CD CA CHANGES IN A DEEP CAPE BASIN CORE OVER THE PAST 730,000 YEARS -RESPONSE OF CIRCUMPOLAR DEEP-WATER VARIABILITY TO NORTHERN-HEMISPHEREICE-SHEET MELTING/

A comparison of cadmium/calcium (Cd/Ca) records of benthic foraminifer a from a deep Cape Basin and a deep eastern equatorial Pacific core su ggests that over the past 400,000 years, the nutrient concentration of Circumpolar Deep Water (CPDW) has always been lower than that of the deep Pacific. The data further suggest that at the 100,000- and 23,000 -year orbital periods, the contribution of North Atlantic Deep Water t o CPDW is at a maximum during periods of ice growth and at a minimum d uring periods of ice decay. These results are not in agreement with re sults based on carbon isotope records of benthic foraminifera, which s uggest intervals of CPDW nutrient enrichment relative to the deep Paci fic and an approximately in-phase relationship between CPDW nutrient c oncentration and ice volume. Resolution of the apparent conflict betwe en delta(13)C and Cd/Ca data may provide important constraints on past deep-ocean circulation and nutrient variability.