These are supplementary datasets of Katsuki et al., submitted to Palaeogeography, Palaeoclimatology, Palaeoecology. They contain the following datasets: 1) Chronology of core R1H1, 2) Depths of sand layer in core R1H1, and 3) Relative abundances of major diatom taxa and the total numbers of diatom assemblages in core R1H1. 