Fig. 5

Results of LCA concentration and \({\text{U}}_{{{37}}}^{{{\text{K}}^{\prime } }}\)-SST. The stratigraphic horizons examined in this study are shown in the left column with the columnar section of core GS-UR-1 described in Nakazawa and Nakazato (2005). a–c Variations in the total number of benthic and planktic foraminifera along with their relative abundance (P/T ratio) (Kaneko et al. 2018). d–e Variations in the LCA concentrations and \({\text{U}}_{{{37}}}^{{{\text{K}}^{\prime } }}\)-SSTs shown in this study. The white dots represent the samples in which LCAs were identified by GC/MS analysis, but clearly separated peaks could not be obtained by the GC chromatograph