The Dalradian Supergroup is interpreted traditionally as recording c. 300 m.y. of ‘episodic’
Neoproterozoic rifting. However, lower Dalradian (pre-Easdale Subgroup) facies architecture is
incompatible with rift-basin fill, and no unambiguous Neoproterozoic extensional structures are present
in those rocks. Consequently, no objective evidence exists to infer that Dalradian sedimentation
was initiated during extensional tectonism. That, combined with the accumulating data for contractile
deformation in Scotland at c. 870–800 Ma, the Knoydartian orogeny, permits the proposal of an alternative
tectonostratigraphic evolution for the Dalradian. I propose that Dalradian basin genesis was
initiated as a foredeep in response to Knoydartian orogenesis. The coarsening- and shallowing-upward,
6–8 km-thick Grampian Group–lower Lochaber Subgroup succession arguably represents a
flysch to molasse Knoydartian foredeep overlain by a moderately stable post-orogenic shelfal sequence
recorded by the relatively uniform thinner (c. 4 km) and compositionally more mature rocks of the
upper Lochaber through Islay subgroups. Lithospheric-scale extensional tectonism and rifting did not
occur until the late Neoproterozoic, as marked by the laterally variable, volcanic- and igneous-bearing
Easdale Subgroup, and was followed by the late Neoproterozoic–early Palaeozoic Iapetan rift-to-drift
transition through the Southern Highland Group.