A revised and expanded lithostratigraphy is presented for the lower part of the Dalradian Supergroup in the Central Highlands. Stratigraphical correlations combined with lateral facies variations and geophysical studies are used to define a framework of NE-SW-trending marine basins that formed during a major phase of Neoproterozoic rifting. These basins extended rapidly and infilled with up to 5.5 km of turbiditic deposits, later thermal subsidence is indicated by the regional development of shallow marine shelf environments. The margins to these basins are characterized by lateral facies and thickness changes, stratigraphical omission and onlap relationships of both Grampian and Appin group strata onto a basement of predominantly gneissose strata. Whilst there is clear evidence for a stratigraphical and sedimentological break at the base of the Grampian Group there is presently insufficient structural or metamorphic evidence to prove an orogenic unconformity. Geochronological data confirm the presence of Precambrian events in the basement but have yet to do so in the cover.

The Lower Palaeozoic stratigraphy of the East Greenland Caledonides, from the fjord region of North-East Greenland northwards to Kronprins Christian Land, is reviewed and a number of new lithostratigraphical units are proposed. The Slottet Formation (new) is a Lower Cambrian quartzite unit, containing Skolithos burrows, that is present in the Målebjerg and Eleonore Sø tectonic windows, in the nunatak region of North-East Greenland. The unit is the source of common and often-reported glacial erratic boulders containing Skolithos that are distributed throughout the fjord region. The Målebjerg Formation (new) overlies the Slottet Formation in the tectonic windows, and comprises limestones and dolostones of assumed Cambrian–Ordovician age. The Lower Palaeozoic succession of the fjord region of East Greenland (dominantly limestones and dolostones) is formally placed in the Kong Oscar Fjord Group (new). Amendments are proposed for several existing units in the Kronprins Christian Land and Lambert Land areas, where they occur in autochthonous, parautochthonous and allochthonous settings.

The Geal Charn-Ossian Steep Belt is a major composite synclinal structure cored by an upward-facing Appin Group succession. It is located at the margin of a west-facing sedimentary basin where more than 8 km of Grampian Group sediment was deposited adjacent to an intrabasin structural ‘high’. The ‘high’ comprises mainly gneissose metasedimentary rocks, the Glen Banchor succession, which acted as the basement to the Grampian and Appin group rocks. Major unconformities are recognized at more than one level as the sedimentary basin successions onlapped onto the 'high'. The primary major upright folds and associated slides of the Steep Belt developed when considerable shortening was focused along the basin margin during the Caledonian Orogeny.

Detailed studies of the relationship between structure and metamorphism in the southern Scottish Highlands and new Rb-Sr isotope data for the Rough Craig Granite have resulted in a revision of the tectonothemal history of the Dalradian. Two main events are recognized. The first (Dl), probably at c. 590 Ma, produced a regiondy inverted stratigraphic succession on the underlib of the Tay Nappe. The second event, possibly between 520 and 470 Ma, encompassed regional D2 and D3 deformation phases and was synchronous with peak Barrovian metamorphic conditions.

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