The principles of growth and isotopic fractionation of stalagmites [Elektronische Ressource] : a numerical model to reconstruct temperature and precipitation records from stalagmites grown under disequilibrium conditions / presented by: Christian Mühlinghaus

AbstractSpeleothems and stalagmites in particular are frequently used as archives of paleocli mate.Theirgrowth,isotopiccarbonandoxygenprofilesandthepossibilityofanexactdating provide time series in a high temporal resolution. However, the interpretationoftheseprofilesisdifficultsincetheisotopicsignalinstalagmitesunderliesseveralin fluencesoutsideandinsidethecave.In this study the basic principles of stalagmite growth and isotopic enrichment underequilibrium and disequilibrium conditions in dependence on climate related parame ters are described quantitatively using numerical models. In a final step these basicsare used to develop a combined model, which enables the reconstruction of tempera ture and drip interval records from isotopic profiles of kinetically grown stalagmites.In contrast to former models, which have been limited in their application to samp lesdevelopedunderequilibriumconditions,thismodelisabletocopewithkineticallygrown samples and hence extends the number of stalagmites, which might be inves tigated. Furthermore the model exceeds the results of former models by yielding dripintervals in addition to temperature records. The model is applied to two stalagmitesfrom Southern Chile and reveals first temperature and drip interval records obtainedbystalagmitesfromextremelylowlatitudes.The study was carried out in the framework of the daphne Forschergruppe in Heidel berg.