Stable carbon and oxygen isotope analyses of Neogloboquadrina pachyderma

DOI

Detailed records of the carbon and oxygen isotopic ratios of Neogloboquadrina pachyderma are compared between nine high-latitude sediment cores, from the Northern and Southern Hemispheres, covering the last 140000 yrs. The strong analogies between the delta13C records permit to define a delta13C stratigraphic scale, with three clear cut transitions simultaneous with the oxygen isotopic transitions 6/5 (125 kyrs.), 5/4 (65 kyrs.), and 2/1 (13 kyrs.). The delta13C records of N. pachyderma in the high-latitude cores, which follow the changes in delta13C of the surface water TCO2 near areas of deep water formation present trends similar to the benthic foraminifera delta13C records in cores V19-30 and M12-392, although amplitudes of the isotopic shifts are different. This implies that a large part of the observed variations represents global changes in the carbon distribution between biosphere and ocean.The 13C/12C ratios of N. pachyderma in the North Atlantic cores display larger regional variations at 18 kyrs. B.P. than at present. To explain these differences, we have plotted the 18 kyrs. B.P. delta13C values of N. pachyderma from 17 cores distributed N of 40°N. Comparison with published surface water temperature distribution at 18 kyrs. B.P. indicates that a strong divergent cyclonic cell, centered approximatively 55°N and 15°W, was active during most of the last ice-age maximum. This hydrology, analogous to the present Weddell Sea, explains the published evidences of bottom water formation, if located on the northern flank of the gyre, and the strong polar front on the southern flank, probable location of intermediate water formation.

Supplement to: Labeyrie, Laurent D; Duplessy, Jean-Claude (1985): Changes in the oceanic 13C/12C ratio during the last 140.000 years: high latitude surface water records. Palaeogeography, Palaeoclimatology, Palaeoecology, 50(2-3), 217-240

Identifier
DOI https://doi.org/10.1594/PANGAEA.726109
Related Identifier https://doi.org/10.1016/0031-0182(85)90069-0
Metadata Access https://ws.pangaea.de/oai/provider?verb=GetRecord&metadataPrefix=datacite4&identifier=oai:pangaea.de:doi:10.1594/PANGAEA.726109
Provenance
Creator Labeyrie, Laurent D; Duplessy, Jean-Claude
Publisher PANGAEA
Publication Year 1985
Rights Creative Commons Attribution 3.0 Unported; https://creativecommons.org/licenses/by/3.0/
OpenAccess true
Representation
Language English
Resource Type Supplementary Publication Series of Datasets; Collection
Format application/zip
Size 21 datasets
Discipline Earth System Research
Spatial Coverage (-83.520W, -54.060S, 67.440E, 79.267N); Atlantic Ocean; South Indian Ocean; South Atlantic; Indian Ocean
Temporal Coverage Begin 1963-04-07T00:00:00Z
Temporal Coverage End 1982-01-01T00:00:00Z