BE-10 MELTWATER SIGNAL IN ORCA BASIN SEDIMENTS, GULF-OF-MEXICO

An increase in the cosmogenic beryllium-10 content of the Orca basin s ediments due to the flooding of the Gulf of Mexico (GM) by meltwaters during the late Wisconsin interglacial is reported. A strong negative correlation (gamma = -0.99) between delta(18)O (in the range of -1.5 p arts per thousand to +0.5 parts per thousand) and Be-10/Al ratio is se en. During intense flooding reflected by a decrease in delta(18)O by s imilar to 2 parts per thousand, this correlation may not hold as some of the sediments with low Be-10/Al ratio and deposited on the shelf an d slope regions of the GM during the earlier glacial period would also be washed into the basin. The deposited sediment would then be a mixt ure with a Be-10/Al ratio lower than expected from the correlation.