Speleothem CaCO3 δ18O is a commonly employed paleomonsoon proxy. However,
inferring local rainfall amount from speleothem δ18O can be complicated due to changing
source water δ18O, temperature effects, and rainout over the moisture transport path. These
complications are addressed using δ18O of planktonic foraminiferal CaCO3, offshore from
the Yangtze River Valley (YRV). The advantage is that the effects of global seawater δ18O
and local temperature changes can be quantitatively removed, yielding a record of local …