Diatom assemblages from IN2023_V01_04_KC02, Cape Darnley, East Antarctica

This dataset comes from the marine sediment core, IN2023_V01_04_KC02, from Cape Darnley, East Antarctica (Post et al., 2024). Quantitative diatom slides were made using the method of Warnock & Scherer (2015). One mL of 30% hydrogen peroxide was added to 50–250 mg of dried sediment per sample every 24 h to oxidize and remove organic carbon until no reaction occurred. One mL of 10% sodium hexametaphosphate was added to aid in disaggregation. Coverslips were positioned within Phipps and Bird BKER2 2 L square beakers filled with deionised water. The sediment sample was added to the water and allowed to settle over a six-hour period. Settled coverslips were permanently mounted to clear microscope slides. Slides were then examined at 1000X magnification using a Leica DM 1000 LED light microscope in transects until >400 diatom valves were counted per slide and identified to the lowest taxonomic level possible, typically to species level. The preservation of diatom material was recorded using the semi-quantitative method of Warnock et al., (2015).