Figure 3
δ18O paleotemperatures for phosphate and carbonate fossils and microfossils from low paleolatitudes (30° S to 30° N). Comparison of δ18O paleotemperature trends (Locfit regressions) for phosphate and carbonate fossils calculated using different corrections for seawater δ18O: (1) constant (ice-free, δ18Osw = −1.08‰ VSMOW), (2) ice volume corrected (IceV), and (3) ice volume and latitude corrected (IceV, lat). For greenhouse climates, the ice-free data (red dotted line) plot atop the ice volume corrected data (blue dotted lines). Aragonite fossils are corrected for aragonite-calcite fractionation (arag; −0.6‰) and belemnite data are corrected for 18O enrichment in belemnites (−1.5% where noted (bel). Locfit regression for data uncorrected for 18O enrichment in belemnites shown as pink line. Gaps in curves are intervals with little or no data. TEXH86 temperatures shown for comparison16,17. See Fig. 1 for key to period/subperiod bar at top.
