Estimating Cambro-Ordovician seawater temperature and isotopic composition using carbonate clumped isotope paleothermometry on calcitic and phosphatic fossils
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منابع مشابه
Carbonate clumped isotope constraints on Silurian ocean temperature and seawater Î ́18O
Much of what we know about the history of Earth’s climate derives from the chemistry of carbonate minerals in the sedimentary record. The oxygen isotopic compositions (dO) of calcitic marine fossils and cements have been widely used as a proxy for past seawater temperatures, but application of this proxy to deep geologic time is complicated by diagenetic alteration and uncertainties in the dO o...
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Isotope data from bulk carbonates, micrite, marine calcite cements, non-skeletal grains and brachiopods indicate deposition of a wide spectrum of warm to cold water carbonates during the Ordovician and the Jurassic. This isotopic interpretation is supported by warm to cold climatic models proposed for the Ordovician and the Jurassic. These carbonates formed during the Greenhouse mode (condition...
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We apply the carbonate clumped isotope thermometer (D47) to macrofossils from the Baculites compressus ( 73.5 Ma) and the Hoploscaphites nebrascensis ( 67 Ma) ammonite zones of the Western Interior Seaway (WIS) of North America, and nearby coeval terrestrial and open marine environments. The carbonate clumped isotope thermometer is based on a single-phase isotope exchange equilibrium that promo...
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Carbonate concretions can form as a result of organic matter degradation within sediments. However, the ability to determine specific processes and formation temperatures of particular concretions has remained elusive. Here, we employ concentrations of carbonate-associated sulfate (CAS), SCAS and clumped isotopes (along with more traditional approaches) to characterize the nature of concretion ...
متن کاملClumped isotope thermometry of carbonatites as an indicator of diagenetic alteration
We measure the clumped isotopic signature of carbonatites to assess the integrity of the clumped isotope paleothermometer over long timescales (10–10 years) and the susceptibility of the proxy to closed system re-equilibration of isotopes during burial diagenesis. We find pristine carbonatites that have primary oxygen isotope signatures, along with a Carrara marble standard, do not record clump...
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