Geochemistry of foraminifera from sediment cores of the central California margin ...

• Main Authors: van Geen, Alexander, Fairbanks, Richard G, Dartnell, Peter, McGann, Mary L, Gardner, James V, Kashgarian, Michaele
• Format: Article in Journal/Newspaper
• Language: English
• Published: PANGAEA 1996
• Subjects: Piston corer; Lamont-Doherty Earth Observatory, Columbia University LDEO; Fairbanks; Gardner; Pacific; North Atlantic; Planktonic foraminifera
• Online Access: https://dx.doi.org/10.1594/pangaea.729962; https://doi.pangaea.de/10.1594/PANGAEA.729962

Under present climate conditions, convection at high latitudes of the North Pacific is restricted to shallower depths than in the North Atlantic. To what extent this asymmetry between the two ocean basins was maintained over the past 20 kyr is poorly known because there are few unambiguous proxy records of ventilation from the North Pacific. We present new data for two sediment cores from the California margin at 800 and 1600 m depth to argue that the depth of ventilation shifted repeatedly in the northeast Pacific over the course of deglaciation. The evidence includes benthic foraminiferal Cd/Ca, 18O/16O, and 13C/12C data as well as radiocarbon age differences between benthic and planktonic foraminifera. A number of features in the shallower of the two cores, including an interval of laminated sediments, are consistent with changes in ventilation over the past 20 kyr suggested by alternations between laminated and bioturbated sediments in the Santa Barbara Basin and the Gulf of California [Keigwin and ... : Supplement to: van Geen, Alexander; Fairbanks, Richard G; Dartnell, Peter; McGann, Mary L; Gardner, James V; Kashgarian, Michaele (1996): Ventilation changes in the northeast Pacific during the last deglaciation. Paleoceanography, 11(5), 519-528 ...