Carbon isotope values (‰ VPDB) of the Porto Rico and El Argoub sections, compared to δ13C curves around the Eocene–Oligocene transition at ODP Site 1218 (Erhardt, Pälike & Paytan, 2013) and reference δ13C composite curve (Cramer et al. 2009; modified by Vandenberghe, Hilgen & Speijer, 2012). EOT – Eocene–Oligocene Transition; U1–U5 – lithological units defined in the text; B1, B2, C1, C2 – fossil-bearing levels