A suite of Tertiary alkaline porphyritic microgranites and hybrid and peralkaline granite from northwest Pakistan is described, with six rock analyses (five of them new). The microgranites, an earlier group of which some contain garnet, have undergone metamorphism, lacking in the granites. The microgranites are shown to be precisely similar to those from the Shewa–Shahbazgarhi area, for which four analyses (two of them new) are presented, and related to a third group from Tarbela. The mineralogy of the rocks is discussed, with seven new analyses of aegirine, riebeckite, ferrohastingsite and astrophyllite, and X-ray determinations of the feldspar compositions. The granites are considered to be related to the undersaturated syenites and associated rocks of Koga, and a petrogenetic scheme for the alkaline province is presented, with a K/Ar age determination, tentatively deriving the source magma (quartz trachytic) from a Himalayan tholeiite.

Identifications of new material collected by Cambridge expeditions and a new find from Hopen are discussed with reference to earlier work and to the stratigraphic setting. All available generic names relating to Svalbard material are listed systematically. A supplement to the alphabetical index of records (Buchan et al., 1965) is added.

The Stokes Anomaly is traced for over 3000 km, from 700 km S of New Caldedonia almost to the eastern edge of the Campbell Plateau. For most of its length the anomaly is a double feature with positive peaks from 30 km to 50 km apart. From outcrops on the western side of the Southland Syncline it is inferred that the northeastern peak is caused by Permian volcanics, and the south-western peak by the associated Permian intrusives. The anomaly is displaced dextrally by a total of 1000 km where it crosses the New Zealand land mass. About 500 km of the displacement is caused by displacement on the Alpine Fault Zone, and the remainder by distributed dextral shear and by displacement on other sub-parallel faults.

Granodiorite stocks were intruded into the alpine peridotites of southern New Caledonia in the Eocene following overthrusting of the ultramafics onto the sialic core of the island. Strong zoning, from mela-diorite to granodiorite, is developed in one pluton and is believed to be the result of assimilation of ultramafic and mafic rocks by the calc-alkaline magma. Evidence in favour of a consanguineous relationship between the felsic and ultramafic rocks is largely circumstantial. In their petrography, mineralogy and chemistry, the rocks show few differences from other felsic plutonics of Tertiary age in the southwest Pacific.

Re-assessment of the idea that the Monian and Longmyndian accumulated along the margin of a palaeo-ocean suggests that Monian sedimentation occurred near the eastern shoreline of a micro-continent. If Monian igneous activity, metamorphism and deformation are attributed to an underlying subduction zone, this must have dipped northwestwards away from a small ocean basin to the southeast. Consumption of this ocean floor brought about collision with the continental shield and simple deformation of the Longmyndian.

The alkali syenites of the Mundwara magmatic suite, Sirohi district, Rajasthan, in north-western India, are chiefly developed in the Musala hill of the complex. They comprise three principal varieties representing different stages of crystallization, viz. nepheline-sodalite syenite, nepheline-barkevikite microsyenite, and nepheline poor leucosyenite. The dominant constituent of these hypersolvus syenites is alkali feldspar, an orthoclase microperthite showing a variable degree of exsolution. The chief mafic mineral is a distinctly green and zoned sodic pyroxene, close to aegirine-augite in composition. A brown calciferous amphibole, identified as a barkevikite, is developed in addition in the microsyenites. Reddish brown biotite of the phlogopite-annite series is common to all the syenites. The petrography and mineralogy of the syenites are discussed, and a comparative study of the Mundwara syenites with similar rocks of the Deccan volcanic province is presented. Chemistry and mineralogy of the syenites of the Mundwara suite suggest that they are related to those associated with the Deccan volcanic province.

A conventional trend surface is symmetrically placed between the observed values of a dependent variable. The proposed median surface is symmetrically placed between the ranks of the observed values. The use of a median surface is illustrated by its application to the distribution of silver in a granodiorite stock.

Sheet-like bodies of dolerite with granophyre within the Hypersthene-gabbro on the NE shore of Sanna Bay are shown to be akin to the granophyric quartz-dolerite, and suggest that the latter originally extended for a considerable distance N of its previously mapped limits.

K–Ar measurements of the Chotanagpur granite and associated intrusive rocks are found to be younger than the geological events in the Singhbhum region of Bihar. The history of metamorphism, granitic activities and igneous intrusions in the Chotanagpur area continued for a period from over 1000 Ma to 185 Ma. The relevant geological sequences and correlations are briefly discussed.