Grain size composition of sediment core PG2208

Before conducting grain-size analysis, we treated 36 samples with hydrogen peroxide (30%), set on a platform shaker for 4–5 weeks to remove organic matter, while keeping the pH neutral using ammonia and acetic acid. After washing, sediment samples were treated with sodium pyrophosphate for dispersion and homogenization of the sediment suspension for a day. At least three measurements per sample were carried out using a laser diffraction particle size analyzer MASTERSIZER 3000. Their mean was used to estimate sand, silt, and clay fractions as sums of volume percentages between 2 and 63 mm, 63 and 2 mm, and <2 mm grain-size classes, respectively.