Twenty-three samples of Quaternary sands from Deep Sea Drilling Project (DSDP) Leg 87 Sites 582 (trench axis) and 583 (lowermost terrace of uplifted trench sediments in the accretionary prism) off Shikoku show a 70–80% volcanic component in the terrigenous grain population. This component comprises 30–40% neovolcanic grains, among which basic and intermediate types are present in roughly equal proportions, and 60–70% palaeovolcanic grains, which are predominantly of acidic composition. No volcanic terrane occurs, in the hinterland of the Shikoku portion of the Nankai Trough, and the first such rocks to the east (up the very slight depositional slope of the Nankai Trough axis) are not encountered for more than 500 km. These, occupying the Izu Peninsula and the majority of the Tokai drainage basin to the north, are Neogene and Recent volcanics which are of comparable variability to the volcanic grains in the sands off Shikoku.

The minor component of sedimentary, metamorphic and plutonic grains in the Leg 87 sand samples can be matched with the basinal clastic ophiolitic Shimanto and Chichibu terranes and the high-pressure metamorphic Sambagawa terrane which border the Nankai Trough fore-arc along southwest Japan. This detritus also most likely derives from the Tokai drainage basin, where the easternmost outcrops of the above-mentioned terranes occur, because most sediments deriving from Shikoku and the Kii regions are ponded in terraced fore-arc basins or in basins on the lower slope. Only three major submarine canyons debouch into the floor of the Nankai Trough. The easternmost of these, the Suruga Trough, taps the volcanic Izu/Tokai hinterland, and is therefore the conduit for most sand fed to the trench off Shikoku.

The Whitby Mudstone Formation in northeast England contains three shale facies (normal, restricted and bituminous) which have previously been differentiated on the basis of sedimentary structures and faunal assemblages. This paper shows that the three facies can also be differentiated by mineralogical, geochemical and microtextural criteria determined using BSEM, EDXRA, XRD and XRF. The bituminous shale facies consists of finely laminated shales containing an early diagenetic mineral assemblage dominated by pyrite, calcite and dolomite. The weakly laminated restricted facies shales contain an early diagenetic assemblage dominated by pyrite. The normal facies shales are very weakly laminated and contain siderite in addition to pyrite. The geochemical conditions which left a dominant early diagenetic imprint on the three facies are interpreted to be carbon-rich sulphidic, carbon-poor sulphidic and very carbon-poor sulphidic respectively.

Fibrous quartz veins in deformed banded iron formation of the Amalia greenstone belt, southwestern Transvaal, are spatially related to gold–pyrite mineralization in both wallrock and vein inclusions. Poles to quartz vein orientations show a general parallelism with mineral elongation and fold plunges of the principal deformation in the wallrock. Quartz vein fibres show a consistent anticlockwise rotation, late components being subparallel to the elongation lineation, suggesting veining was probably synchronous with the principal deformation. Antitaxial fibrous veins, which dominate the mineralized banded iron formation, formed by the process of crack–seal which channelled mineralizing fluids along the vein walls, increasing the potential for fluid–wallrock interaction. Gold mineralization in quartz veins occurs in wall-parallel slivers of banded iron formation which have been plucked off the vein wall during antitaxial fibre growth. Mineralization can be explained by a process of fluid–wallrock interaction with sulphidation and gold precipitation.

In Siberia Vendian is equated with a Yudoma Complex or Yudomian. Yudomian deposits of the Siberian Platform and adjacent geosynclines differ greatly in facies and thickness. According to the composition and structure of Yudomian deposits, four facies provinces may be recognized on the platform. Local stratigraphic charts for each province are presented and their correlation and possibility to subdivide the Vendian System in Siberia into three horizons or stages are substantiated. The upper stage (Nemakit–Daldyn), on the basis of palaeontological evidence, is in its turn subdivided into two zones: Anabarites trisulcatus and Purella antiqua.

The most important Early Baikalian rearrangement is proved to take place around 800±50 Ma. The pre-Vendian (Late Baikalian) movements, though less intensive, make the determination of the Yudomian lower boundary easier.

The specific character of Vendian biostratigraphy is discussed involving all groups of the organic remains, that causes the necessity of recognition, subdivision and correlation on the basis of the whole complex of data.

The boundary between the Vendian System and the Lower Cambrian Tommotian Stage (in type section) is proved to conform to the base of the Pestrozvet Formation, which divides the A. sunnaginicus and P. antiqua zones.

A model is proposed whereby the Caledonian metamorphic basement-cover complex of northwest Scotland (the Moine) is considered as a linked thrust system. This system lies between the Moine thrust at its base and the Naver–Sgurr Beag slide at its top. Ductile fold and thrust zones, which developed at mid crustal levels at metamorphic grades from greenschist to amphibolite facies, are interpreted as decoupling from a detachment presently situated at relatively shallow depths. This model is illustrated by two preliminary balanced cross-sections. These imply shortening across the northwest Scottish Caledonides in excess of 130 km and probably over 200 km. When these structures are restored onto a crustal template a considerable quantity of lower crust is found to be required at depth. The most likely location for the lower crustal wedge is beneath the Grampian Highlands.

Systematic variations in both timing and conditions of metamorphism are observed in the Dalradian rocks of Central Perthshire, Scotland. Early (D2–D3 and syn-D3) relatively low-pressure metamorphism (550 °C, 7 kb) occurs in the Flat belt rocks of the Tay Nappe to the south, and later (post-D3) higher-pressure conditions (550 °C, 9 kb) dominate the Steep belt to the north. The latter appear to be superimposed on earlier low pressure assemblages (chloritoid–biotite) with the pressure increase probably relating to formation of the Tummel Steep Belt, possibly near 460 Ma. This polymetamorphism, in addition to the generally high pressures of Barrovian metamorphism throughout Perthshire, may account for the poor development of the metamorphic zonal pattern in this region compared to the eastern Dalradian.

An early Late Cambrian trilobite faunule of fewer than 20 specimens and including Monkaspis sp. cf. M. serrata Mong, ?Blackwelderia sp. and Cyclolorenzella sp. is recorded from the Trahagam Formation near the village of Trahagam in Hundwara Tehsil, Kashmir, India. The faunule occurs in green shales and provides the first unequivocal Late Cambrian date for sediments in Kashmir; Kashmiri fossil faunas previously ascribed Late Cambrian ages by Reed are now considered Middle Cambrian.

Bipolar bivalve genera probably existed through the greater part of late Mesozoic (i.e. late Jurassic–late Cretaceous) time. Of the various theories put forward to account for their presence, those based on some form of global climatic zonation seem most appropriate. Although equatorial–polar temperature gradients were substantially less in late Mesozoic time than at the present day, high latitude regions were subjected to temperate (or even cool-temperate) climatic regimes. Macrobenthonic marine faunas may have been more susceptible to differentiation in response to these climatic patterns than nektonic ones. This is particularly so in the late Mesozoic strata of the Southern Hemisphere.

A tholeiitic andesite flow unit occurs in tholeiitic basalt lava in the Giant's Causeway region of North Antrim, Northern Ireland. It is the first example of an intermediate differentiate to be found among these quartz-normative basalts. Separate magma batches for the preceding and succeeding basalt formations are indicated by their Zr/P2O5 ratios, and by the differing fractionation trends shown by molecular proportion ratio plots. The tholeiitic andesite was probably extruded in a superheated condition with few crystal nuclei, and subsequent undercooling produced an unusual fasciculate/spherulitic texture in contrast to the very fine and even grain of the host basalt. A liquid–liquid interface between the flow units shows small-scale lava mixing.

The Vendian in a stratotype area in the western part of the East European Platform includes three regional stratigraphic subdivisions: the Vilchanian, Volynian and Valdaian series, which clearly differ in structure and lithology. They are closely interconnected stratigraphically and geochronologically, and form an indivisible Late Baikalian structural stage of the platform sedimentary cover. The upper subdivision, the Valdaian Series, is palaeontologically substantiated and divided into horizons. The Vendian in such a composition has definite boundaries: the upper biostratigraphic, and lower lithostratigraphic ones, and is well correlated with the formations of the same age from other regions.

Two-phase packets of crystals plus liquid form rapidly at a magma contact having a high thermal contrast with its surroundings. The packets can detach from an upper contact and settle rapidly with respect to crystal settling or turbulent stirring velocities. They carry crystals and supercooling downward and act as heat sinks for crystallization of floor cumulates. Evolution of picritic magma toward neutral buoyancy and overturn into overlying basalt magma proceeds most efficiently with two-phase convection. Sinking of hot bronzite-laden liquid into cooler anorthositic liquid destroys the liquid stratification within a day or so. Two-phase convection rarely yields crystal mush thicknesses suitable for compaction of cumulates, which occurs only for a narrow window of cooling rates. Two-phase convection leads to cool, thin boundary layers above and below hot interior magma and may tend to prevent or control turbulence. The critical timing and scale of two-phase layer detachment need further study.

The East Abbotsford translational block landslide failed suddenly on 8 August, 1979, after months and probably years of slowly accelerating movement. A displacement of about 50 m occurred on a bedding plane dipping 7°, about 30 m below ground surface, at or very near the contact between two formations.

The complex graben formed around the head of the landslide is a small scale example of extensional (rift) tectonics. A wedge and prism model is developed to fit the geometry, and meet the constraints of preserving the cross-sectional area and stratal length of the beds involved and also to account for the sequential retrogressive failures of the trailing edge of the sliding block.

Reconstruction of the failure sequence at the toe shows the compressional zone to be dominated by overthrusting on upward sloping surfaces or ramps, with subsidiary backthrusting and buckling.

The energy expended in overthrusting, coupled with the decrease in mass (and hence driving force) resulting from the retrogressive spalling of the trailing edge of the slide block, indicates that the phase of rapid movement was accompanied by a sudden decrease in resistance on the failure surface for a movement of 50 m to have occurred.

Both the rift and thrust structures associated with the landslide have large scale tectonic analogues.

The present paper serves as a review on the stratigraphy and lithological characteristics of the Cambrian–Vendian boundary beds in the northwestern part of the East European Platform. This transition interval is represented by clastic rocks accumulated in humid climatic conditions. According to the lithological and palaeontological data the corresponding (transition) interval comprises two regional series: the Valdai Regional Series and the Baltic one. They both are divided into two regional stages (from below to top): Redkino, Kotlin, Rovno and Lontova.

The Redkino–Kotlin and Kotlin–Rovno boundaries are characterized by distinct contacts reflecting various changes in the sedimentary environment whereas the boundary between the Rovno and Lontova regional stages drawn on the basis of the palaeontological data only falls within the interval of continuous sedimentation.

Proceeding from the study of the fossil distribution and their living conditions during late Vendian and early Cambrian on the East European Platform the lower boundary of the Cambrian is most likely situated at the base of the Baltic Series.

Formations of Cambrian and Ordovician age originally identified by the letters A to E in the southern Amanos Mountains are reviewed using lithostratigraphic units known from the western Taurus Mountains and south-eastern Turkey. The youngest Cambrian rocks in the southern Amanos belong to the Sosink Formation and their age, based on trilobite evidence, ranges from the Badulesia Zone to the Solenopleuropsis Zone of the Middle Cambrian; they are overlain unconformably by conglomerates dated as Triassic? by means of plant fossils. Ordovician rocks – Seydişehir Formation (approx. Arenig) and Bedinan Formation (Caradoc in part) – are exposed further north, in the central Amanos. The unusual position of the allochthonous ophiolites, which rest in part directly upon Lower Palaeozoic rocks, is discussed.

Site investigations for the M25 motorway at Denham proved a maximum depth of 37.5 m of deposits filling an enclosed hollow up to 40 m across beneath a small seasonally dry valley near Higher Denham. This previously unknown very steepsided hollow is infilled with gravel and sand, partially laminated clayey silt and pebbly clay. Within these deposits a bed of organic clay mud up to 4.5 m in thickness is present. Resistivity survey of the hollow proves that it is completely enclosed.

Palaeobotanical investigation shows that the organic sediment contains fossil pollen, spores and macroscopic remains. The pollen spectra indicate that the sediments accumulated during the later half of the Hoxnian interglacial Stage (Ho III/IV). Macroscopic remains include ‘relict’ species Dulichium arundinaceum, and Brasenia schreberi, the latter being new to the Hoxnian Stage. The evidence for waterlevel fluctuation during the interglacial at the site is discussed.

The origin of the hollow is considered and the conclusion reached is that it is a doline formed by solution of the underlying Chalk bedrock. The infilling of the basin is attributed to collapse, solifluction and slope wash of local material under cold climates before and after the interglacial. The interglacial sediment is a shallow water pool accumulation. The hollow is thought to have been formed originally as a solution pipe beneath the Thames' Gerrards Cross Gravel, rapid drainage of a neighbouring glacial lake causing the major collapse in the late Anglian Stage. Subsequent infill took place during the later part of the Anglian, Hoxnian and Wolstonian Stages and possibly even later.

Heavy mineral analyses of the silt-rich sediment above and beneath the interglacial deposits are appended and indicate that it is almost all of local Reading Beds material.

Comagmatic granitic and volcanic rocks are divided into two types depending on whether or not the primary magma contains restite crystals. Examples of both of these types are discussed from the Lachlan Fold Belt of southeastern Australia.

Volcanic rocks containing restite phenocrysts are chemically identical to the associated plutonic rocks containing the same amount of restite. The more mafic granitic rocks correspond in composition to the most phenocryst-rich volcanics (up to 60% phenocrysts), and thus cannot be cumulate rocks produced by fractional crystallization, but must represent true magma compositions. These restite-bearing magmas result from partial melting in a source region up to the rheological critical melt percentage, which we estimate to be about 40% in the S-type Hawkins Suite of volcanics.

Melts which escape their restite at the source, before the critical melt percentage is reached, are able to undergo fractional crystallization in high level magma chambers by heterogeneous crystallization on chamber walls. In this case volcanic products from the top of the chamber are more felsic than the plutonic products, the plutonics are crystal cumulates and the volcanics are composed of the complementary fractionated liquid. Those phenocrysts present in the volcanics were probably eroded from the chamber walls and are less abundant (< 20%) than in the restite-retentive volcanic products.

Agricultural patterns dominate most remotely sensed images of lowland north Europe and camouflage shadow patterns related to topography and hence to underlying geological structure. Images of those parts of the near-infrared spectrum close to absorption features controlled by H–O–H bond stretching in plant cells and soil moisture largely remove this hindrance to interpretation, if they are acquired at an early stage in the growing season. The most easily available and most useful images of this type are those of band 5 from the Landsat Thematic Mapper. Spatial filtering techniques applied to digital images can enhance them for structural interpretation if filter matrices and viewing scales are chosen to match the dimensions of the most common elements of the landscape and the peak of visual acuity. Filters to enhance directional attributes of an agricultural scene give appealing results but contain spurious linear features that masquerade as faults.

The limited amount of fission track data previously available in Northern Britain has shown unexplained Cretaceous ages in the Southern Uplands and Lake District. Apatite fission track analysis has been applied to 23 samples from Caledonian intrusive bodies, to further investigate these ages. Fission track data of sphene has been carried out on seven samples and zircon in one sample.

Apatite fission track ages vary from a maximum of 278 ± 12 Ma in the Cheviot Granite, down to ages of ∼ 60 Ma in the Carrock Fell region, with intermediate ages of ∼ 140 Ma in the Eskdale Granite and ∼ 80 Ma in the Shap Granite. This variation in fission track age is accompanied by changes in the distribution of confined fission track lengths. Samples with the youngest ages (∼ 60 Ma) have long, narrow distributions (mean length > 14 μm; standard deviation ∼ 1 μm) typical of samples which have had all pre-existing tracks erased by elevated temperatures, and subsequently cooled rapidly so that all tracks now observed have formed at low temperatures. As ages increased from 60 Ma, a component of shorter tracks becomes more dominant, representing tracks which have been shortened at elevated temperatures. Thus ages greater than 60 Ma are ‘apparent ages’, representing a partial overprint of a pre-existing track record, while the ∼ 60 Ma ages record a total resetting at this time.

The heating responsible for the observed fission track annealing may be due to residence at temperatures in the range 70–125 °C over many tens of Ma, or to a short lived heat pulse perhaps associated with the Tertiary igneous province of the northwest. In either case, uplift and erosion on a scale of kilometres at ∼ 60 Ma ago is necessary to produce the observed pattern of fission track parameters. This uplift may be related in some way to basin inversions, also on a kilometre scale, known to have taken place at around the Late Cretaceous/Early Tertiary to the southeast (Cleveland, Sole Pit and Broad Fourteens Basins). No previous evidence of such uplift in Northern England has been reported, and the study reported here highlights the unique potential of apatite fission track analysis for the detection of mild thermo-tectonic events, often in areas where no other evidence exists.

The Siluro–Devonian suite of granitic plutons in the British Caledonides known as the Newer Granites, together with their associated extrusive rocks, represent one of the most extensively researched examples of calc-alkaline magmatism apparently related to orogeny. Although recent chemical studies have credibly interpreted some of the Scottish intrusions and volcanic rocks as part of a continental-margin magmatic arc generated by the subduction of lapetus oceanic lithosphere beneath Laurentia, insurmountable problems of distribution and timing arise when attempts are made to relate the magmatic activity as a whole to a traditional two-plate collision model for the orogeny.

Newer Granite magmatism is here discussed in the context of more mobilistic models for the post-Grampian evolution of the British Caledonides which involve E–W closure between Laurentia and Baltica, terminated by collision in the Silurian, followed by the northward accretion of Gondwana-derived terranes in the early Devonian. The former produced the Main Caledonian tectonometamorphism of the Northern Highlands of Scotland, the latter the Late Caledonian deformation of the slate belts in the paratectonic Caledonides. These models imply much more complex convergence geometries which can, in principle, account for the whole Newer Granite suite as a series of subduction-generated magmatic arcs overlapping in space and time.

The model proposed involves three late Caledonian magmatic arcs in addition to the Ordovician ‘Borrowdale arc’ which is not considered in this paper. One is related to Laurentia–Baltica convergence with westward subduction beneath the Scottish sector of the Laurentian margin in the Ordovician and Early Silurian, which generated the early members of the Newer Granite suite in the Highlands; a second is related to northward Silurian–early Devonian subduction at the Solway Line, which generated the younger Newer Granites and volcanic rocks north of the Highland Border; and a third, related to northward accretion of the Armorican terrane in early Devonian time, produced intrusive and extrusive magmatism as far south as Southeast Ireland and the English Midlands.

In the Lublin area of the East European Platform (southeast Poland) sedimentation of the Vendian–Cambrian marine sequence began in Late Vendian times. Vendian and Cambrian strata occur in sedimentary continuity and their features indicate sedimentation in the tidal zone of a shallow epicontinental sea. The Vendian–Cambrian boundary, drawn on the basis of mainly palaeontological data, passes between the Vendotaenia and Sabellidites zones.