The Cadomian belt (ca. 600–500 Ma) extends from North America through Europe to Iran (Figure 1). It is charac- terized mainly by eroded, metamorphosed, and deformed magmatic arcs and back-arc basins developed along the northern margin of Greater Gondwana or Pannotia during Late Ediacaran to Early Cambrian time (e.g. Murphy et al. 2002; Stern 2008; Linnemann et al. 2008, 2014). Nearly all of the Cadomian orogen rifted away from Gondwana during the opening of the Rheic and Tethyan oceanic basins and accreted to the south- ern margin of Eurasia and eastern North America during the Caledonian (by the accretion of the Avalonia), Variscan, and Tethyan orogenic cycles. Consequently, the Cadomian crust is found in the Avalonian, Variscan, and Tethyan belts, where it is often involved in later metamorphism. The significance of these Cadomian fragments for understanding the tectonic evolution of southern Europe and eastern North America is widely appreciated, but the role of Cadomian fragments in the evolution of Turkey and Iran and adjacent regions is less understood.