The clay mineral, dickite, is a common rock-forming mineral of many Carboniferous sandstones in North Wales and Northern England and of Middle Jurassic sandstones over much of North-East Yorkshire. It occurs as well-shaped authigenic crystals associated with highly altered mineral assemblages, including partly dissolved feldspar which is one of the probable sources of the alumina and silica.

A small collection of non-marine lamellibranchs and plants from the Madumabisa Shales of the Gwembi district of Northern Rhodesia is described. It includes a new species of the genus Kidodia, Palaeomutela rhomboidalis, and P. neglecta, associated with Glossopteris indica. The Madumabisa Shales may be correlated with similar beds in Southern Rhodesia assigned to the Tapinocephalus zone of the South African Lower Beaufort Series, and are of Upper Permian age.

The Permian in Durham is the most internally disturbed of the newer or covering beds of England. In deep borings it is a dark dolomitic rock full of sulphates and chlorides; at the surface it has quite a different appearance. The Permian and overlying Secondary beds seem to have been lowered by downwarping. During the subsequent differential uplift and denudation the area remained a land surface and the sulphates were removed by penetrating water, not by subaerial weathering. Horizontal and low angle thrusts occur in the Sunderland area above about the middle of the underlying Coal Measure basin. The movements may have been induced by diminution in rock volume following solution and segregation accompanied by attraction or packing together of the mass of the formation.

Alkaline syenites from the Ruri Hills in Western Kenya are described, and the hypothesis advanced that their present constitutions have been developed partly by replacement. The syenites occur as dykes and small plugs associated with ring complexes of carbonatites which, together with agglomerates, largely form the hills, and are presumed to be congeneric with an ijolite mass at Usaki.

A record has been made of the outliers of Basal Grit occurring on the Limestone of the North Crop of the South Wales Coalfield, some of which have not previously been located. The solution subsidence theory to account for their present anomalous levels when compared with the parent Grit outcrop to the south has been enlarged upon, and an attempt has been made to determine the mechanism of this subsidence which ranges in vertical extent up to a maximum of approximately 600 feet. The outliers are of economic importance since their predominant crumbly quartzose sandstones are a source of almost pure silica sand.

The oldest formation exposed in the Gorsley area is a hard limestone considered by previous authors to be equivalent to the Aymestry Limestone. All the available evidence, however, supports a correlation with the Wenlock Limestone. The succeeding strata comprise 4½ feet of Dayia Beds and 7 feet of Upper Ludlow Beds, so that the total thickness of Ludlovian strata is only 11½ feet. AH the Lower Ludlow Shales and the Aymestry Limestone are cut out by the unconformity below the Dayia Beds. This remarkably thin development is attributed to movement at various times during the Ludlovian epoch along an axis passing through the Gorsley region. The main movements probably took place in middle Ludlow times.

This paper describes a revised method of plotting analyses of igneous rock suites using the Mafic and Felsic Indices as defined. A composite M–F diagram has certain advantages over the triangular iron-magnesia-alkalis diagram and enables a genetic distinction to be made between the tholeiitic and calc-alkaline series.

Of the various members of the Younger Granite Complex columbite is found only in the biotite granites. It occurs as an accessory mineral, and varies in amount in different types.

A new ammonite assemblage from the Ampthill Clay is recorded. Its correlation with the Trigonia clavellata beds of Dorset indicates that these condensed beds are represented by two distinct horizons in the Ampthill Clay—the Boxworth Rock below and the Knapwell Ditch horizon above.

A new species of Palaeechinus from the Lower Carboniferous of Alberta is described.