*The Ampferer-Type Subduction: A Case of Missing Arc Magmatism DOI: http://dx.doi.org/10.5772/intechopen.109406*

several continental blocks such as the Adriatic plate (also known as the Apulian Plate) and Sesia-Dent Blanche unit separated from Gondwana and Briançonnais block separated from Laurasia (**Figure 5**). The Gondwanan continental block Adriatic plate was moving northward into Laurasia. In the Cretaceous period, the Piemont-Liguria Ocean lay between Europe (and a smaller plate called the Iberian plate) in the northwest and the Adriatic plate in the southeast. The European and Adriatic passive margins were likely hyperextended, while the Piemonte-Liguria ocean basin was mainly floored by an exhumed mantle and hyperextended continental crust rather than mature oceanic crust (e.g., [7, 34, 78, 144]. At ca. 85–80 Ma, subduction at the Adriatic margin led to subduction of the Sesia-Dent Blanche unit [145], and progressed from southeast to northwest across the PL Ocean (ca. 50–45 My), the Briançonnais (ca. 45–42 My), and the Valais Basin (ca. 42–35 My) as indicated by the tectono-metamorphic evolution of those units (**Figure 5** [142, 145–148]. However, the onset of subduction initiation at the passive margins of Laurasia allowed the accretion of the hydrated portion of the subducting of the remaining Piemont-Liguria Ocean plate within an orogenic Alpine wedge (**Figure 5**) [29]. It is unclear whether the subducted slab is currently separated or remains attached to the European plate (**Figure 5**) [149].
