Compositional zoning and dissolution in cement is a direct response to the fluctuation of pore water chemistry, the variation of which during burial can be controlled by many factors, including the interaction between pore water and rock-forming minerals and the mixing of fluids from different origins. This paper suggests that tectonic activity can, by altering the hydraulic gradient, also influence pore water chemistry and lead to dissolution of cement, made clear by zoning within siderite crystals. Three different stages of siderite cement have been described from the Tirrawarra Sandstone in the Moorari and Fly Lake fields of the southern Cooper Basin, here referred to as S1 (early), S2 (middle), and S3 (late). Ragged dissolution surfaces separate the main phases, occurring after precipitation of S1 and S2 with incipient dissolution suggested within S2. Back-scattered electron (BSE) images and electron microprobe analyses clearly differentiate each main phase of siderite. S1 is a homogeneous, iron-rich siderite whereas S2 displays patchy compositional zoning associated with several minor dissolution stages, and S3 commences with even compositional banding and grades into a thick homogeneous phase in the terms of composition.

Isotope analyses and fluid inclusion studies indicate that S1 formed at a temperature around 30 °C, S2 precipitated at a minimum temperature of 68 °C, and S3 formed around 102 °C. The heterogeneous, pitted and zoned S2 is thought to have formed during a time of active tectonism in the Cooper Basin, whereas the evenly banded nature of S3 suggests that it precipitated during a quiet tectonic period when pore waters largely remained relatively constant. It appears that siderite cements in the Tirrawarra Sandstone record tectonic activity in the form of irregular growth and dissolution highlighted by compositional zoning with stages of strong dissolution recording particularly active times when pore waters changed composition dramatically. Some zoning could be related in part to tectonic pulses. The temperature recorded by each of the siderite stages allows their precipitation to be tied to a burial history curve, and by making some simple assumptions about that history, the timing of cementation can be estimated. This can be an additional tool for calibrating the thermal history of an area.

The extent of elemental mobility during lower greenschist to amphibolite facies metamorphism of a uniform turbidite suite (Greenland Group, New Zealand) has been evaluated using data for major elements and 19 trace elements. Simple comparison of average compositions at 2 wt % Al2O3 intervals in the data suites shows little contrast between lower greenschist protolith and upper greenschist and amphibolite facies equivalents, except for enrichment of CaO and Sr, and loss of Ba and Rb, particularly in the sandier end members. Division into psammitic and pelitic suites using TiO2/Al2O3 and Zr/Al2O3 ratios allows delineation of individual residual enrichment models on Ti-reference element plots, and both lithotypes can be used to assess potential elemental mobility. These plots show that a large number of elements (Ti, Al, Fe, Mg, Ce, Cr, Ga, La, Nb, Ni, Sc, Th, V, Zn and Zr) constitute immobile reference species, with abundances equal to their equivalent lithotype in the protolith, and little mass loss or residual enrichment. K and Rb also largely conform to the residual model, but in the amphibolite facies some exchange between pelite and psammite may occur. A number of elements show enrichment (Mn, Cu, Pb, U, Na, P) or depletion (Y) in a small number of samples, but the significance of these contrasts is questionable due to relatively large variation in the protolith. In contrast, Ca and Sr show progressive and marked enrichment with increasing grade, and Ba and As are clearly depleted in amphibolite facies psammites. In the amphibolite facies some Si may have been lost by psammites, and gained by the pelites, although there has been no mass change from the suite as a whole. A large part of the Ca and Sr enrichment in the amphibolite facies can be accounted for by metasomatic homogenization of calcareous concretions which occur in the lower grade protolith. The metamorphism of the Greenland Group is thus considered to be essentially isochemical.

The middle and upper members of the Gavilán Formation near Vélez-Rubio (Almería Province, southeast Spain) are interpreted as carbonate platform deposits. The studied outcrops form geologically part of the External Zones of the Betic Cordillera (South Iberian Palaeomargin). A genetic unit limited by intra-Sinemurian and intra-Upper-Carixian sedimentary breaks is defined. The evolution of the parasequence sets in the area, and the development of deeper sedimentation in its northern outcrops, suggest that this platform was isolated with regard to the South Iberian Margin. Three distinct parasequence sets are proposed: progradational parasequence set (only locally present), retrogradational parasequence set (middle member of the Gavilán Formation) and aggradational parasequence set (basically composed of the upper member of the Gavilán Formation). Sedimentary features (such as neptunian dykes, sharp lithological changes, thickness variations), the presence of palaeofaults and the subsidence history all lead to the conclusion of a significant regional tectonic influence in the genetic unit evolution. Normal extensional faulting has been proposed as a major control on sedimentation on this isolated platform. This regional factor has completely distorted the effect of the eustatic fluctuations for this period of time.

The Upper Carboniferous Kent Coalfield lies concealed beneath various Mesozoic formations, its southern areas lying about 20 km north of the commonly accepted position of the main Variscan Deformation Front. However, despite intense intra-coal deformation, the existing literature is ambivalent about compressional Variscan features in Kent, the general view being that coal deformation is largely the product of the depositional environment. The main deformation is interpreted here as the result of Variscan compression, the structural style being imposed by the sandstone-dominated lithology. This conclusion is necessitated by the regularity of deformational structures revealed by mine workings, and supported by coal sequence irregularities suggestive of thrusting, especially in the lower Westphalian strata, all of which is paralleled in parts of the South Wales Coalfield. The Kent data indicate that, as in South Wales, a zone of thrusting many tens of kilometres wide lies in advance of the main deformation front. Structural trends are consistent with an overall swing in the front from east–west across much of central-southern England, to more northwest–southeast across northeastern France. This swing may represent a transpressional transfer zone, within which stress deflection and block rotation produced thrust vergence oblique to the overall direction of maximum compression.

Gondwanan Neoproterozoic tectonothermal events (Pan-African and Brasiliano) are represented in northern mainland of Nova Scotia by volcanic and sedimentary rocks assigned to the Jeffers and Georgeville groups and by gabbroic to granitoid plutons. These rocks comprise part of Avalonia, an exotic terrane in the Appalachian orogen that was deposited in an arc-related environment along the periphery of Gondwana prior to accretion to Laurentia. Lavas sampled in the basal units of the Jeffers and Georgeville groups yielded slightly discordant U–Pb zircon and monazite data that fall on chords with upper intercept ages of 628 Ma and 617.7±1.6 Ma, respectively. Syntectonic to late syntectonic plutons intruded into these groups yielded U–Pb zircon ages of 606.6±1.6 Ma and 603+9−5 Ma. The former intrusion also yielded a concordant titanite age of 607±3 Ma. When combined with previously published ages, these data indicate that the back-arc deposition recorded in these groups lasted 10–15 million years (628–613 Ma) and was closely followed by c. 613–595 Ma metamorphism, intrusion and heterogeneous strike-slip related deformation. Assuming no significant shuffling of fault blocks, the relative locations of the Cobequid–Antigonish back-arc basin and the southern Cape Breton Island volcanic arc are consistent with their genesis above a north-west-dipping subduction zone. The age range of arc-related magmatism in Nova Scotia is similar to that of Avalonian rocks in southeastern Newfoundland and Britain, lending support to hypotheses of Neoproterozoic linkages.

Crystalline crust examined along the seismic profile LT-7 is subdivided into four blocks separated by distinct vertical fractures. The northeastern block belongs to the East European Craton (Baltica). Its three-layer structure is similar to that of the Svecofennian crust farther to the northwest. The southeastern block reveals typical, two-layer Variscan crust. Both central blocks have a peculiar structure not comparable with the crust of the Danish and North German areas: two lower layers, with velocities identical or close to that of the cratonic lower and middle layers, are extremely thin, and an upper layer, 8–11 km thick, shows surprisingly low velocities. This upper layer probably represents the folded and weakly metamorphosed Lower Palaeozoic sequences, although the connection with undeformed epicratonic cover cannot be excluded. Significant differentiation of crustal types in different segments of the Trans-European Suture Zone favours the concept of tectonostratigraphic terranes which collided with Baltica.

Four new specimens of phalangiotarbid (Arachnida: Phalangiotarbida) from the Upper Carboniferous (upper Westphalian A) of Westhoughton, Lancashire, UK, are referred to Mesotarbus peteri sp. nov. An additional Lancashire phalangiotarbid, Phalangiotarbus subovalis (Woodward, 1872), from the Upper Carboniferous (lower/middle Westphalian A) of Burnley, is redescribed and designated the neotype of this species. This material allows new interpretations of the opisthosomal segmentation and respiratory organs of phalangiotarbids, and a reconstruction of Mesotarbus peteri is presented.

A scanning electron microscope based cathodoluminescence technique utilizing a novel collector system reveals complex internal heterogeneities within granitic quartz grains. The technique overcomes the low intensity and limited variation in cathodoluminescence generated by quartz, which hamper conventional cathodoluminescence analysis. Detailed images of zoning patterns in quartz are comparable to those observed in minerals such as feldspar, and attributed to a combination of progressive growth, boundary layer effects and mineral–melt disequilibria produced during fluctuations in melt composition and temperature during the crystallization interval. We attribute such mineral–melt disequilibria to open system, mixing behaviour in the granite plutons sampled.

The Llanrwst Pb–Zn veinfield occupies fractures in an Ordovician volcano-sedimentary sequence, with three separate mineralizing events (M1, M2 and M3). The Llanfair Pb–Zn–Cu veinfield consists of sporadic mineralization in Silurian sediments. Fluid inclusion data from both veinfields indicate mineralization took place from CaCl2-bearing brines, up to 26 wt % NaCl equivalent, between 125 and 190 °C with cooler (< 100 °C), more dilute fluids associated with later thrusting at Llanrwst. Sulphur at both veinfields was derived during the main phases of sulphide precipitation from the host rocks, with paragenetically late sulphides and sulphates deriving sulphur from 34S-enriched surface waters. Carbon and oxygen isotopic data on vein carbonates shows that both deposits formed from waters that had undergone extensive water–rock interaction. Carbon was derived from at least two sources: marine carbonate dominated at Llanfair, whereas organic matter in the host rocks was more significant at Llanrwst. These data indicate that the veins formed from evolved brines which migrated along fault systems to the loci of deposition during a phase of extensional tectonics in late Devonian to Tournasian times.

A new gravity model of the crustal structure of the Trans-European Suture Zone in the northwestern Poland has been constructed. The Bouguer anomaly map, obtained after stripping off the three-dimensional gravity effect of the sedimentary cover down to the Zechstein formations, is characterized by a 50 mGal gravity anomaly. We have assumed that the short-wavelength components derive from upper crustal intrusions and the long-wavelength components reflect crustal thickness and lateral heterogeneity which are strongly supported by the new seismic data along the LT-7 geotraverse. Quantitative modelling of gravity data along three profiles crossing the area indicate the presence of anomalous masses within the Lower Palaeozoic sequence, mainly along the Teisseyre-Tornquist Zone. Two of the profiles crossing the long-wavelength ‘stripped’ gravity high suggest the existence of a zone of 35 km crust above a dense upper mantle along the Teisseyre-Tornquist Zone. The extent of the zone can be determined based on the Bouguer anomalies interpretation.

The South Orkney Islands are the exposed part of a continental fragment on the southern limb of the Scotia arc. The islands are to a large extent composed of metapelites and metagreywackes of probable Triassic sedimentary age. Deformation related to an accretionary wedge setting, with associated metamorphism from anchizone to the greenschist facies, are of Jurassic age (176–200 Ma). On Powell Island, in the centre of the archipelago, five phases of deformation are recognized. The first three, associated with the main metamorphism, are tentatively correlated with early Jurassic subduction along the Pacific margin of Gondwana. D4 is a phase of middle to late Jurassic crustal extension associated with uplift. This extension phase may be related to opening of the Rocas Verdes basin in southern Chile, associated with the breakup of Gondwanaland. Upper Jurassic conglomerates cover the metamorphic rocks unconformably. D5 is a phase of brittle extensional faulting probably associated with Cenozoic opening of the Powell basin west of the archipelago, and with development of the Scotia arc.

Radiolarian and calpionellid dating establish a significant sedimentary hiatus within a reduced pelagic sequence of the central part of the Ionian zone (western Greece). Bottom-current activity probably decreased during the Oxfordian, allowing encroachment of radiolarian-rich sediments onto a Jurassic high (at Kato Kouklessi), and then increased again during Kimmeridgian–Tithonian time. The onset of Vigla Limestone sedimentation is diachronous within the Ionian zone, spanning late Tithonian to various levels of early Berriasian time. This diachroneity can be explained by dispersal of fine-grained sediment by current activity.

A very large pterosaur cervical vertebra is described from the Upper Maastrichtian deposits of Mérigon, in the foothills of the French Pyrenees. It resembles the vertebrae of Quetzalcoatlus, from the Maastrichtian of Texas, more than those of Arambourgiania, from the Maastrichtian of Jordan. The estimated wing span of the Mérigon pterosaur is close to 9 m, which makes it one of the largest known flying creatures. Giant pterosaurs still had a wide geographical distribution at the end of Maastrichtian time, which is not suggestive of a declining group, although it is difficult to obtain an accurate estimate of taxonomic diversity of terminal Cretaceous pterosaurs on the basis of available data.

The morphological diversity, considered as a biological signal, of a series of four Upper Callovian (Middle Jurassic) ammonite populations of Côte-d’Or (France) is quantified. These populations fall within two third-order sequences of a second-order transgression. A sampling method that adheres as closely as possible to the morphological characteristics of the populations is established. It is valuable in that it eliminates the subjectivity related to taxonomy to allow more objective comparisons between the biological signal (shell morphology) and the physical signal (eustasy).

Miocene subtidal sandwave deposits in southwest Japan were influenced by periodic flow and steady flow. The sandwave deposits can be divided into five units, based on lithofacies and thickness. In order of accretion, unit 1 consists of unidirectional sand bedforms without mud drapes, unit 2 of unidirectional sand bedforms with thin, discontinuous mud drapes, unit 3 of bidirectional sand bedforms with thin continuous mud drapes, and units 4 and 5 of relatively thinner and smaller bidirectional sand bedforms with continuous mud drapes. The thickness of units 1 to 3 increase progressively to 2.6 m, and units 4 to 5 subsequently decrease from 2.0 to 1.0 m. Variations between the units are due to differing combinations of periodic and steady flow velocities. Palaeoflow velocity is estimated from grain size and unit thickness. Depth-mean velocities of steady flow components gradually decrease from 0.72 ms−1 to 0.16 ms−1 with unit accumulation.

The Upper Silesian and Małopolska blocks are situated near the southwestern boundary of the East European Platform within the Trans-European Suture Zone. The Lower Palaeozoic lithologies of the blocks reveal different stratigraphic and diastrophic development. In the Upper Silesian Block, unmetamorphosed and gently folded Lower Cambrian to Ordovician sedimentary rocks rest on a Cadomian basement. The Lower Cambrian is represented by an older (sub-Holmia) Borzęta Formation and a younger (Holmia) Goczałkowice Formation. The thickness of the Cambrian lithologies increases from the southwest towards the lateral part of the block. In the Małopolska Block Palaeozoic and Precambrian lithologies are represented by regionally metamorphosed and intensely folded Lower Cambrian–Vendian clastic rocks which are unconformably overlain by Ordovician–Lower Silurian carbonates and Upper Silurian clastic rocks. The crystalline basement of the Małopolska Block has yet to be recognized. The Lower Palaeozoic sediments of both blocks are overlain by Devonian and Carboniferous rocks. The blocks are in direct contact along a narrow tectonic zone, a part of the largely concealed Hamburg–Kraków fault zone, in which tectonic evolution has taken place spasmodically with strike-slip movements predominating.

Sedimentological evidence suggests that sea-water chemistry has oscillated between ‘Aragonite’ and ‘Calcite’ seas during the course of Phanerozoic time. During ‘Calcite’ sea periods aragonite was soluble and dissolved on the sea-floor. Here we propose, using a survey of familial diversity, that during times of such corrosive seas bivalved molluscs which secreted their shells entirely of aragonite were at a selective disadvantage compared to those with calcitic outer shell layers. This is the first case in which it has been suggested that there was a dynamic link between sea-water chemistry and the evolution of a particular taxon throughout Phanerozoic time.

M. B. Edwards comments: Of all the geological occurrences he had seen, this was the most remarkable and revealing. For him it was a spiritual place, and the journey was a pilgrimage; he used this word himself. This was now the seventh time he was making this journey. Thus wrote Rosendahl (1945, p. 22; my translation from Norwegian) about the geologist Sederholm. Decades later, after dozens more publications of innumerable additional outcrops, the ‘Reusch's Moraine’ exposure of upper Proterozoic glacial tillite resting on a glacially striated pavement (Reusch, 1891) remains unique and significant.

Writing about this exposure, Jensen & Wulff-Pedersen (1996) concluded ‘There is no evidence for glacial origin or contribution for the diamictite material’ (p. 137) in the Bigganjargga tillite. This discussion explains why I disagree with their conclusions.