Vegetation diversity and pattern changes, and their relation to tectono-sedimentary histories are compared between selected Euramerican Late Palaeozoic coalfields, to understand better the controls on the dynamics of the Pennsylvanian terrestrial ecosystems and to demonstrate the problems with comparing data from various basins. The analysis is based on data from the following basins of different geotectonic and palaeogeographical positions: the cratonic Pennines Basin, the foreland South Wales and Upper Silesia basins, and the fault-related Intra Sudetic and Central and Western Bohemia basins. The analysis indicates that complex factors are responsible for changes in plant diversity and vegetation patterns. These are related to climate, tectonics, preservation potential, sampling biases and the current state of revision of the flora in each basin. Plant diversity patterns in the basins differ because of local controls and/or the character and detail of the available data. Maximum diversity varies among the basins within the Langsettian and Duckmantian substages. Two apparent step-like drops in diversity were detected within coal-bearing strata of most basins: at the Duckmantian/Bolsovian boundary and at the Bolsovian/Asturian boundary. Further and more prominent falls are related to transitions from coal-bearing to non-coal-bearing (mostly red bed) strata or vice versa during Stephanian times. Interpretation of climatic signals recorded in the sedimentary successions indicates that Westphalian and middle Stephanian times were wet intervals, whereas early and late Stephanian times were drier.

The Blattodea (cockroaches sensu lato or roachoids) from the southern coalfields of the UK are reviewed or examined, especially species occurring in more than one coal basin including Mylacris abrupta (Bolton, 1930) comb. nov., and undescribed material from Writhlington (Somerset). It is proposed that a derived mylacrid Mylacris–Sooblatta assemblage is used to extend the latest Westphalian and earliest Stephanian insect zonation from the continent to southern Britain, thus augmenting the European Pennsylvanian scheme.

A summary is given of the lycophyte species as distributed in fifteen Euramerican coalfields during Asturian (Westphalian D) times. The datasets from the coalfields are analysed using unweighted pair group cluster analyses of Jaccard's Coefficients. Separate analyses were done on the full dataset (the full list of morphospecies) and on a more restricted dataset (only the morphospecies of vegetative organs). Three groupings of coalfields were resolved in the analyses. The two most clearly defined groupings represented the intramontane basin coalfields, and the coalfields of the lowland basins on the Variscan foreland where the lycophyte floras are well documented. The third grouping included those basins with less well-studied lycophyte floras, where the apparently low species diversity has undoubtedly affected the results. More work is needed on these poorly documented floras to produce a more rigorous phytogeographical analysis.

The South Wales Coalfield has the most complete Westphalian macrofloral record anywhere on the Variscan Foreland or adjacent basins, with 135 biodiversity-meaningful morphospecies having been recognized. All of the standard macrofloral biozones of the Westphalian Stage have been recognized, although a detailed comparison with the Central Pennines Coalfields has indicated some discrepancies in the relative positions of the biozonal boundaries. Total Species Richness progressively increases through the Langsettian Substage, and then remains relatively stable through most of the Duckmantian and Bolsovian substages. There is a distinct reduction in Total Species Richness towards the top of the Bolsovian Substage, but this partially recovers in the middle Asturian Substage with the appearance of a range of marattialean ferns, and medullosalean and callistophytaleans pteridosperms. There is no evidence of any significant drop in Total Species Richness towards the top of the succession, indicating that conditions at this time were relatively stable. The change from coastal floodplain to alluvial braidplain conditions in middle Bolsovian times correlates with a marked increase in the proportion of medullosalean remains being preserved in the adpression record, reflecting an expansion of the clastic-substrate habitats.

The coal-bearing succession of the Upper Silesia Coal Basin consists of deposits filling a flexural foredeep basin. Accumulation initially compensated for regional and differentiated subsidence, after which the general depositional surface remained nearly flat. The deposition of the coal-bearing succession started at the end of Mississippian times (Pendleian Subage) and continued with hiatuses through almost the whole of Pennsylvanian times, and stopped in the Westphalian D Subage. The up to 8500 m thick coal-bearing succession traditionally has been divided into four main units called ‘Series’, and all of them are subdivided into subsidiary units known as ‘Beds’. The occurrence of the intervals containing marine faunas within the lower ‘Paralic’ part of the coal-bearing succession resulted from eustatic ingressions. The higher ‘Limnic’ part of the succession was laid down in fluvial systems, while the lower part was formed mostly in a fluvial and, to a lesser extent, complex coastal system. Sedimentation of the coal-bearing succession was controlled by both autogenic and allogenic factors.

The Bolsovian to Cantabrian sediments in the Dobrudzha Coal Field are about 800 m thick. They were deposited in a depression bounded to the east, south and west by active synsedimentary faults. Most of the succession is coal-bearing clay- and siltstones, including occasional lacustrine deposits with fresh water faunas (molluscs and ostracods). Basin-wide sandstone intervals are associated with two periods of erosion and non-sequence. There are also localized sandstone bodies with vitrinized plant remains associated with the basin-margin faults. Conglomerates are only thin and rarely developed, and pebbles are only rarely found in the sandstones. There are only three basin-wide coals (m5 at the middle Makdonka Formation, n1 at the base of the Krupen formation and p3 in the middle Gurkovo Formation) representing times of diminished influx of clastic sediment, and thus of reduced movement along the basin-margin faults. Based on the depth of the erosive down-cutting, it is estimated that the elevation of the basin was at least 180 m above sea-level. The area surrounding the basin is supposed to be an alluvial plain covered with vegetation and swamps. The dense vegetation cover suggests periods of high precipitation, whereas dry conditions with active weathering are most probable during deposition of the Velkovo Formation. Volcanic activity occurred near to the depression, perhaps related to the boundary faults. In the stratigraphically highest part of the succession (the Kabalak Member), volcaniclastics are the main component of the detritic sediments. The basin eventually inverted to become a horst around which Permian sediments were deposited.

The Dobrudzha Coalfield in northeast Bulgaria has coal-bearing deposits ranging from latest Namurian to early Stephanian age (late Bashkirian to Moscovian age). Palynology of the coals in the upper Makedonka, Krupen and Gurkovo formations has been used to identify major changes in the vegetation during late Westphalian and early Stephanian times. The palynomorphs were grouped in two different ways (according to general morphotype and according to parent plant group) and stratigraphical trends in the two sets of groups used to identify vegetation change through the succession. Detrended Correspondence Analysis was also used to identify ecological relationships between the palynofloras. In the upper Makedonka and Krupen formations, lycophyte spores mostly comprise 15–25 % of the palynofloras in the thicker seams, but in the thinner coals they can represent up to 55 %. Of the other plant groups, ferns are the most abundant, representing 31–69 % in the thicker seams, 12–41 % in the thinner seams. This suggests that the arborescent lycophytes were mainly restricted to pioneer vegetation in these upland areas, and were replaced by ferns as the peat substrates became better developed, suggesting better-drained conditions. The thinner seams also have a noticeable component of sphenophyll spores, indicating significant areas of open conditions allowing colonization by these scrambling plants. In the Gurkovo Formation coals, lycophytes form an even smaller part of the palynological spectra, usually less than 10 % and in only one sample just over 25 %; fern spores make up 43–57 % of the palynofloras. This is in contrast to the palynofloras reported from contemporaneous clastic deposits in South Wales, most of which consist mostly of 34–60 % lycophyte spores and 14–34 % fern spores. Even more marked is the difference from the contemporaneous coals formed in lowland settings in the USA, which have mostly > 50 % lycophyte spores. This evidence suggests that the timing of the decline in abundance of arborescent lycophytes varied according to elevation above sea-level. In lowland coastal settings, the lycophytes remained dominant until middle–late Cantabrian times, but in more inland areas they were progressively replaced mainly by arborescent ferns during late Westphalian times.

As an example of microstructural and magnetic fabric evolution, and geochemistry of mafic dykes during a subsequent orogenic overprint, a major Mesoproterozoic dyke complex in Scandinavia, the Västerbotten complex of the Central Scandinavian Dolerite Group, is traced westwards into the crystalline nappes of the early Phanerozoic Caledonian orogen. Using geophysical, field, microscopic, magnetic and geochemical information, dykes and sills are characterized, and their overprint during Caledonian orogeny documented. The Västerbotten complex is composed of sets of dykes, trending NE–SW, NW–SE and WNW–ESE, respectively. Similar dykes are exposed in allochthonous positions (Lower and Middle allochthons) in the Caledonian fold-and-thrust belt. The autochthonous dykes are generally undeformed and retain both their primary texture and mineralogy. Chilled margins are well preserved. In the Caledonian Lower and Middle allochthons, similar dykes in crystalline basement rocks are progressively faulted and sheared when proceeding from the marginal to the interior parts of the orogen. Dyke margins are more likely to be sheared than the interior parts of dykes. In the Lower Allochthon, under very low- and low-grade metamorphic conditions, dykes are distinctly less competent than granitic host rocks. Thick dykes are more competent than gneisses; thin dykes do not show such competence contrasts. In the Middle Allochthon, metre-scale dykes with patches of altered plagioclase phenocrysts can still be discerned in low-strain domains. Highly sheared dykes are drawn out to thin layers of centimetre thickness. Dykes are deformed together with the crystalline country rocks under greenschist-grade metamorphic conditions without major competence contrasts. Magnetic fabrics show an evolution similar to the silicate mineral fabrics. The magnetic fabrics in the dykes are transformed successively from ferromagnetic–magmatic in the Autochthon to ferromagnetic deformational in the Lower Allochthon and, finally, paramagnetic deformational in the Middle Allochthon. As a consequence, the magnetic susceptibility decreases for several orders of magnitude. Geochemically, the dykes are dominantly sub-alkaline basalts typical for continental tholeiites and can be distinguished from the Neoproterozoic dykes in the Särv-Nappe equivalents (highest part of the Middle Allochthon), which show a more MORB-like (E-MORB) magmatic signature. Preliminary age information from a dyke in the Lower Allochthon of the Børgefjell area and the Middle Allochthon is consistent with the assumption that these dykes are time equivalent with the Central Scandinavian Dolerite Group. Therefore, the studied dykes may represent an extension of the Västerbotten complex or a new complex of the Central Scandinavian Dolerite Group. According to section restorations, the Caledonian allochthons were situated further WNW relative to their present position, and, originally, the mafic dykes cut across all of the Fennoscandian lithosphere, at least to the present Atlantic margin and the earlier passive margin of the Baltica terrane. As a consequence, these dykes may provide a link for pre-Caledonian and pre-Grenvillian plate reconstructions.

Rapakivi granites and several small leucogabbroic and gabbroic bodies are located in the Rangnim Massif, North Korea. The largest batholith in the Myohyang Mountains covers an area of 300 km2 and was intruded into Precambrian metamorphosed rocks. It has a SHRIMP U–Pb zircon weighted mean 207Pb/206Pb age of 1861 ± 7 Ma. The country rocks of rapakivi granites are Neoarchaean orthogneisses and Palaeo-Mesoproterozoic graphite-bearing metasedimentary rocks of granulite facies, and they are similar to those of the rapakivi granites and anorthosites exposed in South Korea and in the North China Craton. We conclude that the three massifs in the Korean Peninsula commonly record an identical Palaeo-Mesoproterozoic anorogenic magmatic event, indicating that they have a common Precambrian basement with the North China Craton.

The Gushan diorite pluton, located at the northern margin of the North China block, was emplaced during Middle Devonian times (SHRIMP U–Pb zircon age of 390 ± 5 Ma). Rocks from the pluton are characterized by low SiO2 and high alkali contents, and they show monzodiorite compositions in a total alkali v. silica (TAS) plot. They exhibit light REE-enrichment, no to slightly positive Eu anomalies, strong depletion in Rb, Th, U, Nb, Ta, P, Zr, Hf and Ti, enrichment in Ba, K and Sr, low contents of Y and Yb, and high Sr/Y ratios. They have a relatively narrow range of isotopic compositions with initial 87Sr/86Sr ratios of ∼ 0.7050, εNd(T) values of −9.5 to −7.5 and zircon εHf(T) values from −11.8 to −5.8. These features are remarkably similar to another Middle Devonian intrusion, the Shuiquangou syenitic complex at the northern margin of the North China block. These similarities suggest that the two intrusions probably have a common origin. They were considered to be derived from a type I enriched mantle, ultimately with some involvement of ancient lower crustal components, and were likely emplaced in a back-arc extension environment related to southward subduction of the Palaeo-Asian oceanic plate or during the cessation of the subduction. Aluminium-in-hornblende barometry studies of the Middle Devonian Gushan pluton yielded emplacement depths of about 18 km. Combined with previous geobarometry results on the Carboniferous plutons within the Inner Mongolia Palaeo-uplift on the northern margin of the North China block, it is inferred that the uplift and exhumation of the plutons within the Inner Mongolia Palaeo-uplift during Middle Devonian to Late Carboniferous times were not as distinct as those during Late Carboniferous to Early Jurassic times, and the strong uplift and exhumation of the Inner Mongolia Palaeo-uplift were achieved during Late Carboniferous to Early Jurassic times.

A palynological study of the uppermost Famennian section from Kowala Quarry (Holy Cross Mountains, central Poland) allowed recognition of two miospore zones: LV (Retispora lepidophyta–Apiculiretusispora verrucosa) and LN (Retispora lepidophyta–Verrucosisporites nitidus). Based on palynology and sedimentology, the black shale within the upper part of the section is identified as equivalent to the Hangenberg Black Shale, which is known globally. This black shale contains compounds characteristic of photic zone euxinia, including isorenieratane and its derivatives. Such compounds are absent in the organic-poor marls and shales occurring below the LN Zone, and are present only as traces in the layers just above the black shale, indicating fluctuations in the oxygen minimum zone during uppermost Famennian sedimentation. Palynofacies show high amounts of amorphous organic matter and prasinophyte concentrations in the black shale, and a subsequent significant decrease of amorphous organic matter concomitant with a rapid increase of terrestrial input (mainly miospores with common tetrads) in the layers above the black shale. This supports the relatively rapid change in the taxonomic composition of phytoplankton caused by fluctuations of the chemocline. The whole succession corresponds to one sea-level rise and fall. The presence of high concentrations of peri-condensed polycyclic aromatic hydrocarbons and large amounts of small charcoal particles at the Hangenberg event horizon indicate the occurrence of wildfires. Such observations suggest that atmospheric O22 levels had exceeded the critical threshold of 13 %, above which wildfires may occur, by latest Famennian time.

Field and petrological studies of the Highland Border Ophiolite demonstrate that it was obducted onto the Neoproterozoic–Ordovician rocks of the Dalradian block, and not emplaced against them by post-orogenic strike-slip movement. It was welded onto the upper, southward-younging limb of the already recumbent Tay Nappe (D1), and deformed by the Downbend Antiform (D4). However, its emplacement was not accompanied by significant internal deformation of the Dalradian block. As the ophiolite is correlated with those at Clew Bay, Tyrone and Shetland, this result will necessitate complete revision of the current model for basin closure on the southeastern margin of Laurentia.