The late Ediacaran Serie Negra (Ossa-Morena Zone, Iberian Massif) hosts E- and N-MORB arc metabasites
Ediacaran E-MORB metabasites match younger island arcs with forearc zones affected by extension after subduction initiation.
N-MORB metabasites record early Cambrian rifting developed in a continuum after a protracted subduction.