Stable oxygen isotope and Mg/Ca ratios on Globorotalia inflata, supplement to: Groeneveld, Jeroen; Chiessi, Cristiano Mazur (2011): Mg/Ca ratios of Globorotalia inflata as a recorder of permanent thermocline temperatures in the South Atlantic. Paleoceanography, 26, PA2203


We present a species-specific Mg/Ca-calcification temperature calibration for Globorotalia inflata from a suite of 38 core top samples from the South Atlantic (from 8° to 49°S). G. inflata is a deep-dwelling planktonic foraminifer commonly occurring in subtropical to subpolar conditions, which qualifies it for reconstructions of the permanent thermocline. Apparent calcification depths and calcification temperatures were determined by comparing measured d18O with equilibrium d18O of calcite based on water column properties. Based on our core top samples, G. inflata apparent calcification depth is constant throughout the South Atlantic mid-latitudes with a depth of 350-400 m within the permanent thermocline. The resulting Mg/Ca-calcification temperature calibration is Mg/Ca = 0.72 +/-0.045/0.042 exp (0.076 +0.006 calcification 2 temperature) (r2 = 0.81) and covers the temperature range 3.1-16.5°C. We applied our Mg/Ca calibration to gravity core PS2495-3 from the Mid-Atlantic Ridge at ca. 41°S to test its validity by reconstructing a low-resolution record covering the last two glacial-interglacial cycles. Our paleotemperature record reveals large changes in temperature for Terminations I and II, when permanent thermocline temperature increased by as much as 8°C. The G. inflata paleotemperature record suggests that oceanic fronts repeatedly migrated over the location of site PS2495-3 during the last 160 kyr. This study shows the potential of G. inflata Mg/Ca to reconstruct paleotemperatures in the permanent thermocline.

Related Identifier
Metadata Access
Creator Groeneveld, Jeroen; Chiessi, Cristiano Mazur
Publisher PANGAEA - Data Publisher for Earth & Environmental Science
Publication Year 2011
Funding Reference German Science Foundation
Rights Creative Commons Attribution 3.0 Unported
OpenAccess true
Language English
Resource Type Supplementary Collection of Datasets
Format application/zip
Size 2 datasets
Discipline Earth System Research
Spatial Coverage (-60.092W, -48.912S, 6.788E, -8.143N); Cape Basin; Walvis Ridge; Mid Atlantic Ridge; Namibia Continental Margin; Brazil Basin; Slope off Argentina; Uruguay continental margin; Ascencion Island; western South Atlantic; Central South Atlantic; South Atlantic
Temporal Coverage Begin 1990-03-22T00:00:00Z
Temporal Coverage End 2001-03-24T18:42:00Z