Lago Grande di Monticchio revisited: Revised age model of the last 30 kyrs based on refined tephrostratigraphic constraints of Campanian volcanoes

Annually laminated sediments of Lago Grande di Monticchio, southern Italy, have for long proven a unique palaeoenvironmental archive that facilitated the preservation of numerous (n=340) distal volcanic ash (tephra) layers from central-southern Italian volcanoes for the last 133 kyrs. This study focuses on the establishment of a tephrochronological model for the last c. 30,000 years for a newly retrieved sediment sequence, MON16, and tests volcanic source correlations of previous studies. A total of 29 visible tephra layers in MON16 have been geochemically analysed in terms of their major element glass compositions, and out of these 21 layers were additionally characterised with respect to their trace element concentrations. Using published and newly obtained geochemical datasets of near-vent tephra deposits, most of these tephras (n=22) could be assigned to specific eruptive events of nearby Campanian volcanoes, i.e. Somma-Vesuvius, Campi Flegrei and Ischia. Published radiometric dates of 16 of these tephra correlatives have been implemented into a Bayesian age-depth model to provide a high-precision timescale for evolving palaeoenvironmental datasets of the MON16 sequence. MON16 tephra studies in combination with new and recently published near-vent tephra geochemical datasets allowed for a review of the previously established tephrostratigraphic framework of Monticchio, leading to the revision of 25 tephra correlations and to the addition of a total of five new primary layers to the 30-ka tephra record. Lastly, this study tests the reliability of selected widespread tephras as regional synchronisation marker and discusses the qualification of the Monticchio tephra record for volcanic eruption frequency studies.