Extended Data Figure 3 : Illustration of the results of δ11B-to-pH conversion, and differences in age models.

From: Very large release of mostly volcanic carbon during the Palaeocene–Eocene Thermal Maximum

Extended Data Figure 3

a, We used our δ11B measurements as a proxy to calculate the evolution of pH at Site 401 during the PETM CIE, using either the borate ion47 (red) or the T. sacculifer43 (green) calibration. The age scale used follows ref. 25. b, Direct comparison of our two age models, plotting the reconstructed pH evolution of Site 401 using either the age model of ref. 57 or our preferred age model25. c, Expanded view of b.