Contrary to a previously published view, evidence is given to show that the Galway Granite is entirely later than both the quartzandesine migmatization and the potash-felspar migmatization in Connemara, and that the Oughterard Granite is probably earlier than the Galway Granite, not later. There is also strong evidence against regarding the foliated marginal granite of the north and north-east border of the Galway Granite as being different in origin from the marginal granite often found in the southern, western, and north-western borders. These results agree with the radio-chemical date of 365 m.y. determined for part of the Galway Granite.

Boreal, Tethyan, and Indo-Pacific faunal realms may be recognized in belemnite faunas of Callovian and most of later Mesozoic time. The presence of such clearly-defined realms indicates restriction of belemnite migration and perhaps the belemnites were confined to the shelves, extensive areas of deep water forming barriers. Migration of belemnites in the Tethyan and Indo-Pacific realms may be explained in terms of deep water barriers, but delimitation of the Boreal realm is thought to be a result of climatic zoning.

Theory and experiments show that a component of compressive strain parallel to layering is necessary to develop drag folds. The component of shear strain needed for the monoclinic symmetry of such folds is not sufficient to form the wavy pattern. Based upon fluid dynamic theory and experiments with layered rubber slabs it is suggested that drag folds on flanks of major folds generally evolve as follows: Layer-parallel compression of more or less straight layered rocks causes some layers to shorten essentially by more or less uniform compressive strain and thickening (thick and not-so-competent layers), other layers to shorten essentially by buckling (thin and most component layers). In the course of time, however, the rate of buckling of the thick layers becomes significant relative to the rate of arc-shortening, and the thin layers with the early formed short buckles are forced to mimic the larger folds of the thick layers more or less passively. In this process the early formed short buckles become tilted and assume the typical drag-fold shape.

Spongolite beds are common in the basal Namurian shales of Co. Clare and Co. Limerick, and are especially well developed north of Ardagh, Co. Limerick. Spongolites from this locality are described and are considered to represent a local deposit of siliceous monactinellid spicules. They are compared with the “phtanites” of the Assise de Chokier of Belgium, which are of the same age and similarly preserved. Stylolite seams developed within the rocks are briefly described.

The Dittonian Stage in Pembrokeshire comprises the Lower Marl Group (higher beds), the Sandstone-and-Marl Group, and the Upper Marl Group (at least lower half). These formations cannot be distinguished lithologically from Dittonian strata of the Welsh Borderland 100 miles away along the depositional strike.

Cyclothems of intraformational conglomerate (scoured surface below) → sandstone → siltstone with concretions recur vertically in each area. The conglomerates in both districts consist of intraformational siltstone and concretionary debris. Flat-bedding, primary current lineation, planar cross-bedding, trough cross-bedding, and ripple-drift bedding are common to the sandstones. Suncracked siltstones abound in both Pembrokeshire and the Welsh Borderland. Slumped bedding, sandstone pipes, and animal burrows are the structures penecontemporaneous with deposition in each area.

The Dittonian strata of the Welsh Borderland are shown to be probably floodplain deposits, by reason of their close similarity to the modern sediments of the Colorado Delta floodplain and Colorado River. The occurrence of an identical facies in Pembrokeshire suggests the even wider extent of this floodplain in early Lower Old Red Sandstone times, when the sea lay far to the south of both areas.

A thin vein of dolerite at Slemish, Co. Antrim, shows an unusual plane and smooth contact against the dolerite of a Tertiary plug. A columnar growth at the contact indicates special conditions for crystallization. The selvedge is described and an attempt made to explain the growth and orientation of the olivine.

Ripple marks of unusual dimensions are recorded from the Sandbanks Limestone (Middle Limestone Group) at a foreshore locality 3 miles south of Spittal in North Northumberland. The structures are thought to have been formed in a partially cohesive calcareous mudas wave-oscillation ripples which have undergone penecontemporaneous modification.

Measurements were made of features formed in relation to former sea-levels along the north coast of Sutherland between Melvich and Durness. The results suggest that four raised-levels can be identified. The uppermost, which is at a greater elevation on the east, is related to glacial and fluvio-glacial deposits, which indicate its formation in close proximity to glaciers. This level has been correlated with the “100 ft.” beach. The next level also shows slight tilting up to the east and seems to correspond with the “50 ft.” level elsewhere in Scotland. The two lowest levels are horizontal, and can be correlated with the “25 ft.” and “15 ft.” levels respectively.

A detailed analysis is presented of a small complex bent-fold structure that occurs in the angle of the Donegal Granite outcrop. It is the most northerly expression of the major strike swing in South-West Donegal and may be of considerable importance to the interpretation of that phenomenon. Five different lineation types are related to events leading to the severe bending of a curved tight syncline in massive quartzite. The bending occurs with surprisingly little disruption of the quartzite and must have occured under plastic conditions possibly associated with granite intrusion.

Two types of slumps are described; small sag and drop-shaped structures in the fine sandstones which develop out of iron-ore rich laminae, and the much larger slump folds in the coarse sandstones which have wavelengths of 25 to 200 cm. and are characterized by open “synclines” linked by pointed “anticlines”. Complex structures are common. It is suggested that liquifaction of the lower parts of the slumped beds has resulted in collapse of the upper parts. Kuenen's pseudo-nodule experiments reproduce many of the observed structures.

The Lower New Red Sandstone of Devon outcrops in a north-south band near Torquay to Exmoor. It rests unconformably on the Devonian and Culm. Westwards of Tiverton and again west of Exeter the outcrop extends into the Culm synclinorium. The Lower New Red sediments in the second and longer of these narrow tongues, together with the associated Hatherleigh, Highhampton and Essworthy outliers, form the subject of this paper.

Barth argued that the CIPW conventions governing the calculation of normative pyroxenes and olivines are based upon inadequate or incorrect mineralogical information and should be abandoned. The real occasion for the conventions appears to be petrological, not mineralogical. Qualitative agreement between norms and modes of undersaturated rocks requires the use of these or very similar conventions. Ease of calculation is no longer a major consideration and a more realistic set of rules could now be adopted if it were available.

An extensive pumice raft was encountered by H.M.S. Protector in the area of the South Sandwich Islands on the 14th March, 1962. Evidence is presented which suggests that this material was ejected on the 5th March, 1962, from a submarine eruptive centre 35 miles to the north-west of the existing islands but on the axis of the South Sandwich Arc.

The succession of Lower Old Red Sandstone rocks found in the Welsh Borderland, is reinterpreted to reveal a shifting pattern of facies of far greater complexity than was hitherto realized. The sequence of vertebrate faunas is examined in conjunction with the sediments, and in this way a fuller account is given of the conditions of life of these early vertebrates, than was previously possible. The boundary between the Downtonian and Dittonian Stages is revised to coincide with the major palaeontological break in the region, and this is shown to approximate to a major lithological break, which is here accepted as the division between the local rock units known as the Downton and Ditton Series.

Recent research work has revealed an area of regionally metamorphosed Pre-Cambrian schists (previously undescribed) in south-west Pembrokeshire. The name “Dutch Gin Schists” is proposed for this newly described group of rocks. The Johnston Plutonic Series (Dimetian) are seen to be intruded into these schists, and the nature of the intrusive contact is described. The structure and petrology of the schists, and the nature of diorites adjacent to the contact and that seen elsewhere in the igneous mass is compared, and a suggestion made regarding the age of the foliation. A comparison is made with the Pre-Cambrian metamorphosed rocks of Malvern, Shropshire, and Anglesey.

Large cognate xenoliths showing rhythmic banding in anorthosite and pyroxenite are described from a camptonite dyke. Analyses of the camptonite, a pleochroic titanaugite and a titaniferous brown, hornblende are given.

A study of Metriophyllum gracile has revealed some unusual features in its mode of attachment and growth.

It has been suggested that the Southern Uplands fault of Scotland does not continue across central and western Ireland. Published geophysical evidence, however, strongly suggests that the fault does continue, under the Carboniferous cover, at least as far as the neighbourhood of Galway.

A cordierite-garnet granulite from Assam, India, carries optically positive cordierite, garnet, spinel, biotite, and sillimanite. The optics of the cordierite are: α = 1·534, β = 1·540, γ = 1·548, 2V = + 81°, while the composition of the garnet inferred from the writer's charts, in terms of the end-members, is Al73Py20Sp2An3Gr2. The development of an iron-rich garnet in association with a magnesium-rich cordierite is discussed, and data are presented to show that such garnets have a restricted compositional range. It is doubtful if the FeO/MgO ratio in a cordierite-garnet assemblage can be used for interpretation of the physical conditions governing the formation of the host rock.

A specimen of shale containing an echelon of quartz-filled vertical tension fractures which merge “at depth” with a single filled fissure dipping 65 degrees confirms, in general, E. M. Anderson's interpretation of dyke echelons. Also illustrated are a change in manner of stress relief and an upward diminution of strain.