North Atlantic palaeoceanographic proxy records from DSDP Sites 603 and 610, and IODP Sites U1308 and U1313 between 3.400 and 3.180 Ma.

<p>Circles with white fill are data points from this study, circles with colour fill are from <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0081508#pone.0081508-Naafs1" target="_blank">[30]</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0081508#pone.0081508-Naafs2" target="_blank">[55]</a> (C) and <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0081508#pone.0081508-DeSchepper1" target="_blank">[26]</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0081508#pone.0081508-DeSchepper2" target="_blank">[35]</a> (D). Vertical grey bars represent glacials, white bars are interglacials. (A) palaeomagnetic reversals; (B) benthic isotope age models for each site tuned to the LR04 stack <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0081508#pone.0081508-Lisiecki1" target="_blank">[10]</a> (black line), thin coloured lines are data, thick coloured line is 4-point running mean; (C) alkenone SSTs (0–10 m water depth) including calibration related error (shading), horizontal lines represent modern average annual temperature at 0–50 m water depth for each site; (D) SSTs at 0–60 m water depth based on Mg/Ca of <i>G. bulloides</i>, including a 1°C error bar (shading), horizontal lines represent modern average spring (March-April-May) temperature at 0–50 m water depth for each site; (E) SWT_Mg/Ca of <i>G. inflata</i> at 300–400 m water depth; (F) calculated δ¹⁸O_sw-ice as estimate of salinity; thick coloured lines are a 4-point running mean; (G–J) dinoflagellate cyst assemblage composition. High abundances of <i>O</i>. <i>centrocarpum</i> (yellow) indicate an active NAC. Bluish colours = cool-water species, reddish colours = warm-water species; (G) and (H) contain data presented in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0081508#pone.0081508-DeSchepper1" target="_blank">[26]</a> and <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0081508#pone.0081508-DeSchepper2" target="_blank">[35]</a>. (J) <i>B. tepikiense</i> and <i>F. filifera</i> are grouped together at DSDP Site 603 and are represented by the colour for <i>B. tepikiense</i> (purple); <i>Impagidinium</i> cf. <i>pallidum</i> is represented as <i>Impagidinium pallidum</i>.