Benthic foraminifera stable isotope data for the Mossy Grove sediment core

Sample preparation for benthic foraminiferal stable-isotope analyses: Sediment amples were prepared and analyzed at Kochi University. Samples were washed through a 63 μm screen with Calgon in tapwater, and the residue was dried at 50 °C. Specimens of U. jacksonensis were picked from the >150 µm fraction of the residues, and were found to be present in 38 sediment samples. The specimens are well-preserved appearing transparent to translucent in color under the light microscope (Figure S2). Using a Keyence VHX-2000 digital microscope and a JEOL JSM-6500F scanning electron microscope, the preservation of examined specimens was assessed. The light microscopic image is focus stacking. To extend this record down core, a further five samples were prepared at the University of Birmingham. These samples were dried in a low-temperature oven at 40°C for approximately one week in order to obtain a dry bulk sediment weight and then washed over a 63 µm sieve with de-ionised water. The coarse fraction (>63 µm) was dried in the oven and then dry sieved at 250-300 µm and individuals of the infaunal benthic foraminifera genus Uvigerina picked (wherever possible U. jacksonensis was selected). Any sample with more than two individuals was analyzed for stable isotopes (>10 µg).