Dating late Quaternary planktonic foraminifer Neogloboquadrina pachyderma from the Arctic Ocean using amino acid racemization

• Published in: Paleoceanography
• Main Authors: Kaufman, Darrell S., Polyak, Leonid, Adler, Ruth, Channell, James E. T., Xuan, Chuang
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2008
• Subjects: GE Environmental Sciences; Arctic; Arctic Ocean; Climate change; Foraminifera*; Neogloboquadrina pachyderma; Planktonic foraminifera
• Online Access: http://openknowledge.nau.edu/1800/; http://openknowledge.nau.edu/1800/1/Kaufman_D_etal_2008_dating_late_quaternary_planktonic.pdf; https://doi.org/10.1029/2008PA001618

The long-term rate of racemization for amino acids preserved in planktonic foraminifera was determined by using independently dated sediment cores from the Arctic Ocean. The racemization rates for aspartic acid (Asp) and glutamic acid (Glu) in the common taxon, were calibrated for the last 150 ka using 14C ages and the emerging Quaternary chronostratigraphy of Arctic Ocean sediments. An analysis of errors indicates realistic age uncertainties of about ±12% for Asp and ±17% for Glu. Fifty individual tests are sufficient to analyze multiple subsamples, identify outliers, and derive robust sample mean values. The new age equation can be applied to verify and refine age models for sediment cores elsewhere in the Arctic Ocean, a critical region for understanding the dynamics of global climate change.