Climate reconstructions in speleothems

Speleothems, usually stalagmites (Figure 1), represent the most stable long term continuous climate record for which independent chronology can be established in the late Quaternary. Unlike marine sediment sequences, for which independent ages are available only until the limit of 14C dating (60,000 years) or annually layered ice cores in Greenland to 60,000 years (Svensson et al., 2008), U/Th chronology has successfully dated continuous stalagmite sequences through the last 640,000 years (Hai Cheng et al., 2016). Both stable isotope, and to a lesser extent trace element, geochemistry of stalagmites has been used to infer past variations in various facets of earth’s climate. We are engaged in a number of speleothem research projects, collaborating with R. Larry Edwards and Hai Cheng at the University of Minnesota and Xián Jiaotong University China for U/Th chronology.