C04_P02

New high RESOLUTION project ¹⁴C data from a Glacial sub-fossil pine forest in Furadouro, Portugal

Cercatillo S¹, Friedrich M², Kromer B³, Palecek D¹, Wacker L⁴, Talamo S¹

¹Department of Chemistry G. Ciamician, Alma Mater Studiorum, University of Bologna, Via Selmi 2, 40126, Bologna, Italy, ²Hohenheim Gardens, University of Hohenheim, Ottilie-Zeller-Weg 8, D-70599, Stuttgart, Germany, ³Institute of Environmental Physics, Heidelberg University, D-69120 , Heidelberg, Germany, ⁴Laboratory of Ion Beam Physics, ETH Zurich, 8093 , Zurich, Switzerland

The year 14,226 BP marks an important border in the actual radiocarbon (¹⁴C) calibration curve: the high resolution and precision characterising the first part of the curve thanks to the potential of tree-rings, systematically decrease going back in time, where only a few floating tree-ring chronologies alternate to other low-resolution records.

The lack of resolution in the dating procedure before 14,200 years BP leads to significant issues in the interpretation and untangling of tricky facts of our past.

The research for sub-fossil trees, within the RESOLUTION project, which directly recorded atmospheric carbon (¹²C, ¹³C and ¹⁴C), and the construction of new Glacial tree-ring chronologies can improve the radiocarbon dating and therefore, to resolve puzzles in the Human Evolution history.

The sub-fossil pine trees found in situ under the current coast sediments of Furadouro, Portugal, are remnants of a Glacial lagoonal forest and represent a significant example of the huge potential given by the rare findings of trees grown during the Glacial in refugia areas, where the environmental conditions and climate allowed growth of pine trees.

Here we report of a new 220-year long pine tree-ring chronology, grown during GI 5: we describe the carefully sampling, the dendrochronological analysis and cross-dating of the trees, and the high resolution, highly reliable radiocarbon age-series with tight error ranges that we have achieved by applying the most suitable cellulose extraction protocol for sub-fossil Glacial trees, and the most advanced technologies of the MICADAS system at ETH-Zurich.