Tephrostratigraphy and -chronology of a 430 ka sediment record from the Fucino Basin, central Italy, unites Mediterranean and North Atlantic archives

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The Fucino Basin is the largest and probably the only Central Apennine basin that hosts a continuous, lacustrine sediment succession documenting the sedimentary history from the Early Pleistocene to recent historical times. Its good range of distance from the peri-Tyrrhenian volcanic centres (100 to 150 km) makes the Fucino Basin the best candidate available in the central Mediterranean that allows the assemblage of a long and continuous tephrochronological record independently dated by the 40A/39Ar method and directly anchored to a comprehensive proxy time series from the lacustrine sediments in stratigraphic order. In this framework, the Fucino paleolake adds a nodal point in the network of long terrestrial and marine Mediterranean records, including the Dead Sea, Lake Van, Lake Ohrid, Tenaghi Philippon and the Basin of Corinth. Transferring chronological and stratigraphic information on paleomagnetic excursions and on orbital and millennial-scale climate variability derived from North Atlantic sediment records sets the framework for a better understanding of the spatio-temporal variability, the magnitude, and the different expressions of Quaternary paleoclimatic changes.This project focuses on an 86 m-long sediment succession, which was recovered from the central part of the Fucino Basin in June 2017 and covers the last 430 ka. Detailed tephrostratigraphic work includes major, minor, trace element and isotope analyses at national and international collaboration institutions. Chronostratigraphic work is based on correlation with known tephra layers and direct 40Ar/39Ar dating of so far unknown and/or undated tephra layers. The tephrostratigraphic and chronostratigraphic work will allow us to (i) determine the succession, the timing, the duration and the dynamics of past climate events, (ii) improve the knowledge on volcanology, petrology and geodynamics, and (iii) improve the knowledge of the chronology of paleomagnetic excursions. Moreover, the project will test the limits of 40Ar/39Ar dating with respect to the minimum size of sanidines or leucites required for tephra layers of different age.This project here proposed is a renewal proposal, as the number of tephra layers detected in the recovered sediment succession is 2-3 times higher than expected. This is an excellent precondition to fulfill the goals described above. However, the high number of tephra layers requires more intense analytical work that will be carried out in close collaboration with international partners. The outcome sets the frame to highlight the over-regional significance of the Fucino record and to establish an ICDP funded drilling campaign in the Fucino Basin.