TOC, TN, and sedimentary d15N and δ¹³C ratios of sediment core SO201-2-85

We present high-resolution records of sedimentary nitrogen (d15Nbulk) and carbon isotope ratios (d13Cbulk) from piston core SO201-2-85KL located in the western Bering Sea. The records reflect changes in surface nitrate utilization and terrestrial organic matter contribution in submillennial resoluti...

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Bibliographic Details
Main Authors: Riethdorf, Jan-Rainer, Thibodeau, Benoit, Ikehara, Minoru, Nürnberg, Dirk, Max, Lars, Tiedemann, Ralf, Yokoyama, Yusuke
Format: Dataset
Language:English
Published: PANGAEA 2016
Subjects:
AGE
Carbon
organic
total
Comment
DEPTH
sediment/rock
Element analyser isotope ratio mass spectrometer (EA-IRMS)
KALMAR II
Nitrogen
PC
Piston corer
Shirshov Ridge
SO201/2
SO201-2-85
Sonne
δ13C
organic matter
δ15N
Bering Sea
Greenland
Online Access:https://doi.pangaea.de/10.1594/PANGAEA.807383
https://doi.org/10.1594/PANGAEA.807383
Description
Summary:We present high-resolution records of sedimentary nitrogen (d15Nbulk) and carbon isotope ratios (d13Cbulk) from piston core SO201-2-85KL located in the western Bering Sea. The records reflect changes in surface nitrate utilization and terrestrial organic matter contribution in submillennial resolution that span the last 180 kyr. The d15Nbulk record is characterized by a minimum during the penultimate interglacial indicating low nitrate utilization (~62-80%) despite the relatively high export production inferred from opal concentrations along with a significant reduction in the terrestrial organic matter fraction (mterr). This suggests that the consumption of the nitrate pool at our site was incomplete and even more reduced than today (~84%). d15Nbulk increases from Marine Isotope Stage (MIS) 5.4 and culminates during the Last Glacial Maximum, which indicates that nitrate utilization in the Bering Sea was raised during cold intervals (MIS 5.4, 5.2, 4) and almost complete during MIS 3 and 2 (~93-100%). This is in agreement with previous hypotheses suggesting that stronger glacial stratification reduced the nutrient supply from the subeuphotic zone, thereby increasing the iron-to-nutrient ratio and therefore the nitrate utilization in the mixed surface layer. Large variations in d15Nbulk were also recorded from 180 to 130 ka BP (MIS 6), indicating a potential link to insolation and sea-level forcing and its related feedbacks. Millennial-scale oscillations were observed in d15Nbulk and d13Cbulk that might be related to Greenland interstadials.

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