Isotopic (Sr–Nd) and major element fingerprinting of distal tephras: an application to the Middle-Late Pleistocene markers from the Colli Albani volcano, central Italy

A rare Mid-Würmian lithoid tuff in the Agro Pontino graben (Southern Lazio, Italy) and its identification as an Albano 5-7 related distal tephra deposit (41-36 kaBP): characteristics, provenance and palaeogeographical implications

“…the Campanian Ignimbrite and Neapolitan Yellow Tuff, which contain biotite. Assuming that isotope equilibrium existed between clinopyroxenes and phlogopites, resulting from the contemporaneous crystallization of those mineral phases during a dominant magmatic fractionation process , the measured isotope ratios match with those reported for the <69 kaBP Colli Albano volcano , Giaccio et al 2007, Gaeta et al 2011, Giaccio et al 2013. In particular, the 87 Sr/ 86 ratio of 0.709584 ± 10 (Figure 7) approaches the values of Albano 1 (0.709385-0.7095), falls in the Albano 3 range (0.708477-0.70963), and perfectly overlaps the values of Albano 5-7 (0.709512-0.709675) , Giaccio et al 2007, 2017b.…”

“…All together, the analyses show that the lithoid tuff originates from the Colli Albani volcano and may be a distal variant of the Albano 5-7 unit, more explicitly from the larger events during this eruptive phase: Albano 5 (DU3) or Albano 7 (DU4) from ~40 and ~36 kaBP, respectively [Giaccio et al 2013[Giaccio et al , 2017b. This would be in agreement with the statement by Gaeta et al [2011] that Colli Albani tephra with an age younger than 69 ka can be quite well discriminated from earlier tephra by their Sr-isotopic ratios.…”

“…Tephra from these various eruptions can be identified on the basis of their low K content and associated mineral chemistry [e.g., , and isotope geochemistry, in particular their 87 Sr/ 86 ratio, which is higher for the products from the Colli Albani volcano , Giaccio et al 2007, Gaeta et al 2011, Giaccio et al 2013, and their 143 Nd/ 144 ratio, which is slightly lower for the Campi Flegrei products [Pappalardo et al 2002, Arienzo et al 2010, Di Renzo et al 2011, Piochi et al 2014. Giaccio et al [2013] published an overview of the distribution, age, and isotopic (coupled Sr-Nd) and major element fingerprinting of the distal tephra of the Colli Albani volcano. They extensively report on the occurrence of Late Quaternary Colli Albani tephra Figure 2.…”

“…The micas instead offered a good possibility by both chemistry and coupled Nd and Sr isotope geochemistry to discriminate between the Campanian vs. Latium volcanism. This possibility was stressed in the most recent literature, stating that isotope geochemistry is a good discriminant for the identification of Colli Albani tephra [Gaeta et al 2011, Giaccio et al 2013.…”

“…Because of its thickness and petrology, and the absence of significant soil formation and weathering in this tuff and overlying sediments, the tuff would probably originate from one of the latest eruptions of the Colli Albani and might be linked to the Mid-Wür-mian Peperino Albano eruptive cycle ], more recently described as the Albano 5-7 tephra by Giaccio et al [2013Giaccio et al [ , 2017b.…”