Tephrostratigraphy of the last 170 ka in sedimentary successions from the Adriatic Sea

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In this study are discussed new SEM-EDS analyses performed on glass shards from five cores collected in the Central Adriatic Sea and two cores recovered from the South Adriatic Sea. A total of 26 tephra layers have been characterized and compared with the geochemical features of terrestrial deposits and other tephra archives in the area (South Adriatic Sea and Lago Grande di Monticchio, Vulture volcano). The compositions are compatible with either a Campanian or a Roman provenance. The cores, located on the Central Adriatic inner and outer shelf, recorded tephra referred to explosive events described in the literature: AP3 (sub-Plinian activity of the Somma-Vesuvius, 2710 ± 60 14C years BP); Avellino eruption (Somma–Vesuvius, 3548 ± 129 14C years BP); Agnano Monte Spina (Phlegrean Fields, 4100 ± 400 years BP); Mercato eruption (Somma–Vesuvius, 8010 ± 35 14C years BP; Agnano Pomici Principali eruption (Phlegrean Fields, 10,320 ± 50 14C years BP); Neapolitan Yellow Tuff (Phlegrean Fields, 12,100 ± 170 14C years BP). Some of these layers were also observed in the South Adriatic core IN68-9 in addition to younger ( AP2, sub-Plinian eruption, Somma–Vesuvius, 3225 ± 140 14C years BP), and older layers ( Pomici di Base eruption, Somma–Vesuvius, 18,300 ± 150 14C years BP). Significant is the tephra record of core RF95-7 that, for the first time in the Adriatic Sea, reports the occurrence of tephra layers older than 60 ka: the well known Mediterranean tephra layers X2 (ca. 70 ka), W1 (ca. 140 ka) and V2 (Roman origin, ca. 170 ka) as well as other tephra layers attributed, on the basis of geochemistry and biostratigraphy, to explosive eruptions occurred at Vico (138 ± 2 and 151 ± 3 ka BP) and Ischia (147–140 ka BP). Previous tephra correlations performed on other cores in the Central Adriatic Sea were also critically revised according to new available data, and integrated with the results of this study for a correlation at a regional scale. The most important key beds for correlation are the “Agnano Monte Spina” and “Neapolitan Yellow Tuff” tephra layers, which occur in both Central and South Adriatic sea. Other tephra layers, younger than 15 ka, are relatively less frequent: the Y1 (Etna, 14,180 ± 260 14C years BP) and “Agnano Pomici Principali”. In the more recent record, in the shelf cores north of Gargano Promontory, the AP3 tephra layer is also frequent.