Forming a northern continuation of the Moldanubian Thrust Zone, the Staré Město Belt comprises an E-verging thrust stack of three narrow lithotectonic units that exhibit variations in their respective P–T records. The upper and lower units form the respective margins of the hanging wall and footwall of the suture zone and are dominated by amphibolite grade metasedimentary successions. The middle unit is defined by an elongated body of MORB-like amphibolites that contains inserts of migmatized mica schists. Integrating both structural studies and pseudosection modelling in the MnNCKFMASH system shows that the present-day tectonic architecture of the Staré Město Belt is the result of a polyphase Variscan evolution. During a frontal, WNW–ESE-directed (in present-day coordinates) collision between the Bohemian Massif terranes and the Brunovistulian terrane, the metasedimentary rocks of the Staré Město Belt experienced tectonic burial to depths corresponding to 7–9 kbar. The continuous indentation and underthrusting of the Brunovistulian terrane led to top-to-the-ESE folding and uplift of these rocks to depths corresponding to 5.5–6.0 kbar at peak temperature. At depths corresponding to 5.5 kbar, the Staré Město Belt underwent subsequent dextral (top-to-the-NNE) shearing that was locally associated with nearly isobaric heating, possibly related to the emplacement of a Carboniferous tonalite body in the axial part of the Staré Město Belt. Subsequent tectonic compression resulted in the Variscan WNW-dipping metamorphic foliations becoming locally (N)NE- or ESE-dipping.

The trilobite fauna of the upper Ordovician (middle Katian) Pyle Mountain Argillite comprises a mixture of abundant mesopelagic cyclopygids and other pelagic taxa and a benthic fauna dominated by trilobites lacking eyes. Such faunas were widespread in deep water environments around Gondwana and terranes derived from that continent throughout Ordovician time but this is the only known record of such a fauna from North America and thus from Laurentia. It probably reflects a major sea level rise (the ‘Linearis drowning events’) as does the development of coeval cyclopygid-dominated deep water trilobite faunas in terranes that were marginal to Laurentia and are now preserved in Ireland and Scotland. The Pyle Mountain Argillite trilobite fauna occurs with a deep water Foliomena brachiopod fauna and comprises 22 species. Pelagic trilobites (mostly cyclopygids) constitute 36% of the preserved sclerites, and 45% of the fauna is the remains of trilobites lacking eyes, including one new species, Dindymene whittingtoni sp. nov. Three species of cyclopygid are present, belonging in Cyclopyge, Symphysops and Microparia (Heterocyclopyge). Cyclopygids are widely thought to have been stratified in the water column in life and thus their taxonomic diversity reflects the relative depths of the sea-beds on which their remains accumulated. A tabulation of middle and upper Katian cyclopygid-bearing faunas from several palaeoplates and terranes arranged on the basis of increasing numbers of cyclopygid genera allows an assessment of the relative depth ranges of the associated benthic taxa. The Pyle Mountain Argillite fauna lies towards the deeper end of this depth spectrum.

Lacustrine sediments of the Hajnáčka I maar of southern Slovakia contain teeth and skeletal remains of a mammal fauna, including index Early Villanyian arvicoline rodents. U–Pb dating of magmatic zircons extracted from the redeposited fossiliferous maar sediments revealed a total of six volcanic events. The oldest age of 3.43 Ma was interpreted as that corresponding to the initial phreato-magmatic eruption that created the maar. Most zircons grouped around 3.06 ± 0.03 Ma, the age attributed to the catastrophic eruption that killed the mammal assemblage thriving within and around the maar studied. This age coincides with the 3.1 Ma boundary between the MN 16a and 16b subzones of the European Mammal Neogene chronostratigraphic scale estimated from the succession of Early Villanyian palaeontological localities according to the hypsometry of rodent teeth. Younger zircon ages overlapped those of the neighbouring basaltic lava flows, necks and dykes, thus recording superimposed effusions. The youngest 1.58 Ma old zircon defines the age limit for the final redeposition of the fossiliferous sediments in the maar drainage lake regime.

Out of the 14 agnostoid species/subspecies so far recorded from the Furongian of Scandinavia, seven are excellent biostratigraphical indices and important for correlation between Baltica and other palaeocontinents. Glyptagnostus reticulatus, Aspidagnostus lunulosus and Agnostus (Homagnostus) obesus first appear at the base of the G. reticulatus Zone, allowing a precise correlation of the base of the Paibian Stage into Scandinavia. Tomagnostella orientalis and Pseudagnostus cyclopyge appear near the base of the Parabolina brevispina Zone, suggesting a correlation with the uppermost Paibian through the lowermost Jiangshanian stages. Lotagnostus americanus and Pseudagnostus rugosus have an intercontinental distribution and their first appearance in Scandinavia allows for a correlation with one of the most favourable levels for defining the base of Cambrian provisional Stage 10. In the Furongian of Scandinavia, agnostoids are conspicuously assembled in three different intervals: the lower Glyptagnostus reticulatus Zone, the lower Pseudagnostus cyclopyge Zone and the Lotagnostus americanus through lower Trilobagnostus holmi zones. The agnostoid-barren and largely unfossiliferous succession separating the lower and middle agnostoid-bearing intervals can be explained by means of subsequent dissolution of the calcareous fauna and/or a hostile environment. The middle agnostoid-bearing interval is succeeded by an anomalous succession dominated by the orthide brachiopod Orusia lenticularis, reflecting a regressive event coupled with increasing levels of oxygen at the sediment/water interface. This shallowing evidently resulted in unfavourable conditions for agnostoids.

The giant, agglutinated foraminiferan Bathysiphon Sars, previously Triassic–Recent, occurs in much older sedimentary rock (Early Ordovician, late early Tremadocian) of Avalonia. The genus extends back to c. 485 Ma based on its discovery in platform mudstone of the Chesley Drive Group in Cape Breton Island, Nova Scotia. Elongate (up to 60 mm), epibenthic Bathysiphon tubes occur in wave-rippled, green-grey mudstone with a low diversity, probably dysoxic fauna. The mudstone is coeval with and lithologically similar to the Shineton Formation in Shropshire and the Welsh Borderlands. Scanning microscopy of the Bathysiphon walls shows imbricated mica grains that parallel the long axis of the tests. The lumen has a mélange of packed sediment grains, some of which are spherical structures of siliciclastic mud studded with tetrahedral pyrite crystals. A felt-like, agglutinated test, a lumen packed with spherical structures (probable stercomata) and the domal ends of some specimens are consistent with modern Bathysiphon. This report is the first time that cytoplasmic activity and stercomata formation have been used to refer fossil protists to a modern group. Bathysiphon differs from the Cambrian foraminiferan Platysolenites Pander, which has an open lumen without stercomata, but support a comparable, sediment deposit-feeding niche. Bathysiphon is truly a ‘living fossil’, with a mode of test construction, cytoplasmic activity that formed stercomata and a niche unchanged for almost 500 million years. Foraminiferans have not been found prior to the Cambrian Period, and the Early Cambrian appearance of agglutinated foraminiferans is part of the radiation of Phanerozoic communities.

The Iranian territory is composed of a mosaic of tectonic units, several of which underwent in the Permian and Triassic periods a migration from northern Gondwana to southern Laurussia associated with the opening of the Neo-Tethys Ocean. Although this broad outline of Permo-Triassic palaeogeographical evolution of Iranian microplates is now widely accepted, the individual timing of migration of these blocks, and their biogeographical relationships, remain insufficiently known. Here I review the Late Palaeozoic record of trilobites in Iran and Armenia, and discuss their palaeobiogeographical affinities in an attempt to shed light on the Permian palaeogeographical evolution of Iranian and Armenian terranes. Seven Iranian or Armenian localities, representative of five tectonic units, have yielded Carboniferous and Permian trilobites. Ten species are recognized, including two new taxa, Persia praecox gen. nov. sp. nov. and Pseudophillipsia (s.l.) parvizii sp. nov. P. praecox is the only Carboniferous (Tournaisian) species. The others are Wordian to Wuchiapingian in age and can be separated into three morphological groups, probably representing clades. One is composed of representatives of Acropyge, while the two others (armenica-group and paffenholzi-group) comprise species of Pseudophillipsia. Only P. (s.l.) parvizii sp. nov. from the Zagros Mountains (Arabian Plate) is not attributed to one of these groups. The distribution of trilobites in Iran and Armenia strongly suggests that the Alborz, Central Iran and Transcaucasia microplates represented a single biogeographical unit in Middle and Late Permian times. Special relationships of this biochore with South China can also be stressed.

The late Early Cretaceous greenhouse climate has been studied intensively based on proxy data derived essentially from open marine archives. In contrast, information on continental climatic conditions and on the accompanying response of vegetation is relatively scarce, most notably owing to the stratigraphic uncertainties associated with many Lower Cretaceous terrestrial deposits. Here, we present a palynological record from Albian near-shore deposits of the Lusitanian Basin of W Portugal, which have been independently dated using Sr-isotope signals derived from low-Mg oyster shell calcite. 87Sr/86Sr values fluctuate between 0.707373 ± 0.00002 and 0.707456 ± 0.00003; absolute values and the overall stratigraphic trend match well with the global open marine seawater signature during Albian times. Based on the new Sr-isotope data, existing biostratigraphic assignments of the succession are corroborated and partly revised. Spore-pollen data provide information on the vegetation community structure and are flanked by sedimentological and clay mineralogical data used to infer the overall climatic conditions prevailing on the adjacent continent. Variations in the distribution of climate-sensitive pollen and spores indicate distinct changes in moisture availability across the studied succession with a pronounced increase in hygrophilous spores in late Early Albian times. Comparison with time-equivalent palynofloras from the Algarve Basin of southern Portugal shows pronounced differences in the xerophyte/hygrophyte ratio, interpreted to reflect the effect of a broad arid climate belt covering southern and southeastern Iberia during Early Albian times.

We show that spacing statistics can be obtained for all fracture densities by the same equation. Using the simple ‘shear lag’ theory, it is demonstrated that the results adequately fit experimental measurements. Theoretically, it is shown that two parameters are sufficient to characterize all spacing distributions. It is found that no real spacing saturation exists. Rather, a very low increase in joint densities occurs for a very high incremental stress increase. Moreover the transition to this kind of saturation is gradual and not abrupt. In this way the high density distributions with very small inter-joint distances, which pose a problem for saturation models, are directly explained. Correlation with creep experiments is also established. Comparison of our method with Weibull statistics is performed.

The Poshtuk metapelitic rocks in northwestern Iran underwent two main phases of regional and contact metamorphism. Microstructures, textural features and field relations indicate that these rocks underwent a polymetamorphic history. The dominant metamorphic assemblage of the metapelites is garnet, staurolite, chloritoid, chlorite, muscovite and quartz, which grew mainly syntectonically during the later contact metamorphic event. Peak metamorphic conditions of this event took place at 580 °C and ~3–4 kbar, indicating that this event occurred under high-temperature and low-pressure conditions (HT/LP metamorphism), which reflects the high heat flow in this part of the crust. This event is mainly controlled by advective heat input through magmatic intrusions into all levels of the crust. These extensive Eocene metamorphic and magmatic activities can be associated with the early Alpine Orogeny, which resulted in this area from the convergence between the Arabian and Eurasian plates, and the Cenozoic closure of the Tethys oceanic tract(s).

Study of the lower Silurian black shale succession of the Prague Synform has enabled detailed insight into graptolite faunal dynamics and diversity trends from the mid-Aeronian diversity maximum through to the late Aeronian crisis. Graptolite diversity decreased from 33 taxa in the Lituigraptus convolutus Biozone to 17 taxa in the upper part of the Stimulograptus sedgwickii Biozone and newly erected Lituigraptus rastrum Biozone. The graptolite assemblages of the latter biozones exhibit low species richness along with high dominance. Many graptolite species that became extinct in the early part of the sedgwickii Zone were promptly replaced by new forms. In the later part of the sedgwickii Zone, however, replacement of extinct species by new forms considerably decelerated. The increased rate of graptolite extinction recorded in the convolutus–sedgwickii biozone boundary beds coincided with subtle changes in black shale lithologies and a positive shift in δ13Corg (of 2.2 ‰) compared to baseline values. Sea-level drawdown can be inferred from siltstones and/or temporary nondeposition in the middle sedgwickii Zone. This level also sees total organic carbon (TOC) fluctuations and a strong positive δ13Corg excursion with a peak shift of at least 7 ‰. The sedgwickii Event exhibits substantial reorganization of the graptolite fauna, its taxonomic impoverishment and concomitant increase in species dominance rather than a sudden collapse of the pre-extinction assemblage. Associated changes in lithology, TOC and the pronounced δ13Corg excursion suggest a relatively extended and probably multi-phase period of stressed conditions that affected the pelagic realm inhabited by graptolites in the course of the late Aeronian interval.

Kinematic analysis of mélange fabrics provides critical information concerning tectonic processes and evaluation of the kinematics of ancient relative plate motion. Systematic kinematic analysis of deformed structures within a tectonic mélange exposed along the Zagros Suture Zone elucidates that this zone is an ancient transpressional boundary. The mélange is composed of a greywacke and mudstone matrix surrounding various lenses, blocks and ribbons of radiolarian chert, limestone, sandstone, pillow lava, tuff, serpentinite, shale and marl. The deformation fabrics of the mélange suggest that the mélange units were tectonically accreted at shallow levels within a subduction complex, resulting in layer-parallel extension and shearing along a NW–SE-trending suture that juxtaposes the Afro-Arabian continent to the south and the Central Iranian microcontinents to the north. The tectonic mélange is characterized by subhorizontal layer-parallel extension and subsequent heterogeneous non-coaxial shear resulting in alternating asymmetric and layer-parallel extensional fabrics such as P–Y fabrics and boudinaged layers. Kinematic data suggest that the mélange formed during oblique subduction of the Neo-Tethys oceanic lithosphere in Late Cretaceous time. Kinematic shear sense indicators reveal that the slip direction (N9°E to N14°E) during accretion-related deformations reflects the relative plate motion between the Afro-Arabian continent and Central Iranian microcontinents during Late Cretaceous to Miocene times.

Zoophycos-group burrows are prevalent elements of the post-Cambrian trace fossil record. Here we report the oldest specimens of Zoophycos from Lower Cambrian strata of the Lower Member Wood Canyon Formation in southeastern California. In addition to these being the oldest examples of this well-known trace fossil, the discovery of these specimens also reveals the presence of deposit feeding considerably earlier than has been suggested for the advent of this feeding style. This type of activity may have had a significant impact on sediment mixing during the Precambrian–Cambrian transition, though the rarity and shallow tier position of these specimens suggests otherwise.

LA-ICP-MS U–Pb dating of Lower Devonian detrital zircon samples from three representative sections in the South China block yields dominant Grenvillian and Pan-African populations, similar to the age distribution of early Palaeozoic samples from Gondwana, the Tethyan Himalaya and West Australia, in particular. Hf isotopic compositions indicate the contributions of juvenile crust at 1.6 Ga and 2.5 Ga, and bear a resemblance to their counterparts from SE Australia and West Antarctica, revealing the mixed origin of the Pan-African and Grenvillian grains from juvenile magmas and melting of pre-existing crustal rocks. These results suggest that the South China block should be considered an integral part of East Gondwana in early Palaeozoic time, rather than a discrete continental block in the Palaeo-Pacific or a fragment of Laurentia.