Seatura is a Pliocene caldera-type, shield volcano situated in SW Vanua Levu, Fiji. Shield-building basaltic lavas are predominantly subaerial though there is a shoreline facies of fossiliferous sediment, pillow lava and hyaloclastite. Late-stage events include the intrusion of a dyke swarm in and around the caldera, and deposition of laharic conglomerates. Chemically the rocks are intermediate between tholeiite and alkali basalt and have intraoceanic levels of TiO2. Late-stage derivatives include benmoreite, trachyte, and propylitically altered rocks. The parent magmas are thought to have been partial melts of undepleted mantle at relatively deep levels. Tapping of these deep levels may have been facilitated by extensional plate tectonic conditions existing in the Fiji area during the development of Seatura Volcano.

Late Triassic Radiolaria have been recovered from a bedded chert collected early in 1977 in the South Orkney islands. This is the first reliable palaeontological evidence for the age of the so-called basement complex that forms most of the exposed rock of a microcontinent on the southern limb of the Scotia Ridge. The fossils place a lower limit on the age of deformation of at least part of the complex as post-Karnian or Norian. The basement is overlain by undeformed Jurassic to Cretaceous conglomerates, which suggests this event took place during the early Mesozoic Gondwanian orogeny.

The new data are consistent with the interpretation that the basement complex of the South Orkney Islands represents part of a subduction complex and was accreted to the Pacific margin of Gondwanaland during the late Triassic or early Jurassic time.

In the evolution of the Scottish Dalradian basin, the climax of widespread tholeiitic magmatism pre-dated or coincided with major basement faulting and the onset of deep marine sedimentation in Lower Cambrian times. Earlier basin-deepening and precursory igneous activity had already occurred. Major and trace element chemistry of low-grade metabasites indicates their affinity with basalts from ocean-spreading centres, or transition to ‘within-plate’ types. Geological evidence favours a tectonic setting for this igneous suite and the Highland Border Series on the NW margin of an actively evolving Lower Cambrian ocean basin, possibly a marginal basin to the Iapetus Ocean System.

Trend surface analysis has been used widely in geology and geomorphology but only rarely has it been applied to directional data. This neglect stems from the inapplicability of normal trend surface procedures to such data. An adaptation of normal trend surface procedures specifically designed for use with directional data is, however, available as a FORTRAN IV computer program. This technique is described and its usefulness in generalizing regional patterns of flow is illustrated by applying it to data representing ice flow direction in Central Scotland.

Ultrabasic and basic lavas are interbedded with metamorphosed Lower-Carboniferous sediments in the northern slope of the Alborz mountains, NE Iran. In the outcrop area at least 15 individual units of ultrabasic lava have been observed. Flow units range in thickness from a few metres up to about 70 m. The inner parts of the flow units are holo-crystalline, showing a poikilitic texture with rounded small crystals of serpentinized olivine surrounded by large crystals of clinopyroxene (‘wehrlitic facies’). The upper portions of the thicker units are olivine-free, and pyroxene, sometimes accompanied by brown hornblende, is set in a groundmass of fine-grained epidotized plagioclase (‘doleritic facies’). In the upper and lower margins of flows the groundmass is devitrified to chlorite and tremolite. Small-scale differentiation and igneous lamination is observable in transition zones between the wehrlitic and doleritic ‘facies’. The upper doleritic facies and other individual basic units have a tholeitic chemistry. In contrast, the chemical composition of wehrlitic rocks (which predominate amongst the exposed rocks in the area) is comparable with Archaean ultrabasic lava flows in Canada and southern Africa.

About 300 gravity stations were established at 2–4 km intervals along an E-W profile across the Lower Benue Trough from Gboko-Nsukka-Auchi with the main objectives of investigating the nature and configuration of the basement complex underlying the trough and estimating the thickness of the sedimentary cover rocks. The resulting Bouguer anomaly profile shows a series of alternating positives and negatives. For a preliminary interpretation, the positive anomalies are attributed to shallow basement and the negative anomalies to sediment-fill of maximum thickness, 4250 m.

Devonian Antiarchi in China are chiefly distributed in the S and W of the country. They are represented by 17 genera and more than 26 species, of which three genera are cosmopolitan, namely Asterolepis, Bothriolepis and Remigolepis. The early Devonian Antiarchi fauna, Yunnanolepis, Phymolepis, Zhanjilepis, is an East Asiatic fauna. The middle and late Devonian faunas are essentially endemic and associated with few cosmopolitan elements, their geological ages, however, are different from those of the cosmopolitan antiarch taxa elsewhere. As considered in the present study, six main antiarch assemblages occur: (1) Yunnanolepis-Qujinolepis assemblage (Lower Devonian), (2) Xichonolepis-Wudinolepis assemblage (Eifelian), (3) Hunanolepis tieni-Bothriolepis sinensis assemblage (Givetian), (4) Bothriolepis kwangtungensis-Bothriolepis lochangensis assemblage (Givetian), (5) Remigolepis spp. assemblages (Frasnian-Famennian), (6) Sinolepis-Asterolepis sinensis assemblage (Famennian).

Overbank deposits of the Narrator Brook, exposed by the excavation of a drainage ditch, are described. The deposits, which consist of coarse (sand and gravel), fine (silt and clay) and peat units, were laid down in a floodbasin environment. The coarse units are interpreted as crevasse-splay deposits, rather than being classified as floodbasin sediments along with the fine units. Three stages of development in the evolution of the floodbasin are identified. The first stage is represented by the development of peat at a time when the area was not subjected to flooding, the second by deposition of the fine and coarse sediment units and the third by an upper peat horizon. No precise date for the formation of the deposits is at present available, but it is thought that they may be the result of man's activity in the catchment.

Thin beds composed mainly of quartz and albite occur interstratified with epiclastic rocks in a thick marine Early Permian sequence in the eastern part of the New England Fold Belt, eastern Australia. The sequence has suffered very low grade regional metamorphism and the quartz-albite rocks retain few primary textural features. A pyroclastic origin for these rocks is argued on the basis of inherited sedimentary characters and their distinctive mineralogical and chemical composition, and it is suggested that they accumulated as glass-rich ash-fall tuffs. The present chemical composition of the quartz-albite rocks suggests the tuffs may have initially altered to zeolitic assemblages. Similar quartz-albite rocks, perhaps misidentified as chert or siliceous siltstone, probably occur in other low-grade metamorphic sequences, the progenitors of which accumulated adjacent to active magmatic arcs.

New, well-preserved material of the Ordovician proetacean trilobite Rorringtonia, hitherto of uncertain taxonomic position, indicates that it belongs to the aulacopleurid subfamily Scharyiinae. It also elucidates the position of another problematic proetacean, Analocaspis, which is now considered to be congeneric with Rorringtonia.