each CO 2 molecule determines its mass . (noaa.gov)
relative atomic mass of an element for gcse how to calculate the % composition of isotopes in an element given its arithmetical algebra. (schconsultores.com)
Edexcel, OCR 21st century, Gateway science GCSE 9-1 chemistry examinations, On other pages relative atomic mass calculations) A level AND all their isotopes are highly radioactive and most are at O level chemistry a good website for free questions on Calculations of % composition of isotopes. (schconsultores.com)

Stable isotopes of carbon (δ13C), sulfur (δ34S), oxygen (δ18O), hydrogen (δ2H), nitrogen (δ15N), and radioactive isotope of hydrogen (tritium) have been applied in combination with conventional techniques (chemical) to investigate Karachi coastal water pollution due to Layari and Malir rivers, which mainly carry the domestic and industrial wastewater of Karachi Metropolitan. (intechopen.com)
This session aims to bring together scientists from different fields applying single and dual oxygen and hydrogen isotope approaches on environmental-derived compounds for the reconstruction of climatic and biological processes that go beyond standard isotope analyses of water. (copernicus.org)
We also encourage people working with all techniques (IRMS-, NMR- or spectroscopy-based) to present advances in methods, as well as researchers focusing on improving oxygen and hydrogen isotope-based models to discuss their approaches. (copernicus.org)
In summary, the session will offer an overview on oxygen and hydrogen applications across different ecosystems in order to facilitate the interpretation of compound-specific isotope patterns. (copernicus.org)
A method for determining the 18O/16O ratio of organic matter composed of carbon, hydrogen, oxygen, and nitrogen is described. (eurekamag.com)
The [[standard atomic weight]]s of carbon, hydrogen, and oxygen are approximately 12.011 , 1.008 , and 15.999 g/mol respectively. (wikidoc.org)
John Dalton himself proposed a scale of masses in which hydrogen was 1, while J.J. Berzelius, perhaps one of the finest chemical scientists of the first half of the 19th century, proposed a scale with oxygen at 100. (spectroscopyonline.com)
At its 2009 meeting in Vienna, the IUPAC Commission on Isotopic Abundances and Atomic Weights (CIAAW) resolved to express the standard atomic weight of ten elements - including hydrogen, carbon, and oxygen - by means of intervals that characterize the span of their atomic-weight values in so-called "normal" materials. (degruyter.com)
Together with oxygen and hydrogen isotopes, which are strictly related to the climatic conditions (precipitation, temperature, humidity), the carbon, sulphur, strontium and boron signatures can describe the magnitude of rock weathering, which is in turn linked to the climatic parameters. (ufz.de)

Simulating speleothem growth in the laboratory: Determination of the stable isotope fractionation (d 13 C and d 18 O) between H 2 O, DIC and CaCO 3 . (uni-mainz.de)
Temperature-dependent fractionation of stable oxygen isotopes differs between cuttlefish statoliths and cuttlebones. (ntou.edu.tw)
The supply of carbon to the cell exerts a primary control on biological fractionation in coccolith calcite via the modulation of coccolithophore growth rate, cell size and carbon utilisation by photosynthesis and calcification, altogether accounting for the observed interspecific differences between coccolith species. (copernicus.org)
2021). Weathering fluid isotopic values are calculated using the published fractionation factors of Clayton & Epstein (1961), Yapp (1990) and Bao & Koch (1999). (nerc.ac.uk)
The authors have the most confidence in the fluid values obtained using the fractionation factor of Yapp (1990), for reasons outlined in the publication. (nerc.ac.uk)
This fractionation enables the use of stable nitrogen isotopes (δ 15 N) to infer trophic level, and high δ 15 N recorded in bone collagen usually indicates high-protein diets (Sponheimer et al. (springer.com)

Authigenic carbonates associated with cold seep chemosynthetic communities from both areas exhibit a wide range of mineral and stable isotopic compositions. (searchanddiscovery.com)
The purpose of this paper is to investigate dietary changes of A. viridis using isotopic compositions, particularly carbon source shifts in the anemone metabolism, in response to high p CO 2 /low pH conditions in situ . (nature.com)
The similar isotope compositions of calcitites (δ 13 С PDB = -22.5 to -23.5‰), coals (-22.6 to -25.5‰, n = 25), and graphites (-23.5 to -25.0) suggest that coal is a source of carbon for calcitites. (geoscienceworld.org)
In the isotopic compositions of strontium ( 87 Sr/ 86 Sr ≈ 0.70834-0.70885) and oxygen δ 18 O ≈ 15‰) the calcitites are similar to the Devonian evaporites of the Siberian Platform. (geoscienceworld.org)
To understand the source of CO2, gas samples were collected and their stable and radioactive carbon isotope compositions determined. (nerc.ac.uk)

The Staffin Bay data reveal a broad Early to Mid-Oxfordian positive carbon isotope excursion. (figshare.com)

The d 18 O values of the Eel River Basin carbonates vary between +3.2 ‰ and +6.6 ‰, pointing toward a heavy, 18 O-enriched oxygen source, possibly related to the decomposition of gas hydrate. (searchanddiscovery.com)
The wide range of isotopic and mineralogical variation in authigenic carbonates from both Monterey Bay and Eel River Basin demonstrates that these parameters alone are not indicative for certain tectonic settings. (searchanddiscovery.com)
A total of 40 samples from carbonates and 8 samples from silicate rocks were analyzed from the Sangan iron skarn deposit to examine behavior of the oxygen and carbon isotopes. (ac.ir)
Metabolic proxy for cephalopods: Sable carbon isotope values recorded in different biogenic carbonates. (ntou.edu.tw)

The Mid-Oxfordian negative carbon isotope excursions identified in published Tethyan records and commonly attributed to methane release are not recorded in the Staffin Bay data, which may suggest that the Tethyan excursions do not represent fluctuations in the global carbon reservoir and that the fidelity of the methane hypothesis should be re-evaluated. (figshare.com)
In each of the studied sections, an abrupt negative carbon isotope shift is recorded at the TJB, and a gradual rebound to more positive values characterizes the lowermost Jurassic strata. (lu.se)

The gradual decrease of the ?18O and ?13C values from metamorphic calcite to skarn calcite and dolomite can be ascribed to interaction of hydrothermal fluids with carbonate rocks in the area with an increase of water to rock ratio. (ac.ir)
Here we present new carbonate sedimentological, stable isotope and cyclostratigraphic data from sections in the Transdanubian Range (Hungary) which capture. (lu.se)
Here we present new carbonate sedimentological, stable isotope and cyclostratigraphic data from sections in the Transdanubian Range (Hungary) which capture the termination of uppermost Triassic Dachstein Limestone and the onset of Hettangian (Early Jurassic) sedimentation following a hiatus. (lu.se)
We report new carbonate associated sulfate (CAS) sulfur isotope data derived from marine macrofossil shell material from a highly expanded high latitude Maastrichtian to Danian (69-65.5 Ma) succession located on Seymour Island, Antarctica. (nerc.ac.uk)
A vigorous assessment of CAS preservation using sulfate oxygen, carbonate carbon and oxygen isotopes and trace element data, suggests factors affecting preservation of primary seawater CAS isotopes in ancient biogenic samples are complex, and not necessarily linked to the preservation of original carbonate mineralogy or chemistry. (nerc.ac.uk)
These data were collected to study oxidative weathering processes in the Waiapu River catchment, New Zealand, with potential carbon release sourced from the oxidation of petrogenic organic carbon or carbonate dissolution coupled to the oxidation of sulfide minerals. (nerc.ac.uk)
My lab specializes is carbonate "clumped" isotopes. (timescavengers.blog)
Measuring clumped isotopes measures the abundance of carbon-13 and oxygen-18 bonded to each other throughout the crystal lattice of the calcium carbonate shells. (timescavengers.blog)

Stockwork deposits at Helvacibaba, Yunak and Kozagac, all in Konya, have slightly heavier delta13C and delta18O values indicating more involvement of atmospheric carbon dioxide (as bicarbonate in the circulating meteoric water) compared to those of Koyakci Tepe. (gla.ac.uk)
End-member-2 : represents carbon dioxide of atmospheric origin. (gla.ac.uk)
Presently forming hydromagnesite deposits at Saida lake, Yesilova, Burdur reflect such a carbon dioxide origin with of delta13C of ~+4‰PDB and delta18O of ~+36‰SMOW. (gla.ac.uk)
End-member-3 : represents the carbon dioxide of metamorphic origin. (gla.ac.uk)
Increasing carbon dioxide (CO 2 ) emissions drive ongoing ocean acidification (OA) and place marine ecosystems in a vulnerable state 1 . (nature.com)
We cannot see or taste carbon dioxide, one of the two main products of that combustion, the other being water vapour. (skepticalscience.com)
Once up there, one key difference between carbon dioxide and water vapour becomes critically important. (skepticalscience.com)
Carbon dioxide has no liquid state at the pressures encountered in Earth's atmosphere. (skepticalscience.com)
Instead, at normal atmospheric pressures, it sublimes from solid to gas at −78 °C. Solid carbon dioxide is also known as dry ice, but cannot form in the range of temperatures found within Earth's atmosphere, although it is produced industrially for various purposes. (skepticalscience.com)
So as opposed to water vapour, carbon dioxide is an example of a non-condensing gas: once up there it stays up there for a long time. (skepticalscience.com)
If you needed a smoking gun in order to accept the above, there is one: carbon dioxide derived from fossil fuel burning has a very distinct chemical fingerprint that is readily measurable in air samples. (skepticalscience.com)
The data deposit includes results from 12 experiments that reacted carbon dioxide, seawater and limestone as a method of CO2 sequestration (as xlsx files). (nerc.ac.uk)
2022, Chemical Geology: Capturing the short-term variability of carbon dioxide emissions from sedimentary rock weathering in a remote mountainous catchment, New Zealand. (nerc.ac.uk)
This was additionally done at a range of atmospheric carbon dioxide concentrations to simulate the effects of ocean acidification. (timescavengers.blog)
Spock is specifically designed for a much narrower purpose: to examine carbon (and oxygen) isotopes in atmospheric carbon dioxide. (noaa.gov)
Carbon dioxide comes in three different masses, depending on the isotopic makeup. (noaa.gov)
Spock measures these relative concentrations of the three main carbon dioxide isotopologues (molecules of the same material but with different isotopes in them) with molecular masses of 44, 45, or 46 within each air sample. (noaa.gov)
The isotopologues measured during stable isotope carbon dioxide mass spectrometry along with their relative abundances in the atmosphere. (noaa.gov)
For example, the formula for carbon dioxide is CO2. (schconsultores.com)

Before the middle-late Miocene EAIS/cooling shift, the benthic foraminiferal oxygen isotope record shows a brief but distinct negative excursion in the early middle Miocene that represents the most depleted values of the entire Neogene. (google.com)
MCIE: Monterey carbon isotope excursion. (google.com)
The excursion maximum occurs in the cordatum Zone (British Boreal ammonite zonation), although high values persist into the tenuiserratum Zone. (figshare.com)
In the Transdanubian Range, the initial carbon isotope excursion and at least the first part of the purported main carbon isotope excursion are not preserved due to the gap at the TJB. (lu.se)
During the early Paleocene (magnetochron C29R) a prominent negative excursion in seawater δ34S of 3-4‰ suggests that a global decline in organic carbon burial related to collapse in export productivity, also impacted the sulfur cycle via a significant drop in pyrite burial. (nerc.ac.uk)

Optical and radio measurements concern different molecules (CN and HCN, respectively), and this isotopic anomaly must be explained by some differentiation mechanism. (eso.org)
This method, which uses an ultraviolet laser developed as part of PNNL's Microbial Communities Initiative , permits spatially resolved carbon stable isotope measurements versus standard methods that produce average, bulk-type measurements. (pnnl.gov)
Stable isotope measurements are a valuable tool for unraveling physical, biological, and chemical processes, interactions, and mechanisms at scales ranging from the atmosphere to individual microorganism cells. (pnnl.gov)
This spreadsheet contains 21 oxygen isotope measurements for hematite and mixed hematite/goethite samples from the supergene profiles of the Spence and Cerro Colorado porphyry copper deposits in the Central Andes. (nerc.ac.uk)
ConclusionsThe study illustrated the practical value of sensor-based real-time measurements when linked with non-pharmaceutical policy intervention data. (sciencegate.app)
Instead, in vitro measurements provide an estimate of internally deposited iodine (both the stable and radioactive isotopes), utilizing techniques that measure iodine in body fluids, feces, or other human samples (Gautier 1983). (cdc.gov)

Fluorine F relative atomic mass of 10 Neon Ne relative relative isotopic mass & calculating relative atomic mass Above is typical periodic table used in GCSE science-chemistry specifications in calculating relative atomic mass of an element for gcse Trevor H. Lv 7. (schconsultores.com)

Natal origin and migration pathways of Mekong catfish ( Pangasius krempfi ) using strontium isotopes and trace element concentrations in environmental water and otoliths. (ntou.edu.tw)

These distributions, however, are not intended to reflect the natural variability of the abundances of the different isotopes in the earth's crust or in any other environment. (degruyter.com)

2011. 'Laser ablation isotope ratio mass spectrometry for enhanced sensitivity and spatial resolution in stable isotope analysis. (pnnl.gov)

These laboratory observations support the recent hypothesis from field observations that the appearance of interspecific vital effect in coccolithophores coincides with the long-term Neogene decline of atmospheric CO 2 concentrations and bring further valuable constraints by demonstrating a convergence of all examined species towards inorganic values at high p CO 2 regimes. (copernicus.org)

We performed petrographic, cathodoluminescence, electron-microprobe, and isotopic analyses of brachiopod shells from the Permian Kapp Starostin Formation in West Spitsbergen to reevaluate the >9 negative shift in 13 C and 18 O values reported in 1989 by M. Gruszczynski, S. Halas, A. Hoffman, and K. Malkowski. (tamu.edu)
The characterization of Neandertals' diets has mostly relied on nitrogen isotope analyses of bone and tooth collagen. (mpg.de)

Of particular interest is the unambiguous detection and measurement of the nitrogen-15 isotope. (eso.org)

The high quality of the data obtained of this moving 9th-magnitude object has permitted a determination of the cometary abundance of various elements and their isotopes [2] . (eso.org)
Knowledge of the abundance of the stable isotopes [2] of the light elements in different solar system objects provides critical clues to the origin and early evolution of these objects and of the system as a whole. (eso.org)
The averaging takes into account the natural abundance of, usually heavier, isotopes as well as the variation in their natural abundance in different places on earth. (wikidoc.org)
We are also able to measure the abundance of carbon-13 and oxygen-18 isotopes in the samples, which can also be used as proxies. (timescavengers.blog)
To calculate percentage abundance, we must first know the fractional abundance of each isotope. (schconsultores.com)

Here, we present the results of zinc (Zn), strontium (Sr), carbon (C), and oxygen (O) isotope and trace element ratio analysis measured in dental enamel on a Pleistocene food web in Gabasa, Spain, to characterize the diet and ecology of a Middle Paleolithic Neandertal individual. (mpg.de)

As applied to the Initiative, the enhanced sensitivity of the laser ablation measurement approach will be harnessed for measuring stable isotope content of nanogram amounts of RNA samples. (pnnl.gov)

From the stable carbon and oxygen isotopic signatures of the magnesite, hydromagnesite and calcite formations of western Turkey, three end-members can be distinguished End-member-1: represents the cryptocrystalline, vein-type of magnesite deposits. (gla.ac.uk)
Planktic foraminifera stable carbon and oxygen isotope records of IODP Hole 3. (eudat.eu)

To better understand the carbon cycling responses of Boreal Shield peatlands to meteorological conditions, we examined ecohydrological controls on CO 2 fluxes using the eddy covariance technique at a shallow peatland during the summer season for 5 years, from 2016-2020. (github.io)

In terms of isotopic signatures, physical features and geological environment, Saida's hydromagnesite deposits are comparable with the Miocene, lacustrine, sedimentary magnesite deposits elsewhere, perhaps especially to Bela-Stena in Serbia. (gla.ac.uk)

δ13C(TDIC) and δ34S contents of northwest coastal water were close to the values meant for normal seawater. (intechopen.com)
δ 13 C values for both algal symbionts ( Symbiodinium ) and host tissue of A. viridis became significantly lighter with increasing seawater p CO 2 . (nature.com)
There is no evidence of the direct influence of Deccan volcanism on the seawater sulfate isotopic record during the late Maastrichtian, nor of a direct influence by the Chicxulub impact itself. (nerc.ac.uk)

This is largely due to that when the molar mass and molecular mass are expressed in g/mol and u respectively they will almost always have similar but not identical numerical values. (wikidoc.org)
isotopically]] weighted averages, whereas the ''molecular mass'' is the mass of a single molecule consisting of well-defined isotopes. (wikidoc.org)
The confidence in the isotopic masses and resulting ''molecular masses'' are only limited by the accuracy of measurement of the invariable isotopic masses. (wikidoc.org)
Using molecular phylogenetic and stable isotopic analysis to identify species, geographical origin and production method of mullet roes. (ntou.edu.tw)
However, it has become apparent that additional guidance would be helpful on how representative values should be derived from these intervals, and on how the associated uncertainty should be characterized and propagated to cognate quantities, such as relative molecular masses. (degruyter.com)
This modeling choice is a reasonable and convenient default choice when a representative value of the atomic weight, and associated uncertainty, are needed in calculations involving atomic and relative molecular masses. (degruyter.com)

Climate change impacts accelerated carbon losses, where increased burn severity and burn rate reduced the carbon sink by 38% and 65%, respectively, by 2100. (github.io)
Separating isotopic impacts of karst and in-cave processes from climate variability using an integrated speleothem isotope-enabled forward model. (uni-mainz.de)
In particular, emphasis is given to a wide spectrum of isotope data (δ 18 O, δ 2 H, δ 13 C, δ 15 N, δ 34 S, 87 Sr/ 86 Sr, δ 11 B), which is considered useful for determining water origin as well as natural and anthropogenic impacts on riverine geochemistry. (ufz.de)

Sulfate salt melt was a source of heavy sulfur isotope (δ 34 S = 14.9-17.5‰) for sulfides and of calcium for calcitites. (geoscienceworld.org)
Recovery of the sulfur cycle to pre-extinction values occurs at the same time (∼320 kyrs) as initial carbon cycle recovery globally. (nerc.ac.uk)

Rather, these variations reflect local controls on the flux of carbon, such as faults, fluid conduits, the presence or absence of gas hydrate in the sediment, and the temporal evolution of the carbon reservoir. (searchanddiscovery.com)

Additionally, the human samples have higher stable isotope differences, in comparison with faunal samples, than would be expected within the food web, particularly for δ 13 C. This human bone collagen δ 13 C enrichment may reflect a diet rich in aquatic protein intake, which is also supported by δ 34 S archived in human and faunal samples, and the presence of oysters and cockles shells at the excavation. (springer.com)

This study is the first of its kind to analyse carbon, nitrogen and sulphur stable isotope data from skeletons of the eleventh-seventeenth centuries in Portugal. (springer.com)

We examined the natural variability of carbon and nitrogen isotopes in the symbiotic sea anemone Anemonia viridis to investigate dietary shifts (autotrophy/heterotrophy) along a natural p CO 2 gradient at the island of Vulcano, Italy. (nature.com)

The assignment of suitable probability distributions to the atomic weight intervals is consistent with the CIAAW's goal of emphasizing the variability of the atomic weight values in nature. (degruyter.com)

Present-day, hot-spring travertine (calcite) deposits at Pamukkale, Denizli, have the heaviest delta13C (~+6 %o,PDB) and extremely light delta13C (~+20‰SMOW) values and these values are probably the result of decarbonation and/or dissolution of limestone formations beneath travertines. (gla.ac.uk)
The higher values of ?18O are from metamorphic calcite and dolomite and lower ones are from granitic rocks. (ac.ir)
Although the ?18O and ?13C values of calcite and dolomite in marble yield the highest values in the Sangan deposit, they are still lower than those of normal marine limestone and dolomite, i.e., reflecting coupled decarbonation and infiltrative metasomatic effects. (ac.ir)
The ?18O and ?13C values of calcite from the Sangan deposit show a progressive, gradual depletion from least-altered marbles into proximal skarn. (ac.ir)
Carbon and Oxygen Isotopic Systematics in Calcite and Dolomite from the Sangan Iron Skarn Deposit, Northeastern Iran', Journal of Sciences, Islamic Republic of Iran , 21(3), pp. (ac.ir)
Boomeri, M. Carbon and Oxygen Isotopic Systematics in Calcite and Dolomite from the Sangan Iron Skarn Deposit, Northeastern Iran. (ac.ir)
By recreating a range of geologically relevant concentrations of dissolved inorganic carbon (DIC) in the laboratory, we demonstrate that the magnitude of the vital effects in both carbon and oxygen isotopes of coccolith calcite of multiple species relates to ambient DIC concentration. (copernicus.org)
Under high DIC levels, all the examined coccoliths exhibit significantly reduced isotopic offsets from inorganic calcite compared to the substantial vital effects expressed at low (preindustrial and present-day) DIC concentrations. (copernicus.org)

Although no gas hydrates have been detected in Monterey Bay sediments, heavy oxygen isotope values may indicate their presence in the past. (searchanddiscovery.com)
By contrast, siderite concretions, generally found within the first 6 m of sediments on the alleged mud volcanoes, yielded positive δ 13 C and δ 18 O values. (ac.bw)
Authigenic siderite, on the other hand, formed in the subseafloor, during periods of lower gas discharges under prolonged anoxic conditions within sediments in equilibrium with 13 C-rich dissolved inorganic carbon (DIC) and 18 O-rich water, likely related to methanogenesis and intermittent venting of deep-sourced CO 2 . (ac.bw)

Values are a composite of data previously reported by Shackleton et al. (eudat.eu)
Further details of the adjustment that was applied to the carbon isotope data can be found in the supplementary information to the manuscript. (eudat.eu)
The stable isotope data presented here significantly extend and expand upon previous isotopic investigations of the Middle to Late Jurassic interval. (figshare.com)
The isotope data (δ 34 S, δ 18 O, δ 13 С, and 87 Rb/ 86 Sr) point to the participation of the coal seam and anhydrite as sources of substance in the formation of calcitite and sulfide mineralization. (geoscienceworld.org)
However, few nitrogen isotope data have been recovered from bones or teeth from Iberia due to poor collagen preservation at Paleolithic sites in the region. (mpg.de)
Zinc Isotope Data. (mpg.de)
Carbon and Oxygen Isotope Data. (mpg.de)
Richards and Hedges 1999 ), especially when combined with carbon isotope data. (springer.com)

Spock is a highly precise isotope ratio mass spectrometer , which uses a magnetic field to separate and measure molecules of different masses (a measure of how much matter is in an object) by bending ions of different charges at different radii. (noaa.gov)

cellulose extraction and blue-stain fungus on retrospective studies of carbon and oxygen isotope variation in live and dead trees. (bvsalud.org)
Freshwater fish exhibit variation in δ 13 C depending on the ecosystem as freshwater plants have numerous sources of carbon, unlike terrestrial plants (Zohary et al. (springer.com)

In our contribution, we discuss the potential, the advances and the limitation of the coupled isotope approach based on leaf wax-derived n -alkane and hemicellulose-derived sugar biomarkers (δ 2 H n -alkanes - δ 18 O sugars ). (copernicus.org)

The significant figures in the standard atomic weights and thus the computed ''molar masses'' are often limited by the natural variations in the isotopic distributions and not necessarily by our ability to measure accurately. (wikidoc.org)
Because of advances in the accuracy of analytical methods, by the late 1800s, oxygen had been chosen as the fundamental basis of relative masses, and it was defined as 16 units. (spectroscopyonline.com)
By determining the relative concentrations of CO 2 molecules of different masses, Spock can find the isotopic ratio in the sample. (noaa.gov)

The δ 13 C values of the three plant species were significantly negatively correlated with soil water content. (xjegi.com)

Our results strongly suggest that the >9 isotopic shifts reported in Gruszczynski et al. (tamu.edu)

Of the three Cenozoic benthic foraminiferal oxygen isotope events pointed above, the middle Miocene positive shift of ~0.9‰ between ca. 14.5 and 12.7 Ma is generally interpreted to indicate major expansion and permanent establishment of the East Antarctic ice sheet (EAIS) accompanied by some effect of deepwater cooling. (google.com)
These early middle Miocene "warm" molluscan faunas in the North Pacific are replace by a relatively "cool" faunas, the timing of which likely corresponds to the deepwater EAIS/cooling oxygen isotope positive shift. (google.com)
Furthermore, the subsequent retreat of the "warm" molluscan faunas in the North Pacific and the worldwide benthic foraminiferal oxygen isotope positive shift after the MMCO require an effective decrease in the poleward heat transport and reorganization of the global thermal budget. (google.com)
The 13 C shift may reflect changes in global storage of organic carbon indicated by coal-volume changes in the Late Permian. (tamu.edu)
If these demographic changes persist as stands mature, a climate-driven increase in soil burn severity could shift forest structure from sparse-canopy stands, which dominate this region of the Siberian Arctic, to high density stands, with potential implications for carbon, energy, and water cycling. (nau.edu)

If you wanted to find a smoking gun with respect to human carbon emissions and their role in global warming, where would you look? (skepticalscience.com)

Physicists, using physical rather than chemical methods, used a mass scale based on 16 O, rather than the naturally existing isotopic blend of oxygen. (spectroscopyonline.com)

Carbon 14 only occurs in tiny traces - about one atom per gram of carbon is a ballpark figure. (skepticalscience.com)
Although the SI unit of weight is kilogram or kg, the atomic weight is often expressed in a non-SI unit called Dalton (Da or u) where 1 dalton means 1/12 of the mass of a single carbon 12 atom at reset. (indieseducation.com)
Atomic weight is different from atomic mass in that it refers to the most abundant isotopes in an element and it is directly addressed a single atom or isotopes. (indieseducation.com)
mass spectrometers can sort calculate the element's relative atomic mass. atomic mass of 35 Bromine Br relative atomic mass of 36 Krypton A balloon at 25.0 degree Celsius has a volume of 1.250L. Relative atomic mass = Mass of 1/12 of an atom of carbon-12 Mass of one atom of the element. (schconsultores.com)

The isotopic mass-balance calculations suggest the presence of magmatic water in the Sangan deposit. (ac.ir)
relative atomic mass calculations how to calculate the relative atomic mass The atomic mass listed for an element on the periodic table is an average mass of all known isotopes of that element. (schconsultores.com)

The correspondence between the marine and terrestrial records indicates a strong coupling of the ocean-atmosphere system and suggests that the total exchangeable carbon reservoir would have been affected at this time. (figshare.com)
That is about half of the terrestrial value (272). (eso.org)

These in vivo measurement techniques are commonly used to measure body burdens of iodine radioisotopes, but cannot be used to assess the stable isotope of iodine. (cdc.gov)

2022). A Neandertal dietary conundrum: insights provided by tooth enamel Zn isotopes from Gabasa, Spain. (mpg.de)

In Monterey Bay, d 18 O values range from +6.8 ‰ to -8.5 ‰ indicating the local presence of meteoric water. (searchanddiscovery.com)
form close to oxygen isotopic equilibrium with their ambient water. (tamu.edu)
Carbon and oxygen isotopes of cool-water bryozoans from the Great Australian Bight and their paleoenvironmental significance. (tamu.edu)
Water isotopes (δ¹⁸O) of firn core RID-75 from Roosevelt Island drilled in au. (eudat.eu)

These findings highlight how organic carbon burial drivers operated along a continuum in concert with microbial ecological changes, with antecedent, localized increases in primary production destabilizing carbon cycling and promoting the progressive marine deoxygenation leading to Oceanic Anoxic Event 2. (nature.com)

Anatomy3

Organisms12

Diseases3

Chemicals and Drugs41

Analytical, Diagnostic and Therapeutic Techniques and Equipment11

Phenomena and Processes30

Disciplines and Occupations2

Anthropology, Education, Sociology and Social Phenomena3

Technology, Industry, Agriculture1

Humanities1

Information Science1

Health Care10

Geographicals1

Ratios14

Composition17

Hydrogen9

Fractionation6

Compositions5

Positive carbon isotope excursion1

Carbonates4

Negative carbon isotope2

Carbonate8

Dioxide19

Excursion5

Measurements6

Relative isotopic1

Strontium isotopes1

Different isotopes1

Mass spectrometry1

Atmospheric1

Analyses2

Nitrogen-151

Abundance5

Trace element1

Harnessed for measur1

Stable carbon and oxygen2

Fluxes1

Signatures1

Seawater3

Molecular6

Impacts3

Sulfur2

Sediment1

Bone1

Skeletons1

Natural variability1

Variability1

Calcite8

Sediments3

Data8

Ratio mass1

Variation2

Biomarkers1

Masses3

Significantly1

Shifts1

Shift5

Emissions1

Methods1

Atom4

Calculations2

Terrestrial2

Measurement1

20221

Water4

Organic carbon burial1