The Montalbano Jonico marine succession: An archive for distal tephra layers at the Early–Middle Pleistocene boundary in southern Italy

Abstract

The lithological content and mineralogical assemblage of main tephra layers (V1, V2, V3, V4, V5, V7) embedded in the Montalbano Jonico succession have been fully characterized. Major-element analyses were carried out on the juvenile glass fractions and main crystal phases, and trace-element contents were determined on glasses extracted from the thickest layer of the sequence (V5). Single crystal 40Ar/39Ar laser fusions were performed on sanidine from the V4 layer, yielding a weighted mean age of 773.9 ± 1.3 ka. The Vulture volcano is likely the source of two tephra layers, V3 and V4, embedded to the middle part of the Interval B of the sequence, which represent the oldest products of this center ever found. Moreover, the V4 layer was emplaced near the Matuyama–Bruhnes Chron boundary, and thus serves as an important chronostratigraphic marker. Complete chemical characterization of V5 allows us to suggest the Campanian Volcanic Zone as its eruptive source; corroborating the idea that activity there began at ∼720 ka and spanned most of the Middle Pleistocene. Finally, we insert our new framework from the Montalbano Jonico sequence into a reappraised tephra sequence from the Middle Pleistocene to present in southern Italy, which results in a more robust series of tephrostratotypes and improves the reliability of inter-archive correlations.