Trilobites of upper Ludlow age are described from Member A of the Read Bay Formation on Cornwallis Island. Four new species are represented: Helokybe spio gen. et sp.nov. (Dechenellinae), Encrinurus hyperboreus sp. nov., Kailia? capra sp.nov. (Encrinurinae) and Hemiarges echinatus sp.nov. Other taxa present are: an effaced scutelluid; Cyphaspis sp.; a warburgelline; two more encrinurids; two other forms of Hemiarges. The trilobites occur in sediments indicative of a shallow subtidal environment, with the exception of the warburgelline which occurs in sediments deposited under deeper subtidal conditions below storm wave-base.

The blueschist facies metamorphism has always been one of the most difficult to quantify. This is for two important reasons. Firstly, the temperatures and pressures of the facies tend to be inaccessible to experimental analogues of the blueschist indicator minerals: aragonite, glaucophane, jadeite and lawsonite. Secondly, the conditions of blueschist metamorphism are not typical of the earth's crust. For a rock to be metamorphosed under lower temperatures at a given pressure than those of normal geothermal gradients (considered here as negative deviation metamorphism) requires ‘rapid’ downwarping and reuplifting. The movement during metamorphism, combined with hydration rather than dehydration (a feature of this environment) fails to preserve a single metamorphic culmination and hence the mineralogy and textures of blueschist assemblages may fail to match the conventional phase equilibrium metamorphic model. Thus the simple phase equilibrium interpretative basis of metamorphic petrology is recognized as only a special case of a more general theory of metamorphic chemical/mineral interaction.

Stratigraphical investigations in the Finchley depression (Middlesex depression) are summarized and show that a gravel, laminated deposits and till sequence is present. Compositional study of the gravels indicates that they were derived from S of the present Thames valley. Gravel patches in North Surrey can be subdivided into two terrace fragments formed by a Mole-Wey south bank Thames tributary. The upper unit is correlated with the gravel at Finchley. The lower unit terrace can be shown to grade into the Thames Black Park Terrace Gravel, and the latter is extended through London to Dartford and Chatham. The events leading to the diversion of the Mole-Wey tributary by the Anglian chalky till ice parallel those of the Thames in the Vale of St Albans and suggest that similar events may also have occurred in other S bank tributary valleys to the E.

The rare cladid inadunate crinoid genus Lampadosocrinus is presently known from 2 species, L. minutus (Peck) and L. obtusus Strimple and Koenig, of lower and middle Mississippian age (Tournaisian, Lower Carboniferous). Lampadosocrinus frustulum sp.nov. is described from the Lower Pennsylvanian (Namurian B or C. Upper Carboniferous) of Oklahoma, U.S.A. Some difficulties encountered in orientation of the theca of microcrinoids presently classified as cladid inadunates are discussed.

This paper proposes an alternative to the complex stratigraphical nomenclature introduced in recent descriptions of the stratigraphy of Eastern Svalbard. We believe that the platform nature of the Mesozoic succession in Svalbard enables recognition of individual stratigraphical units over very wide areas. Our principal conclusions are that the Wilhelmøya Formation can be recognized as the upper formation of the Kapp Toscana Group and occurs throughout Eastern Svalbard. It overlies the De Geerdalen Formation on Hopen and Wilhelmøya. The Janusfjellet and Helvetiafjellet Formations can be recognized on Kong Karls Land.