Accretionary wedges are tectonic settings overriding subduction zones and generally show broad structural diversity, which, in first order, is reflected in tectonic accretion or erosion (Clift & Vannucchi, 2004). Therein, the accreted materials can involve variable amounts of oceanic basement or trench-fill sediments, which occur as either coherent units or mélanges (Meneghini et al., 2009). Wedge diversity is further complicated by the fact that mélanges may result from either sedimentary, tectonic or diapiric mechanisms, or a combination thereof (Festa et al., 2012). The nature of the lower plate, including oceanic-basement topography and volume of sediments, exerts a fundamental control on the wedge diversity (Clift & Vannucchi, 2004).