The distribution of Ba in the ocean is similar to the refractory components, silica and alkalinity. Therefore reconstructions of Ba in ancient water masses based on the Ba content of foraminifera shells can be used to probe the circulation and chemistry of past oceans. Previous work has shown that the dramatically altered distribution of Ba in the glacial oceans ban be explained by climatically driven changes in ocean circulation. This research will 1) ascertain how faithfully planktonic and benthic foraminifera recorder seawater Ba via further core top studies as well as culturing of planktonic foraminifera to directly determine the uptake of Ba into their shells; 2) broaden and increase the detail of oceanic Ba measurements at the 18 kyr Glacial Maximum; 3) acquire a long (220 kyr) record of benthic Ba in the equatorial Pacific; and, 4) use planktonic Ba as a tracer of meltwater influx to the Gulf of Mexico at the last deglaciation.
