Slab thermal transitions in the Aeolian arc driven by sub-slab mantle upwelling in the early Pleistocene.

Abstract

Slab tearing and associated asthenospheric upwelling can profoundly affect arc magmatism by heating subducting slabs, yet continuous temporal magmatic records for such slab thermal perturbations remain elusive. Here, we document a magmatic shift in Stromboli volcano, eastern Aeolian arc, where potassium-rich rocks emerged since ~ 13,000 years ago and show isotopic and elemental evidence for high-temperature sediment melting. In contrast, rocks with ages > 13,000 years across the arc record incorporation of bulk sediment without experiencing obvious melting, consistent with a cold subduction setting. These results evidence a transition from cold-slab to hot-slab, linked to a mantle upwelling induced by slab tearing occurred in the early Pleistocene. This tectono-magmatic coupling accounts for the southeastward progression of potassium-rich volcanism across the Italian Peninsula, which coincides with tomographically and topographically inferred slab-tearing propagation. Our results demonstrate rapid (<1-2 million years) magmatic response to sub-slab mantle upwelling and offer critical insights into the drivers of recent volcanism in southeastern Italy, including Mount Vesuvius.