Bahamian speleothem reveals temperature decrease associated with Heinrich stadials

Temperature reconstructions across Heinrich stadials 1-3 are presented from an absolute-dated speleothem from Abaco Island in the Bahamas to understand the nature of climate change across these intervals in the subtropical Atlantic. The stalagmite carbonate record, dated by the U-Th geochronometry technique, includes higher delta O-18 and delta C-13 values within Heinrich stadials 1, 2, and 3 followed by rapid declines at the end of the stadials. To aid in the interpretation of these results, the delta O-18 of fluid inclusions associated with the Heinrich stadials were also analyzed. These measurements, which allowed for the relative influence of temperature and delta O-18 of precipitation to be distinguished, demonstrate minimal changes in the delta O-18 of fluid inclusions, suggesting that change's in the delta O-18 values of the speleothem carbonate associated with Heinrich stadials 1-3 are principally driven by an average similar to 4 degrees C temperature decrease, rather than a change in the delta O-18 of the rainfall (hence rainfall amount). These findings support previous work in the North Atlantic and are consistent with the climate response to a weakening of the Atlantic meridional overturning circulation. (C) 201 5 Elsevier B.V. All rights reserved.