The gradual increase of Nd model age recorded in Ediacaran‒Terreneuvian detrital sedimentary rocks of Iberia has allowed the development of novel approaches to the palaeogeographic position of recognizable tectonostratigraphic units along the northwestern margin of Gondwana. The arrangement of these units confirms previous proposals about the existence of a variability in isotopic sources from the Ediacaran to the early Palaeozoic time. This variability is reflected in two TDM age groups corresponding to two large continuous sedimentary basins, whose boundary would be located along a well-defined area of TDM overlap near the Trans-Saharan Orogen. A Western Cadomian basin exhibits detrital contributions with older model ages (ca. 1.4‒2.4 Ga) and would be situated close to the West African craton. In contrast, an Eastern Cadomian basin, with younger model ages (1.2‒2.1 Ga), was positioned in the vicinity of the Sahara Metacraton, potentially receiving contributions from more juvenile materials from the Tuareg and Arabian Nubian Shields. The distinct Nd isotopic record observed in the metasedimentary successions of both SW and NW Iberian allochthonous and their relative autochthonous terranes aligns with a distinctive position within these two major peri-Gondwanan sedimentary basins, whose sedimentary rocks where deposited in the Western and Eastern basins, respectively. This finding provides a compelling explanation for the current terrain configuration in Iberia, as a consequence of the Variscan accretion of more eastern Iberian domains beneath more western sectors of North Gondwana.