The Morar Group is a sequence of Tonian (lower Neoproterozoic) sedimentary rocks that have been subjected to a series of tectonic and metamorphic events since their deposition.

The contact with the overlying Glenfinnan Group of the Loch Ness Supergroup is everywhere a tectonic one, formed by the Sgurr Beag Thrust or related structures.

[1] In the lower strain areas there are sufficient sedimentary structures preserved to provide constraints on the depositional environment for the Morar Group.

[4] For the Ross succession, the Basal Pelite is interpreted to represent deposition in paleovalleys, similar to the Diabaig Formation of the Torridon Group.

A second cycle began with a return to shallow water deposition in the lower part of the Crom Psammite Formation, grading upwards to a distal braid plain setting, before returning to a tidal shoreline and eventually to shallow water marine deposition in the Diebidale Pelite Formation.

The youngest detrital zircon and rutile ages found for samples from the Morar Group are 1070–1000 Ma (million years ago).

[1] At least four orogenic events have been interpreted to affect the Morar Group, in order of age, the Renlandian, the Knoydartian, and the Grampian and Scandian phases of the Caledonian Orogeny.

[5] The D1 structures in the Glenelg area are affected by two later phases of folding that have been assigned to late Grampian (D2 460–440 Ma) and Scandian (D3).