Hopen (Hope Island) in the Svalbard archipelago is difficult of access and only recently has reliable geological information become available. Published information is reviewed and combined with new observations.

The island, 37 km long and no more than 2.5 km wide or 370 m high is structurally simple with flat-lying arenaceous strata which are described with three measured sections. Three new local stratal units are defined: Iversenfjellet Formation (325 m, base not seen); Flatsalen Shale Formation (55 m); and Lyngefjellet Sandstone Formation (80 m, top not seen).

From a few ammonite, bivalve, saurian and plant megafossil occurrences and 30 palynomorph taxa (newly recorded) the marine and fluviatile facies range in age from possibly late Karnian, through Norian, Rhaetian and possibly into early Jurassic. The Rhaetian flora, well established palynologically, is the first clear evidence of rocks of this age in Svalbard. Associated Sirenites extends the range of this ammonite and suggests that Svalbard may yield significant new evidence for this span of Earth history.

Granitic rocks in the central Transantarctic Mountains were emplaced and crystallized during the Early Ordovician Period, as indicated by Rb-Sr whole-rock isochron dates (488 and 463 Ma) and a concordant U-Pb date on sphene (476 Ma). Other U-Pb data provide evidence for an old inherited component of zircon in the granites.

The ichnogeneric status of trilobite furrows (Cruziana) and resting excavations (Rusophycus) is discussed and the suggestion (Seilacher, 1970) that these two distinct types of trace should be united under the genus Cruziana is rejected.

An assemblage of benthonic Foraminiferida of late Palaeocene age is described from subsurface material from Halesworth, Suffolk. Twenty-two species are listed, and are compared with microfaunas which were described by Haynes (1954–8) from the type Thanetian.

Potassium–argon and rubidium–strontium isotopic age studies of the Wolf Rock phonolite of SW England confirm its age as 131 Ma, with an initial 87Sr/88Sr ratio of 0.703. The existence of a Mesozoic volcanic province of this age on the margin of the Labrador–Biscay rift is discussed with special reference to its implications for the early evolution of the N.Atlantic Ocean, and the general relationship of alkaline igneous activity to major periods of plate reorientation.

The paper reports the occurrence in the 2.9–3.1 B.Y. old charnockitic terrains of Southern India of some basic charnockites that are strikingly similar, chemically, to basaltic komatiite from the 3.4 B.Y. old Barberton greenstone belt of Southern Africa, and suggests that the pre-metamorphic evolution of Archaean charnockitic terrains followed the same trends that characterized the development of Archaean greenstone belts. The main events in the evolution of one such terrain, the ‘Madras granulite belt’, before it was subjected to granulite facies meamorphism some 2.6 B.Y. ago, is outlined in Table 2.

The Palaeozoic rocks of Hydra consist of a sequence of limestones and dolomites with some interbeds of shales and sandstones. Fusulinid foraminifera indicate the sequence is entirely Permian in age and not Carboniferous and Permian as previously thought.

Four vertical holes drilled into the olivine cumulates of the Jimberlana Intrusion all show a decrease in serpentinization with depth, suggesting that serpentinization can be a low temperature, present-day process.

Protoquartzites outcropping in a small anticline in the Plynlimon area of mid-Wales contain numerous flat-lying and low-angle, fibrous quartz veins, which are subparallel to the ab plane of the fold. The quartz crystals are elongated at a high angle to the vein walls, and in some cases exhibit a curvature which is thought to have been adopted as the crystals grew. The orientation and internal structure of the veins suggest that they formed on fractures initiated during compression and extended by hydraulic fracture, the crystal curvature being a result of shearing during syntectonic crystal growth. Pore water was important both in bringing about the critical effective stresses required for fracturing and as a carrier of locally remobilized free silica.