Vendian and Riphean rifting in NW Scotland

In the Neoproterozoic, NW Scotland was located in a tract of extending continental lithosphere that evolved into the eastern passive margin of Laurentia when Iapetus opened in the Vendian. On the NW Caledonian foreland, major rift events are inferred in the Riphean and Vendian, corresponding to the intra-Torridonian and sub-Cambrian unconformities respectively. In this context, current views that the Moine and Dalradian rocks of the Scottish Highlands were subjected to repeated orogeny during the same period become difficult to sustain. We propose a tectonostratigraphic history for the two areas in which Neoproterozoic orogeny plays no part.