Fig. 19

Dinoflagellate cyst record (this study) compared with paleoclimatic and paleoceanographic records through MIS 20 to MIS 18 from the Chiba composite section (CbCS) (from Suganuma et al. 2018, in press). a Organic carbon stable isotope (δ¹³C_org) and b C/N ratio (= total organic carbon [TOC]/total nitrogen [TN]) for bulk samples (Izumi et al. 2021). c Relative abundance of nannofossil F. profunda (Kameo et al. 2020). d Blue shaded area: Radiolarian concentrations (proxy for biological production); red line: Tr values (sea-surface temperature index based on warm- and cold-water radiolarian species). e Relative abundance of planktonic foraminifera and results of factor analysis. f ∆δ¹⁸O_{G. bulloides–G. inflata (bul-inf)}, corresponding to the temperature gradient (hence stratification) between surface and subsurface waters. g Mg/Ca paleotemperature for G. inflata (T_inf) considered to represent the subsurface (> 100 m) winter temperature (Kubota et al. 2021). h Dominant palynofacies component (brown line, terrestrial; blue line, marine amorphous organic matter [AOM]) from Fig. 16. i Dinoflagellate cyst synthetic diagram showing most abundant taxa and local assemblage biozonation (this study). Blue arrow marks the suggested position of a Younger Dryas-type cooling event according to Suganuma et al. (2018)