A high-resolution quantitative mean annual temperature reconstruction for Central Europe for the last 13,300 years using annually laminated speleothems from southern Germany

• Applicant: Dr. Dana Riechelmann
• Subject Area: Geology ; Mineralogy, Petrology and Geochemistry
• Term: since 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 536901244

The detailed understanding of climate variability is rapidly declining in the past due to decreasing numbers of high-resolution, precisely dated proxy records. Such records are needed to address several current research questions, such as the Holocene temperature conundrum, the climate forcing of large volcanic eruptions, and climate variability during the Younger Dryas. In this renewal project, I will generate a high-resolution, precisely dated proxy record, stacked from five annually laminated speleothems, covering the last 13,300 years from Zoolithencave (southern Germany). Two of these stalagmites will be redated using a state-of-the-art Neptune Plus MC-ICPMS to establish precise age models, and stable oxygen isotope ratios will be measured at pentadal and decadal resolution, respectively, from 13,300 to 3,000 years BP. This new Zoolithencave master record, derived from stacked and cross-dated oxygen isotope data, will be calibrated against instrumental climate data to generate a quantitative reconstruction of mean annual temperature back in time. This temperature reconstruction will be validated with low-resolution measurements of stable oxygen and hydrogen isotope composition of fluid inclusions and the organic compound TEX86 generating quantitative temperatures from the stalagmites. Since such a long, high-resolution, and quantitative reconstruction from speleothems is still lacking in Central Europe, the stacked Zoolithencave record provides regional insight on the Holocene temperature conundrum by comparison with climate model results. Since the new high-resolution reconstruction extends back to the Younger Dryas, it will be used to address the question of potential internal climate variability of this major cold period since the last glacial. Due to the high resolution and dating precision, the new record will additionally be used to address the strength and persistence of volcanic forcing on temperature variations over the last 13,300 years. Support of this project will thereby allow the development of an unprecedented reconstruction that could become a potential reference temperature record for Central Europe for the last 13,300 years and be of significance for hemispherical compilations of palaeoclimate records.

• DFG Programme: Research Grants
• Co-Investigator: Professor Dr. Denis Scholz