The pan-European “European Plate Observing System (EPOS)” is focussed on Europe and adjacent regions and includes geophysical monitoring networks, local observations (including permanent in-situ and volcano observatories), topographic/surface dynamics information, surface and subsurface geological information, experimental and laboratory data and functions, and satellite data. In 2021 the Swedish Research Council (VR) approved an application for Sweden to join EPOS-ERIC, formally establishing existing collaborations between EPOS and Swedish research infrastructures.

Konservat-Lagerstätten, such as the Toarcian (Early Jurassic) Posidonia Shale of southwestern Germany, are renowned for their spectacular fossils. Ichthyosaur skeletons recovered from this formation are frequently associated with soft tissues; however, the preserved material ranges from three-dimensional, predominantly phosphatized structures to dark films of mainly organic matter. We examined soft-tissue residues obtained from two ichthyosaur specimens using an integrated ultrastructural and geochemical approach. Our analyses revealed that the superficially-looking ‘films’ in fact comprise sections of densely aggregated melanosome (pigment) organelles sandwiched between phosphatized layers containing fibrous microstructures. We interpret this distinct layering as representing condensed and incompletely degraded integument from both sides of the animal. When compared against previously documented ichthyosaur fossils, it becomes readily apparent that a range of preservational modes exists between presumed ‘phosphatic’ and ‘carbonized’ soft-tissue remains. Some specimens show high structural fidelity (e.g. distinct integumentary layering), while others, including the fossils examined in this study, retain few original anatomical details. This diversity of soft-tissue preservational modes among Posidonia Shale ichthyosaurs offers a unique opportunity to examine different biostratinomic, taphonomic and diagenetic variables that potentially could affect the process of fossilization. It is likely that soft-tissue preservation in the Posidonia Shale was regulated by a multitude of factors, including decay efficiency and speed of phosphatic mineral nucleation; these in turn were governed by a seafloor with sustained microbial mat activity fuelled by high organic matter input and seasonally fluctuating oxygen levels. © 2023 The Authors. 

Marine sediments of the lowermost Eocene Stolleklint Clay and Fur Formation of north-western Denmark have yielded abundant well-preserved insects. However, despite a long history of research, in-depth information pertaining to preservational modes and taphonomic pathways of these exceptional animal fossils remains scarce. In this paper, we use a combination of scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM-EDX), transmission electron microscopy (TEM) and time-of-flight secondary ion mass spectrometry (ToF-SIMS) to assess the ultrastructural and molecular composition of three insect fossils: a wasp (Hymenoptera), a damselfly (Odonata) and a pair of beetle elytra (Coleoptera). Our analyses show that all specimens are preserved as organic remnants that originate from the exoskeleton, with the elytra displaying a greater level of morphological fidelity than the other fossils. TEM analysis of the elytra revealed minute features, including a multilayered epicuticle comparable to those nanostructures that generate metallic colors in modern insects. Additionally, ToF-SIMS analyses provided spectral evidence for chemical residues of the pigment eumelanin as part of the cuticular remains. To the best of our knowledge, this is the first occasion where both structural colors and chemical traces of an endogenous pigment have been documented in a single fossil specimen. Overall, our results provide novel insights into the nature of insect body fossils and additionally shed light on exceptionally preserved terrestrial insect faunas found in marine paleoenvironments. © 2022 by the authors.

Marine deposits of earliest Eocene age in northern Jutland, Denmark, are renowned for yielding diverse teleost assemblages that have proved central for enhancing our understanding of the early evolution of many extant actinopterygian clades. In this study, we investigate diminutive larval fish fossils from the Stolleklint Clay, Ølst Formation, that retain multiple soft-tissue features preserved as distinct dark-coloured stains. To examine the elemental and molecular composition of these soft parts, we employed a combination of time-of-flight secondary ion mass spectrometry (ToF-SIMS), scanning electron microscopy (SEM) and energy-dispersive x-ray spectroscopy (EDS). Our analyses revealed that the preserved structures contain chemically identifiable eumelanin intimately associated with densely aggregated microbodies that are morphologically consistent with melanosome organelles. Thus, we conclude that the carbonaceous structures represent traces of originally melanized body parts, including the eyes and peritoneum. Comparable pigmentation patterns are seen in many extant teleost larvae that use semi-transparency as a means of camouflage in pelagic environments, to suggest a similar visual appearance of the Stolleklint Clay fish fossils. This in turn suggests that adaptations for concealment and UV-protection had already evolved by the beginning of the Eocene, notably during a time interval characterized by an extreme greenhouse climate, when the global fish fauna become increasingly modern in composition. © 2021 The Authors. 

The scale effect of natural and artifically induced rock fractures and replicas up to a 500 mm length are experimentally studied by direct shear tests in a testing program including a newly manufactured large shear testing equipment. The fractures are chatacterised pre-, syn-, and post-shear test. Combinations of different measurements provide a high-quality dataset enabling deeper understanding of, and constitutive model development for rock fractures used for safety assessment of deep geological respoitories for nuclear waste disposal.

The Perseverance rover landed in Jezero crater, Mars, in February 2021. We used the Scanning Habitable Environments with Raman and Luminescence for Organics and Chemicals (SHERLOC) instrument to perform deep-ultraviolet Raman and fluorescence spectroscopy of three rocks within the crater. We identify evidence for two distinct ancient aqueous environments at different times. Reactions with liquid water formed carbonates in an olivine-rich igneous rock. A sulfate-perchlorate mixture is present in the rocks, which probably formed by later modifications of the rocks by brine. Fluorescence signatures consistent with aromatic organic compounds occur throughout these rocks and are preserved in minerals related to both aqueous environments. 

The first samples collected by the Mars 2020 mission represent units exposed on the Jezero Crater floor, from the potentially oldest Séítah formation outcrops to the potentially youngest rocks of the heavily cratered Máaz formation. Surface investigations reveal landscape-to-microscopic textural, mineralogical, and geochemical evidence for igneous lithologies, some possibly emplaced as lava flows. The samples contain major rock-forming minerals such as pyroxene, olivine, and feldspar, accessory minerals including oxides and phosphates, and evidence for various degrees of aqueous activity in the form of water-soluble salt, carbonate, sulfate, iron oxide, and iron silicate minerals. Following sample return, the compositions and ages of these variably altered igneous rocks are expected to reveal the geophysical and geochemical nature of the planet's interior at the time of emplacement, characterize martian magmatism, and place timing constraints on geologic processes, both in Jezero Crater and more widely on Mars. Petrographic observations and geochemical analyses, coupled with geochronology of secondary minerals, can also reveal the timing of aqueous activity as well as constrain the chemical and physical conditions of the environments in which these minerals precipitated, and the nature and composition of organic compounds preserved in association with these phases. Returned samples from these units will help constrain the crater chronology of Mars and the global evolution of the planet's interior, for understanding the processes that formed Jezero Crater floor units, and for constraining the style and duration of aqueous activity in Jezero Crater, past habitability, and cycling of organic elements in Jezero Crater.

Granitic rocks constitute a global raw material key asset for aggregate production. Their technical performance is, however, highly variable and knowledge on the aggregate functionality of granites in different geological settings is incomplete. This study investigates systematic variations in resistance to fragmentation (Los Angeles value) and wear (Micro-Deval value) for granitic rocks along a 150 km long east–west trending metamorphic gradient across the Eastern Segment of the Sveconorwegian Province in Scandinavia. In essence, the metamorphic gradient represents a transition from pristine granite to stromatic migmatitic orthogneiss and granulite. Along this profile, the aggregate functionality is governed by the behaviour of quartz and feldspar during metamorphic recrystallisation. Two critical metamorphic variables were identified: temperature and hydrous fluids. Recrystallisation at comparably low metamorphic temperatures, ≤ 600 °C, result in irregular grain shapes and fine-grained quartz aggregates that in turn result in low Los Angeles and Micro-Deval values, i.e., high-quality materials for road construction. At higher metamorphic temperatures, > 600 °C, grain coarsening and smoothening of grain boundaries result in significantly higher Los Angeles and Micro-Deval values. At high temperatures, high availability of hydrous fluids promoted extensive partial melting and post-deformational crystallisation which resulted in remarkably poor aggregate performance, with Los Angeles and Micro-Deval values consistently above 40% and 12%, respectively. In contrast, deformation at high temperature but low availability of hydrous fluids resulted in inequigranular textures with high proportions of very fine-sized crystals, interlocking textures, and aggregates with Los Angeles and Micro-Deval values down to 19% and 5%. The consistent variation in metamorphic microtextures correlate with macro-fabrics at the outcrop scale, allowing assessment of aggregate functionality already in the field. For migmatitic gneisses, the proportion and strain state of leucosome are the most critical parameters. 

Granitic rocks are durable materials sought after for the production of road and railroad aggregates. Granitic bedrock commonly, however, includes gabbroic components, which may enhance or decrease the aggregate performance. This study evaluates the variation in resistance to fragmentation (Los Angeles value, LA) and wear/abrasion (micro-Deval value, MDE) for the fraction 10/14 mm of gabbro in different metamorphic states. Samples were collected along a 150-km profile where metamorphic conditions grade from epidote–amphibolite to high-pressure granulite-facies, and the degree of metamorphic recrystallization varies with the amount of hydrous fluid. Rocks with no or incipient metamorphic recrystallization preserving their primary igneous fabric and interlocking texture meet the criteria for both asphalt base course and track ballast in railroad, with LA and MDE values below 25% and 14%, respectively. Mafic granulite and fine-grained amphibolite have LA values below 25% and can be used in unbound layers. Mafic granulites crystallize at high temperatures but commonly preserve a relict igneous texture due to limited hydration. Coarse-grained amphibolite and migmatitic amphibolite have the poorest performance. They recrystallized at hydrous conditions, leading to complete recrystallization, grain coarsening, and loss of interlocking igneous texture. This study shows that both temperature and infiltration of hydrous fluids significantly affect the technical properties. Even at high metamorphic temperatures, gabbroic rocks may yield aggregates of high technical performance. At hydrous conditions, however, recrystallization results in rock aggregates suitable for unbound layers only. The variation in metamorphic grade and hydration is easily assessed by the geologist in the field and by using standard petrographic microscopy. © 2022, The Author(s).