Late pleistocene sea level change in the Bahamas from mass spectrometric U-series dating of submerged speleothem

The dating of sea level events by a method independent of orbital tuning techniques and the marine foraminiferal isotopic record provides a test of both the dating of the marine record and the strength and nature of the relationship between climatic change, sea level change and Milankovitch cycles. Dating of fossil corals and submerged speleothem provides such independent information.Results of thermal ionization mass spectrometric U-series dating on layers of flowstone speleothem from Lucayan Caverns, Grand Bahama Island indicate that multiple sea level events have passed through a depth of −10 to −15 m below modern sea level during the last 300,000 years. These data are used to constrain the magnitude and timing of sea-level fluctuations during the late Pleistocene. The new sea level curve constructed from these data correlates closely with the marine isotopic record: sea level peaks occurred at around 233, 215, 125 and 100 ka BP. There is no evidence at the depth from which this speleothem was retrieved of any high sea stands at 195 or 80 ka corresponding to the foraminiferal 7a and 5a oxygen isotope peaks. There is also no evidence of a double rise around the 125 ka (5e) peak, although such an oscillation could have occurred above −10 m leaving no record in the Lucayan Caverns speleothem.