The Hornkullen mineralisation is situated in the westernmost part of the Bergslagen ore province, south-central Sweden. Here, polymetallic sulphides and oxides are hosted by an inlier of Svecofennian, c. 1.9 Ga skarn-bearing metavolcanic units, enclosed in the c. 1.8 Ga Filipstad granite belonging to the Transscandinavian Igneous Belt. The Ag- and Au-bearing mineralisation is dominated by veins and impregnations of magnetite, pyrrhotite, galena, chalcopyrite and arsenopyrite with subordinate pyrite, sphalerite, ilmenite, löllingite, Pb–Fe–Ag–Cu–Sb sulphosalts and rare gudmundite, pentlandite and molybdenite. Overall, a detailed textural and mineralogical study of the ore assemblages suggests significant deformation and remobilisation at high temperature, which is corroborated by sulphide geothermobarometry. The arsenopyrite geothermometer yields an average temperature of c. 525 °C, which is likely to be the result of metamorphic re-equilibration. Sphalerite geobarometry gives peak pressures of c. 300–400 MPa, albeit with caveats. The combined observations suggest that the present mineralogical and textural nature of the ore assemblages at Hornkullen is primarily related to remobilisation during Svecokarelian regional metamorphism of a pre-existing, most likely syn-volcanic mineralisation. This scenario is likely to be applicable to many other Svecofennian metasupracrustal-hosted deposits in the Bergslagen ore province.

Carbonate hardgrounds are unevenly distributed in the Silurian of Estonia, with only three bioeroded hardgrounds in the Telychian and one in the late Pridoli. There seem to be no trends in the bioerosion intensities and ichnotaxonomical diversity in the Silurian of Estonia. Only Trypanites occurs in the hardgrounds of the Silurian of Estonia and ichnological diversity of bioeroded organic hard substrates, containing Trypanites, Palaeosabella and Osprioneides is higher than inorganic substrates. The small number of bioeroded inorganic substrates could indicate that these substrates were probably less important than the organic hard substrates for the development of seafloor ecological niches in the Silurian of Estonia. The average bioerosion intensities of the hardgrounds are relatively high, but not unusual for the Silurian.

During the last decades, postglacial faults (PGFs) have been found in northern Fennoscandia, the first fault scarps being discovered in western Finnish Lapland in the 1960s. With LiDAR-based digital elevation models (DEMs), a new and accurate remote sensing mapping methodology has been acquired. It allows the relatively rapid and low-cost detection and mapping of late- or PGFs and, for instance, mapping of landslides from areas where they have not previously been recognized. We describe the approach of the Geological Survey of Finland to the systematic search for (screening) and mapping of PGFs, paleolandslides, and other morphological features of Quaternary deposits related to post- and late-glacial seismic activity in Finland. The observations have been collected and classified into a file geodatabase with ArcGis (© ESRI) using a procedure that includes several steps. We also provide examples from western and northern Finland of how sites of late- and postglacial fault scarps and landslides have been detected and described from LiDAR DEM data.

A single specimen of a new genus and species of the trilobite family Burlingiidae from the lower part of the Middle Cambrian in Morocco augments both the geographic distribution to the Cambrian continent West Gondwana and the modern continent Africa and the stratigraphic range of the family to base of the Middle Cambrian. A reconsideration of species assigned to Schmalenseeia requires a revision of the genus. Schmalenseeia acutangula Westergård, 1948, previously discussed as atypical for the genus Schmalenseeia, is separated as the type species of the new genus Niordilobites, and its characters and relation to the other Burlingiidae are discussed. Schmalenseeia jagoi Whittington, 1994 is discussed to differ from Schmalenseeia and Burlingia as well and is raised to the type species of Alumenella n. gen. Schmalenseeia fusilis Peng et al., 2004, unique because of the fusion of its tagmata, is the type species of the new genus Pengia. Burlingia laevis Westergård, 1936 is retained as a distinct species, and its suggested synonymy with Burlingia hectori is challenged. Additional discussions deal with a clarification of its stratigraphic origin, the possible origin of the clade, and morphological developments.http://zoobank.org/urn:lsid:zoobank.org:pub:79F59028-5C03-4AF5-891D-F08B6FECAC81

A sharply cross-cutting lamprophyre dyke inside the Idefjorden terrane and along the Mylonite Zone in the Sveconorwegian orogen, Sweden, yields a plateau 40Ar–39Ar biotite age of 914.6 ± 1.2 Ma. This result confirms a published K–Ar age and is interpreted to record magmatic intrusion of the dykes. The lamprophyres are coeval to the similarly oriented but less potassic 916 ± 11 Ma noritic to anorthositic Hakefjorden Complex exposed west of the Göta Älv Shear Zone in the Idefjorden terrane. The lamprophyres are characterized by high magnetic susceptibility, chilled margins, biotite phenocrysts and deuteric alteration of the groundmass. They classify as kersantite and minette, and are interpreted to represent rare, minor explosive mantle-derived magmas, intruded along deep-reaching, east-west trending, extensional structures related to the waning stages of the Sveconorwegian orogeny. Since the host bedrock, at the current level of erosion, was responding to brittle deformation prior to the intrusion of the lamprophyre dykes, the age of 914.6 ± 1.2 Ma sets a minimum limit for the termination of Sveconorwegian ductile deformation inside the Idefjorden terrane and along the Mylonite Zone, north of Lake Vänern. This contrasts to the situation in the westernmost Rogaland–Vest Agder sector of the Sveconorwegian orogen, in Norway, where 930–920 Ma anorthosite to granite plutonism was spatially related to high temperature-low pressure metamorphism and ductile deformation during the waning stages of the Sveconorwegian orogeny. The new age underscores the diachronic exhumation of the orogen.

The structure of the shell wall, particularly at the apertural margin, is described in the Callovian ammonoid Quenstedtoceras from Lukow, Poland. Ventral and lateral sides of the shell wall show periodic interruptions in shell secretion. As shown in the present study, these interruptions divide the shell wall into calcareous sublayers that are separated by thin intermediate layers of organic substance. In places, the organic layers increase considerably in thickness. The presence of organic layers between the calcareous sublayers increases the amount of organic substance in the shell wall. The shell aperture has a ventral rostrum. At the shell aperture, the shell wall decreases in thickness and forms a sharp-edged, thin, apertural margin that probably retains its shape in the adult stage. In comparison with Nautilus, the shell wall of Quenstedtoceras is much thinner at the aperture, has a longer growth zone and probably does not form a gerontic thickening. The shape of the apertural margin of Quenstedtoceras is also compared with that of the Callovian ammonoid Kosmoceras and of scaphitid ammonoids. Its significance in ammonoid anatomical design and function is discussed.

Latest Ordovician and earliest Silurian tabulate corals of the South China paleoplate are summarized at the generic level. In contrast to the abundant late Katian records, there is no record of tabulate corals in the early–middle Hirnantian rocks in South China, lithostratigraphically represented by the Kuanyinchiao Formation and its equivalents. The tabulate fauna from the late Hirnantian and the earliest Silurian rocks of South China is characterized by the occurrence of three cosmopolitan genera: Paleofavosites, Propora and Halysites. They differ morphologically from the pre-Hirnantian tabulate corals of South China. Such a long-ranging and low-diversity tabulate coral fauna also indicates a warm but somewhat unfavorable living environment during the survival interval after the second pulse of the end-Ordovician mass extinction.

A new fossil species from Cambrian strata of Jinsha, south China, is interpreted as the earliest known hexactinellid dictyosponge. Phragmodictya jinshaensis sp. nov. occurs within the Niutitang Biota, the oldest known Burgess Shale-type biota. The new species is characterized by a convex, disc-shaped body consisting of reticular skeletal network surrounded by frill-bearing radial ridges. The discovery of this sponge is unexpected and provides additional evidence bearing on the nature of Precambrian sponges and the early evolution of hexactinellid dictyosponges. It also invites re-evaluation of the taxonomy of both Ediacaran and Phanerozoic sponges.