(Table A1) Diatom isotope measurements from ODP Hole 145-882A

In comparison to other sectors of the marine system, the palaeoceanography of the subarctic North Pacific Ocean is poorly constrained. New diatom isotope records of d13C, d18O, d30Si (d13Cdiatom, d18Odiatom, and d30Sidiatom) are presented alongside existing geochemical and isotope records to documen...

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Bibliographic Details
Main Authors: Swann, George E A, Snelling, Andrea M
Format: Dataset
Language:English
Published: PANGAEA 2015
Subjects:
145-882A
AGE
Carbon
Coscinodiscus marginatus
Coscinodiscus radiatus
DEPTH
sediment/rock
Diatoms
other
δ18O
δ30Si
DRILL
Drilling/drill rig
DSDP/ODP/IODP sample designation
Element analyser CHN
Costech and Optima mass spectrometer
Joides Resolution
Leg145
Mass spectrometer
Finnigan
MAT 253
North Pacific Ocean
Ocean Drilling Program
ODP
Reference/source
Sample code/label
δ13C
diatom-bound organic matter
Subarctic
Online Access:https://doi.pangaea.de/10.1594/PANGAEA.856071
https://doi.org/10.1594/PANGAEA.856071
Description
Summary:In comparison to other sectors of the marine system, the palaeoceanography of the subarctic North Pacific Ocean is poorly constrained. New diatom isotope records of d13C, d18O, d30Si (d13Cdiatom, d18Odiatom, and d30Sidiatom) are presented alongside existing geochemical and isotope records to document changes in photic zone conditions, including nutrient supply and the efficiency of the soft-tissue biological pump, between Marine Isotope Stage (MIS) 4 and MIS 5e. Peaks in opal productivity in MIS 5b/c and MIS 5e are both associated with the breakdown of the regional halocline stratification and increased nutrient supply to the photic zone. Whereas the MIS 5e peak is associated with low rates of nutrient utilisation, the MIS 5b/c peak is associated with significantly higher rates of nutrient utilisation. Both peaks, together with other smaller increases in productivity in MIS 4 and 5a, culminate with a significant increase in freshwater input which strengthens/re-establishes the halocline and limits further upwelling of sub-surface waters to the photic zone. Whilst d30Sidiatom and previously published records of diatom d15N (d15Ndiatom) (Brunelle et al., 2007, 2010) show similar trends until the latter half of MIS 5a, the records become anti-correlated after this juncture and into MIS 4, suggesting a possible change in photic zone state such as may occur with a shift to iron or silicon limitation.

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