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Discovered over a century ago, the lower Cambrian (Series 2, Stage 4) Cranbrook Lagerstatte of southeastern British Columbia's Eager Formation is one of the oldest Burgess Shale-type deposits in North America. This Konservat-Lagerstatte is rich in olenelloid trilobites, but also yields a very low-diversity soft-bodied fossil assemblage including Tuzoia and Anomalocaris, and a low-diversity ichnofauna. Its scientific study, however, remains limited. A 2015 field-based investigation by the Royal Ontario Museum has revealed new information about the site's biota, depositional environment and taphonomic conditions. Not only is the Cranbrook Lagerstatte significant for early Cambrian biostratigraphy and comparisons with other Burgess Shale-type deposits, it also reveals some of the little-known diversity of life in a distal outer shelf environment during the Cambrian period.

Pyrite is the most common among the group of sulfide minerals in the Earth and abundant in most geological settings. This gangue mineral in association with garnet, hematite, magnetite, and other sulfide minerals acts as an indicator mineral in the Kubi concession of the Asante Gold corporation in Ghana. X-ray diffraction (XRD), air annealing in a furnace, energy-dispersive x-ray spectroscopy (EDX), and X-ray photoelectron spectroscopy (XPS) were applied to investigate the crystal structure, identify individual elements, permanence, transformation, and chemical/electronic properties of such pyrite. The study aims to identify individual elements and to gain an understanding of the surface reaction mechanisms, as well as the properties of precipitated pyrite particles observed during the hydrothermal formation of the ore deposit. XRD shows that pristine and annealed samples contain some hematite and quartz besides pyrite. Results from air annealing indicate that the relationship between pyrite and hematite-magnetite is controlled by temperature. EDX reveals that the sample has O and C as contaminants, while XPS in addition reveals Ba, Au, P, Al, and N. These elements are attributed to pyrite that bonds metallically or covalently to neighboring ligands/impurity minerals such as oxides, chalcogenide sulfides, as well as the gangue alteration minerals of magnetite and hematite in the pyrite sample. These findings suggest that during the hydrothermal flow regime, pyrite, pathfinder elements, and impurity minerals/metals were in contact with quartz minerals before undergoing hematite transformation, which thus becomes an indicator mineral in the Kubi gold concession., Funding Agencies|Linkoping University

Global resource extraction raises concerns about environmental pressures and the security of mineral supply. Strategies to address these concerns depend on robust information on natural resource endowments, and on suitable methods to monitor and model their changes over time. However, current mineral resources and reserves reporting and accounting workflows are poorly suited for addressing mineral depletion or answering questions about the long-term sustainable supply. Our integrative review finds that the lack of a robust theoretical concept and framework for mass-balance (MB)-consistent geological stock accounting hinders systematic industry-government data integration, resource governance, and strategy development. We evaluate the existing literature on geological stock accounting, identify shortcomings of current monitoring of mine production, and outline a conceptual framework for MB-consistent system integration based on material flow analysis (MFA). Our synthesis shows that recent developments in Earth observation, geoinformation management, and sustainability reporting act as catalysts that make MB-consistent geological stock accounting increasingly feasible. We propose first steps for its implementation and anticipate that our perspective as “resource realists” will facilitate the integration of geological and anthropogenic material systems, help secure future mineral supply, and support the global sustainability transition., Validerad;2024;Nivå 2;2024-01-16 (hanlid);Funder: Norwegian University of Science and Technology;Full text license: CC BY

Human impacts on Earth's atmosphere, hydrosphere, litosphere and biosphere are so significant as to naming a new geological epoch, the Anthropocene. Lakes and their biota are highly sensitive to environmental changes. Among aquatic organisms, microbial eukaryotes play fundamental roles associated with lake ecosystem functioning, food webs, nutrient cycling, and pollutant degradation. However, the response of lake microbial eukaryotic community during the Anthropocene to changes in environmental conditions remain poorly understood. Here, we applied a 18S metabarcoding approach to sedimentary DNA to reconstruct the temporal dynamics of microbial eukaryotic community over the past 160 years. We investigated the influence of environmental conditions and of biotic interactions on the microbial eukaryotes in Sihailongwan Maar Lake, one of the candidate sites of Global boundary Stratotype Section and Point (GSSP) for demarcation of the Anthropocene. Microbial eukaryotes were dominated by dinoflagellates, chlorophytes, ciliates, pirsoniales, rotifers, ochrophytes, apicomplexans and cercozoans that were divided into four functional groups that are photoautotrophs, mixotrophs, consumers and parasites. The predominance of phototrophs and their strong associations with organisms from other trophic levels, confirmed their crucial roles in nutrient cycling, energy flows and ecosystem services in freshwater ecosystems. Abrupt changes in the 1950s in microbial eukaryotic diversity and composition were consistent with changes observed in the pollutants emissions i.e., heavy metals, combustion indices (spheroidal carbonaceous particles, polycyclic aromatic hydrocarbon, Soot F14C), radioactivity indicators (239,240Pu, 129I/127I), nutrients (total organic carbon, total nitrogen, phosphorus), and temperature. Statistical analysis revealed that anthropogenic drivers controlled the temporal dynamic of microbial eukaryotic community. Our findings provide additional biostratigraphy evidence

With several upcoming sample return missions, such as the Mars Sample Return Campaign, non-destructive methods will be key to maximizing their scientific output. In this study, we demonstrate that the combination of neutron and X-ray tomography provides an important tool for the characterization of such valuable samples. These methods allow quantitative analyses of internal sample features and also provide a guide for further destructive analyses with little to no sample treatment, which maintains sample integrity, including minimizing the risk of potential contamination. Here, we present and review the results from four case studies of terrestrial impactites and meteorites along with their analytical setup. Using combined X-ray and neutron tomography, a Ni-Fe silicide spherule, that is, projectile material, was located within a Libyan Desert Glass sample and the distribution of hydrous phases was pinpointed in selected impactite samples from the Chicxulub IODP-ICDP Expedition 364 drill core and the Luizi impact structure, as well as in the Miller Range 03346 Martian meteorite. Neutron and X-ray tomography give complementary three-dimensional information about the distribution of different phases within a geologic sample. We demonstrate that these two methods can be successfully used to locate meteoritic material (i.e., from the impacting object) and hydrous components in terrestrial impactites and meteorites. This can help shed light on aqueous processes in the Solar System as well as the impact cratering process. Non-destructive methods like these will be important for up-coming sample return missions to characterize the returned samples and guide further destructive analyses. Combined neutron and X-ray imaging was used to locate projectile material and hydrous phases in meteorites and terrestrial impactites Locating and identifying projectile material can shed light on the impact cratering process Combined neutron/X-ray tomography can serve as a fundamental metho

Reconstructions of past land use and related land-cover changes at local and regional scales are needed to evaluate the potential long-term impacts of land use on the coastal waters of the Baltic Sea. In this purpose, we selected the Gamleby area at the Swedish Baltic Sea coast for a case study. We use a new, high resolution pollen record from a small lake (Lillsjön) located 3.6 km NNW of the bay Gamlebyviken and detailed analysis of the available archeological data to reconstruct local land-use changes over the last 3000 years. To estimate land-cover change at local (2–3 km radius area) and regional (50 km radius area) scales we use four additional, published pollen records from two small and two large lakes (25–70 km S of Lillsjön) and the Landscape Reconstruction Algorithm, a pollen-vegetation modeling scheme. Results show that regional and local (small lakes Lillsjön and Hyttegöl) land-cover changes are comparable over the last 1500 years (Late Iron Age to present), and that landscape openness was much larger locally than regionally (difference of 20–40% cover over the last 500 years). The periods of largest potential impacts on the Gamlebyviken Bay from regional and local land use are 200–950 CE (Late Iron Age) and 1450 CE to present, and of lowest potential impacts 950–1450 CE. The question on whether the large landscape openness 1150–50 BCE and significant afforestation 50 BCE–200 CE reconstructed for Lillsjön’s area are characteristic of the Gamlebyviken region will require additional pollen records in the catchment area.

New organic-walled microfossil (OWM) assemblages are reported from upper Neoproterozoic glacial and interglacial siliciclastic deposits in Finnmark, northern Norway. A nearly continuous sedimentary succession of the Vestertana Group contains two glaciogenic units, the Smalfjorden and Mortensnes formations, interpreted as end-Cryogenian Marinoan and Ediacaran glaciations, respectively. We investigated the OWM record in the Nyborg, Mortensnes, and St ' ahpogieddi formations to assess the impact of a glacial interval on the diversity of microscopic eukaryotes. A modified acid-extraction technique was applied to recover OWM from the diamictite matrix. The upper Nyborg Formation contains morphologically complex Doushantuo-Pertatataka acritarchs (DPA), restricting the age of the Nyborg Formation to early-mid Ediacaran. DPA occur below the dolostones that record a negative carbon isotope excursion correlated with the Shuram anomaly and below a glacial diamictite. A decline in species richness and compositional change is observed in the Mortensnes glacial assemblage. DPA are replaced by bacterial filaments and cell aggregates. The overlying Indreelva Member, St ' ahpogieddi Formation contains Ediacara-type biota and palaeopascichnids, but only a depauperate OWM assemblage of leiosphaerids and flask-shaped microfossils characteristic of the late Ediacaran.The succession of assemblages in the Vestertana Group demonstrates a turnover from large eukaryotic OWM to a microbial community in the glacial interval, to a low diversity post-glacial assemblage during the rise of macroscopic life. We compared the Vestertana record to global DPA occurrences. Although one DPA assemblage zone postdates the Shuram excursion, no DPA occur above Ediacaran glacial diamictites in successions where those deposits are present. Considering this, and the community changes in the Vestertana succession, we suggest that DPA were affected by the onset of an Ediacaran glaciation. Lastly, we combined the

Brachiopods first appeared in the early Cambrian and persist till present. They are one of the main lineages of marine invertebrates that diversified throughout the Paleozoic and reached their maximum diversity of high-rank taxonomy during the Ordovician. During this time interval, brachiopods were mainly dominated by the articulated Orthida and Strophomenida, which represent major components of the Paleozoic Evolutionary Fauna; however, the inarticulated lingulid brachiopods (Order Lingulida) were comparatively less abundant and received less attention during this time period. Here, we report a new record of the lingulid brachiopod Anomaloglossa porca from the Upper Ordovician (Sandbian) Pingliang Formation of the Xilinggou Section, Shaanxi Province, North China. Collected specimens are preserved as calcium phosphatic shells with highly mineralization which preserve detailed morphology and shell ornamentation of both ventral and dorsal valves. The new occurrence of A. porca extends its paleogeographic distribution from Gondwana and Tarim to North China Platform. Moreover, comprehensive geometric morphometric analysis of A. porca is performed and the results indicate that both the shell shape and pseudointerarea are very close to the recent infaunal lingulids. If interpreted correctly, the fossils represent the first example of infaunal lifestyles achieved by Ordovician lingulids from North China, exhibiting the ecological complexities of the Late Ordovician benthos composed of epibenthos and infaunas as well.

The vast oxygen-depleted area of the central Baltic Sea is the largest human-induced dead zone in the world with 70,000 km(2) or approximately three times the second largest one in the Gulf of Mexico. Methane occurs in high concentrations in bottom waters (3200 nM) and sediments (30 mM), and its dynamics is better constrained for the water column, but still poorly understood on sediments. Here we show that sediment accumulation rate plays a major role in regulating the quantity of organic matter and its residence time in the sulphate reduction and methanogenesis zones and, therefore, affects methane generation, consumption, and diffusive flux in sediments near the seafloor (< 1 m). High fluxes found in high sediment accumulation rate areas and competition for substrate (organoclastic sulphate reduction vs. anaerobic oxidation of methane with sulphate), compromise the ability of the thin microbial filter to consume and prevent methane diffusion through the seafloor.

Garnet is an exceptionally useful mineral for reconstructing the evolution of metamorphic rocks that have experienced multiple tectonic or thermal events. Understanding how garnet crystallizes and its mechanical behaviour is important for establishing a petrological and temporal record of metamorphism and deformation and for recognizing multiple geologic stages within the growth history of an individual crystal. Here, we integrate fine-scale microstructural (electron backscatter diffraction [EBSD]) and microchemical (Laser Ablation Inductively Coupled Plasma Mass Spectrometry [LA-ICP-MS] mapping) data obtained on a polycyclic garnet-bearing micaschist from the Alpine belt. Results suggest that fragmentation of pre-Alpine garnet porphyroblasts occurred during the late pre-Alpine exhumation and/or the onset of the Alpine burial, such that the older pre-Alpine garnet fragments were transported/redistributed during Alpine deformation and acted as nucleation sites for Alpine garnet growth. These processes produced a bimodal garnet size distribution (millimetre- and micrometre-sized grains). Thermodynamic modelling indicates that Alpine garnet grew during the final stage of burial (from 1.9 GPa 480°C to 2.0 GPa 520°C) and early exhumation (down to 1.6 GPa 540°C) forming continuous idioblastic rims on and sealing fractures in pre-Alpine garnet grains. We propose that fragmentation–overgrowth processes in polycyclic rocks, coupled with ductile deformation, may produce a bimodal garnet size distribution in response to fragmentation and re-distribution of pre-existing grains; these clasts can act as new nucleation sites during a subsequent orogenic cycle.

Field data from recent geological mapping over a major part of the north-central Scandinavian Caledonides combined with published information give a detailed view of early Cambrian basin successions, comprising the Gärdsjön formation (Gf; Jämtland supergroup) in the Lower Allochthon and autochthonous equivalents (Dividal Group). The Gf comprises ten units of sandstone and siltstone or mudstone (Gf I—X, > 300 m thick). Green siltstones with red layers (Gf VI, c. 521 to 519 Ma) and green–grey siltstones at the top (Gf X, c. 516.5 to 513.5 Ma) are regional key horizons. Gf V, VI, VII, IX, and X deposition may be related to eustatic events. Restoration of Caledonian shortening reveals a major “Hornavan-Vattudal basin” (HVB; > 330 km NW–SE, > 400 km NE-SW) between the Grong–Olden culmination in the S and the Akkajaure–Tysfjord culmination in the N. Published zircon ages imply the latter separated the HVB from those shed from the Timan orogen in the N. The eastern basin margin straddles the present Caledonian erosional margin. Basement highs identified here within the Nasafjället, Bångonåive, and Børgefjellet “basement” windows define the western margin. They separate the HVB from the outer shelf towards the Iapetus Ocean in the W. The onset of sedimentation is time-related with E–W extension at c. 544–534 Ma. NNE–SSW-directed extension occurs after c. 518 Ma, perhaps related with Timan late-orogenic extension. The HVB is distinctly younger (c. 535–513.5 Ma) than Rodinia break-up and Iapetus ocean formation (> 550 Ma), comparable with post-rift basins in inner parts of modern passive margins.

The Siljan Ring in Dalarna, Sweden is the site of the largest meteor impact crater in Europe and has long been a topic of discussion regarding methane production. However, the source of this methane and the timing of production in relation to the impact remain unclear. An outcrop of red Ordovician limestone preserved on the edge of a downfaulted zone encircling the crater’s central plateau is crosscut by fractures surrounded by pale-coloured reduction haloes within which precipitates can be observed. These haloes suggest interaction with a reducing agent mobilised within a fluid flow, of which methane would be a prime candidate. A field study was subsequently undertaken to establish the reaction whereby these haloes were formed, as well as the timing of their formation relative to the Siljan impact based upon petrological, geochemical, and structural data obtained in the field. Results from this study show that a methane-bearing hydrothermal fluid mobilised within the fractures has preserved the original mineralogy of the limestone within the reaction haloes whilst the country rock beyond was being oxidised. Pyrite is shown to be preserved within the pale reaction haloes, whilst its oxidation within the country rock is shown to be the source of the limestone’s distinct red colouring. Fracture and bedding orientation at the study site suggest the hydrothermal event to have been simultaneous with the meteor impact, with the fractures forming part of a wider complex network of impact features. Whilst mobilisation associated with the meteor impact is a likely cause of methane release, the exact source of the methane active at the study site is unclear.

The concept of gamification is being increasingly explored and applied to offer new teaching or training tools to teachers, students or employees. The field of geology and geometallurgy wasn’t particularly discussed in the topic of gamification. With the objective of creating a synthetic geometallurgical database and a game structure for a gamified simulation of a metal mine, the eastern part of the Malmberget deposit in Sweden was simplified and modelled.The geological model was obtained with assumptions of continuity and proximity, and the lack of data was reconciled using targeted randomization and regular statistics to achieve a smoother and realistic result. A rule book was created to establish the framework that a geometallurgy game should follow,using a slightly adapted version of the Desing thinking framework by the Nielsen group, which consists of elaborating ideas and concepts, implementing them and testing the results before integrating feedbacks to the creation of future elements. The accent was put on obtaining an interactive experience where the player can try various things with a reasonable difficulty, and an accessibility to feedbacks.The purpose of this project is to elaborate a mining simulation game, that could be a valuable tool in the understanding of the interdisciplinary concept of geometallurgy, as well as raising the awareness about sustainable development and how mining can be a part of it. The starting point of this project is another attempt at gamifying geometallurgy by P. Lamberg. The simulation of mineral processing was done using the HSC Sim utilizing 8 different flowsheets that were designed to offer a variety and enable strategic choices. The events occurring at a real mine and beneficiation plant were translated into simple rules. The outcome is a realistic geological and processing model, which through the addition of mining, economics and market strategy, becomes a comprehensive geometallurgy database.

Efficient outgassing of shallow magma bodies reduces the risk of explosive eruption. Silica-rich magmas are too viscous for exsolved gas bubbles to escape the system through buoyant forces alone, and so volatile overpressure is often released through deformation-related processes. Here we present a case study on magma-emplacement-related deformation in a shallow (500 m depth) rhyolite intrusion (the Sandfell laccolith, Eastern Iceland) to investigate the establishment and evolution of degassing and outgassing networks in silicic sub-volcanic intrusions. We observe viscous and brittle deformation features: from vesiculated flow bands that organized into 'pore channels' in the ductile regime, to uniform bands of tensile fractures (‘fracture bands’) that grade into breccia and gouge in the brittle regime. Through field mapping, structural analysis, and anisotropy of magnetic susceptibility (AMS), we show that the deformation spectrum, observed all over the laccolith, represents stages of degassing (viscous processes) and outgassing (brittle processes) that resulted in the formation of interconnected permeable networks through the growth and linkage of fracture bands. Areas with concentrations of higher degrees of brittle deformation are proximal to abruptly changing AMS fabrics and point to laccolith-scale strain partitioning in the magma linked to different stages of laccolith growth. The establishment of intrusion-scale permeable networks through the cumulation of discrete magma fractures would have profoundly assisted the outgassing of the entire laccolith. Therefore, fracture banding captures viscous and brittle processes working in tandem as an efficient outgassing mechanism, and should be considered in sub-volcanic intrusions elsewhere.

While basaltic volcanism is dominant during rifting and continental breakup, felsic magmatism may be a significant component of some rift margins. During International Ocean Discovery Program (IODP) Expedition 396 on the continental margin of Norway, a graphite-garnet-cordierite bearing dacitic unit (the Mimir dacite) was recovered in two holes within early Eocene sediments on Mimir High (Site U1570), a marginal high on the Vøring Transform Margin. Here, we present a comprehensive textural, petrological, and geochemical study of the Mimir dacite in order to assess its origin and discuss the geodynamic implications. The major mineral phases (garnet, cordierite, quartz, plagioclase, alkali feldspar) are hosted in a fresh rhyolitic, vesicular, glassy matrix that is locally mingled with sediments. The major element chemistry of garnet and cordierite, the presence of zircon inclusions with inherited cores, and thermobarometric calculations all support an upper crustal metapelitic origin. While most magma-rich margin models favor crustal anatexis in the lower crust, thermobarometric calculations performed here show that the Mimir dacite was produced at upper-crustal depths (<5 kbar, 18 km depth) and high temperature (750–800°C) with up to 3 wt% water content. In situ U-Pb analyses on zircon inclusions give a magmatic crystallization age of 54.6 ± 1.1 Ma, consistent with emplacement that post-dates the Paleocene-Eocene Thermal Maximum. Our results suggest that the opening of the Northeast Atlantic was associated with a phase of low-pressure, high-temperature crustal anatexis preceding the main phase of magmatism.

Substantial uncertainties exist regarding how future climate change will affect storminess (storm frequency and intensity) in Ireland and the United Kingdom (UK). Knowledge about spatiotemporal variations of past storminess gives us a better understanding of its mechanisms on centennial to millennial time scales, as well as the impact of external forcing on future storminess in climate models. Here, we present the oldest storm record to date from Ireland, covering the last 8000 years, reconstructed from the Roycarter Bog, a coastal blanket bog in north-western Ireland. The sequence was analysed for grain-size, chemical, mineral and organic molecular composition. The chronology was built on 11 AMS radiocarbon dates. The deposit characteristics, location and low inorganic content suggest aeolian transport of particles to the bog throughout the studied period. Cluster analysis of the grain-size frequency curves, along with the coarse to fine sand ratio, allowed the identification of eleven storm periods (cal yr BP): 6150–5500 (1); 4970–4130 (2); 4000 (3); 3490–3290 (4); 3230 (5); 2850–2590 (6); 2170–1920 (7); 1440 (8); 1225–890 (9); 620–470 (10); and 290–230 (11). During the mid-Holocene, the relative sea level was lower and the local beach sources located further away, giving a longer transport distance compared to the late Holocene. In the latter part of the mid-Holocene (6150–4130 cal yr BP), during the Holocene thermal maximum, increased storminess and wind strengths were inferred for north-western Ireland, manifested as two longer storm periods. During the late Holocene the storm frequency increased, and a greater number (9) of shorter storm periods were recorded. Comparison between our results and regional peat palaeostorm records from Scotland, north of our study site, showed an antiphase relationship between storminess in Ireland and Scotland during the latter part of the mid-Holocene, but mostly in-phase storminess over the last 3000 years. Taken together, enh

The potential for enhanced geothermal energy production in the Kalmar and Nybro municipalities is investigated by reviewing existing data on the regional geothermal gradient and the extent of fracture zones with depth of the crystalline crust in the research area. Existing geophysical and hydrological models along with bedrock maps and results of earlier studies in the nearby region are integrated in this report. The geothermal gradient in the Kalmar-Nybro area is currently not quantified, but proximal measurements indicate that the temperature is not likely to increase significantly more than 16-17°C/km considering local bedrock properties. Target depths would in this scenario be up to 6-7 km for production drilling. The only major deformation zone in the area stretches in a WNW direction from Kalmar and has potential for containing deep open fractures. The Boda-Örsjö area appears to host an extensive fracture network of multiple converging fracture zones. However, prediction of fracture occurrence at depths of several kilometres is highly speculative since no deep drill data has been produced in the area. Suggestions for further studies required in order to develop a deep geothermal project in the region are provided, with emphasis on locating favourable structural settings and bedrock stress conditions. Nevertheless, technical method developments regarding drilling and fluid injection are likely required for enabling deep geothermal energy production in the relatively cold depths of the exposed crystalline bedrock characterizing both the examined area in this report and the predominant parts of Scandinavia.

The chemical and isotopic characteristics of terrestrial basalts are constrained within the concept of mantle chemical geodynamics that explains the existing variety of basaltic rocks within a framework of several end-member reservoirs in Earth's mantle. In contrast, there is no comparable fully developed model explaining the isotopic composition of lunar basaltic rocks, in part owing to the lack of well-constrained age-isotope relationships in different groups of basalts identified on the Moon. Notably, the absence of agreement upon ages includes basalts from a unique group of meteorites collectively known as 'YAMM' (basalts Yamato-793169: Y-793169, Asuka-881757: A-881757, Miller Range 05035: MIL 05035 and regolith breccia Meteorite Hill 01210: MET 01210), which appear to show chemical signatures different from all other known lunar basaltic rocks. We present high-precision Pb-Pb ages and initial Pb isotopic ratios for two samples from this group, MIL 05035 and A-881757. These meteorites have Pb isotope ratios different from those of the other lunar basalts, suggesting they are derived from a distinct and depleted mantle source, with a U-238/Pb-204 ratio (mu value) lower than any other mantle source. Their depletion in rare earth elements, in conjunction with recalculated initial Nd and Sr isotopic ratios from published data and using our new age, appear to support this conclusion. The chemical and Sr-Nd-Pb isotopic characteristics of this low-mu source appear to be the opposite of those of the KREEP reservoir and many, if not all, features described in other lunar basalts (such as low- and high-Ti mare basalts) can be explained by a binary mixing of material derived from low-mu and KREEP-like reservoirs. This mixing might be the result of a slow, convection-like mantle overturn.

Northern peatlands are terrestrial ecosystems that provide specialized habitats in which biomass production exceeds decomposition, resulting in accumulation of organic matter. Understanding what factors drive species changes in future climate conditions in these systems is of high importance since this has the potential to affect ecosystem functioning and biodiversity, and by extension carbon sequestration. In ecology, a common method for investigating species’ relationships with climate variation, linked with spatial information, is species distribution modelling (SDM). This method typically uses information about current climate conditions tied to locations of species occurrences, forecasting the effects of change on future geographic distributions based on the implicit assumption that temporal variation can be substituted by contemporary spatial variation. This assumption might not be met for several reasons, namely (1) species changes often occur over much longer time-scales than the ones involved in contemporary ecology, and therefore (2) responses to climatic changes are time-lagged. Incorporating paleo-records of actual (past) changes in species distributions and climate conditions therefore provides a much more direct way to model species responses to climate change. In this project, a combination of methods from the fields of paleoecology and ecology were employed to create a novel approach to explore species distribution changes over time in boreal peatlands. This was done by first reconstructing the vegetation of two proximal peatlands (Store Mosse and Dala Mosse bogs; Paper I and III) in south-central Sweden, followed by statistical modeling of the species data and climatic parameters over time (obtained from independent paleoclimate data; Paper II and III), creating Temporal Paleo-Species Distribution Models (Temporal Paleo-SDMs). Paper I identifies factors driving species changes in Store Mosse bog based on internal (successional steps and biotic int

I denna uppsats analyseras utbredningen av fornlämningar i Mälardalen och deras förhållande till miljö och geologi, med fokus på att hitta okända fornlämningar med hjälp av digitala verktyg. Kulturmiljöregistret baserat på inventeringar genomförda över tid studeras. Verktygen GIS och MaxEnt beskrivs, samt deras användning för arkeologiska landskapsstudier. De används för analys av fornlämningarnas spridningsbild. Ett antal lämningskategorier valdes ut för analys, och resultaten jämförs med tidigare forskning. Arkeologi och statistik kombinerat med naturvetenskapliga metoder används för att skapa modeller av okända lämningar som kan användas för att försöka återfinna dessa genom historiska kartor, LiDAR eller med geofysik. Spridningsmönster av figurristningar från bronsåldern påvisas ha en stark korrelation till bergarten kvartsarenit, en upptäckt som kan leda till nya tolkningar av lämningskategorin och landskapsutnyttjandet i Uppland. Uppsatsen visar på modeller och tekniker för landskapsanalys som kan vara användbara för att identifiera tidigare okända mönster och bättre förstå förhistoriska landskap samt för att skapa en brygga till framtida arkeologisk forskning med stöd av AI, drönare och stora datamängder., In this paper, the distribution of ancient remains in the Mälardalen and their relationship to the environment and geology is analysed, focusing on finding unknown ancient remains using digital tools. Kulturmiljöregistret created from inventories carried out over time is studied. The tools GIS and MaxEnt are described, as well as their use for archaeological landscape studies and for analysis of distribution patterns of ancient remains. A number of categories of remains were selected for analysis, and the results were compared with previous research. Archaeology and statistics combined with natural science are used to create models of unknown remains for recovering them with the aid of historical maps, LiDAR or geophysics. Distribution patterns of figure carvings from the Bronze Age are shown to have a strong correlation to the rock type quartz arenite, a discovery that can lead to new interpretations of this category of remains and the landscape utilization in Uppland. The paper shows models for landscape analysis which can be useful for identifying previously unknown patterns and for better understanding of prehistoric landscapes, as well as to create a bridge to future archaeological research supported by AI, drones and large data sets.

Varved lake sediments offer valuable insight into past environmental conditions with high temporal resolution and precise chronological control. A combination of diatom and geochemical analyses of the recently deposited sediments of Odensjön, a small dimictic lake in southern Sweden, shows alternating light and dark laminae composed of greater amounts of biogenic silica and organic matter, respectively. As confirmed by independent radiometric dating and Pb pollution data, and supported by scanning electron microscopy of individual laminae, these features represent ongoing deposition of biogenic varves. Corresponding diatom and geochemical data obtained from a 92-cm long freeze core provide evidence of substantial lake-ecosystem dynamics during the last six centuries, related mainly to variations in light penetration and wind shear driven by human-induced changes in catchment vegetation. The diatom assemblage of Odensjön’s varved sediments is dominated by planktonic species, primarily Asterionella formosa, Fragilaria saxoplanktonica and Discostella lacuskarluki during periods of forest cover, while increased catchment openness from the mid-1500s to the late 1800s led to increased abundance of Lindavia comensis. Long-term variations in climate and land use, mediated through changing length of the ice-cover season and nutrient input, respectively, probably contributed to the observed trends, as well as to variations in the appearance and visibility of the varve record across the sampled sediment sequence. Odensjön represents the southernmost varved sediment record in Fennoscandia documented to date, offering potential to study the effects of various types of external forcing on its sensitive lacustrine ecosystem since the Late Weichselian deglaciation. In the present study, we investigated the possibility of assessing the local impacts of two major, historically documented volcanic events, Laki 1783–84 and Tambora 1815, which are known to have affected European societi

The Lundy Island granite (Bristol Channel, UK) is a felsic expression of the southernmost igneous centre of the North Atlantic Igneous Province (NAIP) that emplaced millions of km3 of magma in the Paleogene. The distinctive S-type, peraluminous, two mica ± garnet ± tourmaline composition has led to the hypothesis that eruptions from the Lundy volcanic centre may be the source of thick felsic ash layers within the early Eocene Fur Formation (Denmark) that act as key marker horizons for the onset and duration of the Paleocene–Eocene Thermal Maximum (PETM). This study presents high-precision zircon U-Pb emplacement ages of 57.24 ± 0.11/0.12/0.13 Ma for the granite and 55.970 ± 0.021/0.030/0.070 Ma for a felsic ‘lundyite’ dyke. Trace and REE element patterns indicate close similarities between late-stage Lundy activity and ash layer ‘-33’ in Denmark that was deposited during the PETM carbon isotope excursion, suggesting that this centre is likely to be the source of this key ash horizon and that magmatism at Lundy likely continued into the early Eocene.

To support economic decisions and exploration targeting, as well as to understand processes controlling the mineralization, three-dimensional structural and lithological boundary models of the Kiruna mining district have been built using surface (outcrop observations and measurements) and subsurface (drill hole data and mine wall mapping) data. Rule-based hybrid implicit-explicit modeling techniques were used to create district-scale models of areas with high disproportion in data resolution characterized by dense, clustered, and distant data spacing. Densely sampled areas were integrated with established conceptual studies using geologic conditions and the addition of synthetic data, leading to variably constrained surfaces that facilitate the visualization, interpretation, and further integration of the geologic models. This modeling approach proved to be efficient in integrating local, frequently sampled areas with district-scale, sparsely sampled regions. Dominantly S-plunging lineation on N-S–trending fracture planes, characteristic fracture mineral fill, and weak rock mass at the ore contact indicated by poor core orientation quality and rock quality description suggest that ore-parallel fractures in the Kiirunavaara area were more commonly reactivated. Slight variation in the angular relationship of fracture sets situated in different fault-bounded blocks suggests that strain accommodation across the orebodies was uneven. The location of brittle faults identified in drill core, deposit-scale structural analysis, and aeromagnetic geophysical maps indicate a close relationship between fault locations and the iron oxide-apatite mineralization, suggesting that uneven stress accommodation and proximity of conjugate fault sets played an important role in juxtaposing blocks from different crustal depths and control the location of the iron oxide-apatite orebodies., Validerad;2024;Nivå 2;2024-09-06 (joosat);Full text: CC-BY-NC license;Funder: Luossavaara Kiirunavaara AB (LKAB)

The Carpathian belt is one of Europe's major metallogenic provinces, where magmatic ore mineralization is associated with the past subduction environment. The upper crust is mapped for the first time in the Northeast Carpathian Volcanic Arc using magnetotelluric data inversion. The obtained 3-D electrical resistivity model is interpreted in conjunction with geological information and magnetic anomaly data. The model illustrates the deep magmatic plumbing system including kilometer-scale plutonic bodies at a depth of 2–7 km. The model implies that the transport of magma and fluids in the uppermost crust was controlled by pre-existing faults and décollement horizons. Present ore mineralization, mined since historical times, can be attributed to an electrically conductive conduit that is mapped from the surface to a depth of about 30 km. It is suggested that this conduit connected a shallow magmatic chamber to a deep source region in the southeast during late Miocene time. An observed northwest deflection of the deep magmatic conduit at a depth of more than 10 km may explain the spatial gap in the distribution of the Miocene volcanic activity along the Eastern Carpathians., Validerad;2024;Nivå 2;2024-08-08 (hanlid);Funder: Norway Grants 2014‐2021 (12/2020);Full text license: CC BY-NC-ND;Part of special issue: Solid Earth Geophysics as a Means to Address Issues of Global Change

The Skellefte district in northern Sweden hosts many volcanogenic massive sulfide (VMS) deposits and is considered one of the most important European mining districts for Cu, Zn, Pb, Ag, and Au. The volcanic and sedimentary rocks that the VMS deposits are hosted in were deformed during the Svecokarelian orogeny, with three documented regional deformation phases. These events imparted a distinct attitude and geometry to the deposits, their host succession, and discordant zones of synvolcanic hydrothermal alteration. Few studies have investigated the detailed deformation effects on the sulfide minerals. In this contribution, we document the structural characteristics and remobilization history of mineralization at the Rävliden North Zn-Pb-Cu-Ag deposit—one of the most important recent discoveries in the district consisting of 8.5 million tonnes (Mt) grading 1.01% Cu, 3.45% Zn, 0.53% Pb, 78.60 g/t Ag, and 0.23 g/t Au. At Rävliden, massive to semimassive sphalerite-rich mineralization with lesser pyrrhotite, galena, pyrite, and silver minerals occurs structurally above stringer-type mineralization dominated by chalcopyrite, pyrrhotite, and pyrite. These mineralization types exhibit evidence of deformation and remobilization such as (1) sulfide-alignment parallel to tectonic foliations; (2) rounded wall-rock tectonoclasts in a ductile deformed sulfide matrix (“ball ore” or durchbewegt ore); and (3) sulfides in tension gashes, strain shadows, piercement veins, and late, straight veinlets crosscutting tectonic fabrics. These features are attributed to polyphase deformation during the D1, D2, and D3 events at temperature ranging from 200° to 550°C. Remobilization of sulfides was mostly within the bounds of the main mineralization (i.e., 10–100 m), with few local external occurrences. A combination of solid-state and fluid-assisted remobilization processes are inferred. Rare brittle veinlets and zeolite-cemented breccias with sphalerite, galena, and silver minerals occur in, Validerad;2024;Nivå 2;2024-06-27 (joosat);Full text license: CC-BY;Funder: Boliden

A marked sedimentological change in subsurface sediments from the entire Baltic Proper, the Baltic Sea, has been previously noted. Our detailed work on a variety of multi-cores from basin-wide transects indicates that this sedimentological change was caused by a large shift in environmental conditions during the 1950s. Until the 1950s, the water column was rather weakly stratified and winter-time convection - although weakened during the post Little Ice Age warming - was still able to ventilate the bottom waters of the Baltic Proper. Therefore, complete sediment sequences only accumulated in calm waters deeper than 150-160 m. High-resolution benthic foraminiferal records of subsurface sediments obtained along the saline water inflow pathway in combination with historical data indicate that the depositional environment changed drastically owing to the giant saline water inflow in AD 1951. The accompanied sharpening of the halo(pycno)cline triggered a collapse in the ventilation of the basin, resulting in oxygen-deficient bottom waters. This deficiency, in turn, caused the onset of phosphate release from the sediments, which accelerated primary production. The ventilation collapse also enabled the onset of deposition of organic carbon-rich sediments also in shallower water areas as calm conditions prevailed up to the modern winter mixing depth (60-70 m). A slight return to Little Ice Age-type conditions was observed during the late 1980s when temperatures decreased and stratification weakened. These conditions gave rise to a reduction in hypoxic areas and to a bottom-water ventilation, most pronounced in the north of the so-called Baltic Sea Klint, a hydrographic and topographic barrier. However, the general environmental conditions essentially have not changed since the 1950s. Remarkably, external (temperature and stratification) in combination with internal factors (e.g. ventilation collapse and phosphate release) were able to change the redox conditions of the Balt

Borings of microscopic organisms (euendoliths) are described from the Henson Gletscher Formation (middle Cambrian, Miaolingian Series, Wuliuan Stage) of Peary Land, North Greenland (Laurentia). Partially phosphatised sclerites of Chancelloria and valves of the brachiopod Nisusia reveal abundant casts of borings following dissolution of skeletal calcium carbonate in weak acetic acid. Threads referred to Scolecia dominate, occurring together with coccoids (Planobola) and the branching Fascichnus, in a suite comparable to a lower Cambrian assemblage from the Maidiping Formation of Sichuan, China.

The periostracum, a non-calcified organic layer that envelops the mineralized shell layer ('ostracum') of molluscs, acts as an initial framework for the calcified 'ostracum.' Despite its significance in biomineralization in molluscs, fossil examples of the periostracum are limited in the geological record, especially from the Palaeozoic era, due to its susceptibility to post-mortem decay. In this study, we describe radial threads found on the outer surface of Cambrian molluscs, including helcionelloids and rostroconchs, which we interpret as fossilized periostracal structures. These radial threads are observed in 13 species from five valid genera, exhibiting a widespread palaeogeographical distribution encompassing Gondwana (Australia), Siberia, western Laurentia (Utah), and eastern Laurentia (Greenland), and spanning Cambrian Stage 4-Drumian deposits. These radial threads always cover the outermost surface of shells, dividing it into regular intervals, and develop through incremental growth. They originate from the apical area of helcionelloids or the umbo of rostroconchs. Detailed examination has revealed that the radial threads initiate at the apical region, but may be absent from the protoconch (embryonic shell). The radial threads are most likely preserved by mineral encrustation on the periostracum. Similar, but not homologous, radial threads are found in other fossil and modern molluscan taxa, such as the adhesive radial lines of anomalodesmatan bivalves or the periostracal ridges of viviparid gastropods.

We present a combined experimental and numerical study of failure and damage in faulted Opalinus Clay shale around an opening at the Mont Terri Rock Laboratory, Switzerland. An experiment borehole with a diameter of 0.6 m and a length of 12.9 m intersecting a major fault zone at an acute angle of ∼ 40° was drilled, with subsequent overbreaks closely monitored. To investigate the underlying mechanisms that lead to the observed overbreaks, we developed a 3D geomechanics model to simulate the deformation and failure behaviour of faulted Opalinus Clay shale. To represent geological structures including the major fault zone and secondary fracture sets, a site-specific fracture network was constructed. Our model captured many important geomechanical properties and responses of the faulted Opalinus Clay shale, such as anisotropy of the shale matrix, deformation of the fault zone, dislocation of secondary fractures, and growth of new cracks as well as generation of overbreaks around the opening. We compared our simulation results with in-situ experimental observation of short-term overbreak patterns along the borehole and found that the overbreak occurrence is strongly controlled by both stress conditions and geological structures. Our results indicate that the damaged zone is characterised by an inner shell and an outer shell, where the former (dominated by extensive tensile/shear cracks) has a thickness of about one quarter of the borehole diameter and the latter (dominated by sparse shear cracks) extends by half to one borehole diameter into the surrounding rock. We further elucidated the impacts of the major fault zone and secondary fracture sets as well as the borehole–fault intersection angle on the deformation, damage, and failure characteristics. The findings and insights obtained in this study have important implications for the stability evaluation of waste emplacement drifts and long-term safety assessments of nuclear waste galleries in faulted argillaceous rocks

The ultramafic rocks of the Herbeira Massif in the Cabo Ortegal Complex (NW Iberia) host chromitite bodies. The textural and compositional study of the host rocks and the chromitites classified them into: (1) Type-I chromitites, forming massive pods of intermediate-Cr chromite (Cr# = 0.60–0.66) within dunites; and (2) Type-II chromitites forming semi-massive horizons of high-Cr chromite (Cr# = 0.75–0.82) interlayered with dunites and pyroxenites. Minor and trace elements (Ga, Ti, Ni, Zn, Co, Mn, V and Sc) contents in the unaltered chromite cores from both types show patterns very similar to fore-arc chromitites, mimicked by the host dunites and pyroxenites. Calculated parental melt compositions suggest that Type-I chromitites crystallized from a melt akin to fore-arc basalt (FAB), while Type-II chromitites originated from a boninite-like parental melt. Both melts are characteristic of a fore-arc setting affected by extension during rollback subduction and have been related to the development of a Cambrian-Ordovician arc. These chromitites are extremely enriched in platinum-group elements (PGE), with bulk-rock PGE contents between 2,460 and 3,600 ppb. Also, the host dunites and pyroxenites exhibit high PGE contents (167 and 324 ppb, respectively), which are higher than those from the primitive mantle and global ophiolitic mantle peridotites. The PGE enrichment is expressed in positively-sloped chondrite-normalized PGE patterns, characterized by an enrichment in Pd-group PGE (PPGE: Rh, Pt and Pd) over the Ir-group PGE (IPGE: Os, Ir and Ru) and abundant platinum-group minerals (PGM) dominated by Rh-Pt-Pd phases (i.e. Rh-Ir-Pt-bearing arsenides and sulfarsenides, Pt-Ir-Pd-base-metal-bearing alloys, and Pt-Pd-bearing sulfides). The PGM assemblage is associated with base-metal sulfides (mostly pentlandite and chalcopyrite) and occurs at the edges of chromite or embedded within the interstitial (serpentinized) silicate groundmass. Their origin has been linked to direct cry, Validerad;2024;Nivå 2;2024-06-14 (signyg);Full text license: CC BY;Funder: Spanish Projects (CGL2015-65824); MINECO (BES-2016-076887); Ciencia Básica (A1-S- 14574); Consejo Nacional de Ciencia y Tecnología (CONACYT)

The Chachahuén Volcanic Complex is an eroded Upper Miocene arc to back-arc volcanic system that was emplaced in the north-eastern edge of the Neuquén Basin, southern Mendoza province, Argentina. It was formed as the result of shallowing followed by steepening of the Nazca plate during Miocene-Pliocene, and is characterized by a volcanism which ranges from trachydacites to basalts. Thanks to erosion, the stratigraphy and the shallow plumbing systems of the volcano are well-exposed. A new evolution for the volcano stratigraphy is proposed, based on new field observations, satellite imagery, and incorporating the radiometric and petrological data of previous works. The stratigraphy is constrained around one main explosive event, recorded by a thick dacitic pyroclastic density current (PDC) deposit (the Corrales Ignimbrite) (>150m). The main units forming the Chachahuén Volcanic Complex are (1) the pre-dacite PDC deposits (trachydacitic to rhyolitic) Vizcachas Formation, (2) the thick Corrales Ignimbrite, (3) a post-dacite trachyandesitic PDC deposits (dominated by block and ash (BAF) deposits) and thick lava flows, and (4) thin mafic basaltic lava flows. The collapse of a large elliptical caldera occurred during the Trachyandesite phase. The main magma transport channels and feeders are sub-vertical dykes, which exhibit a radial distribution centred on the main caldera depression. Moreover, cryptodomes mainly preserved outside the rim of the caldera accommodated the transport and emplacement of the more silicic magma during the Trachyandesite phase.

A low abundance but diverse fauna of tergomyan molluscs is described from the Llangynog Inlier, Carmarthenshire, South Wales. The specimens originate from a single quarry exposing shallow-water siltstone and mudstone beds of the Early Arenig (early Floian) Bolahaul Member of the Ogof Hen Formation. The fauna includes Proplina areniga sp. nov., Proplina? obtusa sp. nov., Celtopileus calvapex gen. et sp. nov. with preserved muscle scars, Costulaconus mirificus gen. et sp. nov., and Hypseloconus? sp. Comparable tryblidiid taxa are mainly found in the Lower Ordovician of Midwestern USA among species of Proplina Kobayashi, 1933 and Gasconadeoconus Stinchcomb, 1986. The tentative assignment of the predominantly late Cambrian Hypseloconus is symptomatic of the many uncertainties regarding the phylogeny of the tryblidiids. The diverse assemblage of organisms preserved at the single locality represents one of the most remarkable faunas of this age worldwide.

Primary granitic melt inclusions are trapped in garnets of eclogites in the garnet peridotite body of Pfaffenberg, Granulitgebirge (Bohemian Massif, Germany). These polycrystalline inclusions, based on their nature and composition, can be called nanogranitoids and contain mainly phlogopite/biotite, kumdykolite, quartz/rare cristobalite, a phase with the main Raman peak at 412 cm - 1 , a phase with the main Raman peak at 430 cm - 1 , osumilite and plagioclase. The melt is hydrous, peraluminous and granitic and significantly enriched in large ion lithophile elements (LILE), Th, U, Li, B and Pb. The melt major element composition resembles that of melts produced by the partial melting of metasediments, as also supported by its trace element signature characterized by elements (LILE, Pb, Li and B) typical of the continental crust. These microstructural and geochemical features suggest that the investigated melt originated in the subducted continental crust and interacted with the mantle to produce the Pfaffenberg eclogite. Moreover, in situ analyses and calculations based on partition coefficients between apatite and melt show that the melt was also enriched in Cl and F, pointing toward the presence of a brine during melting.The melt preserved in inclusions can thus be regarded as an example of a metasomatizing agent present at depth and responsible for the interaction between the crust and the mantle. Chemical similarities between this melt and other metasomatizing melts measured in other eclogites from the Granulitgebirge and Erzgebirge, in addition to the overall similar enrichment in trace elements observed in other metasomatized mantle rocks from central Europe, suggest an extended crustal contamination of the mantle beneath the Bohemian Massif during the Variscan orogeny.

The opening and closure of the Paleozoic Iapetus Ocean, leading to the collision of Laurentia and Baltica forming the Caledonian orogen, is one of the prime examples of a Wilson cycle. In this perspective article, we summarize and discuss the content of 10 new research articles within a 5-stage framework of the Caledonian Wilson cycle from a North Atlantic perspective. Stage 1 covers Neoproterozoic rifting of both the Laurentian and Baltican margins, where the plate tectonic configurations and the timing for the onset of rifting are far from resolved; Stage 2 covers the onset of sea-floor spreading within Iapetus, with several different oceanic basins opening at different times, and with variable geometries of the rifted margins; Stage 3 covers the narrowing of the Iapetus basins along several subduction zones, the number, location and orientation of which are debated; Stage 4 covers the main continent-continent collision, documenting advances in our understanding of (U)HP metamorphism within the Western Gneiss Region; Stage 5 covers post-orogenic extension, transitioning into stage 1 of the subsequent Atlantic Wilson cycle. We review the evolution of the Caledonian Wilson cycle in the light of the recent literature from the past decade and highlight open questions and unresolved issues.

Biologically-controlled mineralization producing organic-inorganic composites (hard skeletons) by metazoan biomineralizers has been an evolutionary innovation since the earliest Cambrian. Among them, linguliform brachiopods are one of the key invertebrates that secrete calcium phosphate minerals to build their shells. One of the most distinct shell structures is the organo-phosphatic cylindrical column exclusive to phosphatic-shelled brachiopods, including both crown and stem groups. However, the complexity, diversity, and biomineralization processes of these microscopic columns are far from clear in brachiopod ancestors. Here, exquisitely well-preserved columnar shell ultrastructures are reported for the first time in the earliest eoobolids Latusobolus xiaoyangbaensis gen. et sp. nov. and Eoobolus acutulus sp. nov. from the Cambrian Series 2 Shuijingtuo Formation of South China. The hierarchical shell architectures, epithelial cell moulds, and the shape and size of cylindrical columns are scrutinised in these new species. Their calcium phosphate-based biomineralized shells are mainly composed of stacked sandwich columnar units. The secretion and construction of the stacked sandwich model of columnar architecture, which played a significant role in the evolution of linguliforms, is highly biologically controlled and organic-matrix mediated. Furthermore, a continuous transformation of anatomic features resulting from the growth of diverse columnar shells is revealed between Eoobolidae, Lingulellotretidae, and Acrotretida, shedding new light on the evolutionary growth and adaptive innovation of biomineralized columnar architecture among early phosphatic-shelled brachiopods during the Cambrian explosion.

Accelerations of ecosystem transformation raise concerns, to the extent that high rates of ecological change may be regarded amongst the most important ongoing imbalances in the Earth system. Here, we used high-resolution pollen and diatom assemblages and associated ecological indicators (the sum of tree and shrub pollen and diatom-inferred total phosphorus concentrations as proxies for tree cover and lake-water eutrophication, respectively) spanning the past 150 years to emphasize that rate-of-change records based on compositional data may document transformations having substantially different causes and outcomes. To characterize rates of change also in terms of other key ecosystem features, we quantified for both ecological indicators: (i) the percentage of change per unit time, (ii) the percentage of change relative to a reference level, and (iii) the rate of percentage change per unit time relative to a reference period, taking into account the irregular spacing of palaeoecological data. These measures document how quickly specific facets of nature changed, their trajectory, as well as their status in terms of palaeoecological indicators. Ultimately, some past accelerations of community transformation may document the potential of ecosystems to rapidly recover important ecological attributes and functions. In this context, insights from palaeoecological records may be useful to accelerate ecosystem restoration.

How and when sedimentary rocks record Earth's magnetic field is complex. Most studies assume a time-progressive lock-in mechanism during sediment deposition called depositional remanent magnetization (DRM). However, magnetic minerals can also form in situ, recording a chemical remanent magnetization (CRM) that is discontinuous in time. Disentangling the two mechanisms represents a major hurdle, and differences in their recording efficiencies remain unexplored. Here, our theoretical solutions demonstrate that CRM intensities exceed DRM by a factor of six when acquired in the same magnetic field. Novel experiments growing greigite (Fe3S4) in sediments and subsequent redeposition under identical magnetic field conditions confirm the predicted difference in recording efficiency. Thus, if left unrecognized, CRM leads to overestimated paleointensity and deserves more attention when interpreting Earth's magnetic history from sedimentary records. Recognition of fundamental differences between CRM and DRM characteristics provide a way forward to distinguish the recording mechanisms through routine laboratory protocols.

The Soi crater region (0° to 60°N, 180°W to −110°W), which includes the well-preserved Soi crater in its center, spans a region from Titan's aeolian-dominated equatorial regions to fluvially-dominated high northern latitudes. This provides a rich diversity of landscapes, one that is also representative of the diversity encountered across Titan. Schoenfeld et al. (2023) mapped this region at 1:800,000 scale and produced a geomorphological map showing that the area consists of 22 types of geomorphological units. The Visual and Infrared Mapping Spectrometer (VIMS) coverage of the region enabled the detailed analysis of spectra of 261 different locations using a radiative transfer technique and a mixing model, yielding compositional constraints on Titan's optical surface layer. Additional constraints on composition on the near-surface substrate were obtained from microwave emissivity. We have derived combinations of top surface materials between dark materials, tholins, water-ice, and methane suggesting that dark mobile organic material at equatorial and high latitudes indicates “young” terrains and compositions, while tholin/water-ice mixtures that dominate areas around latitude 35°N show a material that is older plains deposits that we interpret to be the end stage of aeolian and fluvial transport and deposition. We found no spectral evidence of CO2, HC3N, and NH3 ice. We use the stratigraphic relations between the various mapping units and the relation between the geomorphology and the composition of the surface layers to build hypotheses on the origin and evolution of the regional geology. We suggest that sedimentary deposits, likely aeolian, are dominant in the region with fluvial activity and leaching changing the nature of the top surfaces of the midlatitude areas of the Soi crater region., QC 20240827

The fossils of the Lebanese Upper Cretaceous Lagerst & auml;tten, especially the articulated fish, are world renowned. Famous for their soft tissue preservation and highly sought after by fossil collectors, Lebanese fossils provide key information concerning the evolution of several major extant and extinct groups of Mesozoic organisms including cephalopods, crustaceans, hagfish, sharks, marine reptiles and pterosaurs. In fact, fossils from Lebanon are so exceptional that historical documentation describing them extends back to the Roman Empire. However, despite over 1600 years of knowledge of these fossils, a thorough understanding of the depositional environments, taphonomy and palaeoecology of the four main sites, Haqel, Hjoula, Nammoura (each Cenomanian in age) and Sahel Aalma (Santonian), is lacking. Here we compile a review of the palaeoenvironments, fauna and flora of these four Lebanese Lagerst & auml;tten. Our synthesis outlines the history of fossil discovery, and describes the current understanding of the geology, ages, mode of preservation and organisms found at these four sites. We also undertake a bibliometric and holotype analysis to investigate the impact that scientific colonialism has had on Lebanon. Our data confirm that local Lebanese researchers are typically not included in publications pertaining to Lebanese fossils and that the majority of Lebanese type material is stored in large historical collections outside Lebanon, predominantly in institutions within the northern hemisphere. Here, we recommend some basic practices for researchers utilizing historical collections that can help develop local Lebanese fossil collections and establish more research opportunities for local palaeontologists., QC 20240813

MIL090206, MIL090405, NWA6077, NWA5363 and NWA11187 are achondrite meteorites currently belonging to the ungrouped meteorites. In particular MIL090206, MIL090405, NWA6077, NWA5363 are classified as brachinite-like ungrouped meteorites. NWA11187, resembling an ureilite in the oxygen isotopic values, was then classified as an ungrouped achondrite based on the exsolution lamellae of pigeonite and the forsteritic olivine composition. The aim of this thesis work is to characterize the petrography and the geochemistry of these five samples of meteorites by means of Scanning Electron Microscope (SEM), Laser Ablation Inductively Coupled Plasma Mass Spectrometer (LA-ICP-MS) and Electron Probe Micro- Analyzer (EPMA) to better constrain their geochemical composition and as a consequence their potential association to a specific achondrite group. All these meteorites have similar mineralogical phases and petrographic textures. They are composed of olivine, orthopyroxene, clinopyroxene, plagioclase and accessory Cl-rich apatite, chromite, troilite and Fe-Ni phases. The samples also display a poikilitic texture. One noticeable difference between NWA11187 and the other four meteorites is the presence of exsolution lamellae of pigeonite in addition to its high magnesium content. NWA11187 displays also important differences in the trace elements chemical data in olivine, orthopyroxene and clinopyroxene. For olivine, NWA11187, has a mean Ca44 value of 1906.36 ppm (other meteorites 544.50-722.21 ppm), for orthopyroxene, has a mean Al27 value of 4612.69 ppm (other meteorites 1228.12-2985.50 ppm), for clinopyroxene, has a mean Mn55 of 2845.29 ppm (other meteorites 1667.42-2024.28 ppm).

The Varanger Peninsula in northern Norway is made up of two geological units of metasedimentary sequences, the Barents Sea Region and the Tanafjorden-Varangerfjorden Region. The two units are divided by a large, NW-SE oriented strike slip fault zone called the Trollfjorden Komagelva Fault Zone. Mafic intrusions in the form of dyke swarms have been emplaced into the metasedimentary sequences on both sides of the fault zone. Three different dyke swarms have been described and dated: One Devonian aged swarm on the eastern side of the peninsula, one of Ediacaran age in the north and one from the Carboniferous along the fault zone and continuing westward off the peninsula. Geophysical modelling of the two geological units shows evidence of strike slip movement along the TKFZ as well as deeper structures suggesting thrusting as well. Geochemical analysis of dykes in two sampling locations, the villages Kongsfjord and Båtsfjord, indicate that the dykes consist mainly of basalts based on very low silica and alkali contents. They are tholeiitic in nature and show some similarities to crustal sources based on trace element data. Chemical analyses also show that the two sampling locations differ from each other chemically. Comparison within the two, as well as to legacy data reveals different kinds and intensity of alteration and crustal assimilation. Finally, a comparison with similarly aged mafic rocks on southwestern Spitsbergen Island, Svalbard, shows that there is most likely no connection between the two spatially, as the geochemical data from Varanger and those of Svalbard do not generally share trends in any analysis, suggesting that, tectonically, the two terranes were not connected at the point of the mafic intrusions in either region.

Examensarbetet har undersökt Galileo HAS (High Accuracy Service), en satellitmeddelandekorrektions tjänst utvecklad av Europeiska unionens rymdprogrambyrå (EUSPA). Tjänsten syftar till att erbjuda positionsbestämning med decimeter precision och fungerar som en förbättring av befintliga globala gratistjänster. Galileo HAS kommer inte konkurrera med professionella betaltjänster då dessa erbjuder betydligt högre precision ner till centimeternivå. Galileo HAS är implementerat i två servicenivåer och tre faser. Fas 1 lanserades den 24 januari 2023, vilket inkluderar klock-, ban- och kodkorrektioner men inte faskorrektioner. I fas 1 erbjuds tjänsten med en avslappnad noggrannhet på < 2 dm i plan och < 4 dm i höjd, detta innebär att mätningar förväntas uppnå kraven till viss del. Framtida och slutliga fasen, fas 2, kommer erbjuda de lovade noggrannheterna för fas 1 då faskorrektioner tillkommer. I studien utvärderades mätkvaliteten med HAS-korrektioner med hjälp av mottagaren Arrow Gold + och en iPad som handenhet. Applikationerna EOS Tools PRO och ArcGIS Field Maps användes för att genomföra och följa mätningarna i realtid. Mätningarna utfördes i tre olika miljöer: bra, medelsvår och svåra förhållanden. Statisk och semi-kinematisk detaljmätning utfördes i respektive mätmiljö. En känd punkt i respektive miljö användes till den statiska mätningen. Statisk mätning genomfördes i 2 timmar totalt 4 gånger. Till studien valdes 12 detaljer med låg sannolikhet att rubbas under arbetets gång inför detaljmätning. Mätningen genomfördes genom att samla in 5 stycken 1-sekundersmätningar och skapa en medelpunkt av dessa i ArcGIS Field Maps. Varje detalj mättes 4 gånger var för beräkning av spridningen. Resultaten visade att vid statisk mätning uppnåddes fixlösning, vilket i detta fall innebär en mätkvaliteten under 1 dm enligt instrumentet, enbart i bra miljö och vid ett fall i medelsvår miljö. Däremot uppnåddes aldrig fixlösning i svår mätmiljö. De statiska mätningarna visade att, This work has examined Galileo HAS (High Accuracy Service), a satellite message correction service developed by the European Union Agency for the Space Programme (EUSPA). The service aims to provide positioning with decimeter precision and serves as an enhancement to existing global free services. Galileo HAS will not compete with professional paid services, as these offer significantly higher precision down to the centimeter level. Galileo HAS is implemented in two service levels and three phases. Phase 1 was launched on January 24, 2023, which includes clock, orbit, and code corrections but not phase corrections. In phase 1, the service is offered with a relaxed accuracy of < 2 dm in horizontal and < 4 dm in vertical, meaning that measurements are expected to meet the requirements to some extent. The future and final phase, phase 2, will offer the promised accuracies of phase 1 when phase corrections are added. The study evaluated the measurement quality with HAS corrections using the Arrow Gold + receiver and an iPad as the handheld device. The applications EOS Tools PRO and ArcGIS Field Maps were used to perform and monitor the measurements in real-time. Measurements were carried out in three different environments: good, moderate, and difficult environments. Static and semi-kinematic “detail” measurements were performed in each measurement environment. A known point in each environment was used for the static measurement. Static measurement was conducted for 2 hours a total of 4 times. Twelve details with a low probability of being disturbed during the work were selected for the semi-kinematic measurements. The measurement was performed by collecting five 1-second measurements and creating an average point from these in ArcGIS Field Maps. Each detail was measured 4 times for the calculation of the spread. The results showed that in static measurement, a fixed solution was achieved, which in this case means a measurement quality under 1 dm according to the

The increasing demand of raw materials, allied to the tendency of scarcity, increase in complexity and decreasing in grade of ore deposits requires innovation and advances in the mining and processing sectors. Many authors have cited the influence of ore texture in downstream processing performances, and how a fast, accurate, unbiased and quantitative texture information acquisition can be valuable for optimizing these processes. Therefore, new methodologies, such as automated approaches for texture classification, could provide a more consistent and objective way to capture complex patterns within ore textures. This master’s thesis explores various unsupervised machine learning models to develop an automated system for ore texture classification. Using a novel image acquisition method, this research applies two datasets consisting of mineral and X-ray maps, specifically false-color images generated from µ-XRF analysis of drill cores from Sweden's iron ore deposits. Algorithms such as GLCM, PCA and edge detection were tested for feature extraction, while k-means was applied for the image clustering. Among the combinations tested, the application of GLCM for feature extraction and PCA for dimensionality reduction presented the best clustering results. The features extracted from both datasets were combined aiming to complement the texture information and therefore increase the clustering accuracy. At last, the classification results were compared against Leeb hardness data, allowing for an evaluation of the correlation between ore texture and rock hardness. The findings provide insights into the influence of texture on ore properties, such as hardness, providing valuable information for future resource processing strategies.

Global mining trends of increasingly low-grade base metal sulfide ores present an environmental and economic challenge. Flotation of low-grade ores has a significant and increasing footprint in chemical consumption, water consumption, and disposal storage. The current study is focused on pretreating low-grade chalcopyrite and sphalerite-galena ores using electrical separation to remove dry gangue material and reduce the amount of gangue sent to downstream flotation. The approach used is to remove barren gangue particles from the feed through high-tension electrical separation, taking advantage of the differences of conductivity between the sulfide ores and the gangue minerals. Three different ores and slags: a low-grade chalcopyrite ore, a medium-grade sphalerite-galena ore, and slag from electronic waste, were tested. Roller speed, voltage, and particle size distribution parameters were tested at different intervals using Design of Experiment to determine acceptable conditions for recovery and grade of targeted minerals as well as rejection of gangue. Separation quality was gauged by grades and recoveries of the targeted minerals. Both increased grade and high recovery separations were achieved with different particle sizes and machine parameters. Feasible preconcentration was seen in the ores and a good recovery of metals was seen in the E-waste as a result, opening the door for further research in optimizing pretreatment methods.

The Myrmalm Target is located in the southern Trøndelag, a region consisting of a sequence of nappes, stratigraphically overturned and emplaced on the autochthonous crystalline basement. Trøndelag is a historically important mining region in Norway. In the past, it produced Cu, Zn and Au from Volcanogenic Massive Sulphide (VMS) mineralisation, located within the tectonostratigraphic units of Caledonides. Although the last operational mine was closed at the end of the 20th century, the potential of this metallogenic province has not yet been exploited. In modern days this metallogenic province is considered under-explored. Increased demand for metals and an introduction of new European strategies including the transition to the green economy brought attention back to Trøndelag. The Geological Survey of Norway performed a range of exploration projects including mapping, sampling campaigns and geophysical surveys to promote the area and increase the understanding of its units. Several junior exploration companies, such as Kuniko Limited established exploration projects to identify drilling targets, potentially hosting economic mineralisation. One of them is the Myrmalm target, appointed for drilling in 2023, which resulted in obtaining a wealth of geochemical data. This study aims to investigate the prospectivity of the Myrmalm Target to host an economic VMS-type mineralisation. The initial logging identified the main lithology groups such as metasediments, metavolcanics and mineralisation horizons, all cut by intrusions of Trondhjemite. A clustering methodology based on major elements Na, Mg, Al, P, S, K, Ca, Mn, Fe, and Ti utilising centred log ratio – principal component analysis – k-means clustering was performed to classify the geochemical samples. Each of the clusters was analysed based on microscopy observations and geochemical data. Cluster one was identified to portray Trondhjemite, defined to be post-volcanic, and thus cannot be considered as an indicator of

Reconstructing the original geometry of a high-pressure tectonic unit is challenging but important to understand the mechanisms of mountain building. While a single nappe is subducted and exhumed, nappe-internal thrusts may disrupt it into several subunits. The Middle-CBU nappe of the Cycladic Blueschist Unit (Hellenide subduction orogen, Greece) shows evidence of such disruption along a Trans-Cycladic-Thrust (TCT), however, the timing of this thrusting is unknown. Here, we report multi-petrological and geochronological data from the Middle-CBU nappe from the Thera and Ios islands (Greece). Using Zr-in-rutile thermometry coupled with quartz-in-garnet elastic barometry, average P-T and phase equilibrium thermodynamic modelling, we show that garnet growth in Ios occurred during prograde metamorphism at 6.7 +/- 1.4 kbar to 13.0 +/- 1.6 kbar and 326 +/- 20 degrees C to 506 +/- 13 degrees C (2 sigma uncertainty) followed by early exhumation to 10.1 +/- 0.6 kbar and 484 +/- 14 degrees C and a greenschist facies overprint at 5.7 +/- 1.2 kbar and 416 +/- 14 degrees C. For Thera, we constrain peak HP conditions of 7.6 +/- 1.8 kbar and 331 +/- 18 degrees C, followed by exhumation and equilibration at similar to 2 kbar and similar to 275 degrees C using average P-T and phase equilibrium thermodynamic modelling. For Ios, Uranium-Pb garnet geochronology provides ages of 55.7 +/- 5.0 Ma (2 sigma uncertainties) for prograde and 40.1 +/- 1.4 Ma for peak HP metamorphism. Combining our new P-T-t data from Thera and Ios islands with existing data from Naxos island, we conclude that the studied nappe segments represent remnants of a former coherent nappe. The P-T-t data define an Eocene subduction rate of 2.1 +/- 1.0 km/Ma, which is distinctly slower than the current subduction rate of 40-45 km/Ma. After subduction, the exhumation of the Middle-CBU nappe occurred during the Oligocene at different rates for different localities. The Middle-CBU nappe of Naxos was exhumed at a rate of sim