Barium , foraminiferal

Lea D. W. (1993) Constraints on the alkalinity and circulation of glacial circumpolar deep water from benthic foraminiferal barium. Global Biogechem. Cycles 7, 695 -710. 

Lea D. W. and Boyle E. A. (1990) Foraminiferal reconstmc-tions of barium distributions in water masses of the glacial oceans. Paleoceanography 5, 719-742. 

Event III (65.9 Ma ago) entailed the gradual return of the surface-to-deep water carbon isotope signal, a slight increase in barium accumulation rates and a gradual decline in planktonic foraminiferal accumulations. This implies that surface water productivity started rising about 0.5 Ma after the Cretaceous/Tertiary Boundary event. Temperature fluctuations of several degrees Celsius are inferred from variations in nannofossil and foraminferal values. 

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