Sentences with phrase «on isotope composition»
Not exact matches
The ratio of oxygen isotopes in seawater depends on the water temperature; the value of this ratio at any point in evolutionary time is «frozen» into the chemical composition of certain marine fossils.
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The examination of the isotope composition of individual amino acids in the collagen shows that the bears lived on a strictly vegan diet.
They then performed chemical extraction on the samples to analyze the sulfur isotope compositions in order to estimate the chemistry of the global ocean.
Unlike previous methods, the clumped isotope paleothermometer technique does not rely on assumptions about the isotopic composition of seawater.
The difference between using DNA analysis and isotope tracking is a variation on the nature versus nurture debate: DNA records an organism's genetic inheritance, and isotopes reflect the composition of the environment in which it grows.
«We therefore had to use a different method, so we measured the composition of carbon isotopes — the ratio of protein and mineral content — in the fossilized sloth bones,» explains Bocherens, and he continues, «Our measurements show that Megatherium lived on an exclusively vegetarian diet.»
Isotopes of argon also show enrichment of the heavy isotope, matching previous estimates of atmosphere composition derived from studies of Martian meteorites on Earth.
However, there is no evidence, based on the HED meteorites, to suggest that Vesta is heterogeneous as all have the same oxygen isotope composition.
«It is based on a sophisticated statistical analysis of the isotope composition of sediment in old French wines.
Because different isotopes of water freeze at different rates at different temperatures, ice composition depends on the temperature at which it formed.
Isotope ratios are based on present day composition of sea water.
However, (1) this group's work on varved Finnish lake sediments continues, with analysis expanded to include additional characteristics, e.g. stable isotope composition.