Ground truthing the Cd/Ca-carbon isotope relationship in foraminifera of the Greenland-Iceland-Norwegian Seas

K McIntyre*, AC Ravelo, ML Delaney, LD Anderson, T Johannessen

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

3 Citations (Scopus)

Abstract

In order to examine whether the paleoceanographic nutrient proxies, delta(13)C and cadmium/calcium in foraminiferal calcite, are well coupled to nutrients in the region of North Atlantic Deep Water formation, we present data from two transects of the Greenland-Iceland-Norwegian Seas. Along Transect A (74.3 degrees N, 18.3 degrees E to 75.0 degrees N, 12.5 degrees W, 15 stations), we measured phosphate and Cd concentrations of modern surface sea water. Along Transect B (64.5 degrees N, 0.7 degrees W to 70.4 degrees N, 18.2 degrees W, 14 stations) we measured Cd/Ca ratios and delta(13)C Of the planktonic foraminifera Neogloboquadrina pachyderma sinistral in core top sediments. Our results indicate that Cd and phosphate both vary with surface water mass and are well correlated along Transect A. Our planktonic foraminiferal delta(13)C data indicate similar nutrient variation with water mass along Transect B. Our Cd/Ca data hint at the same type of nutrient variability, but interpretations are hampered by row values close to the detection limit of this technique and therefore relatively large error bars. We also measured Cd and phosphate concentrations in water depth profiles at three sites along Transect A and the delta(13)C Of the benthic foraminifera Cibicidoides wuellerstorfi along Transect B. Modem sea water depth profiles along Transect A have nutrient depletions at the surface and then constant values at depths greater than 100 meters. The delta(13)C of planktonic and benthic foraminifera from Transect B plotted versus depth also reflect surface nutrient depletion and deep nutrient enrichment as seen at Transect A, with a small difference between intermediate and deep waters. Overall we see no evidence for decoupling of Cd/Ca ratio and delta(13)C in, foraminiferal calcite from water column nutrient concentrations along these transects in a region of North Atlantic Deep Water formation. (C) 1997 Elsevier Science B.V.

Original languageEnglish
Pages (from-to)61-73
Number of pages13
JournalMarine Geology
Volume140
Issue number1-2
DOIs
Publication statusPublished - Jul-1997
Externally publishedYes

Keywords

  • C-13/C-12
  • cadmium
  • Neogloboquadrina pachyderma
  • Norwegian Sea
  • Greenland Sea
  • Iceland Plateau
  • seawater
  • OCEAN CIRCULATION
  • DEEP-WATER
  • CADMIUM
  • ATLANTIC
  • PACIFIC
  • COPPER
  • ZINC
  • DELTA-C-13
  • DISTRIBUTIONS
  • PARTICLES

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