Variability in the sources of North Gondwana Cadomian basins tracked by Nd isotopic systematics (Iberian Massif)

•TDM ages suggest a different Cadomian provenance for Variscan Iberian terranes.•Two contiguous Cadomian sedimentary basins were located along the North Gondwana margin.•A western basin (close to the WAC) for Iberian allochthonous sedimentary rocks.•An eastern basin (close to the SMC) for Iberian autochthonous sedimentary rocks.•A bipartite shelf along the North Gondwana margin would extend into Ediacaran times.