Pore fluid constraints on deep ocean temperature and salinity during the last glacial maximum

Pore water records of delta O-18 and [Cl] from ODP Site 1063A on the Bermuda Rise constrain the change in seawater delta O-18 and salinity from the Last Glacial Maximum (LGM) to the Holocene to be 0.75+/-0.05 parts per thousand and 2.5+/-0.1% respectively. Coupled with a measured benthic foraminiferal delta O-18 change, this result means that bottom waters were 4.6+/-0.8 degreesC cooler than the Holocene at the LGM and therefore at or near the seawater freezing point. Coupled delta O-18 and chlorinity results give an extrapolated mean ocean LGM to Holocene change in delta O-18 of 0.95+/-0.09 parts per thousand. These data also constrain the past southern source deep-water salinity to be 35.76+/-0.04 psu, which is within error of the mean deep ocean value for this time.