Past carbonate preservation events in the deep Southeast Atlantic Ocean (Cape Basin) and their implications for Atlantic overturning dynamics and marine carbon cycling ...

• Main Authors: Gottschalk, Julia, Hodell, David, Skinner, LC, Crowhurst, Simon, Jaccard, Samuel, Charles, Christopher
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley-Blackwell 2018
• Subjects: Southern Ocean; carbonate preservation; carbonate compensation; glacial cycles; AMOC; XRF; Greenland
• Online Access: https://dx.doi.org/10.17863/cam.30877; https://www.repository.cam.ac.uk/handle/1810/283514

Micropaleontological and geochemical analyses reveal distinct millennial-scale increases in carbonate preservation in the deep Southeast Atlantic (Cape Basin) during strong and prolonged Greenland interstadials that are superimposed on long-term (orbital-scale) changes in carbonate burial. These data suggest carbonate oversaturation of the deep Atlantic and a strengthened Atlantic Meridional Overturning Circulation (AMOC) during the most intense Greenland interstadials. However, proxy evidence from outside the Cape Basin indicate that AMOC changes also occurred during weaker and shorter Greenland interstadials. Here we revisit the link between AMOC dynamics and carbonate saturation in the deep Cape Basin over the last 400 kyr (sediment cores TN057-21, TN057-10 and ODP Site 1089) by reconstructing centennial changes in carbonate preservation using mm-scale X-ray fluorescence (XRF) scanning data. We observe close agreement between variations in XRF Ca/Ti, sedimentary carbonate content and foraminiferal shell ...