Coral Sr thermometer simplified from Sr/Ca thermometer

摘要

Cubic sub-samples obtained from a Porites coral slice collected from Xisha Islands, South China Sea, were weighed with precise micro-balance. The Sr and Ca concentrations were analyzed with isotope dilution thermal Ionization mass spectrometry. Our results demonstrate that Ca concentrations in all samples are very uniform (mean= 9.52mmol/g, 2σ=0.02mmol/g); Sr concentrations and Sr/Ca ratios are well correlated (correlation coefficient r = 0.9968). It implies that the Sr thermometer can replace Sr/Ca thermometer and the determination of Ca can be omitted. This can save up to 50/100 time and cost, and more importantly, paleoclimate study using coral proxy can now be carried Out in routine Sr isotope laboratories