Fig. 2: Multi-proxy time series and their correlation for stalagmites MD12 and CXY1701.
From: The 2.8 ka climatic event contributed to the collapse of the Western Zhou Dynasty
a Stable isotope (δ18O, δ13C), trace element ratios (Mg/Ca, Sr/Ca, Ba/Ca), and PC1 of the trace element ratios (X/Ca) of stalagmite MD12 from northeastern China. The vertical gray bar highlights the 2.8 ka event. b Same as (a) but for stalagmite CXY1701 from southeastern China. c, d Correlation heat map of the stable isotope and trace element data for MD12 and CXY1701, respectively. The correlation is calculated using 3-year bins when the records had different resolutions. “*” denotes p ≤ 0.05, “**” denotes p ≤ 0.01.
