Central European warm phases recorded by episodic speleothem growth during MIS 3

Abstract

Speleothems provide exceptional age control and are a valuable archive for the identification of warm phases in temperate climates. Here we present a speleothem composite record from Germany, which shows episodic growth during the last glacial period, coinciding with several Greenland Interstadials. Using a combined approach of high-resolution solution and in-situ laser ablation 230Th/U-dating, we were able to precisely constrain the timing and duration of several particularly warm phases during Marine Isotope Stage 3. Climatic conditions favourable for speleothem growth occurred episodically until 32,000 years ago, much longer than reported from existing speleothem records. The inception of speleothem growth lags the onset of Greenland Interstadials and covers approximately 88% of their total duration during early, and approximately 25% during middle and late Marine Isotope Stage 3. This indicates progressive climatic cooling during Marine Isotope Stage 3, with the speleothem growth phases representing persistent Central European warm phases. Precisely dated growth phases of speleothems from Bleßberg Cave, Germany, provide snapshots of particularly warm and stable climate during Marine Isotope Stage 3 in Central Europe using both high-resolution solution and in situ 230Th/U dating.