Protactinium-231 dating of carbonates by thermal ionization mass spectrometry: Implications for quaternary climate change

Measurement of protactinium-231 (²³¹Pa) in carbonates by thermal ionization mass spectroscopy yields ²³¹Pa ages that are more than 10 times more precise than those determined by decay counting. Carbonates between 10 and 250,000 years old can now be dated with ²³¹Pa methods. Barbados corals that have identical ²³¹Pa and thorium-230 (²³⁰Th) ages indicate that the timing of sea level change over parts of the last glacial cycle is consistent with the predictions of the Astronomical Theory. Two Devils Hole calcite subsamples record identical ²³¹Pa and ²³⁰Th ages, suggesting that the chronology of this climate record is accurate.