Foraminiferal magnesium in Globeriginoides sacculifer

We improved cleaning methods and reduced errors introduced by partial dissolution by sampling from well-preserved cores in the equatorial Atlantic and the Caribbean Sea with different dissolution histories.

All cores reveal a synchronous 25% increase in Mg/Ca from the stage 2/3 boundary to the Holocene core top, indicating that dissolution is not a controlling factor. Modern temperatures estimated from core top Mg/Ca are 24.5°-25.0°C, equal to mean annual water temperatures at 50-100 m. We estimate that sea surface temperature increased by 2.6°C (±1.3) from the last glacial maximum to the Holocene.