CHANGES IN THE DEPOSITIONAL FLUX OF BE-10 IN THE ORCA BASIN, GULF OF MEXICO - INVERSE CORRELATION WITH DELTA-O-18

We report a statistically significant negative correlation between the concentration (and the deposition rate) of the cosmogenic radionuclide Be-10 and delta-O-18 (of Globigerinoides ruber) in the sediments deposited in the anoxic Orca Basin (OB) of the Gulf of Mexico during the past approximately 20 ka. Possible causes for this finding consecutively include: (1) enrichment of Be-10 in the soils/easily erodable crustal material which were discharged into the OB during the Late Wisconsin Interglacial; (2) introduction of significant amounts of Be-10 into the oceans due to the melting of continental ice sheets resulting in the enrichment of the radionuclide in the sediments deposited during that time; and (3) generation of a focussing effect resulting in the Be-10 enrichment of the OB sediment.