It is dated to about 820–725 Ma (million years ago), predating the deposition of the Cryogenian to Cambrian Dalradian Supergroup.
Evidence for a Precambrian event affecting Moine rocks (as then understood) came from the identification of a set of "older" pegmatites, thought to predate Caledonian tectonic and metamorphic effects, in a number of localities, including Morar and Knoydart, in the 1960s.
[3] As more dating was carried out on samples covering a larger geographical area, using techniques with significantly greater precision, the full age range of 820–725 Ma became apparent.
The dates produced also show clustering, suggesting that the Knoydartian consisted of several separate tectonothermal events.
There is no general agreement as to the position of northern Scotland within Rodinia but some models locate it close to a postulated convergent margin.