The only known regional dyke swarm in New Zealand is described. Dykes are 1·5–2 feet thick and have been intruded vertically into unconsolidated Cretaceous sediments. The present attitude of dykes is found to be affected by compaction of these sediments and by regional folding and bedding-plane slip. A rough measure of total compaction is obtained.

The textures of the chilled marginal gabbro of the Skaergaard intrusion and of the coarser marginal gabbros 25 yards further in are described and related to counts of the number of separate crystals of the chief mineral species per cubic centimetre of the rock. An explanation of the textures and number of crystal individuals is attempted in terms of various degrees of supersaturation in the magma. In the chilled rock abundant nucleation of plagioclase and olivine, presumably at the middle labile stage of supersaturation, is inferred. This is followed by ophitic or poikilitic crystallization of pyroxene and ilmenite about scarce nuclei, produced at lower temperatures, presumably during the early labile stage of supersaturation for these two minerals. The coarser gabbro, further in from the margin, has about half the number of plagioclase crystals per cm.3 compared with the chilled rock and only one twenty-fifth the number of olivine crystals, and these have a tendency to be ophitic in texture. Under these slower cooling conditions, supersaturation apparently still reached into the middle labile region for plagioclase, giving many nuclei, while olivine, like pyroxene, separated under early labile supersaturation conditions and only relatively few nuclei formed. The contrasting textures of the plateau magma-type basalts of Mull and the tholeiitic basalts of Northern Ireland are explained along similar lines.

The Torridonian rocks of Rhum are divided into five sub-divisions on lithological grounds and the succession is found to be closely comparable with that of Skye. On the basis of the comparison, four sub-divisions, totalling 8,500 feet in thickness, are allocated to the Diabaig Group while the 6,000 feet of strata belonging to the fifth and highest sub-division are allocated to the Applecross Group. The sediments of the Diabaig Group are now seen to form a great wedge thickening and coarsening consistently from Gairloch south-south-westwards to Rhum; a phenomenon obscured by the previously held correlation of the Rhum Torridonian with that of Skye and the Mainland.

This paper reviews the stratigraphic micropalaeontology of the Lapithos Group of Cyprus, which is now known to be Upper Cretaceous to Lower Miocene in age. A three-fold subdivision, on the basis of planktonic foraminifera, into Lower (Upper Cretaceous) Middle (Danian to Eocene) and Upper (Oligocene to Lower Miocene) Lapithos Formations is suggested and a summary of the outcrops of each formation is given. The foraminiferal faunas of the Lapithos Group are discussed and it can be shown that a planktonic and a neritic faunal assemblage is present in each formation. The Terra Limestone, hitherto considered as part of the Dhali Group, shows faunal affinities with the Upper Lapithos neritic facies and is therefore placed in the Lapithos Group.

This paper gives a definitive description of the lithology and thicknesses of the Upper Middle Hecla Hoek rocks of Ny Friesland, Spitsbergen, arising out of Cambridge expeditions since 1951. The succession is the late Pre-Cambrian part of the Hecla Hoek Geosyncline, lying below the Tillite horizons and characterized essentially by limestones and dolomites.

In the Musa Valley area rocks of the Papuan Ultramafic Belt outcrop discontinuously over an area of 25 miles by 45 miles. The rocks are part of a folded layered sequence ranging from magnesian dunite and peridotite, chemically and petrographically typical of the alpine ultramafic suite, to olivine gabbro and bytownite gabbro. Agglomerate like breccias consisting of fragments of ultramafic rock in a variable matrix occur as irregular vent-like bodies in the peridotite and dunite and as horizontal sheets in a Pleistocene-Recent sedimentary sequence. The breccias are interpreted as vent and extrusive breccias resulting from the penetration, brecciation and local entrainment (fluidization) of peridotitic country rock by volcanic gases. Olivine alkali basalt was probably the parental magma responsible for the gaseous activity. The breccias show a sequence of stability fields for the assemblages mesh-texture serpentine and bastite (i.e. chrysotile and lizardite mixtures); antigorite; olivine and enstatite; and these are correlated qualitatively with variation in intensity of the brecciation process. Chemically the brecciation process was responsible for the addition of H2O, SiO2, CO2, Al2O3 and O2 and the removal of Fe and Mg from the fragmented rock. Minerals which are of direct crystallization in the matrix fluid environment include chalcedony, fibrous serpentine (chrysotile), magnesite, quartz, andradite, and garnierite. There is no evidence of the presence of an ultramafic, serpentine magma in the genesis of the breccias.

Following a recent re-mapping of the district east of Pontesford Hill, Shropshire, it now seems likely that the Uriconian and Longmyndian rocks at The Lyd Hole are faulted against one another, and that the Pontesford Shales form two outcrops, separated by faulting, and not a single outcrop as previously suggested. Doubt is cast on the validity of the so-called “rhyolite” of Habberley Brook, and the faunas and correlation of the Pontesford Shales are reviewed in the light of new evidence.

Cross-bedding within the sandstones of eastern Fife indicates a predominant north to north-easterly source for the clastic debris. This inference is in accordance with cross-bedding data from sandstones of similar age in southern Fife and West Lothian.

A study of the morphometry of an ephemeral stream system which is incising itself into a terrace of the Farmington River, Connecticut, supports the regional relationship between stream-channel gradient and valley-side slope angle suggested by Strahler (1950). The continuing areal extension of the system allows stream order to be employed here as a relative measure of the passage of time. Thus it is possible to recognize that steepening and parallel development of a given valley-side slope may have their place in a sequence of early stage erosional development characterized by headward channel extension and ramification.

A narrow layer of quartzite, emplaced within epidiorite by foldthrusting, is transformed to albite-trondhjemite aplite and contiguous zones of the epidiorite are enriched in biotite. By reference to six chemical analyses it is found that, with but small additions of potash these transformations can be accounted for by the combined processes of (a) mechanical mixing of the initial quartzite and epidiorite, and (b) metamorphic inter-diffusion between this mixture and the adjoining epidiorite.

Lower Carboniferous strata are shown to be absent from the Amazon basin and Ghana, the Bermejo series of Bolivia is Permo-Triassic, the Sekondi series of Ghana does not include glacial deposits and may prove to be Devonian, early Carboniferous glaciation is unknown in Africa and restricted to Argentina in South America. In the light of these interpretations the extent to which late Carboniferous glaciation affected northern South America and Africa is briefly reviewed and shown to conflict with the reconstructions by L. C. King (1958). The non-glaciation of Africa and South America north of at least latitude 25 degrees South during early Carboniferous times is regarded as proving that these areas did not pass through the south polar region at that time. The known distribution of early and late Carboniferous glacial deposits is considered in relation to continental drift and movement can only have been westwards during the Carboniferous period.

The known carbonatite eruptive centres in Northern Rhodesia fall within a linear belt trending N.E.-S.W. the most conspicuous elements of which are the colinear troughs of the mid-Zambezi valley and the Luangwa rift. This lineament is an important and longstanding zone of crustal weakness. Its extensions outside Northern Rhodesia are briefly indicated and its ramifications inside the Territory are examined, particularly in reference to the localization of carbonatite activity around rift intersections.

Five-sixths of all the continental area on the Earth's surface has antipodes in oceanic regions. This proportion is not significantly different from what one would expect on the assumption that the continents are randomly situated.

The paper describes a conodont fauna from the Namurian of North Staffordshire. Seventeen genera and thirty-four species are identified in the fauna, of which Hibbardella fragilis, Hibbardella pennata, Lambdagnathus macrodentata, Mestognathus bipluti, Neoprioniodus spathatus, and Subbryantodus subaequalis are new species. The composition of the fauna and its correlation with similar faunas in the United States of America and Germany are discussed.

The uncertainty of the most frequent orientations of β and fold axes relative to tectonic co-ordinates has possibly been overemphasized in tectonic literature. The β concentrations of obliquely deformed folds will be spread along characteristic paths. The superposed deformation would in most cases of flexural slip appear as folds in certain predominant directions and on suitably oriented surfaces. In tectonites with a single, nearly horizontal mode for the orientations of the lamination, β maxima formed by flexural slip should mostly be parallel to the axes of rotation.

A sequence of reversed graded beds occurs in a group of flaggy rocks intercalated within the Upper Dalradian grits of Inishowen. Usually these beds have a thickness between ½ inch and 2 inches, and are characterized by a laminated, argillaceous base which grades up into a fine-grained, arenaceous upper member.

Two large gravel deposits, at Corran on Loch Linnhe, Inverness-shire, and at the entrance to Loch Etive, Argyll, are described, and it is considered that they are fluvio-glacial fans, marking a contemporaneous halt in the retreat of the valley glaciers which occupied the sites of these two lochs. Orientation analysis of the pebbles in the Corran deposit supports this conclusion. Similar analysis on gravels along the northern shore of Loch Etive indicates that they are not raised beaches, but were deposited in lakes held up by the glacier which deposited the Loch Etive fan.

The Cornbrook Sandstone of Titterstone Clee Hill has plants of Westphalian (Middle Coal Measures) age. It is thus probably a correlative of the lower Kinlet Group of the Forest of Wyre. The base is unconformable to the Old Red Sandstone and Carboniferous Limestone while the top is apparently conformable with Productive Coal Measures of the Sweet Coal Group, also of Middle Coal Measures age.

The paper describes an unconformable junction of Upper Llandovery upon Malvernian in the Gullet Quarry of the South Malvern Range and discusses the evidence for and the significance of other comparable junctions in the Malverns. It is considered that Taconic movements are a factor in Malvern tectonics and that the importance of a “ western boundary fault ” to the Malvernian has been overstressed in the past.

Evidence is presented which shows that nepheline develops a preferred c-axis orientation in response to deformative stresses. It is believed that this is the first record of a stress-induced preferred orientation of nepheline.