A re-examination of the Moine—Sub-Moine boundary of the Morar dome shows it to be a zone of transition between two metamorphic states. Some notes on the structure accompany a mineralogical description of the changes across the boundary; discussion is made of evidence that the metamorphic boundary transgresses the geological boundaries. The schists of the core are thought to be in a lower metamorphic state than those of the envelope.

The detailed examination of rocks recently collected from a traverse and from isolated points within this intrusion has led to the conclusion that it is a large, layered intrusion showing rhythmic and cryptic variation, and comparable in many respects with the Great Dyke of Southern Rhodesia.

Primary shears with oblique-slip displacement can only arise by failure after a rotation of two of the three principal axes of stress from an expected vertical and horizontal position relative to the earth's crust, and are either normal-wrench or thrust-wrench hybrids. As a consequence of a full 90° clockwise or anticlockwise rotation, the changes in pitch of striations on slicken-sided fault planes belonging to both categories are stereographically represented by two small circle courses which are ∠90°–ø apart for the normal-wrench association, and ∠180°–ø apart for the thrust-wrench one: ∠ø being the angle of internal friction. Using these assumptions to analyse the distribution of oblique-slip shears exposed in the south-western part of the Midland Valley of Scotland, it appears probable that two unrelated sets of commonly occurring normal-dextral shears are of primary origin, for the inferred azimuthal orientations of the principal axes of stress are remarkably close to those estimated for other, more orthodox tectonic features found elsewhere in the Midland Valley and appropriately absent in the south-west.

The peninsula between Ekmanfjorden and Dicksonfjorden has been mapped geologically. Devonian sandstones are overlain unconformably by a Permo-Carboniferous sequence of limestones (200 m.) and dolomites and gypsum (300 m.). This is followed by more than 150 metres of Permian cherts. The strata show a slight but consistent dip towards the SSE. A fault having the trend of this dip has been proved in Ekmanfjorden. Sills are intruded in the higher levels of the succession and it is suggested that the intrusions are contemporaneous with the faulting. By comparing the lithology the area can be correlated with the known sections of Billefjorden and Kongsfjorden.

Sedimentary dykes from the Dalradian of the South-west Highlands of Scotland are described. It is suggested that these features are characteristic of certain geosynclinal environments.

Small isolated masses of highly olivine-rich lavas within a dominantly basaltic series of pillowed flows have been found in the northern foothills of the Troodos Igneous Massif. The rock is characterized by abundant phyric olivine usually set in a glassy, basaltic groundmass. Both intrusive and extrusive varieties of the rock have been found. It is suggested that the rock originated as a melt, possibly from the Troodos ultrabasic complex. Comparison is made with the serpentine lavas of Turkey.

By means of measurements of the direction of magnetization, talus may be distinguished from rock which has remained in situ. A criterion has been developed for the conditions under which the boundary between talus and rock in situ can be identified. This method is particularly useful when the upper portion of the rock in situ is broken and weathered and it has been applied with success to a scarp in the dolerite of the Western Tiers in Tasmania. Here the results suggest that in the upper part of the talus the jointed blocks have definitely fallen into a sub-horizontal position, whereas at lower levels they are only slightly tilted.