Gabriel West, Darrell S. Kaufman, Francesco Muschitiello, Matthias Forwick, Jens Matthiessen, Jutta Wollenburg, Matt O'Regan
The dataset contains data on the extent of racemization and concentration of amino acids in well-dated foraminifera samples (0 – 227 ka) from the Yermak Plateau, Arctic Ocean. The data were used to test whether the extent of racemization of amino acids in two foraminifera species (Neogloboquadrina pachyderma and Cassidulina neoteretis) could be utilised to estimate sample ages.
All measurements were performed at the Amino Acid Geochronology Laboratory, Northern Arizona University in 2018.
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Citation
Gabriel West, Darrell S. Kaufman, Francesco Muschitiello, Matthias Forwick, Jens Matthiessen, Jutta Wollenburg, Matt O'Regan (2019) Amino acid racemization data from the Yermak Plateau, Arctic Ocean, 0 – 227 ka. Dataset version 1. Bolin Centre Database. https://doi.org/10.17043/west-2019-amino-acid-1
References
West, G., Kaufman, D. S., Muschitiello, F., Forwick, M., Matthiessen, J., Wollenburg, J., and O'Regan, M. (2019): Amino acid racemization in Quaternary foraminifera from the Yermak Plateau, Geochronology Discuss., in review. https://doi.org/10.5194/gchron-2019-5
Data description
The dataset contains amino acid racemization (D/L) data on planktic (Neogloboquadrina pachyderma) and benthic (Cassidulina neoteretis) foraminifera samples from sites on the Yermak Plateau.
Data are provided in one file containing nineteen data columns, in both xlsx and csv format. The data include extent of amino acid racemization (D/L) and concentration (pM/vial) for aspartic acid (Asp), glutamic acid (Glx), serine (Ser), screening criteria for rejected subsamples, number of foraminifera tests/vial used.
Data column headers: Lab ID (UAL), Ocean, Area, Core Core depth (m), Latitude (°N), Longitude (°E), Water depth (m), Genus, Species, Number of tests, Rejection criterion, DL Asp, DL Glu, DL Ser, L-Ser/L-Asp, Asp Concentration (pM/vial), Glu Concentration (pM/vial), Ser Concentration (pM/vial).
Rejection criteria are provided below the data table.
Abbreviations:
D/L = ratio of D and L isomers
Asp = aspartic acid
Glu = glutamic acid
Ser = serine
Comments
This study investigates racemization rates in foraminifera from three well-dated sediment cores taken from the Yermak Plateau during the 2015 TRANSSIZ Expedition on RV Polarstern. D and L isomers of the amino acids, aspartic acid (Asp) and glutamic acid (Glu), were separated in samples of the planktic foraminifera, Neogloboquadrina pachyderma and the benthic species, Cassidulina neoteretis to quantify the extent of racemization. In total, 241 subsamples were analysed, extending back to marine oxygen isotope stage (MIS) 7. Two previously published power functions, which relate the extent of racemization of Asp and Glu in foraminifera to sample age are revisited, and a comparison is made between the ages predicted by these calibrated age equations and independent geochronological constraints available for the cores. Our analyses reveal an excellent match between ages predicted by a global compilation of racemization rates for N. pachyderma, and confirm that a proposed Arctic-specific calibration curve is not applicable at the Yermak Plateau. These results generally support the rates of amino acid racemization (AAR) determined for other cold bottom water sites, and further highlight the anomalous nature of the purportedly high rate of racemization indicated by previous analyses of central Arctic sediments.