Subduction-related Hypotheses

Evidence in favour of subduction-related hypotheses for the magmatism along the Italian peninsula and in the southern Tyrrhenian Sea includes  

Abundant arc-type Plio-Quatemary calc-alkaline magmatism occurring in the Aeolian arc and seamounts, along the Tyrrhenian Sea floor and in some places along the Italian peninsula (e.g. Tuscany, Campania)  

Crustal-like geochemical and isotopic signatures for most rocks along the Italian peninsula (Fig. 10.4), requiring crustal contamination of their mantle sources, a process that can be only accomplished by subduction processes  

Occurrence of an active seismic zone beneath the eastern Aeolian arc, defined by deep focus earthquakes extending to a depth of about 500 km until the Campania area (Fig. 10.2)  

Occurrence of a vertical rigid body cutting the asthenosphere beneath the Apennine chain, interpreted as a remnant of a young subduction zone  

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The occurrence of abundant calc-alkaline andesites and the high LILE/HFSE ratios of rocks have brought to a general, though not unanimous consensus that the Aeolian arc is genetically related to subduction processes. Such a hypothesis is strongly supported by the occurrence of deep-focus earthquakes beneath the eastern sector of the arc. 

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