15.01.2021 - 19:59
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Speleothem Based Palaeoclimate

We use speleothems like stalagmites and flowstones from areas which are relevant for human evolution and migration to investigate past climate conditions. Speleothems provide rich archives of climate change that are dateable at very high precision back to approximately 600 ka BP using the U-Th technique. The chronology of speleothem growth itself already provides important information about palaeoclimatic conditions. For example, speleothem growth is related to the climatic conditions above the cave and depends on water availability which in turn depends on rainfall. Speleothems found in areas which are currently too dry for speleothem formation indicate substantially different climate conditions in the past. Or speleothems from currently submerged caves  can be used to constrain past sea levels. Changes of the speleothem growth rates are often related to changes in precipitation intensity, temperature or vegetation cover above the cave. Speleothems are also archives for palaeoclimate proxies such as stable oxygen and carbon isotopes or trace element (e.g. Mg, Sr, P) concentrations. Multiproxy studies on stalagmites, involving combinations of stable isotopes and trace elements have enormous potential in identifying process controls of speleothem formation in palaeoenvironmental studies. Our work is currently focussed on speleothems from Northern Africa and the Iberian Peninsula.