The Late Devonian South Mountain Batholith (SMB) of southwestern Nova Scotia is the largest batholith in the Appalachian Orogen of Eastern North America and contains economic deposits of U and Sn. The SMB comprises at least 11 individual plutons, which range in composition from granodiorite to biotite monzogranite, leucomonzogranite and leucogranite. Previous studies have suggested that a combination of fractional crystallization, assimilation of Meguma Supergroup country rocks and an influx of magmatic fluids contributed to the chemical evolution of the SMB. The amount of crustal assimilation is estimated to be as high as 33%. MELTS modelling assuming a starting composition of granodiorite with H2O = 4 wt%, pressure = 4 kbar (~12 km) and fO2 = FMQ can reproduce the chemical evolution observed in the SMB. However, some leucogranites likely require an additional component (e.g. hydrothermal fluids) to explain their alkali metal enrichment (e.g. Na, K, Rb). Zircon saturation thermometry estimates indicate the Salmontail Lake and Scrag Lake granodiorite plutons had high minimum initial temperatures of 823 ± 6°C and 832 ± 2°C, respectively, which are similar to low zircon-inheritance granitoids. The TiO2/Al2O3 and alkali-lime ratios of the surrounding country rocks and the leucogranites indicate the amount of crustal assimilation is likely to be between 10% and 20%. Our findings suggest the granodiorites of the SMB were likely produced by partial melting of the sub-Meguma Supergroup (e.g. Avalon terrane) lower crust caused by the contemporaneous injection of high temperature mafic to ultramafic magmas.

The Mississippian Strathclyde Group of the Midland Valley of Scotland yields some of the earliest non-marine ostracods. The succession records shallow marine, deltaic, estuarine, lagoonal, lacustrine, fluvial and swamp environments representing a series of staging-posts between fully marine and limnetic settings. Macrofossils and ostracods are assigned to marine, marginal marine, brackish and freshwater environments based on their faunal assemblage patterns. Key brackish to freshwater ostracods are Geisina arcuata, Paraparchites circularis n. sp., Shemonaella ornata n. sp. and Silenites sp. A, associated with the bivalves Anthraconaia, Carbonicola, Cardiopteridium, Curvirimula, Naiadites, the microconchid ‘Spirorbis’, Spinicaudata and fish. Many Platycopina and Paraparchiticopina ostracods are interpreted as euryhaline, which corresponds with their occurrence in marine to coastal plain water bodies, and supports the ‘estuary effect’ hypothesis of non-marine colonization. The success of non-marine colonization by ostracods was dependent on the intrinsic adaptations of ostracod species to lower salinities, such as new reproductive strategies and the timing of extrinsic mechanisms to drive non-marine colonization, such as sea-level change. The genus Carbonita is the oldest and most common freshwater ostracod, and went on to dominate freshwater environments in the Late Palaeozoic.

A new odontopleurid trilobite, Meadowtownella serrata, is described from a new Llanvirnian (Darriwilian; Didymograptus murchisoni Biozone) locality in the Builth Inlier, Mid-Wales. This unusually spinose species displays a remarkable array of pygidial spines and extends the stratigraphic range of the genus back into the Abereiddian. Benthic faunas are rare in the predominantly ‘anoxic’ D. murchisoni Biozone of the Welsh Basin, and these beds are an unusual habitat for odontopleurids. Environmental analyses (framboidal pyrite and associated total organic carbon) in this study, together with the distribution of benthic faunas (described and figured) in the section, indicate a likely oxic water column and episodically oxic bottom waters. A new diagnosis for Meadowtownella is presented with a review of the genus, as a clarification of previous work. The greater spinosity of earlier members of the lineage may reflect either changing environmental preferences, or the derivation of Meadowtownella from an original more spinose lineage.

Most karst terranes develop slowly on static limestone substrates as part of the global hydrological cycle. Here we introduce the novel concept of a karst morphology developing very rapidly on a more soluble substrate of salt (NaCl) that is moving through its own global cycle. We open with a reminder of karst features and processes in limestone. We then illustrate the global salt cycle using the 180 or so extrusions of Hormoz salt in the Zagros Mountains of Iran. After describing the geology of an example, we consider how it fits into the evolution of salt extrusions. This example, Konarsiah, was chosen for its simple hydrology. Konarsiah is covered by residual soils of the insoluble components that remain in place as the Hormoz salt is dissolved. Dolines in the surface of these soils enlarge and the soils thicken as the moving salt dissolves. The long-term rate of salt dissolution and soil production on Konarsiah are estimated using traditional methods. The calculated age of the thickest, most distal soil is used to constrain the average rate at which the underlying salt flows downslope after extruding from two vents. The average velocities constrained for salt flow are lower than rates of displacement of markers near the summit of Konarsiah measured at irregular intervals over five years. Salt extruding from recently truncated diapirs near the arid south coast of Iran exhibit all the features seen in classical karst terranes. In the more humid mountains inland, vegetated soils protect salt extrusions like Konarsiah from erosion and limit their salt karst features. Soil covers also probably even out salt flow velocities. Salt extrusions advance when such protective covers grow and thicken in humid conditions. They retreat when such protection is lost to erosion in drier conditions. These external signs complement internal recumbent folds in extruded salt that signal intervals of faster salt flow when wet than dry. They also add to the features that render salt extrusions records of climate change.

The Tufiti di Tusa Formation, a siliciclastic turbidite system of lower Miocene age in southern Italy, is mainly composed of volcaniclastic and quartzolithic sandstones interbedded with mudrocks. Sandstones are subdivided into four distinctive petrofacies, evolving from quartzolithic to volcaniclastic lithofeldspathic and feldspatholithic, reflecting detrital evolution from growing orogen (quartzolithic petrofacies) to active volcanism (volcaniclastic petrofacies). The mineralogical composition of the associated mudrocks is predominantly characterized by phyllosilicates, mainly illite/smectite mixed layers (I/S R1 associated with minor amounts of I/S R0 in the lower part of the succession, and I/S R3 in its upper part), together with illite, detrital micas and chlorite, and minor amounts of chlorite/smectite mixed layers and kaolinite, in addition to quartz, calcite and feldspars. The most abundant phyllosilicates are I/S mixed layers, 10-Å minerals (illite and micas) and chlorite, while kaolinite and chlorite–smectite mixed layers are present as a few per cent or in trace amounts. X-ray diffraction patterns show the occurrence of the ordered I/S R1 mixed layers in most samples but, at the top of the succession, some samples are characterized by I/S R3 mixed layers, whilst in the lower part of the succession I/S R1 is associated with a lower amount of I/S R0. These features suggest that the Tufiti di Tusa Formation experienced a medium diagenetic grade, and the occurrence of I/S R3 could be explained by K-availability in samples in the upper part of the succession. The lithic fragments in sandstones are metasedimentary rocks of Palaeozoic age, and andesite to dacite volcanic rocks of early Miocene age. The associated mudrocks also contain trace element ratios (Cr/V, Y/Ni, La/Sc, Th/Sc, Th/Co, Th/Cr, Cr/Th and Eu/Eu*) consistent with a provenance containing intermediate to silicic sources with scarce or absent basic rocks. The chemical index of alteration (63.2 to 71.6) suggests a moderate degree of weathering in the source. Furthermore, the K/Cs ratios of sediments confirm likely moderate rather than intense weathering. The index of compositional variability (ICV) values (from 1.2 to 2.5) are high enough to suggest the mudrocks are first-cycle sediments with little recycling. The Al–Ti–Zr diagram and the Th/Sc v. Zr/Sc plot indicate poor sorting and rapid deposition of the sediments. Detrital and sedimentary evolution of the Tufiti di Tusa Formation provides constraints, in terms of relations between a growing orogenic system and active volcanism in the Central Mediterranean, to contribute to geodynamic and palaeogeographic reconstructions of the earliest collision in the southern Apennines region.

Age spectra of detrital zircons from metamorphosed quartzites of the Krkonoše–Jizera Massif in the northeastern part of the Saxothuringian Domain were obtained by U–Pb laser ablation inductively coupled plasma mass spectrometry dating. The zircon ages cluster in the intervals of 450–530 Ma and 550–670 Ma, and show individual data between 1.6 and 3.1 Ga. Zircons in the analysed samples are predominantly of Cambrian–Ordovician and Neoproterozoic age, and the marked peak at c. 525–500 Ma suggests a late Cambrian maximum age for the sedimentary protolith. Detritus of the quartzites probably originated from the erosion of Cambrian–Ordovician granitoids and their Neoproterozoic (meta)sedimentary or magmatic country rocks. The lack of Neoproterozoic (meta)sedimentary rocks in the central and eastern part of the Krkonoše–Jizera Massif suggests that the country rocks to voluminous Cambrian–Ordovician magmatic bodies were largely eroded during the formation of early Palaeozoic rift basins along the southeast passive margin of the Saxothuringian Domain. The detrital zircon age spectra confirm the previous interpretation that the exposed basement, dominated by Neoproterozoic to Cambrian–Ordovician granitoids, was overthrust during Devonian–Carboniferous subduction–collision processes by nappes composed of metamorphosed equivalents of the uppermost Cambrian–Devonian passive margin sedimentary formations. Only a negligible number of Mesoproterozoic ages, typically from the Grenvillian event, supports the interpretation that the Saxothuringian Neoproterozoic basement has an affinity to the West African Craton of the northwestern margin of Gondwana.

The Quanzhou (QZ) and Huacuo (HC) gabbro–granite complexes on the southeast coast of Fujian, South China, are important components of a Late Mesozoic calc-alkaline volcanic–plutonic belt in the region. The complexes provide an excellent opportunity to investigate the genetic relationships between acid and basic magmas, and their interactions within the intrusive environment. The complexes are composed mainly of monzogranite and biotite granodiorite in the QZ complex, and biotite granite in the HC complex, with lesser amounts of hornblende gabbro. Zircon U–Pb dating provides consistent crystallization ages of 109 ± 1 Ma and 108 ± 1 Ma for the QZ gabbros and monzogranites, and an age of 111 ± 1 Ma for the HC gabbro, which is contemporaneous with the spatially associated HC granites. Both the mafic and felsic intrusions in these complexes are enriched in light rare earth elements (LREEs) and large-ion lithophile elements (LILEs), and are depleted in high-field-strength elements (HFSEs; e.g. Nb and Ta). They show similarly homogeneous Sr–Nd isotopic compositions. All these factors indicate a close genetic relationship between the gabbroic and granitic rocks in the QZ and HC complexes. Although the enriched Sr–Nd isotopic signatures of the QZ and HC gabbros seemingly point to an enriched mantle source (EM-1), they have highly variable zircon Hf isotopic compositions, with εHf(t) values ranging from negative to positive (specifically –4.6 to +6.1 for the QZ gabbros and –4.8 to +11.6 for the HC gabbros). We interpret the parental basic magmas of these gabbros to have received contributions from a depleted mantle source and crustal components. Contributions from such a depleted mantle source resulted in the growth of juvenile basaltic lower crust, the partial melting of which generated the parental felsic magmas of the QZ and HC complexes. Furthermore, based on a synthesis of petrography, geochronology, elemental and isotopic geochemistry and tectonics, we propose that break-off and rollback of the Late Mesozoic subducted Palaeo-Pacific Plate triggered the upwelling of asthenospheric mantle below the coastal area of the South China Block, which induced extension of the overlying continental lithosphere, and finally initiated the large-scale Late Yanshanian magmatism in the study area.

The tectonic history and time of closure of the Palaeo-Asian ocean of the Altaids are issues of lively current debate. To address these issues, this paper presents detailed geological, petrological and geochemical data of the Liuyuan complex (LC) in the Beishan region in NW China, located in the southernmost Altaids, in order to constrain its age, origin and tectonic setting. The LC mainly comprises massive basalts, pillow basalts, basaltic breccias, gabbros and ultramafic rocks together with cherts and tuffs. Most prominent are gabbros and large volumes of basaltic lavas. These mafic rocks have high TiO2 contents, flat rare earth element (REE) patterns and show high-field-strength elements (HFSEs) similar to those of mid-ocean ridge basalts (MORB). The mafic rocks exhibit positive εNd(t) (6.6–9.0) values, representing magmas derived from the mantle. But these basic rocks are also enriched in Th relative to REEs, and are systematically depleted in Nb–Ta–(Ti) relative to REEs. There is also a large range in initial 87Sr/86Sr (0.7037–0.7093). All these variables indicate that mantle-derived magma was contaminated by fluids and/or melts from a subducting lithospheric slab, and formed in a supra-subduction zone (SSZ) setting. A gabbro intruded in the complex was dated by LA-ICP-MS on 20 zircons that yielded a 206Pb–238U weighted average age of 286 ± 2 Ma. Considering the fact that all these basalts are imbricated against Permian tuffaceous sediments and limestone, we propose that the LC formed as an ophiolite in a fore-arc in Carboniferous–Permian time. This indicates that the Palaeo-Asian ocean still existed at 286 ± 2 Ma in early Permian time, and thus the time of closure of the Palaeo-Asian ocean was in or after the late Permian.

The shale-dominated hemipelagic succession exposed in the southwestern part of the Prague Synform preserves the most complete Ludfordian graptolite record so far encountered from peri-Gondwanan Europe. Four graptolite biozones – the Neocucullograptus inexpectatus, Nc. kozlowskii, Pseudomonoclimacis latilobus–Slovinograptus balticus and Pristiograptus fragmentalis biozones – are recognized in the middle and late Ludfordian, between the Bohemograptus tenuis Biozone and the base of the Pridoli Series. Conodont occurrences are restricted to scattered limestone beds, but enable tentative integration of the graptolite and conodont biozonal schemes. Particular attention was paid to faunal and sedimentary changes and the carbon isotope record across the middle Ludfordian Kozlowskii extinction Event. The Kozlowskii Event caused the almost simultaneous extinction of graptolites with ventrally curved rhabdosomes. The genera Bohemograptus, Polonograptus and Neocucullograptus, along with Pseudomonoclimacis dalejensis, disappeared from the fossil record. The offshore conodont fauna recorded in the section was not strongly affected and similarly the pelagic orthocerids and nektonic Ceratiocaris passed unaffected through the extinction interval. The abundant and widespread pelagic myodocopid ostracod Entomis, however, became extinct. The late Ludfordian graptolite recovery gave origin to a novel fauna of Pridoli type from taxa that emerged or just reappeared above the Kozlowskii crisis. In Všeradice and elsewhere in the Prague Synform, the recovery, manifested by the appearance of Pseudomonoclimacis latilobus and Slovinograptus balticus, closely postdates the end of the isotope excursion but pre-dates the first appearance of the conodont index ‘Ozarkodina’ snajdri. Here the graptolite recovery was delayed relative to the recovery of the benthic fauna. A canalized intraformational limestone conglomerate corresponds with a gap in the sedimentary record above the Kozlowskii extinction and just below the graptolite recovery. The benthic faunas from the conglomerate matrix and pebbles permit correlation with the shallower part of the basin indicating a distinct fall in sea-level. The present data demonstrate the coincidence of the graptolite crisis with benthic faunal change and eustatic fall in sea-level manifested by facies change and the carbon isotope excursion. Polonograptus chlupaci sp. nov., from the Nc. kozlowskii Biozone, is described and several other graptolite taxa are redescribed.

The lava domes in the northwestern (Cuma), northern (Punta Marmolite) and central (Accademia) parts of the Phlegrean Fields are the subject of this study. The Cuma and Punta Marmolite trachyphonolitic lava domes are among the oldest Phlegrean products cropping out. The Cuma rocks have an agpaitic groundmass, with early alkali feldspar, Fe-rich clinopyroxene, Fe-edenite and sodalite and late rosenbuschite, fluorite, baddeleyite, pyrochlore, britholite, monazite, aegirine (often Zr-rich) and exceptionally Fe–Mn-rich olivine. The bulk-rock compositions at Cuma have some of the highest concentrations of Zn, Mn, Zr, Nb, Th, U and lanthanides among the Phlegrean Fields rocks, and some of the lowest MgO, P2O5, Sr, Eu and Ba. The Punta Marmolite dome is chemically less evolved, and lacks characteristic agpaitic minerals, but features alkali feldspar, sodalite, nepheline and relatively Na-poor, Fe-rich hedenbergite, with rare Ca-rich plagioclase xenocryst cores. The Accademia dome, belonging to the recent activity, is latitic to trachytic in composition, has highly forsteritic olivine (with chromiferous spinel inclusions), calcic plagioclase and Mg-rich diopside (± phlogopite) xenocrysts in an evolved host rock (with phenocrysts and microlites of alkali feldspar, Fe-rich clinopyroxene, Fe-rich amphibole, magnetite, Fe-rich olivine and accessory baddeleyite, zirconolite and fluorite). There is clear evidence of open-system magma crystallization in the form of interaction between a crystallizing, primitive shoshonitic basalt in a reservoir already filled by rather evolved trachytic magma. The magmatic evolution towards the evolved compositions is dominated by crystallization of more and more Na-rich alkali feldspar in a Cl-, F-rich and relatively H2O-poor environment. Input of mafic magma is evident in many trachytic eruptions of the Phlegrean Fields and even in the products of the Campanian Ignimbrite, but eruptions having mineral assemblages rich in xenocryst phases as well as eruptions virtually free of mafic magma input are also frequently observed throughout the history. This suggests a variable pattern of open- and closed-system crystallization, which may or may not be linked to explosive activity, and that can be caused by intermittent supply of basaltic magma from depth.

In an Original Article by Melluso et al. recently published online (1 November 2011), the mineral named as rosenbuschite should be named låvenite throughout, having the chemical composition broadly corresponding to the chemical formula (Na, Ca)2(Mn, Fe)(Zr, Ti)Si2O7(O, OH, F)2 (see Sørensen, 1997).

The anterior end of a lower jaw bearing long slender teeth, from the Bathonian Stonesfield Slate of Oxfordshire, was hitherto referred to the crocodilian Teleosaurus. It is reinterpreted as belonging to a ctenochasmatid pterosaur reminiscent of Gnathosaurus. It is the earliest known representative of the Ctenochasmatidae, and one of the earliest known pterodactyloids. The diversity of pterosaurs from the Stonesfield Slate is higher than previously recognized, comprising at least three taxa.