Comparison of water mass changes in the deep tropical Atlantic derived from Cd/Ca and carbon isotope records: Implications for changing Ba composition of deep Atlantic water masses

Atlantic Deep Water contribution to this site are estimated by scaling the V30-49 Cd/Ca record to values of modem end-member water masses; these estim ates agree well with the relative structure and timing of circulation chang es in the eastern tropical Atlantic reconstructed from a delta(13)C record- based mixing model [Rqymo et al., 1997]. Temporal differences between V30-4 9 CdiCa and Ba/Ca records suggest that the Ba/Ca record reflects changes in circulation with an additional increase in the Ba composition of deep Atla ntic water masses during glacial episodes, possibly resulting from increase d productivity. Similarity between the delta(13)C andd Ba/C records suggest s that carbon isotopes in the deep glacial Atlantic also reflect productivi ty increases.