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  • 1.
    Adediran, Gbotemi A.
    et al.
    Department of Soil and Environment Swedish University of Agricultural Sciences Uppsala Sweden;UK Centre for Ecology and Hydrology Wallingford United Kingdom.
    Kielman-Schmitt, Melanie
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Kooijman, Ellen
    Naturhistoriska riksmuseet, Enheten för geovetenskap. Department of Geosciences Swedish Museum of Natural History Stockholm Sweden.
    Gustafsson, Jon‐Petter
    Department of Soil and Environment Swedish University of Agricultural Sciences Uppsala Sweden.
    Significance of phosphorus inclusions and discrete micron‐sized grains of apatite in postglacial forest soils2022Inngår i: European Journal of Soil Science, ISSN 1351-0754, E-ISSN 1365-2389, Vol. 73, nr 5, artikkel-id e13310Artikkel i tidsskrift (Fagfellevurdert)
  • 2. Anand, Rajagopal
    et al.
    Balakrishnan, Srinivasan
    Kooijman, Ellen
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Mezger, Klaus
    Neoarchean crustal growth by accretionary processes: Evidence from combined zircon–titanite U–Pb isotope studies on granitoid rocks around the Hutti greenstone belt, eastern Dharwar Craton, India2014Inngår i: Journal of Asian Earth Sciences, ISSN 1367-9120, E-ISSN 1878-5786, Vol. 79, s. 72-85Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The Neoarchean Hutti greenstone belt hosts mesothermal gold deposits and is surrounded by granitoid rocks on all sides. Combined U–Pb dating of zircon and titanite from the granitoid rocks constrains their emplacement history and subsequent geologic evolution. The Golapalli and Yelagatti granodiorites occurring to the north of the Hutti greenstone belt were emplaced at 2569 ± 17 Ma. The Yelagatti granodiorite yielded a younger titanite age of 2530 ± 6 Ma which indicates that it was affected by a post-crystallization thermal event that exceeded the titanite closure temperature. The western granodiorites from Kardikal have identical titanite and zircon ages of 2557 ± 6 Ma and 2559 ± 19 Ma, respectively. The eastern Kavital granodiorites yielded titanite ages of 2547 ± 6 Ma and 2544 ± 24 Ma which are identical to the published U–Pb zircon SHRIMP ages. These ages imply that the granitoid rocks surrounding the Hutti greenstone belt were formed as discrete batholiths within a short span of ca. 40 Ma between 2570 Ma and 2530 Ma ago. They were juxtaposed by horizontal tectonic forces against the supracrustal rocks that had formed in oceanic settings at the end of the Archean. The first phase of gold mineralization coincided with the last phase of granodiorite intrusion in the Hutti area. A metamorphic overprint occurred at ca. 2300 Ma ago that reset the Rb–Sr isotope system in biotites and possibly caused hydrothermal activity and enrichment of Au in the ore lodes. The eastern Dharwar Craton consists of quartz monzodiorite–granodiorite–granite suites of rocks that are younger than the greenstone belts that are older than ~2650 Ma reported from earlier studies. The granitoid magmatism took place between 2650 and 2510 Ma ago indicating accretionary growth of the eastern Dharwar Craton.

  • 3. Andersson, Joel B.H.
    et al.
    Logan, Leslie
    Martinsson, Olof
    Chew, David
    Kooijman, Ellen
    Naturhistoriska riksmuseet, Enheten för geovetenskap. Department of Geosciences Swedish Museum of Natural History Stockholm Sweden.
    Kielman-Schmitt, Melanie
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Kampmann, Tobias C.
    Bauer, Tobias E.
    U-Pb zircon-titanite-apatite age constraints on basin development and basin inversion in the Kiruna mining district, Sweden2022Inngår i: Precambrian Research, ISSN 0301-9268, E-ISSN 1872-7433, Vol. 372, s. 106613-106613, artikkel-id 106613Artikkel i tidsskrift (Fagfellevurdert)
  • 4. Augustsson, Carita
    et al.
    Rüsing, Tobias
    Niemeyer, Hans
    Kooijman, Ellen
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Berndt, Jasper
    Bahlburg, Heinrich
    Zimmermann, Udo
    0.3 byr of drainage stability along the Palaeozoic palaeo-Pacific Gondwana margin; a detrital zircon study2015Inngår i: Journal of the Geological Society, ISSN 0016-7649, E-ISSN 2041-479X, Vol. 172, s. 186-200Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The palaeo-Pacific margin of Gondwana in the present-day south–central Andes is marked by tectonic activity related to subduction and terrane accretion. We present detrital zircon U–Pb data encompassing the Palaeozoic era in northern Chile and northwestern Argentina. Cathodoluminescence images reveal dominantly magmatic zircon barely affected by abrasion and displaying only one growth phase. The main age clusters for these zircon grains are Ediacaran to Palaeozoic with an additional peak at 1.3–0.9 Ga and they can be correlated with ‘Grenvillian’ age, and the Brasiliano, Pampean, and Famatinian orogenies. The zircon data reveal main transport from the nearby Ordovician Famatinian arc and related rocks. The Silurian sandstone units are more comparable with Cambrian units, with Brasiliano and Transamazonian ages (2.2–1.9 Ga) being more common, because the Silurian deposits were situated within or east of the (extinct) Famatinian arc. Hence, the arc acted as a transport barrier throughout Palaeozoic time. The complete suite of zircon ages does not record the accretions of exotic terranes or the Palaeozoic glacial periods. We conclude that the transport system along the palaeo-Pacific margin of Gondwana remained stable for c. 0.3 byr and that provenance data do not necessarily reflect the interior of a continent. Hence, inherited geomorphological features must be taken into account when detrital mineral ages are interpreted.

  • 5. Barnes, Christopher J.
    et al.
    Bukała, Michał
    Callegari, Riccardo
    Walczak, Katarzyna
    Kooijman, Ellen
    Naturhistoriska riksmuseet, Enheten för geovetenskap. Department of Geosciences Swedish Museum of Natural History Stockholm Sweden.
    Kielman-Schmitt, Melanie
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Majka, Jarosław
    Zircon and monazite reveal late Cambrian/early Ordovician partial melting of the Central Seve Nappe Complex, Scandinavian Caledonides2022Inngår i: Contributions to Mineralogy and Petrology, ISSN 0010-7999, E-ISSN 1432-0967, Vol. 177, nr 9, artikkel-id 92Artikkel i tidsskrift (Fagfellevurdert)
  • 6. Barnes, Christopher J..
    et al.
    Majka, Jarek
    Jeanneret, Pauline
    Ziemniak, Grzegorz
    Kooijman, Ellen
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Kośmińska, Karolina
    Kielman-Schmitt, Melanie
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Schneider, D.A.
    Using Th-U-Pb geochronology to extract crystallization ages of Paleozoic metamorphic monazite contaminated by initial Pb2021Inngår i: Chemical Geology, ISSN 0009-2541, E-ISSN 1872-6836, Vol. 582, s. 120450-120450, artikkel-id 120450Artikkel i tidsskrift (Fagfellevurdert)
  • 7. Björlykke, Arne
    et al.
    Bingen, Bernard
    Billström, Kjell
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Kooijman, Ellen
    The sandstone-hosted Osen lead deposit, Norway: new Pb isotope evidence for sourcing in the underlying granitoid basement2019Inngår i: Norwegian Journal of GeologyArtikkel i tidsskrift (Fagfellevurdert)
  • 8. Bose, Swayoma
    et al.
    Anand, R.
    D'Souza, Joseph
    Hartnady, Michael
    Kirkland, Chris
    Kooijman, Ellen
    Naturhistoriska riksmuseet, Enheten för geovetenskap. Department of Geosciences, Swedish Museum of Natural History, Stockholm, Sweden.
    Zircon U Pb and Hf isotope insights into the Mesoproterozoic breakup of supercontinent Columbia from the Sausar Belt, Central Indian Tectonic Zone2023Inngår i: Chemie der Erde, ISSN 0009-2819, E-ISSN 1611-5864, s. 126054-126054, artikkel-id 126054Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Credible records of rifting and associated sedimentation and granitoid magmatism coinciding with the Columbia breakup event are not common in the Precambrian Indian continent. We report a 1322 ± 3 Ma concordia age for magmatic zircons from the granitoid rocks of the Sausar mobile belt, Central Indian Tectonic Zone (CITZ). The rocks exhibit geochemical characteristics of A-type granitoid rocks and were generated by the dehydration melting of shallow crust in an extensional tectonic setting. The predominantly negative εHf(t) values and partial melting modelling imply their origin by the reworking of pre-existing granitoid crust. TDM2 (Hf) model ages for these rocks range from 2856 Ma to 1885 Ma suggesting a prolonged period of crustal evolution and reworking of Archean to Paleoproterozoic basement rocks. The temperature for magma generation, determined from the calculated zircon saturation temperature of 874.2 °C is suggestive of melting of a thinned crust that was heated by the upwelling asthenosphere in an extensional tectonic setting. The obtained ages provide evidence for the existence of an extensional event during mid-Mesoproterozoic coinciding with the Columbia breakup event. The extension could also be argued as a local event related to far-field stresses generated due to the ca. 1.6 to 1.5 Ga subduction-collision event at the plate margin farther to the north of the studied region of the CITZ. The recrystallized margins of zircon grains yield 207Pb/206Pb ages between 0.95 Ga and 1.0 Ga implying their alteration during a metamorphic event that can be identified with the final amalgamation and stabilization of the northern and southern Indian blocks along the CITZ, coinciding with the Rodinia assembly, during which the regional structural fabric developed.

  • 9.
    Callegari, Riccardo
    et al.
    Faculty of Geology, Geophysics and Environmental Protection, AGH University of Science and Technology, Kraków, Poland;Department of Earth Sciences, Uppsala University, Uppsala, Sweden.
    Kośmińska, Karolina
    Faculty of Geology, Geophysics and Environmental Protection, AGH University of Science and Technology, Kraków, Poland.
    Barnes, Christopher J.
    Institute of Geological Sciences, Polish Academy of Sciences, Kraków, Poland.
    Klonowska, Iwona
    Faculty of Geology, Geophysics and Environmental Protection, AGH University of Science and Technology, Kraków, Poland;Department of Earth Sciences, Uppsala University, Uppsala, Sweden.
    Barker, Abigail K.
    Department of Earth Sciences, Uppsala University, Uppsala, Sweden.
    Rousku, Sabine
    Department of Earth Sciences, Uppsala University, Uppsala, Sweden.
    Nääs, Erika
    Department of Earth Sciences, Uppsala University, Uppsala, Sweden.
    Kooijman, Ellen
    Naturhistoriska riksmuseet, Enheten för geovetenskap. Department of Geosciences, Swedish Museum of Natural History, Stockholm, Sweden.
    Witt-Nilsson, Patrik
    Rosmarus Enviro, Uppsala, Sweden.
    Majka, Jarosław
    Faculty of Geology, Geophysics and Environmental Protection, AGH University of Science and Technology, Kraków, Poland;Department of Earth Sciences, Uppsala University, Uppsala, Sweden.
    Early Neoproterozoic magmatism and Caledonian metamorphism recorded by the Mårma terrane, Seve Nappe Complex, northern Swedish Caledonides2023Inngår i: Journal of the Geological Society, ISSN 0016-7649, E-ISSN 2041-479X, Vol. 180, nr 5Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Petrology, geochronology and bulk-rock chemistry are combined to investigate the early Neoproterozoic magmatismand Cambrian–Ordovician metamorphism in the northern Swedish Caledonides. This work includes several lithologies of theMårma terrane in the Seve Nappe Complex exposed in the Kebnekaise region. U–Pb zircon geochronology yielded crystallizationages of 835 ± 8 Ma for a mylonitic orthogneiss, 864 ± 3 Ma for the Vistas Granite and 840 ± 7 Ma for an intruded granitic dyke,whereas a gabbro and a granodiorite intrusion gave U–Pb zircon crystallization ages of 856 ± 3 Ma and 850 ± 1 Ma, respectively.U–Pb monazite dating of the mylonitic orthogneiss gave an upper intercept age of 841 ± 7 Ma and a lower intercept age of443 ± 20 Ma. Pressure–temperature estimates derived for the mylonitic orthogneiss reveal metamorphic peak-pressure and peaktemperatureof 10.5–11.75 kbar and 550–610°C and 7.4–8.1 kbar at 615–675°C, respectively.Metamorphic pressure–temperatureestimates for the Vistas Granite yield 6.5–7.5 kbar at 600–625°C. Whole-rock chemistry coupled with U–Pb geochronologyindicates that bimodal magmatism was related to attempted rifting of Rodinia between 870 and 840 Ma.

  • 10.
    Carter, Isabel S. M.
    et al.
    Faculty of Geology, Geophysics and Environmental Protection, AGH University of Kraków, al. Mickiewicza 30, 30-059 Kraków, Poland;Department of Earth Sciences, Uppsala University, Villavägen 16, SE-752 36 Uppsala, Sweden.
    Cuthbert, Simon J.
    Faculty of Geology, Geophysics and Environmental Protection, AGH University of Kraków, al. Mickiewicza 30, 30-059 Kraków, Poland.
    Walczak, Katarzyna
    Faculty of Geology, Geophysics and Environmental Protection, AGH University of Kraków, al. Mickiewicza 30, 30-059 Kraków, Poland.
    Ziemniak, Grzegorz
    Institute of Geological Sciences, University of Wrocław, Pl. M. Borna 9, 50-204 Wrocław, Poland.
    Kooijman, Ellen
    Naturhistoriska riksmuseet, Enheten för geovetenskap. Department of Geosciences, Swedish Museum of Natural History, Stockholm, Sweden.
    Majka, Jarosław
    Faculty of Geology, Geophysics and Environmental Protection, AGH University of Kraków, al. Mickiewicza 30, 30-059 Kraków, Poland;Department of Earth Sciences, Uppsala University, Villavägen 16, SE-752 36 Uppsala, Sweden.
    Cambrian ages for metavolcanic rocks in the Lower Köli Nappes, Swedish Caledonides: implications for the status of the Virisen arc terrane2023Inngår i: Journal of the Geological Society, ISSN 0016-7649, E-ISSN 2041-479X, Vol. 180, nr 6Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The Köli Nappe Complex (KNC) of the Scandinavian Caledonide orogen originated as oceanic terranes within the Iapetus Ocean. These terranes have characteristics of magmatic arcs and associated forearc or back-arc basins and underwent several periods of rifting and magmatism prior to their accretion to the Baltican margin. We present new U–Pb zircon ages from the Lower Köli Ankarede Volcanite Formation in Västerbotten, Sweden. U–Pb ages of magmatic zircon grains from metamorphosed dacitic to andesitic rocks show ages of 512 ± 3.5, 497 ± 2, 491 ± 1 and 488 ± 4 Ma. The three younger ages fit with previous ages for Lower Köli volcanic rocks, but the 512 Ma age is older than any previous age for this unit. These dates constrain the age of magmatism in an ensimatic arc system within Iapetus. We compare this evolution with published information from the other Köli nappes. Magmatic ages within the KNC overlap with ages for an early episode of ultrahigh-pressure (UHP) metamorphism within the underlying Seve Nappe Complex (SNC), supporting the hypothesis that attributes UHP metamorphism within the SNC to subduction beneath the island arc now preserved within the Lower Köli Nappes.

  • 11. Caton, Summer A.
    et al.
    Smit, Matthijs A.
    Emo, Robert B.
    Musiyachenko, Kira A.
    Kielman-Schmitt, Melanie
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Kooijman, Ellen
    Naturhistoriska riksmuseet, Enheten för geovetenskap. Department of Geosciences Swedish Museum of Natural History Stockholm Sweden.
    Scherstén, Anders
    Halla, Jaana
    Bleeker, Wouter
    Hoffmann, J. Elis
    Pandey, Om Prakash
    Ravindran, Arathy
    Maltese, Alessandro
    Mezger, Klaus
    Evolution of the sources of TTG and associated rocks during the Archean from in-situ 87Sr/86Sr isotope analysis of apatite by LA-MC-ICPMS2022Inngår i: Lithos, ISSN 0024-4937, E-ISSN 1872-6143, Vol. 428-429, s. 106830-106830, artikkel-id 106830Artikkel i tidsskrift (Fagfellevurdert)
  • 12. Chatterjee, Sukalpa
    et al.
    Mezger, Klaus
    Pandey, Om Prakash
    Kielman-Schmitt, Melanie
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Hofer, Alina
    Kooijman, Ellen
    Naturhistoriska riksmuseet, Enheten för geovetenskap. Department of Geosciences, Swedish Museum of Natural History, Stockholm, Sweden.
    The Singhbhum Craton (India) records a billion year of continental crust formation and modification2023Inngår i: Chemical Geology, ISSN 0009-2541, E-ISSN 1872-6836, Vol. 641, s. 121772-121772, artikkel-id 121772Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The petrogenesis of continental crust from its ultimate mantle source can be reconstructed from the element abundances and radiogenic isotope compositions of ideally pristine igneous rocks. The initial isotope compositions of igneous rocks provide geochemical constraints on the age, composition and evolution of their source(s). Determining initial isotope ratios for rock samples can be challenging, especially in rocks with a long and protracted thermal history. The Rb-Sr system is highly sensitive to parent-daughter element fractionation during magma differentiation. This makes the Rb-Sr isotope systematics ideal to trace the precursor composition of Archean felsic crust and constrain the time of element fractionation during the formation and subsequent modification of continental crust. Initial isotope compositions can be obtained directly from minerals that strongly prefer the daughter element and effectively exclude the parent element of the radio-isotope system of interest. Apatite, having a near zero Rb/Sr ratio, is ideal for preserving its initial 87Sr/86Sr and zircon records initial 176Hf/177Hf compositions. Combined modelling of Sr and Hf isotope data from granitoids of the Archean Singhbhum Craton, indicates that the older Paleoarchean granitoids, emplaced between 3.53 Ga and 3.44 Ga, were derived from a mafic precursor (∼52–54 wt% SiO2) sourced from a depleted mantle at ∼3.71 Ga. Initial 87Sr/86Sr isotope signatures of matrix apatite and apatite inclusions in zircon from the younger Paleoarchean granitoids (3.4–3.2 Ga) of the Singhbhum Craton indicate these younger granitoids were produced by mixing of magma generated from an older mafic source and partial melts derived from the older granitoids. The combined Sr-Hf isotope modelling links the timing of mantle extraction of the precursor material for Paleoarchean Singhbhum granitoids with a known mafic crust extraction event at ∼3.71 Ga. In combination, the new Sr isotope data from apatite combined with whole rock and zircon Hf isotope data from the literature reveal a ∼1 Ga protracted crustal growth and differentiation history of the nucleus of the Singhbhum Craton. By combining radio-isotope systems like 87Rb-87Sr and 176Lu-176Hf, the petrogenesis of Archean felsic crust from the extraction of mafic material from the mantle to reworking in an orogenic cycle to emplacement can be reconstructed. This approach can be applied to other greenstone-gneiss terranes to quantify the spatio-temporal and compositional evolution of voluminous felsic crust and the formation of cratons in the Archean.

  • 13. Cutts, Jamie
    et al.
    Smit, Matthijs
    Kooijman, Ellen
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Schmitt, Melanie
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Two‐Stage Cooling and Exhumation of Deeply Subducted Continents2019Inngår i: Tectonics, ISSN 0278-7407, E-ISSN 1944-9194Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The burial and exhumation of continental crust during collisional orogeny exert a strong controlon the dynamics of mountain belts and plateaus. Constraining the rates and style of exhumation of deeply buried crust has proven difficult due to complexities in the local geology and thermochronometric methods typically used. To advance this field, we applied trace‐element and U‐Pb laser ablation inductively coupled plasma mass spectrometry analyses to rutile from eclogite and amphibolite samples from the Western Gneiss Complex of Norway—an archetypal continental (ultra)high‐pressure (UHP) terrane. Peak temperature and timing of midcrustal cooling were constrained for samples collected along a subduction‐ and exhumation‐parallel transect, using Zr‐in‐rutile thermometry and U‐Pb rutile geochronology, respectively. Peak temperatures decrease from 830 °C in the UHP domain to 730 °C at the UHP‐HP transition, remain constant at 730 °C across most of the terrane, and decrease to 620 °C at the eclogite‐out boundary. U‐Pb results show that most of the terrane cooled through 500 °C at 380–375 Ma except for the lowest grade region, where cooling occurred approximately 20 million years earlier. The results indicate that exhumation was a two stage process, involving (1) flexural rebound and slab flattening at depth combined with foreland‐directed extrusion, followed by (2) synchronous cooling below 500 °C across the, by then, largely flat‐lying Western Gneiss Complex. The latter implies and requires relatively homogeneous mass removal across a large area, consistent with erosion of an overlying orogenic plateau. The Caledonides were at near‐equatorial latitudes at the time. A Caledonian paleo‐plateau thus may represent a so far unrecognized factor in Devonian and Carboniferous atmospheric circulation and climate forcing.

  • 14. Dekov, Vesselin
    et al.
    Darakchieva, K
    Billström, Kjell
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Garbe-Schönberg, C-D
    Kamenov, G
    Gallinari, M
    Dimitrov, L
    Ragueau, O
    Kooijman, E
    Element enrichment and provenance of the detrital component in Holocene sediments from the western Black Sea2019Inngår i: OceanologiaArtikkel i tidsskrift (Fagfellevurdert)
  • 15. Drake, Henrik
    et al.
    Ivarsson, Magnus
    Tillberg, Mikael
    Whitehouse, Martin
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Kooijman, Ellen
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Ancient Microbial Activity in Deep Hydraulically Conductive Fracture Zones within the Forsmark Target Area for Geological Nuclear Waste Disposal, Sweden2018Inngår i: Geosciences, Vol. 8, nr 211Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Recent studies reveal that organisms from all three domains of life—Archaea, Bacteria, and even Eukarya—can thrive under energy-poor, dark, and anoxic conditions at large depths in the fractured crystalline continental crust. There is a need for an increased understanding of the processes and lifeforms in this vast realm, for example, regarding the spatiotemporal extent and variability of the different processes in the crust. Here, we present a study that set out to detect signs of ancient microbial life in the Forsmark area—the target area for deep geological nuclear waste disposal in Sweden. Stable isotope compositions were determined with high spatial resolution analyses within mineral coatings, and mineralized remains of putative microorganisms were studied in several deep water-conducting fracture zones (down to 663 m depth), from which hydrochemical and gas data exist. Large isotopic variabilities of δ13Ccalcite (−36.2 to +20.2‰ V-PDB) and δ34Spyrite (−11.7 to +37.8‰ V-CDT) disclose discrete periods of methanogenesis, and potentially, anaerobic oxidation of methane and related microbial sulfate reduction at several depth intervals. Dominant calcite–water disequilibrium of δ18O and 87Sr/86Sr precludes abundant recent precipitation. Instead, the mineral coatings largely reflect an ancient archive of episodic microbial processes in the fracture system, which, according to our microscale Rb–Sr dating of co-genetic adularia and calcite, date back to the mid-Paleozoic. Potential Quaternary precipitation exists mainly at ~400 m depth in one of the boreholes, where mineral–water compositions corresponded.

    Fulltekst (pdf)
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  • 16.
    Drake, Henrik
    et al.
    Linnaeus University, Kalmar.
    Kooijman, Ellen
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Kielman-Schmitt, Melanie
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Using 87Sr/86Sr LA-MC-ICP-MS Transects within Modern and Ancient Calcite Crystals to Determine Fluid Flow Events in Deep Granite Fractures2020Inngår i: Geosciences, Vol. 10, s. 1-23, artikkel-id 345Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The strontium isotope signature (87Sr/86Sr) of calcite precipitated in rock fractures and faults is a frequently used tool to trace paleofluid flow. However, bedrock fracture networks, such as in Precambrian cratons, have often undergone multiple fracture reactivations resulting in complex sequences of fracture mineral infillings. This includes numerous discrete calcite crystal overgrowths. Conventional 87Sr/86Sr analysis of dissolved bulk samples of such crystals is not feasible as they will result in mixed signatures of several growth zonations. In addition, the zonations are too fine-grained for sub-sampling using micro-drilling. Here, we apply high spatial resolution 87Sr/86Sr spot analysis(80 um) in transects through zoned calcite crystals in deep Paleoproterozoic granitoid fractures using laser ablation multi-collector inductively coupled plasma mass spectrometry (LA-MC-ICP-MS) to trace discrete signs of paleofluid flow events. We compare the outermost calcite growth zone with 87Sr/86Sr values of the present-day groundwater sampled in the same boreholes to distinguish potential modern precipitates. We then connect our results to previously reported radiometric dating and C and O isotope signatures to understand the temporal history and physicochemical evolution of fluid flow within the fractures. Comparisons of modern calcite precipitated in a borehole over a period of 17 years with modern waters prove the concept of using 87Sr/86Sr as a marker for fluid origin in this environment and for how 87Sr/86Sr changed during marine water infiltration. Intermittent calcite precipitation over very long time spans is indicated in calcite of the currently open fractures, showing an evolution of 87Sr/86Sr from ~0.705–0.707—a population dated to ~1.43 billion years—to crystal overgrowth values at ~0.715–0.717 that overlap with the present-day groundwater values.This shows that high spatial resolution Sr isotope analysis of fine-scaled growth zonation within single calcite crystals is applicable for tracing episodic fluid flow in fracture networks.

    Fulltekst (pdf)
    Drake et al. 2020
  • 17. Drake, Henrik
    et al.
    Roberts, Nick M. W.
    Heim, Christine
    Whitehouse, Martin J.
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Siljeström, Sandra
    Kooijman, Ellen
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Broman, Curt
    Ivarsson, Magnus
    Åström, Mats E.
    Timing and origin of natural gas accumulation in the Siljan impact structure, Sweden2019Inngår i: Nature Communications, E-ISSN 2041-1723, Vol. 10, nr 1Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Fractured rocks of impact craters may be suitable hosts for deep microbial communities on Earth and potentially other terrestrial planets, yet direct evidence remains elusive. Here, we present a study of the largest crater of Europe, the Devonian Siljan structure, showing that impact structures can be important unexplored hosts for long-term deep microbial activity. Secondary carbonate minerals dated to 80 ± 5 to 22 ± 3 million years, and thus postdating the impact by more than 300 million years, have isotopic signatures revealing both microbial methanogenesis and anaerobic oxidation of methane in the bedrock. Hydrocarbons mobilized from matured shale source rocks were utilized by subsurface microorganisms, leading to accumulation of microbial methane mixed with a thermogenic and possibly a minor abiotic gas fraction beneath a sedimentary cap rock at the crater rim. These new insights into crater hosted gas accumulation and microbial activity have implications for understanding the astrobiological consequences of impacts.

    Fulltekst (pdf)
    fulltext
  • 18.
    Drake, Henrik
    et al.
    Institutionen för biologi och miljö, Linneuniversitet.
    Roberts, Nick M. W.
    Geochronology and Tracers Facility, British Geological Survey.
    Reinhardt, Manuel
    Department of Biology and Environmental Science, Linnæus University.
    Whitehouse, Martin
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Ivarsson, Magnus
    Naturhistoriska riksmuseet, Enheten för paleobiologi.
    Karlsson, Andreas
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Kooijman, Ellen
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Kielman-Schmitt, Melanie
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Biosignatures of ancient microbial life are present across the igneous crust of the Fennoscandian shield2021Inngår i: Communications Earth & Environment, E-ISSN 2662-4435, Vol. 2, nr 1, artikkel-id 102Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Earth’s crust contains a substantial proportion of global biomass, hosting microbial life up to several kilometers depth. Yet, knowledge of the evolution and extent of life in this environment remains elusive and patchy. Here we present isotopic, molecular and morphological signatures for deep ancient life in vein mineral specimens from mines distributed across the Precambrian Fennoscandian shield. Stable carbon isotopic signatures of calcite indicate microbial methanogenesis. In addition, sulfur isotope variability in pyrite, supported by stable carbon isotopic signatures of methyl-branched fatty acids, suggest subsequent bacterial sulfate reduction. Carbonate geochronology constrains the timing of these processes to the Cenozoic. We suggest that signatures of an ancient deep biosphere and long-term microbial activity are present throughout this shield. We suggest that microbes may have been active in the continental igneous crust over geological timescales, and that subsurface investigations may be valuable in the search for extra-terrestrial life.

  • 19. Drake, Henrik
    et al.
    Roberts, Nick M. W.
    Reinhardt, Manuel
    Whitehouse, Martin
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Ivarsson, Magnus
    Naturhistoriska riksmuseet, Enheten för paleobiologi.
    Karlsson, Andreas
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Kooijman, Ellen
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Kielman-Schmitt, Melanie
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Biosignatures of ancient microbial life are present across the igneous crust of the Fennoscandian shield2021Inngår i: Communications Earth & Environment, E-ISSN 2662-4435, Vol. 2, nr 1, artikkel-id 102Artikkel i tidsskrift (Fagfellevurdert)
  • 20. Drake, Henrik
    et al.
    Roberts, Nick M. W.
    Reinhardt, Manuel
    Whitehouse, Martin
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Ivarsson, Magnus
    Naturhistoriska riksmuseet, Enheten för paleobiologi.
    Karlsson, Andreas
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Kooijman, Ellen
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Kielman-Schmitt, Melanie
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Biosignatures of ancient microbial life are present across the igneous crust of the Fennoscandian shield2021Inngår i: Communications Earth & Environment, E-ISSN 2662-4435, Vol. 2, nr 1, artikkel-id 102Artikkel i tidsskrift (Fagfellevurdert)
  • 21. Drake, Henrik
    et al.
    Roberts, Nick M. W.
    Reinhardt, Manuel
    Whitehouse, Martin
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Ivarsson, Magnus
    Naturhistoriska riksmuseet, Enheten för paleobiologi.
    Karlsson, Andreas
    Kooijman, Ellen
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Kielman-Schmitt, Melanie
    Biosignatures of ancient microbial life are present across the igneous crust of the Fennoscandian shield2021Inngår i: Communication Earth & Environment, Vol. 2, nr 1, artikkel-id 102Artikkel i tidsskrift (Fagfellevurdert)
  • 22.
    Drake, Henrik
    et al.
    Department of Biology and Environmental Science Linnæus University Kalmar Sweden.
    Tillberg, Mikael
    Department of Biology and Environmental Science Linnæus University Kalmar Sweden;Department of Earth Sciences University of Gothenburg Gothenburg Sweden.
    Reinhardt, Manuel
    Department of Biology and Environmental Science Linnæus University Kalmar Sweden;Department of Geobiology Geoscience Centre University of Göttingen Göttingen Germany.
    Whitehouse, Martin J.
    Naturhistoriska riksmuseet, Enheten för geovetenskap. Swedish Museum of Natural History Stockholm Sweden.
    Kooijman, Ellen
    Naturhistoriska riksmuseet, Enheten för geovetenskap. Department of Geosciences, Swedish Museum of Natural History, Stockholm, Sweden.
    In Situ Rb/Sr Geochronology and Stable Isotope Geochemistry Evidence for Neoproterozoic and Paleozoic Fracture‐Hosted Fluid Flow and Microbial Activity in Paleoproterozoic Basement, SW Sweden2023Inngår i: Geochemistry Geophysics Geosystems, E-ISSN 1525-2027, Vol. 24, nr 5Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Recent studies have shown that biosignatures of ancient microbial life exist in mineral coatings in deep bedrock fractures of Precambrian cratons, but such surveys have been few and far between. Here, we report results from southwestern Sweden in an area of 1.6–1.5 Ga Paleoproterozoic rocks heavily reworked by the 1.14–0.96 Ga Sveconorwegian orogeny, a terrane previously scarcely explored for ancient microbial biosignatures. Calcite-pyrite-adularia-illite-coated fractures were analyzed for stable isotopes via Secondary Ion Mass Spectrometry (δ13C, δ18O, δ34S) and in situ Rb/Sr geochronology via Laser-ablation inductively coupled plasma mass spectrometry. The Rb/Sr ages for calcite-adularia and calcite-illite show that several fluid flow events can be discerned (797 ± 18–769 ± 7, 391 ± 5–387 ± 6, 356 ± 5–347 ± 4, and 301 ± 7 Ma). The δ13C, δ18O and 87Sr/86Sr values of different calcite growth zones further confirmed episodic fluid flow. Pyrite δ34S values down to −49.9‰V-CDT, together with systematically increased δ34S from crystal core to rim, suggest formation following microbial sulfate reduction under semi-closed conditions. Assemblages involving MSR-related pyrite generally have Devonian to Permian Rb/Sr ages, indicating an association to extension-related fracturing and fluid mixing during foreland-basin formation linked to Caledonian orogeny in the northwest. An assemblage with an age of 301 ± 7 Ma is potentially related to Oslo Rift extension, whereas the Neo-Proterozoic ages relate to post-Sveconorwegian extensional tectonics. Remnants of short-chained fatty acids in the youngest calcite coatings further indicate a biogenic origin, while the absence of organic molecules in older calcite is in line with thermal degradation, potentially related to heating during Caledonian foreland basin burial.

  • 23. Emo, Robert
    et al.
    Smit, Matthijs
    Schmitt, Melanie
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Kooijman, Ellen
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Scherer, Erik
    Sprung, Peter
    Bleeker, Wouter
    Mezger, Klaus
    Evidence for evolved Hadean crust from Sr isotopes in apatite within Eoarchean zircon from the Acasta Gneiss Complex2018Inngår i: Geochimica et Cosmochimica Acta, ISSN 0016-7037, E-ISSN 1872-9533, Vol. 235, s. 450-462Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Current models for the properties of Hadean-Eoarchean crust encompass a full range of possibilities, involving crust that is anywhere from thick and differentiated to thin and mafic. New data are needed to test and refine these models, and, ultimately, to determine how continents were first formed. The Rb-Sr system provides a potentially powerful proxy for crustal evolution and composition. However, this system has thus far been underutilized in studies on early crustal evolution due to its susceptibility to re-equilibration. Overcoming this issue requires new analytical approaches to micro-sample ancient Sr-rich mineral relics that may retain primary Rb-Sr systematics, allowing for the precise and accurate determination of initial 87Sr/86Sr values. In this study, we used a novel application of laser-ablation multi-collector inductively coupled plasma mass spectrometry to determine the Sr isotope composition of apatite inclusions in >3.6 Ga zircon grains from Eoarchean granodiorite gneisses of the Acasta Gneiss Complex, Slave Province, Canada. The 87Rb-corrected 87Sr/86Sr values of these inclusions are largely identical and are distinctly different from values obtained from altered matrix apatite. The inclusion data provide the first direct estimate of initial 87Sr/86Sr for these ancient rocks. Combining this result with information on the protolith and source-extraction age yields estimates for the range of Rb/Sr values, and by extension composition, that the source of these rocks may have had. The data indicate that continental crust containing over 60 wt% of SiO2 was present in the ca. 4.2 Ga source of the Acasta Gneiss Complex. Thus vestiges of evolved crust must have existed within the primitive proto-continents that were present on the Hadean Earth.

  • 24. Glykou, Aikaterini
    et al.
    Eriksson, Gunilla
    Storå, J.
    Schmitt, Melanie
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Kooijman, Ellen
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Lidén, Kerstin
    Intra- and inter-tooth variation in strontium isotope ratios from prehistoric seals by laser ablation multi-collector inductively coupled plasma mass spectrometry2018Inngår i: Rapid Communications in Mass Spectrometry, ISSN 0951-4198, E-ISSN 1097-0231, Vol. 32, s. 1215-1224Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Rationale

    Strontium isotope ratios (87Sr/86Sr) in modern‐day marine environments are considered to be homogeneous (~0.7092). However, in the Baltic Sea, the Sr ratios are controlled by mixing seawater and continental drainage from major rivers discharging into the Baltic. This pilot study explores if variations in Sr can be detected in marine mammals from archaeological sites in the Baltic Sea.               

    Methods

    87Sr/86Sr ratios were measured in tooth enamel from three seal species by laser ablation multi‐collector inductively coupled plasma mass spectrometry (LA‐MC‐ICP‐MS). The method enables micro‐sampling of solid materials. This is the first time that the method has been applied to marine samples from archaeological collections.               

    Results

    The analyses showed inter‐tooth 87Sr/86Sr variation suggesting that different ratios can be detected in different regions of the Baltic Sea. Furthermore, the intra‐tooth variation suggests possible different geographic origin or seasonal movement of seals within different regions in the Baltic Sea through their lifetime.               

    Conclusions

    The method was successfully applied to archaeological marine samples showing that: (1) the 87Sr/86Sr ratio in marine environments is not uniform, (2) 87Sr/86Sr differences might reflect differences in ecology and life history of different seal species, and (3) archaeological mobility studies based on 87Sr/86Sr ratios in humans should therefore be evaluated together with diet reconstruction.

    Fulltekst (pdf)
    fulltext
  • 25.
    Grasse, P.
    et al.
    GEOMAR Helmholtz Centre for Ocean Research Kiel, Germany.
    Brezezinski, M.
    Marine Science Institute and the Department of Ecology, Evolution, and Marine Biology & University of California, USA.
    Cardinal, D.
    Sorbonne Universités, Paris, France.
    de Souza, G.F.
    ETH Zurich, Institute of Geochemistry and Petrology, Switzerland.
    Andersson, Per
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Closset, I.
    Sorbonne Universités, Paris, France.
    Cao, Z.
    State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, China.
    Dai, M.
    State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, China.
    Ehlert, C.
    Max Planck Research Group for Marine Isotope Geochemistry, University of Oldenburg, Germany.
    Estrade, N.
    University of British Columbia, Vancouver, British Columbia,.
    Francois, R.
    University of British Columbia, Vancouver, British Columbia,.
    Frank, M.
    GEOMAR, Helmholtz Centre for Ocean Research Kiel, Germany.
    Jiang, G.
    Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, China.
    Jones, J.L.
    Marine Science Institute and the Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara USA.
    Kooijman, E.
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Liu, Q.
    Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, China.
    Lu, D.
    Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, China.
    Pahnke, K.
    Institute for Chemistry and Biology of the Marine Environment, University of Oldenburg, Germany.
    Ponzevera, E.
    Unité de Recherche Géosciences Marines, IFREMER, Brest, France.
    Schmitt, M.
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Sun, S.
    Department of Environmental Science and Analytical Chemistry, Stockholm University, Sweden.
    Sutton, J.N.
    Universite de Brest, CNRS, IRD, IFREMER, LEMAR, IUEM, France.
    Thil, F.
    LSCE/IPSL - Laboratoire des Sciences du Climat et de l'Environnement, Gif sur Yvette, France.
    Weis, D.
    University of British Columbia Pacific Center for Isotopic and Geochemical Research, Vancouver, British Columbia,Canada .
    Wetzel, F.
    ETH Zurich, Institute of Geochemistry and Petrology, Switzerland.
    Zhang, A.
    State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai, China.
    Zhang, J.
    State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai, China.
    Zhang, Z.
    State Key Laboratory of Marine Environmental Science,Xiamen University,.
    GEOTRACES Intercalibration of the Stable Silicon Isotope Composition of Dissolved Silicic Acid in Seawater2017Inngår i: Journal of Analytical Atomic Spectrometry, ISSN ISSN 0267-9477, Vol. 32, s. 562-578Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The first inter-calibration study of the stable silicon isotope composition of dissolved silicic acid in seawater, d30Si(OH)4, is presented as a contribution to the international GEOTRACES program. Eleven laboratories from seven countries analyzed two seawater samples from the North Pacific subtropical gyre (Station ALOHA) collected at 300 m and at 1000 m water depth. Sampling depths were chosen to obtain samples with a relatively low (9 mmol L-1, 300 m) and a relatively high (113 mmol L-1, 1000 m) silicic acid concentration as sample preparation differs for low- and high concentration samples. Data for the 1000 m water sample were not normally distributed so the median is used to represent the central tendency for the two samples. Median d30Si(OH)4 values of +1.66‰ for the low-concentration sample and +1.25‰ for the high-concentration sample were obtained. Agreement among laboratories is overall considered very good; however, small but statistically significant differences among the mean isotope values obtained by different laboratories were detected, likely reflecting inter-laboratory differences in chemical preparation including preconcentration and purification methods together with different volumes of seawater analyzed, andthe use of different mass spectrometers including the Neptune MC-ICP-MS (Thermo Fisher™, Germany), the Nu Plasma MC-ICP-MS (Nu Instruments™, Wrexham, UK), and the Finnigan™ (now Thermo Fisher™, Germany) MAT 252 IRMS. Future studies analyzing d30Si(OH)4 in seawater should also analyze and report values for these same two reference waters in order to facilitate comparison of data generated among and within laboratories over time.

    Fulltekst (pdf)
    fulltext
  • 26. Hirst, Catherine
    et al.
    Andersson, Per
    Naturhistoriska riksmuseet, Forskningsavdelningen centralt.
    Kooijman, Ellen
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Schmitt, Melanie
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Kutscher, Liselott
    Maximov, Trofim
    Mörth, Carl-Magnus
    Porcelli, Don
    Iron isotopes reveal the sources of Fe-bearing particles and colloids in the Lena River basin2019Inngår i: Geochimica et Cosmochimica Acta, ISSN 0016-7037, E-ISSN 1872-9533Artikkel i tidsskrift (Fagfellevurdert)
  • 27. Hirst, Catherine
    et al.
    Andersson, Per S.
    Mörth, Carl-Magnus
    Murphy, Melissa J.
    Schmitt, Melanie
    Kooijman, Ellen
    Naturhistoriska riksmuseet, Enheten för geovetenskap. Department of Geosciences, Swedish Museum of Natural History, Stockholm, Sweden.
    Kutscher, Liselott
    Petrov, Roman
    Maximov, Trofim
    Porcelli, Don
    Iron isotopes reveal seasonal variations in the mechanisms for iron-bearing particle and colloid formation in the Lena River catchment, NE Siberia2023Inngår i: Geochimica et Cosmochimica Acta, ISSN 0016-7037, E-ISSN 1872-9533, Vol. 363, s. 77-93Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Large Arctic rivers are an important source of iron (Fe) to the Arctic Ocean, though seasonal variations in the terrestrial source and supply of Fe to the ocean are unknown. To constrain the seasonal variability, we present Fe concentrations and isotopic compositions (δ56Fe) for particulate (>0.22 µm) and colloidal (<0.22 µm–1 kDa) Fe from the Lena River, NE Russia. Samples were collected every month during winter baseflow (September 2012–March 2013) and every 2–3 days before, during and after river ice break-up (May 2015).

    Iron in particles have isotope ratios lower than crustal values during winter (e.g., δ56FePart = −0.37 ± 0.16‰), and crustal-like values during river ice break-up and spring flood (e.g., δ56FePart = 0.07 ± 0.08‰), indicating a change in the source of particulate Fe between winter and spring flood. Low isotope values are indicative of mineral dissolution, transport of reduced Fe in sub-oxic, ice-covered sub-permafrost groundwaters and near-quantitative precipitation of Fe as particles. Crustal-like isotopic compositions result from the increased supply of detrital particles from riverbank and soil erosion during river ice break-up and flooding. Iron colloids (<0.22 μm) have δ56Fe values that are comparable to or lower than crustal values during winter (e.g., δ56FeCol = −0.08 ± 0.05‰) but similar to or higher than crustal values during spring flood (e.g., δ56FeCol = +0.24 ± 0.11‰). Low δ56Fe ratios for colloidal Fe during winter are consistent with precipitation from isotopically light Fe(II)aq transported in sub-permafrost groundwaters. Higher colloidal δ56Fe ratios during the spring flood indicate that these colloids are supplied from surface soils, where Fe is fractionated via oxidation or organic carbon complexation, similar to during summer. Approximately half of the annual colloidal Fe flux occurs during spring flood while most of the remaining colloidal Fe is supplied during summer months. The total amount of colloidal Fe transported during winter was relatively low. The seasonal variation in colloidal Fe isotope values may be a useful tool to trace the source of colloidal Fe to the Arctic Ocean and monitor future changes in the sources and supply of Fe from the permafrost landscape to the Lena River basin.

  • 28. Kershaw, Jane
    et al.
    Merkel, Stephen W.
    Oravisjärvi, Jani
    Kooijman, Ellen
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Kielman-Schmitt, Melanie
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    The scale of dirham imports to the Baltic in the ninth century: new evidence from archaeometric analyses of early Viking-Age silver2021Inngår i: Fornvännen, ISSN 0015-7813, E-ISSN 1404-9430, Vol. 116, nr 3, s. 185-204Artikkel i tidsskrift (Fagfellevurdert)
  • 29.
    Kooijman, Ellen
    et al.
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Smit, Matthijs
    Ratschbacher, Lothar
    Kylander-Clark, Andrew
    A view into crustal evolution at mantle depths2017Inngår i: Earth and Planetary Science Letters, ISSN 0012-821X, E-ISSN 1385-013X, Vol. 465, s. 59-69Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Crustal foundering is an important mechanism in the differentiation and recycling of continental crust. Nevertheless, little is known about the dynamics of the lower crust, the temporal scale of foundering and its role in the dynamics of active margins and orogens. This particularly applies to active settings where the lower crust is typically still buried and direct access is not possible. Crustal xenoliths derived from mantle depth in the Pamir provide a unique exception to this. The rocks are well-preserved and comprise a diverse set of lithologies, many of which re-equilibrated at high-pressure conditions before being erupted in their ultrapotassic host lavas. In this study, we explore the petrological and chronological record of eclogite and felsic granulite xenoliths. We utilized accessory minerals – zircon, monazite and rutile – for coupled in-situ trace-element analysis and U–(Th–)Pb chronology by laser-ablation (split-stream) inductively coupled plasma mass spectrometry. Each integrated analysis was done on single mineral zones and was performed in-situ in thin section to maintain textural context and the ability to interpret the data in this framework. Rutile thermo-chronology exclusively reflects eruption (), which demonstrates the reliability of the U–Pb rutile thermo-chronometer and its ability to date magmatic processes. Conversely, zircon and monazite reveal a series of discrete age clusters between 55–11 Ma, with the youngest being identical to the age of eruption. Matching age populations between samples, despite a lack of overlapping ages for different chronometers within samples, exhibit the effectiveness of our multi-mineral approach. The REE systematics and age data for zircon and monazite, and Ti-in-zircon data together track the history of the rocks at a million-year resolution. The data reveal that the rocks resided at 30–40 km depth along a stable continental geotherm at 720–750 °C until 24–20 Ma, and were subsequently melted, densified, and buried to 80–90 km depth – 20 km deeper than the present-day Moho – at . The material descended rapidly, accelerating from 0.9–1.7 mm yr−1to 4.7–5.8 mm yr−1 within 10–12 Myr, and continued descending after reaching mantle depth at 14–13 Ma. The data reflect the foundering of differentiated deep-crustal fragments (2.9–3.5 g cm−3) into a metasomatized and less dense mantle wedge. Through our new approach in constraining the burial history of rocks, we provided the first time-resolved record of this crustal-recycling process. Foundering introduced vestiges of old evolved crust into the mantle wedge over a relatively short period (c. 10 Myr). The recycling process could explain the variability in the degree of crustal contamination of mantle-derived magmatic rocks in the Pamir and neighboring Tibet during the Cenozoic without requiring a change in plate dynamics or source region.

  • 30. Krall, Lindsay
    et al.
    Evins, Lena Z.
    Kooijman, Ellen
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Whitehouse, Martin
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Tullborg, Eva-Lena
    Tracing the palaeoredox conditions at Forsmark, Sweden, using uranium mineral geochronology2019Inngår i: Chemical Geology, ISSN 0009-2541, E-ISSN 1872-6836, Vol. 506, s. 68-78Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    U-Pb isotope systems have been used to constrain the timing of formation, alteration, and oxidation of U minerals from the meta-granitic bedrock at Forsmark, eastern Sweden. Secondary ion mass spectrometry (SIMS) has been used to collect U-Pb data from uraninite. Discordant data suggest a ~1.8 Ga emplacement of uraninite-bearing pegmatites and an event of uraninite alteration at ~1.6 Ga. The latter age is contemporaneous with the Gothian orogeny in Scandinavia, which was associated with hydrothermal fluid circulation in the Fennoscandian Shield. Ca-uranyl silicates haiweeite and uranophane predominately formed 1.3–1.2 Ga, contemporaneous with the emplacement of the Satakunta complex of the Central Scandinavian Dolerite Group. A Palaeozoic group of Ca-U(VI)-silicates is also present, which indicates that the geochemical composition of geologic fluids was heterogeneous throughout the fracture network during this time. Low Pb concentrations in the U(VI) silicates of several samples are compatible with a recent (<100 Ma) alteration or precipitation of these minerals in connection to reaction with carbonate-rich fluids. The results support a geologically early oxidation of U(IV) to U(VI) and provide insight into the palaeoredox conditions that may impart an on-going influence on the mobility of natural U in the Forsmark fracture network.

  • 31.
    Matetski, Lagle
    et al.
    Estonian Marine Institute University of Tartu Tartu Estonia.
    Rohtla, Mehis
    Estonian Marine Institute University of Tartu Tartu Estonia.
    Svirgsden, Roland
    Estonian Marine Institute University of Tartu Tartu Estonia.
    Kesler, Martin
    Estonian Marine Institute University of Tartu Tartu Estonia.
    Saks, Lauri
    Estonian Marine Institute University of Tartu Tartu Estonia.
    Taal, Imre
    Estonian Marine Institute University of Tartu Tartu Estonia.
    Hommik, Kristiina
    Estonian Marine Institute University of Tartu Tartu Estonia.
    Paiste, Päärn
    Department of Geology University of Tartu Tartu Estonia.
    Kielman-Schmitt, Melanie
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Kooijman, Ellen
    Naturhistoriska riksmuseet, Enheten för geovetenskap. Department of Geosciences Swedish Museum of Natural History Stockholm Sweden.
    Birzaks, Jānis
    Department of Ecology University of Daugavpils Daugavpils Latvia.
    Saura, Ari
    Natural Resource Institute Finland Helsinki Finland.
    Ziņģis, Mārcis
    Aquaculture Research and Education Centre Institute of Food Safety Animal Health and Environment Fish Farm “Tome” Ķegums Latvia.
    Vaittinen, Matti
    Centre of Economic Development, Transport and the Environment for Southeast Finland Kouvola Finland.
    Vetemaa, Markus
    Estonian Marine Institute University of Tartu Tartu Estonia.
    Variability in stream water chemistry and brown trout ( Salmo trutta L.) parr otolith microchemistry on different spatial scales2021Inngår i: Ecology of Freshwater Fish, ISSN 0906-6691, E-ISSN 1600-0633, Vol. 31, nr 2, s. 438-453Artikkel i tidsskrift (Fagfellevurdert)
  • 32.
    Matetski, Lagle
    et al.
    Estonian Marine Institute University of Tartu Tartu Estonia.
    Rohtla, Mehis
    Estonian Marine Institute University of Tartu Tartu Estonia.
    Svirgsden, Roland
    Estonian Marine Institute University of Tartu Tartu Estonia.
    Kesler, Martin
    Estonian Marine Institute University of Tartu Tartu Estonia.
    Saks, Lauri
    Estonian Marine Institute University of Tartu Tartu Estonia.
    Taal, Imre
    Estonian Marine Institute University of Tartu Tartu Estonia.
    Hommik, Kristiina
    Estonian Marine Institute University of Tartu Tartu Estonia.
    Paiste, Päärn
    Department of Geology University of Tartu Tartu Estonia.
    Kielman-Schmitt, Melanie
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Kooijman, Ellen
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Birzaks, Jānis
    Department of Ecology University of Daugavpils Daugavpils Latvia.
    Saura, Ari
    Natural Resource Institute Finland Helsinki Finland.
    Ziņģis, Mārcis
    Aquaculture Research and Education Centre Institute of Food Safety Animal Health and Environment, Fish Farm “Tome” Ķegums Latvia.
    Vaittinen, Matti
    Centre of Economic Development, Transport and the Environment for Southeast Finland Kouvola Finland.
    Vetemaa, Markus
    Estonian Marine Institute University of Tartu Tartu Estonia.
    Variability in stream water chemistry and brown trout (Salmo trutta L.) parr otolith microchemistry on different spatial scales2021Inngår i: Ecology of Freshwater Fish, ISSN 0906-6691, E-ISSN 1600-0633Artikkel i tidsskrift (Fagfellevurdert)
  • 33.
    Mulder, Jacob
    et al.
    School of Earth and Environmental Sciences The University of Queensland Queensland Australia;Department of Earth Sciences University of Adelaide Adelaide Australia.
    Hagen‐Peter, Graham
    Department of Geoscience Aarhus University Denmark;Geological Survey of Norway.
    Ubide, Teresa
    School of Earth and Environmental Sciences The University of Queensland Queensland Australia.
    Andreasen, Rasmus
    Department of Geoscience Aarhus University Denmark.
    Kooijman, Ellen
    Naturhistoriska riksmuseet, Enheten för geovetenskap. Department of Geosciences, Swedish Museum of Natural History, Stockholm, Sweden.
    Kielman‐Schmitt, Melanie
    The Vegacenter Swedish Museum of Natural History Sweden.
    Feng, Yue‐Xing
    Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai) Zhuhai China.
    Paul, Bence
    School of Geography, Earth and Atmospheric Sciences The University of Melbourne Victoria Australia;Elemental Scientific Lasers LLC. Bozeman Montana USA.
    Karlsson, Andreas
    Naturhistoriska riksmuseet, Enheten för geovetenskap. The Vegacenter Swedish Museum of Natural History Sweden.
    Tegner, Christian
    Department of Geoscience Aarhus University Denmark.
    Lesher, Charles
    Department of Geoscience Aarhus University Denmark;Department of Earth and Planetary Sciences University of California Davis California USA.
    Costa, Fidel
    Institut de Physique du Globe de Paris France.
    New Reference Materials, Analytical Procedures and Data Reduction Strategies for Sr Isotope Measurements in Geological Materials by LA‐MC‐ICP‐MS2023Inngår i: Geostandards and Geoanalytical Research, ISSN 1639-4488, E-ISSN 1751-908X, Vol. 47, nr 2, s. 311-336Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Laser ablation multi-collector mass spectrometry (LA-MC-ICP-MS) has emerged as the technique of choice for in situ measurements of Sr isotopes in geological minerals. However, the method poses analytical challenges and there is no widely adopted standardised approach to collecting these data or correcting the numerous potential isobaric inferences. Here, we outline practical analytical procedures and data reduction strategies to help establish a consistent framework for collecting and correcting Sr isotope measurements in geological materials by LA-MC-ICP-MS. We characterise a new set of plagioclase reference materials, which are available for distribution to the community, and present a new data reduction scheme for the Iolite software package to correct isobaric interferences for different materials and analytical conditions. Our tests show that a combination of Kr-baseline subtraction, Rb-peak-stripping using βRb derived from a bracketing glass reference material, and a CaCa or CaAr correction for plagioclase and CaCa or CaAr + REE2+ correction for rock glasses, yields the most accurate and precise 87Sr/86Sr measurements for these materials. Using the analytical and correction procedures outlined herein, spot analyses using a beam diameter of 100 μm or rastering with a 50–65 μm diameter beam can readily achieve < 100 ppm 2SE repeatability ("internal") precision for 87Sr/86Sr measurements for materials with < 1000 μg g-1 Sr.

  • 34. Nisson, D.M.
    et al.
    Kieft, T.L.
    Drake, H.
    Warr, O.
    Sherwood Lollar, B.
    Ogasawara, H.
    Perl, S.M.
    Friefeld, B.M.
    Castillo, J.
    Whitehouse, Martin J.
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Kooijman, Ellen
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Onstott, T.C.
    Hydrogeochemical and isotopic signatures elucidate deep subsurface hypersaline brine formation through radiolysis driven water-rock interaction2023Inngår i: Geochimica et Cosmochimica Acta, ISSN 0016-7037, E-ISSN 1872-9533, Vol. 340, s. 65-84Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Geochemical and isotopic fluid signatures from a 2.9–3.2 km deep, 45–55 °C temperature, hypersaline brine from Moab Khotsong gold and uranium mine in the Witwatersrand Basin of South Africa were combined with radiolytic and water–rock isotopic exchange models to delineate brine evolution over geologic time, and to explore brine conditions for habitability. The Moab Khotsong brines were hypersaline (Ca-Na-Cl) with 215–246 g/L TDS, and Cl− concentrations up to 4 mol/L suggesting their position as a hypersaline end-member significantly more saline than any previously sampled Witwatersrand Basin fluids. The brines revealed low DIC (∼0.266–∼1.07 mmol/L) with high (∼8.49–∼23.6 mmol/L) DOC pools, and several reduced gaseous species (up to 46 % by volume H2) despite microoxic conditions (Eh = 135–161 mV). Alpha particle radiolysis of water to H2, H2O2, and O2 along with anhydrous-silicate-to-clay alteration reactions predicted 4 mol/L Cl− brine concentration and deuterium enrichment in the fracture waters over a period > 1.00 Ga, consistent with previously reported 40Ar noble gas-derived residence times of 1.20 Ga for this system. In addition, radiolytic production of 7–26 nmol/(L × yr) H2, 3–11 nmol/(L × yr) O2, and 1–8 nmol/(L × yr) H2O2 was predicted for 1–100μ g/g 238U dosage scenarios, supporting radiolysis as a significant source of H2 and oxidant species to deep brines over time that are available to a low biomass system (102–103 cells/mL). The host rock lithology was predominately Archaean quartzite, with minerals exposed on fracture surfaces that included calcite, pyrite, and chlorite. Signatures of �18Ocalcite, �13Ccalcite, Δ33Spyrite, �34Spyrite and 87Sr/86Sr obtained from secondary ion mass spectrometry (SIMS) microanalyses suggest several discrete fluid events as the basin cooled from peak greenschist conditions to equilibrium with present-day brine temperatures. The brine physiochemistry, geochemistry, and cellular abundances were significantly different from those of a younger, shallower, low salinity dolomitic fluid in the same mine, and both were different from the mine service water. These results indicate the discovery of one of few long-isolated systems that supports subsurface brine formation via extended water–rock interaction, and an example of a subsurface brine system where abiotic geochemistry may support a low biomass microbial community.

  • 35. Piličiauskas, Gytis
    et al.
    Simčenka, Edvardas
    Lidén, Kerstin
    Kozakaitė, Justina
    Miliauskienė, Žydrūnė
    Piličiauskienė, Giedrė
    Kooijman, Ellen
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Šinkūnas, Petras
    Robson, Harry K.
    Strontium isotope analysis reveals prehistoric mobility patterns in the southeastern Baltic area2022Inngår i: Archaeological and Anthropological Sciences, ISSN 1866-9557, E-ISSN 1866-9565, Vol. 14, nr 4, artikkel-id 74Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We measured 87Sr/86Sr for all available human remains (n = 40) dating from the Mesolithic to the Bronze Age (ca. 6400–800 cal BC) in Lithuania. In addition, local baselines of archaeological fauna from the same area were constructed. We identified significant and systematic offsets between 87Sr/86Sr values of modern soils and animals and archaeological animals due to currently unknown reasons. By comparing 87Sr/86Sr human intra-tooth variation with the local baselines, we identified 13 non-local individuals, accounting for 25–50% of the analysed population. We found no differences in the frequency of local vs. nonlocals between male and female hunter-gatherers. Six Mesolithic-Subneolithic individuals with 87Sr/86Sr values > 0.7200 may have come from southern Finland and/or Karelia. Two Mesolithic-Subneolithic individuals from the Donkalnis cemetery with 87Sr/86Sr values < 0.7120 likely came from the Lithuanian Baltic coast. These data demonstrate coastal-inland mobility of up to 85 km, which is also supported by archaeological evidence. The standard deviation in the intra-tooth 87Sr/86Sr indicates that mobility did not decrease with the adoption of pottery technology at ca. 5000 cal BC but rather slowly decreased during the Neolithic and Bronze Age periods. We interpret this as a result of the introduction and subsequent intensification of farming. The least mobile way of life was practised by Subneolithic coastal communities during the 4th millennium cal BC, although 87Sr/86Sr do not exclude that they migrated along the coastline.

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  • 36. Piličiauskienė, Giedrė
    et al.
    Kurila, Laurynas
    Simčenka, Edvardas
    Lidén, Kerstin
    Kooijman, Ellen
    Naturhistoriska riksmuseet, Enheten för geovetenskap. Department of Geosciences Swedish Museum of Natural History Stockholm Sweden.
    Kielman-Schmitt, Melanie
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Piličiauskas, Gytis
    The Origin of Late Roman Period–Post-Migration Period Lithuanian Horses2022Inngår i: Heritage, E-ISSN 2571-9408, Vol. 5, nr 1, s. 332-352Artikkel i tidsskrift (Fagfellevurdert)
  • 37. Ravindran, Arathy
    et al.
    Mezger, Klaus
    Balakrishnan, S
    Kooijman, Ellen
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Schmitt, Melanie
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Berndt, Jasper
    Initial 87Sr/86Sr as a sensitive tracer of Archaean crust-mantle evolution: Constraints from igneous and sedimentary rocks in the western Dharwar Craton, India2020Inngår i: Precambrian Research, ISSN 0301-9268, E-ISSN 1872-7433, Vol. 337, s. 1-15, artikkel-id 105523Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Among the rocky planets of the solar system only the Earth has “granitic” continental crust. The timing and processes involved in the formation of Earth’s first extensive crust is still enigmatic. The chemical and isotope compositions of ancient crustal rocks preserve a record of their genesis. The Rb-Sr system proves to be an efficient proxy for the reconstruction of crust-mantle evolution since it can bring together information from seawater as preserved in chemical sedimentary rocks and information from magmatic rocks that can trace the time and extent of crust formation and concomitant mantle depletion during the Archaean eon. The Dharwar Craton in India preserves a suite of metamorphosed igneous and sedimentary rocks that record its early crustal evolution. To overcome the susceptibility for resetting and the difficulty in determining initial 87Sr/86Sr, the minerals barite and apatite are used to obtain precise and accurate 87Sr/86Sr, because these minerals preferentially incorporate Sr and exclude Rb and preserve the initial Sr isotope compositions at the time of their formation. Initial 87Sr/86Sr of apatite were obtained in situ using Laser Ablation Multi-Collector Inductively Coupled Plasma Mass Spectrometry. The robustness and only minor dispersion of the isotope ratios demonstratethe capability of matrix apatites in preserving initial Sr ratios. The least radiogenic value is used as the best estimate for the initial 87Sr/86Sr. The 87Sr/86Sr ratios of apatite from igneous rocks that formed from 3.5 Ga to 2.6 Ga constrain the Rb/Sr of the source over the whole time-span. A comparison of the Sr isotopes between seawater-derived barite and initial Sr isotope ratios in apatite from igneous rocks reveals that significant mafic to intermediate crust had formed by 3.2 Ga. Studying the entire Archaean time window, a dominantly mafic crust was the main source for the granitoid rocks in the Dharwar Craton from 3.5 to 3.1 Ga, whereas the rocks from 2.9t o 2.7 Ga were extracted dominantly from the depleted mantle.

  • 38. Ravindran, Arathy
    et al.
    Mezger, Klaus
    Balakrishnan, Srinivasan
    Kooijman, Ellen
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Schmitt, Melanie
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Berndt, Jasper
    Initial 87Sr/86Sr as a sensitive tracer of Archaean crust-mantle evolution: constraints from igneous and sedimentary rocks in the western Dharwar Craton, India2019Inngår i: Precambrian Research, ISSN 0301-9268, E-ISSN 1872-7433Artikkel i tidsskrift (Fagfellevurdert)
  • 39. Robinson, Frank
    et al.
    Pease, Victoria
    Whitehouse, Martin
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Kooijman, Ellen
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Preliminary detrital zircon signatures from the southern Asir terrane, Saudi Arabia: A link to Yemen or the Nubian Shield?2018Inngår i: Precambrian Research, ISSN 0301-9268, E-ISSN 1872-7433, Vol. 311, s. 247-261Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The Arabian Shield comprises early Neoproterozoic to Cambrian (∼850–530 Ma) tectonostratigraphic terranes formed by the closure and accretion of juvenile volcanic arcs and back-arc basins associated with Gondwana assembly. Unlike the Nubian Shield which preserves crustal isotopic signatures, the Arabian Shield is distinctly juvenile with the exception of the Paleoproterozoic (∼1800–1670 Ma) Khida subterrane in Saudi Arabia and the terranes of Yemen. This study presents the first combined zircon U-Pb, O and Hf isotope data of metavolcanic and metasedimentary rocks from southwestern most Saudi Arabia, near the Yemen border – a region thought to contain some of the oldest (>815 Ma) lithologies in Saudi Arabia, including the Atura Formation and the Tayyah Belt. One volcaniclastic metasediment sample from the Atura Formation yields zircon U-Pb age peaks of 741, 672, 646 Ma (n = 131), δ18O(V-SMOW) ranging from 4.6 to 8.3‰ and ɛHf (t) from +7.7 to +12.5. Two samples from the Tayyah Belt include an older metasandstone and a late intruding granitic dyke which provides a minimum age for the Tayyah Belt. The former yields two significant U-Pb peaks of 812 (n = 8) and 999 (n = 6) Ma, δ18O and ɛHf (t) values ranging from 4.4 to 9.6‰ and −10.1 to +12.4, respectively; the later yields a concordia age of 645.8 [±1.7] Ma (n = 29), δ18O ranging from 5.7 to 6.6‰, and ɛHf (t) of +5.9 to +9.6. The zircon age and juvenile Hf signatures from the Atura Formation are consistent with the synorogenic phase in the Shield. Sedimentation was likely associated with arc volcanism during the previously documented eastward phase of accretion at ∼740–640 Ma and the closure of the Mozambique Ocean. In contrast, the data from the texturally more mature Tayyah Belt metasediment indicate a more distal, and more evolved crustal input at the time of sediment deposition which is unusual for the Saudi Arabian Shield. Consequently, the Tayyah metasediments are likely sourced from areas with greater continental affinity, such as the cratonic basement and/or reworked crust of the Sahara metacraton in NE Africa.

  • 40. Rohtla, Mehis
    et al.
    Silm, Maidu
    Tulonen, Jouni
    Paiste, Päärn
    Wickström, Håkan
    Kielman-Schmitt, Melanie
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Kooijman, Ellen
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Vaino, Väino
    Eschbaum, Redik
    Saks, Lauri
    Verliin, Aare
    Vetemaa, Markus
    Conservation restocking of the imperilled European eel does not necessarily equal conservation2020Inngår i: ICES Journal of Marine Science, ISSN 1054-3139, E-ISSN 1095-9289, s. 1-11Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    To stop the decline of the European eel population, one of the measures taken is translocating eels for restocking, despite its conservational value being largely unknown. We aimed to contribute to this knowledge gap by (i) investigating the origin of eels caught in coastal waters of Estonia and Finland using otolith microchemistry and (ii) directly estimating restocked eel escapement from Narva River Basin District (NRBD), which is part of the primary Eel Management Unit in Estonia. In Estonia, 74% of the sampled eels (n=140) were natural recruits and 26% were restocked. In Finland, 27% of the sampled eels (n=235) were natural recruits and 73% were restocked. Only 1% of all the coastally collected eels were originally restocked to NRBD. These new data together with the reported commercial landings from the escapement route conflict with the current silver eel escapement estimation for NRBD and question the accuracy and value of such indirect calculations compiled for most Eel Management Units throughout the European Union. It is concluded that restocking eels to freshwaters may be futile as a conservation measure in some situations, and better escapement is likely achieved in restocking eels to coastal waters or undammed freshwater systems with a direct connection to the sea.

  • 41. Sahlström, Fredrik
    et al.
    Troll, Valentin R.
    Palinkaš, Sabina Strmić
    Kooijman, Ellen
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Zheng, Xin-Yuan
    Iron isotopes constrain sub-seafloor hydrothermal processes at the Trans-Atlantic Geotraverse (TAG) active sulfide mound2022Inngår i: Communications Earth & Environment, E-ISSN 2662-4435, Vol. 3, nr 1, artikkel-id 193Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Sub-seafloor hydrothermal processes along volcanically active plate boundaries are integral to the formation of seafloor massive sulfide deposits and to oceanic iron cycling, yet the nature of their relationship is poorly understood. Here we apply iron isotope analysis to sulfide minerals from the Trans-Atlantic Geotraverse (TAG) mound and underlying stockwork, 26°N Mid-Atlantic Ridge, to trace hydrothermal processes inside an actively-forming sulfide deposit in a sediment-free mid-ocean ridge setting. We show that data for recently formed chalcopyrite imply hydrothermal fluid–mound interactions cause small negative shifts (<−0.1‰) to the δ56Fe signature of dissolved iron released from TAG into the North Atlantic Ocean. Texturally distinct types of pyrite, in turn, preserve a δ56Fe range from −1.27 to +0.56‰ that reflects contrasting precipitation mechanisms (hydrothermal fluid–seawater mixing vs. conductive cooling) and variable degrees of progressive hydrothermal maturation during the >20 kyr evolution of the TAG complex. The identified processes may explain iron isotope variations found in fossil onshore sulfide deposits.

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  • 42. Schmitt, Axel K.
    et al.
    Zack, Thomas
    Kooijman, Ellen
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Logvinova, Alla M.
    Sobolev, Nikolay V.
    U–Pb ages of rare rutile inclusions in diamond indicate entrapment synchronous with kimberlite formation2019Inngår i: Lithos, ISSN 0024-4937, E-ISSN 1872-6143, Vol. 350-351Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The timing of diamond crystallization is generally inferred from radiometric dating of individual or multiple mineral inclusions in diamond, where ages are derived from isochrons or isotopic evolution models. Resulting ages often significantly predate the emplacement ages of host kimberlites, but age information from both approaches can be ambiguous due to long-lived mantle heterogeneities where mixing can mimic isochrons or in-situ aging. Direct dating of accessory mineral inclusions in diamonds, by contrast, has rarely been attempted because of the scarcity of such inclusions, requiring careful high grading of large amounts of diamond concentrates. Here, we report secondary ionization mass spectrometry (SIMS) U–Pb ages from a suite of rare rutile inclusions which were extracted from diamond in an eclogitic paragenesis from the Mir kimberlite pipe, Siberia. One population of rutile inclusions shows diamond crystal-shapes and was petrographically identified as completely enclosed in diamond prior to host burning for inclusion extraction. These rutile inclusions were screened for U abundances (0.24–23 μg/g U) and those with the highest U contents were dated, yielding a uniform U–Pb concordia age of 375.5 ± 7.0 Ma (error 95% confidence; mean square of weighted deviates MSWD = 0.74; number of spots n = 19). This age is nearly coeval with, but significantly (at the 95% confidence level) older than combined U–Pb rutile ages for rutile intergrown with polycrystalline fibrous diamond (362.9 ± 9.5 Ma; MSWD = 0.96; n = 7) and rutile from the eclogitic xenolith matrix (369 ± 16 Ma; MSWD = 0.30; n = 5). Rutile ages are consistent with published ages for kimberlite emplacement (ca. 360 Ma), but much younger than Re–Os sulfide isochron ages between ca. 913 Ma and 2.1 Ga for groups of individual inclusions in diamond from the same location. When assuming the oldest Re–Os sulfide age as the timing of rutile entrapment, diffusive Pb-loss from rutile inclusions over ca. 2 Ga would require diffusivities of Pb in diamond of >10−22 m2/s, as well as Pb partitioning coefficients between diamond and rutile at near or greater unity. Alternatively, if Pb is immobile in diamond, ancient rutile ages could have been reset due to processes other than volume diffusion through diamond (e.g., due to fluid migration along cracks). However, in this scenario it remains difficult to explain why all rutile inclusions dated here would have been located along cracks, whereas sulfide inclusions investigated in other studies were not. Another explanation is that rutile inclusions were entrapped at the time of diamond formation, and that this event is recorded by U–Pb rutile ages, whereas sulfides predate diamond crystallization and their Re–Os systematics were incompletely reset. Trace element heterogeneity in rutile suggests that they originated in chemically different environments, and thus rutile likely predates diamond formation. However, due to rapid diffusion of Pb in rutile, radiogenic Pb accumulated only after entrapment in diamond (for inclusions) or eruptive quenching (for intergrown or matrix rutile). Overall, rutile geochronology indicates that at least some diamond from the Mir pipe formed briefly (within the ca. 20 Ma age difference between U–Pb rutile ages for inclusions and intergrown/matrix rutile) before kimberlite eruption, supporting models that link diamond formation with carbon-rich precursors of kimberlite magmas.

  • 43. Sengupta, Pulak
    et al.
    Raith, Michael
    Kooijman, Ellen
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Talukdar, Moumita
    Chowdhury, Priyadarshi
    Sanyal, Sanjoy
    Mezger, Klaus
    Mukhopadhyay, Dhruba
    Provenance, timing of sedimentation and metamorphism of metasedimentary rock suites from the Southern Granulite Terrane, India2015Inngår i: Precambrian Basins of India: Stratigraphic and Tectonic Context / [ed] R. Mazumder & P.G. Eriksson, London: Geological Society of London, 2015Kapittel i bok, del av antologi (Fagfellevurdert)
    Abstract [en]

    The Southern Granulite Terrane of India exposes remnants of an interbanded sequence of orthoquartzite–metapelite–calcareous rocks across the enigmatic Palghat–Cauvery Shear Zone (PCSZ), which has been interpreted as a Pan-African terrane boundary representing the eastward extension of the Betsimisaraka Suture Zone of Madagascar. Zircon U–Pb geochronology of metasedimentary rocks from both sides of the PCSZ shows that the precursor sediments of these rocks were sourced from the Dharwar Craton and the adjoining parts of the Indian shield. The similarity of the provenance and the vestiges of Grenvillian-age orogenesis in some metasedimentary rocks contradict an interpretation that the PCSZ is a Pan-African terrane boundary. The lithological association and the likely basin formation age of the metasedimentary rocks of the Southern Granulite Terrane show remarkable similarity to the rock assemblage and timing of sedimentation of the Palaeoproterozoic to Neoproterozoic shallow-marine deposits of the Purana basins lying several hundred kilometres north of this terrane. Integrating the existing geological information, it is postulated that the shallow-marine sediments were deposited on a unified land-mass consisting of a large part of Madagascar and the Indian shield that existed before Neoproterozoic time, part of which was later involved in the Pan-African orogeny.

  • 44. Skublov, Sergei
    et al.
    Krasotkina, Anna
    Makayev, Aleksandr
    Rizvanova, Nailya
    Kooijman, Ellen
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    The first data on the U-Pb age (TIMS and LA-ICP-MS) of rutile from the Ichetju polymineral occurrence, The Middle Timan2018Inngår i: Journal of Mining Institute, Vol. 232, s. 357-363Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A study on the U-Pb age of rutile from the Ichetju polymineral occurrence has been done for the first time by LA-ICP-MS and TIMS methods. It was established that rutile originates from various sources with different ages (presumably, ca. 1000, 1660, 1860 and 1980 Ma), but all the rutile types have undergone a common thermal event at ca. 580 Ma. Obtained results are consistent with U-Pb zircon data for the Ichetju occurrence and the Pizhemskoe deposit. According to modern concepts, the closure temperature for the U-Pb system in rutile is higher than 500 С, which suggests fairly high-temperature conditions of the rutile hydrothermal transformation during the formation of the deposits in Riphean. Obviously, a placer hypothesis of formation of titanium deposits of the Middle Timan which is supported by a number of researchers does not explain such temperature of rutile alteration.

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  • 45. Smit, Matthijs
    et al.
    Ratschbacher, Lothar
    Kooijman, Ellen
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Stearns, Michael
    Early evolution of the Pamir deep crust from Lu-Hf and U-Pb geochronology and garnet thermometry2014Inngår i: Geology, ISSN 0091-7613, E-ISSN 1943-2682, Vol. 42, nr 12, s. 1047-1050Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Determining early orogenic processes within the Pamir-Tibet orogen represents a critical step toward constructing a comprehensive model on the tectonic evolution of the region. Here we investigate the timing and cause of prograde metamorphism of Cenozoic metamorphic rocks from the Pamir plateau through Lu-Hf geochronology, U-Pb rutile thermochronology, and garnet thermometry. Regional prograde metamorphism and heating to 750–830 °C, as constrained by thermometry, occurred between 37 and 27 Ma. Prograde growth of garnet first occurred in the South Pamir and spread to the Central Pamir during the following 10 m.y. The early metamorphism is attributed to high mantle heat flow following the ca. 45 Ma break-off of the Indian slab south of the Pamir. Our investigation confirms a long-lived thermal history of the Pamir deep crust before the Miocene, and provides a causal link between break-off, enhanced mantle heat flow, and prograde heating of the subduction hanging wall.

  • 46.
    Tillberg, Mikael
    et al.
    Department of Biology and Environmental Science Linnaeus University Kalmar Sweden;Department of Earth Sciences University of Gothenburg Gothenburg Sweden.
    Drake, Henrik
    Department of Biology and Environmental Science Linnaeus University Kalmar Sweden.
    Zack, Thomas
    Department of Earth Sciences University of Gothenburg Gothenburg Sweden;Department of Earth Sciences University of Adelaide Adelaide SA Australia.
    Hogmalm, Johan
    Department of Earth Sciences University of Gothenburg Gothenburg Sweden.
    Kooijman, Ellen
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Åström, Mats
    Department of Biology and Environmental Science Linnaeus University Kalmar Sweden.
    Reconstructing craton‐scale tectonic events via in situ Rb‐Sr geochronology of poly‐phased vein mineralization2021Inngår i: Terra Nova, ISSN 0954-4879, E-ISSN 1365-3121, Vol. 33, nr 5, s. 502-510Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Fault- and fracture-hosted multi-stage mineral assemblages that formed by fracture reactivation and fluid migration, constitute archives of the tectonic evolution of Precambrian cratons. Complex intergrowth patterns of these mineral records often hinder absolute dating of mineralization events for geological models. We apply LA-ICP-MS/MS in situ Rb-Sr dating of single crystal growth zones in sub-mm-wide vein mineralization assemblages including illite, K-feldspar, albite, calcite, mica, zeolites, fluorite and/or epidote at three Palaeoproterozoic crystalline bedrock sites over 300 km apart in the Fennoscandian Shield. The dating campaign reveals multiple age clusters between ca. 1757 ± 15 and 355 ± 12 Ma correlating with fluid flow and fracture reactivation events initiated by far-field orogens and their foreland basin evolution. This new approach for reconstructing geological histories of Precambrian cratons connects micro-scale age determinations of different mineral growth zones in fractures with regional-scale crustal dynamic responses to tectonic events.

  • 47. Tillberg, Mikael
    et al.
    Drake, Henrik
    Zack, Thomas
    Kooijman, Ellen
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Whitehouse, Martin J.
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Åström, Mats E.
    In situ Rb-Sr dating of slickenfibres in deep crystalline basement faults2020Inngår i: Scientific Reports, E-ISSN 2045-2322, Vol. 10, nr 1Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Establishing temporal constraints of faulting is of importance for tectonic and seismicity reconstructions and predictions. Conventional fault dating techniques commonly use bulk samples of syn-kinematic illite and other K-bearing minerals in fault gouges, which results in mixed ages of repeatedly reactivated faults as well as grain-size dependent age variations. Here we present a new approach to resolve fault reactivation histories by applying high-spatial resolution Rb-Sr dating to fine-grained mineral slickenfibres in faults occurring in Paleoproterozoic crystalline rocks. Slickenfibre illite and/or K-feldspar together with co-genetic calcite and/or albite were targeted with 50 µm laser ablation triple quadrupole inductively coupled plasma mass spectrometry analyses (LA-ICP-MS/MS). The ages obtained disclose slickenfibre growth at several occasions spanning over 1 billion years, from at least 1527 Ma to 349 ± 9 Ma. The timing of these growth phases and the associated structural orientation information of the kinematic indicators on the fracture surfaces are linked to far-field tectonic events, including the Caledonian orogeny. Our approach links faulting to individual regional deformation events by minimizing age mixing through micro-scale analysis of individual grains and narrow crystal zones in common fault mineral assemblages.

  • 48. Tillberg, Mikael
    et al.
    Ivarsson, Magnus
    Naturhistoriska riksmuseet, Enheten för paleobiologi.
    Drake, Henrik
    Whitehouse, Martin
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Kooijman, Ellen
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Schmitt, Melanie
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Re-Evaluating the Age of Deep Biosphere Fossils in the Lockne Impact Structure2019Inngår i: GeosciencesArtikkel i tidsskrift (Fagfellevurdert)
  • 49. Troll, Valentin R.
    et al.
    Weis, Franz A.
    Jonsson, Erik
    Andersson, Ulf B.
    Majidi, Seyed Afshin
    Högdahl, Karin
    Harris, Chris
    Millet, Marc-Alban
    Chinnasamy, Sakthi Saravanan
    Kooijman, Ellen
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Nilsson, Katarina P.
    Global Fe–O isotope correlation reveals magmatic origin of Kiruna-type apatite-iron-oxide ores2019Inngår i: Nature Communications, E-ISSN 2041-1723, Vol. 10, nr 1Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Kiruna-type apatite-iron-oxide ores are key iron sources for modern industry, yet their origin remains controversial. Diverse ore-forming processes have been discussed, comprising low-temperature hydrothermal processes versus a high-temperature origin from magma or magmatic fluids. We present an extensive set of new and combined iron and oxygen isotope data from magnetite of Kiruna-type ores from Sweden, Chile and Iran, and compare them with new global reference data from layered intrusions, active volcanic provinces, and established low-temperature and hydrothermal iron ores. We show that approximately 80% of the magnetite from the investigated Kiruna-type ores exhibit δ56Fe and δ18O ratios that overlap with the volcanic and plutonic reference materials (> 800 °C), whereas ~20%, mainly vein-hosted and disseminated magnetite, match the low-temperature reference samples (≤400 °C). Thus, Kiruna-type ores are dominantly magmatic in origin, but may contain late-stage hydrothermal magnetite populations that can locally overprint primary high-temperature magmatic signatures.

  • 50. Tual, Lorraine
    et al.
    Smit, Matthijs A.
    Cutts, Jamie
    Kooijman, Ellen
    Naturhistoriska riksmuseet, Enheten för geovetenskap. Department of Geosciences Swedish Museum of Natural History Stockholm Sweden.
    Kielman-Schmitt, Melanie
    Naturhistoriska riksmuseet, Enheten för geovetenskap.
    Majka, Jarosław
    Foulds, Ian
    Rapid, paced metamorphism of blueschists (Syros, Greece) from laser-based zoned Lu-Hf garnet chronology and LA-ICPMS trace element mapping2022Inngår i: Chemical Geology, ISSN 0009-2541, E-ISSN 1872-6836, Vol. 607, s. 121003-121003, artikkel-id 121003Artikkel i tidsskrift (Fagfellevurdert)
12 1 - 50 of 56
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