Reconstruction of Phanerozoic climate using carbonate clumped isotopes and implications for the oxygen isotopic composition of seawater.

ABSTRACT: The oxygen isotope ratio ¹⁸O/¹⁶O (expressed as a δ¹⁸O_VSMOW value) in marine sedimentary rocks has increased by ~8‰ from the early Paleozoic to modern times. Interpretation of this trend is hindered by ambiguities in the temperature of formation of the carbonate, the δ¹⁸O_seawater, and the effects of postdepositional diagenesis. Carbonate clumped isotope measurements, a temperature proxy, offer constraints on this problem. This thermometer is thermodynamically controlled in cases where carbonate achieves an equilibrium internal distribution of isotopes and is independent of the δ¹⁸O of the water from which the carbonate grew; therefore, it has a relatively rigorous chemical-physics foundation and can be applied to s

SUBMITTER: Thiagarajan N 

PROVIDER: S-EPMC11388280 | biostudies-literature | 2024 Sep

REPOSITORIES: biostudies-literature