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  • 1. Abu El-Enen, M.M.
    et al.
    Abu-Alam, T.S.
    Whitehouse, Martin J.
    Swedish Museum of Natural History, Department of Geology.
    Ali, K.A.
    Okrusch, M.
    P–T path and timing of crustal thickening during amalgamation of East and West Gondwana: A case study from the Hafafit Metamorphic Complex, Eastern Desert of Egypt.2016In: Lithos, ISSN 0024-4937, E-ISSN 1872-6143, Vol. 263, p. 213-238Article in journal (Refereed)
    Abstract [en]

    The southeastern sector of the Hafafit Metamorphic Complex, southern Eastern Desert of Egypt comprises infrastructural orthogneisses of tonalite and syenogranite parentage, amphibolites, and a volcano-sedimentary association. These are overthrust by an obducted suprastructural ophiolite nappes via the Nugrus thrust. The protolith of the biotite–hornblende-gneisses was formed during island-arc accretion, while that of the garnet–biotite gneisses were formed in a within-plate regime, consistent with a transition to a post-collisional setting. The volcano-sedimentary association comprises interbedded and intercalated highly foliated metapelitic schists, metabasites, and leucocratic gneisses, deposited in a back-arc basin. The metapelites and the leucocratic gneisses originated from immature Fe-shales and arkoses derived from intermediate-mafic and acidic igneous rocks, respectively, via weak chemical weathering in a tectonically active island arc terrane. The intercalated amphibolites were derived from tholeiitic basalts generated in a back-arc setting.

    The volcano-sedimentary association was metamorphosed under upper-amphibolite facies conditions with pressures of 9–13 kbar and temperatures of 570–675 °C, as derived from conventional geothermobarometry and pseudosection calculation. A steep, tight clockwise P–T path is constrained and a geothermal gradient around 20 °C/km is estimated for the peak metamorphism. We assume that deformation and metamorphism are due to crustal thickening during the collision of East and West Gondwana, where peak metamorphism took place in the middle to lower crust at 33 km average crustal depth. This was followed by a subsequent quasi-isothermal decompression due to rapid exhumation during wrench tectonics. Sinistral transcurrent shearing with extensional denudation resulted in vertical ductile thinning that was accompanied by heat input from magmatism, as indicated by a higher geothermal gradient during retrograde metamorphism and exhumation of the complex.

    U–Pb data from magmatic zircons yields protolith ages of 731 ± 3 Ma for the biotite–hornblende gneisses and 646 ± 12 Ma for the garnet–biotite gneisses. Conforming to field evidence, our geochronology data point to a depositional age of the volcano-sedimentary cover at around 650 Ma. The age of metamorphism is constrained by a low Th/U ratio of a zircon grain crystallized at an age of 597 ± 6 Ma.

  • 2.
    Alexander, Louise
    et al.
    Birkbeck College, University of London, United Kingdom.
    Snape, Joshua
    Swedish Museum of Natural History, Department of Geology.
    Joy, Katherine
    University of Manchester, United Kingdom.
    Downes, Hilary
    Birkbeck College, University of London, United Kingdom.
    Crawford, Ian
    Birkbeck College, University of London, United Kingdom.
    An analysis of Apollo lunar soil samples 12070,889, 12030,187, and 12070,891: Basaltic diversity at the Apollo 12 landing site and implications for classification of small-sized lunar samples2016In: Meteoritics and Planetary Science, ISSN 1086-9379, E-ISSN 1945-5100, Vol. 51, p. 1654-1677Article in journal (Refereed)
    Abstract [en]

    Lunar mare basalts provide insights into the compositional diversity of the Moon's interior. Basalt fragments from the lunar regolith can potentially sample lava flows from regions of the Moon not previously visited, thus, increasing our understanding of lunar geological evolution. As part of a study of basaltic diversity at the Apollo 12 landing site, detailed petrological and geochemical data are provided here for 13 basaltic chips. In addition to bulk chemistry, we have analyzed the major, minor, and trace element chemistry of mineral phases which highlight differences between basalt groups. Where samples contain olivine, the equilibrium parent melt magnesium number (Mg#; atomic Mg/[Mg + Fe]) can be calculated to estimate parent melt composition. Ilmenite and plagioclase chemistry can also determine differences between basalt groups. We conclude that samples of approximately 1–2 mm in size can be categorized provided that appropriate mineral phases (olivine, plagioclase, and ilmenite) are present. Where samples are fine-grained (grain size <0.3 mm), a “paired samples t-test” can provide a statistical comparison between a particular sample and known lunar basalts. Of the fragments analyzed here, three are found to belong to each of the previously identified olivine and ilmenite basalt suites, four to the pigeonite basalt suite, one is an olivine cumulate, and two could not be categorized because of their coarse grain sizes and lack of appropriate mineral phases. Our approach introduces methods that can be used to investigate small sample sizes (i.e., fines) from future sample return missions to investigate lava flow diversity and petrological significance.

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  • 3. Ali, K.A.
    et al.
    Surour, A.A:
    Whitehouse, Martin J.
    Swedish Museum of Natural History, Department of Geology.
    Andresen, A.
    Single zircon Hf-O isotope constraints on the origin of A-type granites from the Jabal Al-Hassir ring complex, Saudi Arabia.2015In: Precambrian Research, ISSN 0301-9268, E-ISSN 1872-7433, Vol. 256, p. 131-147Article in journal (Refereed)
    Abstract [en]

    The Jabal Al-Hassir ring complex in the southern Arabian Shield is an alkaline granite complex comprising an inner core of biotite granite that outwardly becomes a porphyritic sodic-calcic amphibole (ferrobarroisite–katophorite) granite. A combined study of mineral chemistry and single zircon Hf–O zircon isotope analyses was carried out to infer the magma sources of the Neoproterozoic post-collisional A-type granitoids in Saudi Arabia. The granitic rocks show high positive initial ɛHf(t) values of +7.0 to +10.3 and δ18O values of +5.8‰ to +7.4‰ that are consistent with melting of a juvenile crustal protolith that was formed during the Neoproterozoic assembly of the Arabian-Nubian Shield (ANS). Crustal-model ages (Hf-tNC) of 0.71–0.94 Ga indicate minor contribution from an older continental crust in the formation of the Jabal Al-Hassir granitic rocks (crystallization age = 620 ±3 Ma), but any such component is likely to be Neoproterozoic in age. Temperature and oxygen fugacity (ƒO2) estimates suggested that the Jabal Al-Hassir A-type granite magma was generated at high temperature (820–1050 °C) and low ƒO2. Geochemical characteristics (e.g., low ƒO2), geochronological data, and Hf and O isotope compositions, indicate that the magmas of the Neoproterozoic A-type granites of the Jabal Al-Hassir ring complex were likely generated by crustal partial melting of a juvenile Neoproterozoic lower crustal tholeiitic rocks, following collision between East and West Gondwana in the final stages of the evolution of the Arabian Shield.

  • 4. Al-Khirbash, Salah
    et al.
    Heikal, Mohamed Th. S.
    Whitehouse, Martin J.
    Swedish Museum of Natural History, Department of Geology.
    Windley, Brian F.
    Al Selwi, Khaled
    Evolution and Mineralization of the Precambrian Basement of Yemen2021In: The Geology of the Arabian-Nubian Shield, Regional Geology Reviews / [ed] Z. Hamimi et al. (eds.), Springer, 2021Chapter in book (Refereed)
  • 5. Alroy, John
    et al.
    Bernor, R. L.
    Fortelius, Mikael
    Werdelin, Lars
    Swedish Museum of Natural History, Department of Paleobiology.
    The MN System: regional or continental?1998In: Mitteilungen der Bayerischen Staatssammlung für Paläontologie und historische Geologie, Vol. 38, p. 243-258Article in journal (Refereed)
  • 6. Altieri, Alessandra
    et al.
    Pezzotta, Federico
    Skogby, Henrik
    Swedish Museum of Natural History, Department of Geology.
    Hålenius, Ulf
    Swedish Museum of Natural History, Department of Geology.
    Bosi, Ferdinando
    Blue growth zones caused by Fe2+ in tourmaline crystals from the San Piero in Campo gem-bearing pegmatites, Elba Island, Italy2022In: Mineralogical magazine, ISSN 0026-461X, E-ISSN 1471-8022, Vol. 86, no 6, p. 910-919Article in journal (Refereed)
  • 7. Altieri, Alessandra
    et al.
    Pezzotta, Federico
    Skogby, Henrik
    Swedish Museum of Natural History, Department of Geology.
    Hålenius, Ulf
    Swedish Museum of Natural History, Department of Geology.
    Bosi, Ferdinando
    Dark-coloured Mn-rich overgrowths in an elbaitic tourmaline crystal from the Rosina pegmatite, San Piero in Campo, Elba Island, Italy: witness of late-stage opening of the geochemical system2023In: Mineralogical magazine, ISSN 0026-461X, E-ISSN 1471-8022, Vol. 87, no 1, p. 130-142Article in journal (Refereed)
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  • 8.
    Amano, Kazutaka
    et al.
    Department of Geoscience, Joetsu University of Education, Joetsu, Japan.
    Kiel, Steffen
    Swedish Museum of Natural History, Department of Paleobiology.
    Hryniewicz, Krzysztof
    Institute of Paleobiology, Polish Academy of Sciences, Warszawa, Poland.
    Jenkins, Robert
    College of Science and Engineering, Kanazawa University, Kanazawa, Japan.
    Bivalvia in ancient hydrocarbon seeps2022In: Ancient Hydrocarbon Seeps / [ed] Kaim, Andrzej; Landman, Neil H.; Cochran, J. Kirk, Berlin: Springer Berlin/Heidelberg, 2022, p. 267-321Chapter in book (Refereed)
    Abstract [en]

    Bivalves are an important part of the methane seep fauna ever since seeps appeared in the geologic record. The chronostratigraphic ranges of seep-inhabiting chemosymbiotic bivalves show an overall increase in diversity at seeps since the Paleozoic. The most common group at Paleozoic and early Mesozoic seeps are modiomorphids, with a few additional records of solemyids and anomalodesmatans. The most common infaunal chemosymbiotic bivalve taxa at modern seeps, lucinids and thyasirids, appeared at seeps in the Late Jurassic and earliest Cretaceous. They diversified during the Cretaceous synchronous with the peak of the “Mesozoic Marine Revolution” and first occurrences of gastropod predatory drill holes in the shells of seep-inhabiting bivalves, soon after the appearance of these gastropods in the mid-Cretaceous. The two dominant bivalve clades of the modern vent and seep fauna, bathymodiolins and vesicomyids, appeared in the Eocene. Their origin has been linked to a deep-water extinction event at the Paleocene-Eocene Thermal Maximum. However, the fossil record of chemosymbiotic bivalves at seeps during this time interval does not display any extinction. Rather, the mid-Eocene appearance of semi-infaunal and epifaunal bivalves such as bathymodiolins and vesicomyids might be linked to a dramatic rise in seawater sulfate concentrations at this time.

  • 9. Anand, Rajagopal
    et al.
    Balakrishnan, Srinivasan
    Kooijman, Ellen
    Swedish Museum of Natural History, Department of Geology.
    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, India2014In: Journal of Asian Earth Sciences, ISSN 1367-9120, E-ISSN 1878-5786, Vol. 79, p. 72-85Article in journal (Refereed)
    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.

  • 10.
    Anders, Bebhinn
    et al.
    Earth and Ocean Sciences, School of Natural Sciences, NUI Galway, University Road, Galway, Ireland;Sediment Origins Research Team (SORT), NUI Galway, Ireland.
    Tyrrell, S.
    Earth and Ocean Sciences, School of Natural Sciences, NUI Galway, University Road, Galway, Ireland;Sediment Origins Research Team (SORT), NUI Galway, Ireland;Irish Centre for Research in Applied Geosciences (iCRAG), Ireland.
    Chew, D.
    Department of Geology, Trinity College Dublin, College Green, Dublin 2, Ireland;Irish Centre for Research in Applied Geosciences (iCRAG), Ireland.
    Mark, C.
    Swedish Museum of Natural History, Department of Geology. UCD School of Earth Sciences, University College Dublin, Belfield, Dublin 4, Ireland.
    O'Sullivan, G.
    UCD School of Earth Sciences, University College Dublin, Belfield, Dublin 4, Ireland.
    Murray, J.
    Earth and Ocean Sciences, School of Natural Sciences, NUI Galway, University Road, Galway, Ireland;Irish Centre for Research in Applied Geosciences (iCRAG), Ireland.
    Graham, J.R.
    Department of Geology, Trinity College Dublin, College Green, Dublin 2, Ireland.
    Badenszki, E.
    Irish Centre for Research in Applied Geosciences (iCRAG), Ireland;UCD School of Earth Sciences, University College Dublin, Belfield, Dublin 4, Ireland.
    Spatial variation in provenance signal: identifying complex sand sourcing within a Carboniferous basin using multiproxy provenance analysis2022In: Journal of the Geological Society, ISSN 0016-7649, E-ISSN 2041-479X, Vol. 179, no 1, article id jgs2021-045Article in journal (Refereed)
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  • 11. Anders, Bébhinn
    et al.
    Tyrrell, Shane
    Chew, David
    O’Sullivan, Gary
    Mark, Chris
    Swedish Museum of Natural History, Department of Geology.
    Graham, John
    Badenszki, Eszter
    Murray, John
    Wildfires and Monsoons: Cryptic Drivers for Highly Variable Provenance Signals within a Carboniferous Fluvial System2022In: Geosciences, E-ISSN 2076-3263, Vol. 12, no 1, p. 20-20Article in journal (Refereed)
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  • 12. Andersson, Joel B.H.
    et al.
    Logan, Leslie
    Martinsson, Olof
    Chew, David
    Kooijman, Ellen
    Swedish Museum of Natural History, Department of Geology. Department of Geosciences Swedish Museum of Natural History Stockholm Sweden.
    Kielman-Schmitt, Melanie
    Swedish Museum of Natural History, Department of Geology.
    Kampmann, Tobias C.
    Bauer, Tobias E.
    U-Pb zircon-titanite-apatite age constraints on basin development and basin inversion in the Kiruna mining district, Sweden2022In: Precambrian Research, ISSN 0301-9268, E-ISSN 1872-7433, Vol. 372, p. 106613-106613, article id 106613Article in journal (Refereed)
  • 13. Armands, Gösta
    et al.
    Claesson, Stefan
    Swedish Museum of Natural History, Department of Geology.
    Johansson, Åke
    Swedish Museum of Natural History, Department of Geology.
    Lundqvist, Thomas
    En pionjär inom svensk isotopgeologi. In memoriam, Eric Welin, 1923-20142015In: Geologiskt forum, Vol. 22, no 85, p. 26-27Article in journal (Other (popular science, discussion, etc.))
  • 14. Augustsson, Carita
    et al.
    Rüsing, Tobias
    Niemeyer, Hans
    Kooijman, Ellen
    Swedish Museum of Natural History, Department of Geology.
    Berndt, Jasper
    Bahlburg, Heinrich
    Zimmermann, Udo
    0.3 byr of drainage stability along the Palaeozoic palaeo-Pacific Gondwana margin; a detrital zircon study2015In: Journal of the Geological Society, ISSN 0016-7649, E-ISSN 2041-479X, Vol. 172, p. 186-200Article in journal (Refereed)
    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.

  • 15. BADAWY, AHMED SALAH
    et al.
    Mehlqvist, Kristina
    Vajda, Vivi
    Swedish Museum of Natural History, Department of Paleobiology.
    Ahlberg, Per
    Calner, Mikael
    Late Ordovician (Katian) spores in Sweden: oldest land plant remains from Baltica2014In: GFF, ISSN 1103-5897, E-ISSN 2000-0863, Vol. 136, no 1, p. 16-21Article in journal (Refereed)
    Abstract [en]

    A palynological study of the Ordovician–Silurian boundary (Katian–Rhuddanian) succession in the Röstaånga-1 drillcore, southern Sweden, has been performed. The lithology is dominated by mudstone and graptolitic shale, with subordinate limestone, formed in the deeper marine halo of southernBaltica. The palynological assemblages are dominated by marine microfossils, mainly chitinozoans and acritarchs. Sparse but well-preserved cryptospores, including Tetrahedraletes medinensis, Tetrahedraletes grayii and Pseudodyadospora sp., were encountered in the Lindegård Formation (late Katian–early Hirnantian), with the oldest record just above the first appearance of the graptolite species Dicellograptus complanatus. This represents the earliest record of early land plant spores from Sweden and possibly also from Baltica and implies that land plants had migrated to the palaeocontinent Baltica by at least the Late Ordovician.

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  • 16. Ballirano, Paolo
    et al.
    Skogby, Henrik
    Swedish Museum of Natural History, Department of Geology.
    Gianchiglia, Flaminia
    Di Carlo, Maria Cristina
    Campopiano, Antonella
    Cannizzaro, Annapaola
    Olori, Angelo
    Pacella, Alessandro
    Chemical and structural characterization of UICC amosite fibres from Penge mine (South Africa)2022In: Periodico di Mineralogia, ISSN 0369-8963, E-ISSN 2239-1002, Vol. 91, p. 143-154Article in journal (Refereed)
  • 17. Barnes, Christopher J.
    et al.
    Bukała, Michał
    Callegari, Riccardo
    Walczak, Katarzyna
    Kooijman, Ellen
    Swedish Museum of Natural History, Department of Geology. Department of Geosciences Swedish Museum of Natural History Stockholm Sweden.
    Kielman-Schmitt, Melanie
    Swedish Museum of Natural History, Department of Geology.
    Majka, Jarosław
    Zircon and monazite reveal late Cambrian/early Ordovician partial melting of the Central Seve Nappe Complex, Scandinavian Caledonides2022In: Contributions to Mineralogy and Petrology, ISSN 0010-7999, E-ISSN 1432-0967, Vol. 177, no 9, article id 92Article in journal (Refereed)
  • 18.
    Barnes, Christopher
    et al.
    Faculty of Geology, Geophysics and Environmental Protection, AGH University of Science and Technology, Kraków, Poland.
    Jarosław, Majka
    Department of Earth Sciences, Uppsala University, Uppsala, Sweden.
    Schneider, David
    Department of Earth and Environmental Sciences, University of Ottawa, Ottawa, Canada.
    Walczak, Katarzyna
    Faculty of Geology, Geophysics and Environmental Protection, AGH University of Science and Technology, Kraków, Poland.
    Bukała, Michał
    Faculty of Geology, Geophysics and Environmental Protection, AGH University of Science and Technology, Kraków, Poland.
    Kośmińska, Karolina
    Faculty of Geology, Geophysics and Environmental Protection, AGH University of Science and Technology, Kraków, Poland.
    Tokarski, Tomasz
    Academic Center for Materials and NanotechnologyAGH University of Science and TechnologyKrakówPoland.
    Karlsson, Andreas
    Swedish Museum of Natural History, Department of Geology.
    High-spatial resolution dating of monazite and zircon reveals the timing of subduction–exhumation of the Vaimok Lens in the SeveNappe Complex (Scandinavian Caledonides)2019In: Contributions to Mineralogy and Petrology, ISSN 0010-7999, E-ISSN 1432-0967, Vol. 174, no 1, article id 5Article in journal (Refereed)
    Abstract [en]

    In-situ monazite Th–U–total Pb dating and zircon LA–ICP–MS depth-profiling was applied to metasedimentary rocks from the Vaimok Lens in the Seve Nappe Complex (SNC), Scandinavian Caledonides. Results of monazite Th–U–total Pb dating, coupled with major and trace element mapping of monazite, revealed 603 ± 16 Ma Neoproterozoic cores surrounded byrims that formed at 498 ± 10 Ma. Monazite rim formation was facilitated via dissolution–reprecipitation of Neoproterozoic monazite. The monazite rims record garnet growth as they are depleted in Y2O3 with respect to the Neoproterozoic cores. Rims are also characterized by relatively high SrO with respect to the cores. Results of the zircon depth-profiling revealed igneous zircon cores with crystallization ages typical for SNC metasediments. Multiple zircon grains also exhibit rims formedby dissolution–reprecipitation that are defined by enrichment of light rare earth elements, U, Th, P, ± Y, and ± Sr. Rims also have subdued Eu anomalies (Eu/Eu* ≈ 0.6–1.2) with respect to the cores. The age of zircon rim formation was calculated from three metasedimentary rocks: 480 ± 22 Ma; 475 ± 26 Ma; and 479 ± 38 Ma. These results show that both monazite and zircon experienced dissolution–reprecipitation under high-pressure conditions. Caledonian monazite formed coeval with garnet growth during subduction of the Vaimok Lens, whereas zircon rim formation coincided with monazite breakdown to apatite, allanite and clinozoisite during initial exhumation.

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  • 19.
    Bellucci, Jeremy
    et al.
    Swedish Museum of Natural History, Department of Geology.
    Nemchin, Alexander
    Grange, Marion
    Collins, Gareth
    Whitehouse, Martin
    Swedish Museum of Natural History, Department of Geology.
    Snape, Joshua
    Norman, Marc
    Kring, David
    Terrestrial-like zircon in an Apollo 14 breccia.2019In: Earth and Planetary Science Letters, ISSN 0012-821X, E-ISSN 1385-013X, Vol. 510, p. 173-185Article in journal (Refereed)
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  • 20.
    Bellucci, Jeremy
    et al.
    Swedish Museum of Natural History, Department of Geology.
    Whitehouse, Martin J.
    Swedish Museum of Natural History, Department of Geology.
    Nemchin, Alexander
    Pidgeon, Robert
    Grange, Marion
    Reddy, Steven
    Timms, Nick
    A scanning ion imaging investigation into the micron-scale U-Pb systematics in a complex lunar zircon2016In: Chemical Geology, ISSN 0009-2541, E-ISSN 1872-6836, Vol. 438, p. 112-122Article in journal (Refereed)
    Abstract [en]

    The full U-Pb isotopic systematics in a complex lunar zircon ‘Pomegranate’ from lunar impact breccia 73235 have been investigated by the development of a novel Secondary Ion Mass Spectrometry (SIMS) scanning ion imaging (SII) technique. This technique offers at least a four-fold increase in analytical spatial resolution over traditional SIMS analyses in zircon. Results from this study confirm the hypothesis that the Pomegranate zircon crystallized at 4.302 ± 0.013 Ga and experienced an impact that formed, U-enriched zircon around primary zircon cores at 4.184 ± 0.007 Ga (2σ, all uncertainties). The increase in spatial resolution offered by this technique has facilitated targeting of primary zircon that was previously inaccessible to conventional spot analyses. This approach has yielded results indicating that individual grains with a diffusive distance of less than ~4 μm have been reset to the young impact age, while individual grains with a diffusive distance larger than ~6 μm have retained the old crystallization age. Assuming a broad range in cooling rate of 0.5–50 °C/year, which has been observed in a suite of similar lunar breccias, a maximum localized temperature generated by the impact that reset small prima- ry zircon and created new, high-U zircon is estimated to be between 1100 and 1280 °C.

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  • 21.
    Bellucci, Jeremy
    et al.
    Swedish Museum of Natural History, Department of Geology.
    Whitehouse, Martin
    Swedish Museum of Natural History, Department of Geology.
    Snape, Joshua
    Swedish Museum of Natural History, Department of Geology.
    Nemchin, Alexander
    A Pb isotopic resolution to the Martian meteorite age paradox2016In: Earth and Planetary Science Letters, ISSN 0012-821X, E-ISSN 1385-013X, Vol. 433, p. 241-248Article in journal (Refereed)
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  • 22.
    Bellucci, Jeremy
    et al.
    Swedish Museum of Natural History, Department of Geology.
    Whitehouse, Martin
    Swedish Museum of Natural History, Department of Geology.
    Snape, Joshua
    Swedish Museum of Natural History, Department of Geology.
    Nemchin, Alexander
    The Pb isotopic evolution of the Martian mantle constrained by initial Pb in Martian meteorites2015In: Journal of Geophysical Research - Planets, ISSN 2169-9097, E-ISSN 2169-9100, Vol. 120, p. 2224-2240Article in journal (Refereed)
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  • 23.
    Bengtson, Stefan
    Swedish Museum of Natural History, Department of Paleobiology.
    Presentation of the 2010 Charles Schuchert Award of the Paleontological Society to Philip C. J. Donoghue.2011In: Journal of Paleontology, ISSN 0022-3360, E-ISSN 1937-2337, Journal of Paleontology, Vol. 85, no 5, p. 1015-Article in journal (Refereed)
    Abstract [en]

    LADIES AND gentlemen, friends and colleagues, the winner of the 2010 Charles Schuchert Award is Professor Philip Donoghue of the University of Bristol. In the natural progression of our personal lives, the transition from young snot to old fart is so gradual that one tends not to recognize it, least of all in oneself. Most of us— those further along in their careers— have passed through the stage of young, promising paleontologist to become middleaged promising paleontologists. Not so Phil Donoghue. I first met him when he was a graduate student at the University of Leicester. We got into a discussion about the nature of conodonts and certain pet ideas of mine that I had published. Phil did not agree with me so he went down in my book as a young snot. Soon thereafter, he published a ground-breaking, paradigm-changing paper, together with Peter Forey and Dick Aldridge, on the phylogenetic position of conodonts. Now, I realized that it was I who was the old fart. Phil had demonstrated that he had skipped the young-and-promising stage. He was, and is, young and delivering. Most people who start working on conodonts tend to remain with them. There is something about that mouth apparatus and the way in which it grabs hold of you. But Phil quickly tore himself loose from its grip. He quickly demonstrated an unquenchable zeal in attacking central issues in evolutionary paleontology, such as the origin of microstructures in teeth, the origin of teeth in jaws, the origin of jaws in vertebrates, the origin of vertebrates among animals, the origin of animals in the biosphere, and so on. I fear he will not stop until he has solved the question of the origin of life, the universe, and everything else. The breadth of questions he has already addressed is one aspect of Phil’s work. The diversity of tools he brings to bear on them is another. There is a lot of grinding powder under his fingernails, and lots of devo in his evo. After a sabbatical at the University of Bath, where he seems to have broken every rule of the Sabbath, he came out as a full-fledged molecular biologist, with RNA libraries at his fingertips. He is at the forefront in marrying data from living organisms with that from fossil taxa in phylogenetic analyses. Recently, he came out in defense of the paraphyletic stem group with arguments such that I have high hopes for his post-Schuchert development. Yes, paraphyletic groups are much more interesting than the monophyletic dead-ends called clades, although Phil of course refuses to call them groups. When Phil and some colleagues published a paper in Nature on the Cambrian fossil embryo Markuelia (again showing me wrong on a central issue), it caught the eye of Marco Stampanoni, a physicist who works at the Swiss Light Source (SLS) synchrotron near Zu¨ rich, in Switzerland. Marco had been developing methods of X-ray microtomography, using SLS beamlines. He contacted Phil with a proposal to collaborate, and Phil contacted me. Now, our collaboration based on this revolutionary technique, with Phil at the forefront, has opened our eyes to a huge amount of information to which we did not have access only a few years ago. Taphonomy is like the weather, people speak about it, but few do anything about it. But if you neglect it, you are in deep peril. Phil is much more concerned about taphonomy than most colleagues I know, and he does something about it. He started a project with embryologist Rudy Raff to determine how bacteria go about decomposing embryos in ways such that they are upgraded to exquisite fossils. He is engaging many colleagues, post-docs and students in the investigation of these processes and their end results. As a result, we are gaining insight into how bacteria can invade, devour and faithfully replicate intracellular features, and how different populations of bacteria play different roles in the process. An intriguing observation has emerged from Phil’s taphonomic work with Mark Purnell. Taphonomic degradation tends to bring about a stemward slippage of taxa in their apparent phylogenetic relationships, on account of sequential disappearance of preserved apomorphies. The general significance of this observation has still to be tested, but its potential importance for the phylogenetic analysis of fossils is obvious. Phil is leading an amazingly diverse and successful program in paleontology at the University of Bristol, permeated by his holistic approach and addressing everything from organismbased paleontology to molecular biology. Molecular, organismic, orgiastic paleontology—that’s the realm of Phil Donoghue. Mr. President, please hand the Schuchert Award for 2010 over to Phil. He thoroughly deserves it.

  • 24.
    Bengtson, Stefan
    Swedish Museum of Natural History, Department of Paleobiology.
    Presentation of the 2010 Paleontological Society Medal to Bruce Runnegar.2011In: Journal of Paleontology, ISSN 0022-3360, E-ISSN 1937-2337, Journal of Paleontology, Vol. 85, no 5, p. 1012-Article in journal (Refereed)
    Abstract [en]

    Ladies and gentlemen, friends and colleagues, the 2010 Paleontological Society Medal is awarded to Professor Bruce Runnegar of the University of California at Los Angeles. Preparing for this presentation, I got hold of a list of Bruce’s invited lectures, given during the past ten years. There are 86 titles on almost as many subjects. I will mention what these presentations were about, so you can get an impression of this Renaissance mind: Carbon isotopes and ocean evolution; Precambrian–Cambrian stratigraphy; Molecular evolution and the fossil record; Ediacaran organisms; Life on Mars; Oxygen and metazoan evolution; Orbital dynamics of the Earth–Moon system; Snowball Earth; Multiplated mollusks; Mass-independent fractionation of sulfur; Biomineralization; The Cambrian Explosion; Geobiology in the Archean; Cross-calibration of geological and astronomical time scales; Origins of biological complexity; Astrobiology of the Earth; Astrobiology of everything else; The Acraman impact of the Ediacaran; Biosignatures in ancient rocks; Microbial metabolism in the Early Archean. Now, most people can waffle about almost anything. A good teacher can read up on such topics and deliver useful lectures on them to students. But, as you will know if you are the least bit familiar with Bruce’s work, these are nearly all topics in fields where he has made startlingly innovative and pioneering contributions. Some would say that his most important contributions are missing from this list, such as molecular paleobiology, for example, or—if you prefer more tangible fossils—the systematics and evolution of Cambrian and Permian mollusks. But what is represented on the list is sufficient to document several brilliant careers in science: Bruce broke new ground in understanding the biomineralization processes of early mollusks by working with natural phosphatic replicas of the now vanished crystals of various species of calcium carbonate. He published a seminal set of papers on the evolution of the earliest mollusks, together with his longtime friend John Pojeta. And, as a leader of the astrobiology movement, Bruce has not only inspired everyone to start looking at life in a universal context, he has also brought his visions to life as Director of NASA’s Astrobiology Institute. It was in this context that Bruce was formally transformed from a U.S.-based Aussie to a full-fledged Australian– American (which is, I think, the politically correct term). In reference to molecular paleontology, I have some personal recollections. Bruce and I both have backgrounds as editors of paleontological journals. Bruce founded and for several years edited the successful Australasian journal Alcheringa, which is still going strong. Some of my first interactions with Bruce occurred in the 1970s, when he submitted manuscripts to Lethaia, of which I was an editor. One of my early forays was to question the number of authors of one of these manuscripts. I knew that no less than five authors of a single paper was excessive and confronted Bruce with this. It may have been the first time I really annoyed him, as he politely told me not to forget to turn my brain on, next time I wrote to him. Well, recently I saw an article in Nature with 230 authors, at which point it finally became clear to me that Bruce was ahead of his time. But back in those times I was a wee bit miffed, so when Bruce sent me a manuscript in which he estimated geological ages of major animal lineages using molecular clock techniques, I knew I could get my revenge. I sent the paper out for review by the sharpest molecular biologists of the day, smugly expecting to receive patronizing comments about paleontologists who should stick to their snail shells rather than pretending to be real scientists. No such luck. The reviews that came in were extravagant in their praise of the paper. Published in 1982, it predated by almost 15 years the avalanche of contributions that later came out on this topic. As usual, Bruce was ahead of the pack, but when others reached the spot where he had stood 15 years earlier, he wasn’t there anymore. Discrepancies between molecular and fossil data for a while seemed insurmountable, not to mention the discrepancies between different sets of molecular data and different sorts of analyses. But Bruce had inspired a bright set of younger biologists and paleontologists to refine their calculations. When the dust settled, one of those with whom Bruce had shared his spark, Kevin Peterson, was able to show that there is no significant conflict between the dates provided by fossils and by molecules. But I mentioned molecular paleontology. In 1986, Bruce published a seminal paper with just that title. In it he expressed his credo, thus: ‘‘palaeontologists should use all available sources of information to understand the evolution of life and its effect on the planet.’’ These are not empty words; they present a formidable challenge. Like all splendid visions, they stake out a direction rather than a goal. That it is possible to pursue this vision we see from the example set by this year’s Schuchert Award winner, Phil Donoghue, who together with Kevin Peterson and Roger Summons wrote a stimulating twenty-first century follow-up to Bruce’s earlier paper. But the foremost example is Bruce Runnegar himself. Here is a taste of the way in which his productive mind works. In 1982, Bruce used the anatomy and hypothesized physiology of the Ediacaran fossil Dickinsonia to estimate constraints for ambient oxygen levels in the Ediacaran atmosphere. This paper is much cited, and geochemists are only now catching up with him, developing geochemical proxies to test the hypothesis that a rising oxygen level was a trigger for the Cambrian Explosion, or, as Bruce so aptly put it, that one ‘‘ingredient, as in most explosives, may well have been a strong oxidising agent.’’ Finally, consider another example. In 1998, Bruce published a cladistic analysis of glaciogenic sediments, testing and corroborating the hypothesis that there were only two major Neoproterozoic glaciations, a result that still seems to stand. Who but Bruce would have thought of such a preposterous idea, using cladistics to resolve a stratigraphical conundrum? Bruce Runnegar has, over the years, formed collegial bonds with many scientists. The many younger people inspired by him include Phil Donoghue, now standing on Bruce’s shoulders. Bruce himself has stood on the shoulders of other giants, as he is quick to acknowledge. But, like Sir Isaac Newton, he has no reason to be bashful about his success, and I don’t think he is. The Paleontological Society Medal was really made for Bruce Runnegar, so please, Mr. President, give it to him!

  • 25.
    Bengtson, Stefan
    et al.
    Swedish Museum of Natural History, Department of Paleobiology.
    Collins, Desmond
    Chancelloriids of the Cambrian Burgess Shale2015In: Palaeontologia Electronica, ISSN 1935-3952, E-ISSN 1094-8074, Vol. 18, no 1, p. 1-67Article in journal (Refereed)
    Abstract [en]

    The cactus-like chancelloriids from the Middle Cambrian Burgess Shale are revised on the basis of Walcott’s (1920) original collections and new material containing several hundred specimens collected by Royal Ontario Museum field expeditions from 1975 to 2000. Walcott’s interpretation of chancelloriids as sponges was based on a misinterpretation of the dermal coelosclerites as embedded sponge-type spicules, an interpretation that further led to the lumping of three distinct taxa into one species, Chancelloria eros Walcott, 1920. The other two taxa are herein separated from C. eros and described as Allonnia tintinopsis n.sp. and Archiasterella coriacea n.sp., all belonging to the Family Chancelloriidae Walcott, 1920. Chancelloriids were sedentary animals, anchored to shells or lumps of debris in the muddy bottom, or to sponges, or to other chancelloriids. They had a radially symmetrical body and an apical orifice surrounded by a palisade of modified sclerites. Well-preserved integuments in Al. tintinopsis and Ar. coriacea do not show any ostium-like openings. Neither is there any evidence for internal organs, such as a gut. Partly narrowed specimens suggest that the body periodically contracted from the attached end to expel waste material from the body cavity. Chancelloriids were close in organization to cnidarians but shared the character of coelosclerites with the bilaterian halkieriids and siphogonuchitids. The taxon Coeloscleritophora is most likely paraphyletic.

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  • 26.
    Bengtson, Stefan
    et al.
    Swedish Museum of Natural History, Department of Paleobiology.
    Cunningham, John A.
    Yin, Chongyu
    Donoghue, Philip C.J.
    University of Bristol.
    A merciful death for the “earliest bilaterian,” Vernanimalcula.2012In: Evolution and Development, ISSN 1520-541x, Vol. 14, no 5, p. 421-427Article in journal (Refereed)
    Abstract [en]

    Fossils described as Vernanimalcula guizhouena, from the nearly 600 million-year-old Doushantuo Formation in South China, have been interpreted as the remains of bilaterian animals. As such they would represent the oldest putative record of bilaterian animals in Earth history, and they have been invoked in debate over this formative episode of early animal evolution. However, this interpretation is fallacious. We review the evidential basis of the biological interpretation of Vernanimalcula, concluding that the structures key to animal identity are effects of mineralization that do not represent biological tissues, and, furthermore, that it is not possible to derive its anatomical reconstruction on the basis of the available evidence. There is no evidential basis for interpreting Vernanimalcula as an animal, let alone a bilaterian. The conclusions of evolutionary studies that have relied upon the bilaterian interpretation of Vernanimalcula must be called into question.

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  • 27.
    Bengtson, Stefan
    et al.
    Swedish Museum of Natural History, Department of Paleobiology.
    Ivarsson, Magnus
    Swedish Museum of Natural History, Department of Paleobiology.
    Astolfo, Alberto
    Paul Scherrer Institute.
    Belivanova, Veneta
    Swedish Museum of Natural History, Department of Paleobiology.
    Broman, Curt
    Stockholm University.
    Marone, Federica
    Paul Scherrer Institute.
    Stampanoni, Marco
    ETH Zürich.
    Deep-biosphere consortium of fungi and prokaryotes in Eocene sub-seafloor basalts.2014In: Geobiology, ISSN 1472-4677, E-ISSN 1472-4669, Vol. 12, no 6, p. 489-496Article in journal (Refereed)
    Abstract [en]

    The deep biosphere of the subseafloor crust is believed to contain a significant part of Earth’s biomass, but because of the difficulties of directly observing the living organisms, its composition and ecology are poorly known. We report here a consortium of fossilized prokaryotic and eukaryotic microorganisms, occupying cavities in deep-drilled vesicular basalt from the Emperor Seamounts, Pacific Ocean, 67.5 meters below seafloor (mbsf). Fungal hyphae provide the framework on which prokaryote-like organisms are suspended like cobwebs and iron-oxidizing bacteria form microstromatolites (Frutexites). The spatial interrelationships show that the organisms were living at the same time in an integrated fashion, suggesting symbiotic interdependence. The community is contemporaneous with secondary mineralizations of calcite partly filling the cavities. The fungal hyphae frequently extend into the calcite, indicating that they were able to bore into the substrate through mineral dissolution. A symbiotic relationship with chemoautotrophs, as inferred for the observed consortium, may be a prerequisite for the eukaryotic colonization of crustal rocks. Fossils thus open a window to the extant as well as the ancient deep biosphere.

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  • 28.
    Bengtson, Stefan
    et al.
    Swedish Museum of Natural History, Department of Paleobiology.
    Rasmussen, Birger
    Curtin University.
    Ivarsson, Magnus
    Swedish Museum of Natural History, Department of Paleobiology.
    Muhling, Janet
    Curtin University.
    Broman, Curt
    Stockholm University.
    Marone, Federica
    Stampanoni, Marco
    Bekker, Andrey
    University of California Riverside.
    Fungus-like mycelial fossils in 2.4-billion-year-old vesicular basalt.2017In: Nature Ecology & Evolution, ISSN 2397-334X, Vol. 1, no 6, p. 1-6, article id 0141Article in journal (Refereed)
    Abstract [en]

    Fungi have recently been found to comprise a significant part of the deep biosphere in oceanic sediments and crustal rocks. Fossils occupying fractures and pores in Phanerozoic volcanics indicate that this habitat is at least 400 million years old, but its origin may be considerably older. A 2.4-billion-year-old basalt from the Palaeoproterozoic Ongeluk Formation in South Africa contains filamentous fossils in vesicles and fractures. The filaments form mycelium-like structures growing from a basal film attached to the internal rock surfaces. Filaments branch and anastomose, touch and entangle each other. They are indistinguishable from mycelial fossils found in similar deep-biosphere habitats in the Phanerozoic, where they are attributed to fungi on the basis of chemical and morphological similarities to living fungi. The Ongeluk fossils, however, are two to three times older than current age estimates of the fungal clade. Unless they represent an unknown branch of fungus-like organisms, the fossils imply that the fungal clade is considerably older than previously thought, and that fungal origin and early evolution may lie in the oceanic deep biosphere rather than on land. The Ongeluk discovery suggests that life has inhabited submarine volcanics for more than 2.4 billion years.

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  • 29.
    Bengtson, Stefan
    et al.
    Swedish Museum of Natural History, Department of Paleobiology.
    Rasmussen, Birger
    School of Earth Sciences, The University of Western Australia, Perth.
    Zi, Jian-Wei
    State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, Wuhan.
    Fletcher, Ian R.
    School of Earth Sciences, The University of Western Australia, Perth.
    Gehling, James G.
    Palaeontology, South Australian Museum, Adelaide.
    Runnegar, Bruce
    Department of Earth, Planetary and Space Sciences, University of California, Los Angeles.
    Eocene animal trace fossils in 1.7-billion-year-old metaquartzites2021In: Proceedings of the National Academy of Sciences of the United States of America, ISSN 0027-8424, E-ISSN 1091-6490, Vol. 118, no 40, p. 1-8, article id e2105707118Article in journal (Refereed)
    Abstract [en]

    The Paleoproterozoic (1.7 Ga [billion years ago]) metasedimentary rocks of the Mount Barren Group in southwestern Australia contain burrows indistinguishable from ichnogenera Thalassinoides, Ophiomorpha, Teichichnus, and Taenidium, known from firmgrounds and softgrounds. The metamorphic fabric in the host rock is largely retained, and because the most resilient rocks in the sequence, the metaquartzites, are too hard for animal burrowing, the trace fossils have been interpreted as predating the last metamorphic event in the region. Since this event is dated at 1.2 Ga, this would bestow advanced animals an anomalously early age. We have studied the field relationships, petrographic fabric, and geochronology of the rocks and demonstrate that the burrowing took place during an Eocene transgression over a weathered regolith. At this time, the metaquartzites of the inundated surface had been weathered to friable sandstones or loose sands (arenized), allowing for animal burrowing. Subsequent to this event, there was a resilicification of the quartzites, filling the pore space with syntaxial quartz cement forming silcretes. Where the sand grains had not been dislocated during weathering, the metamorphic fabric was seemingly restored, and the rocks again assumed the appearance of hard metaquartzites impenetrable to animal burrowing.

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  • 30.
    Bengtson, Stefan
    et al.
    Swedish Museum of Natural History, Department of Paleobiology.
    Sallstedt, Therese
    Swedish Museum of Natural History, Department of Paleobiology.
    Belivanova, Veneta
    Swedish Museum of Natural History, Department of Paleobiology.
    Whitehouse, Martin
    Swedish Museum of Natural History, Department of Geology.
    Three-dimensional preservation of cellular and subcellular structures suggests 1.6 billion-year-old crown-group red algae2017In: PLoS biology, ISSN 1544-9173, E-ISSN 1545-7885, Vol. 15, no 3, p. 1-38, article id e2000735Article in journal (Refereed)
    Abstract [en]

    The ~1.6 Ga Tirohan Dolomite of the Lower Vindhyan in central India contains phosphatized stromatolitic microbialites. We report from there uniquely well-preserved fossils interpreted as probable crown-group rhodophytes (red algae). The filamentous form Rafatazmia chitrakootensis n. gen, n. sp. has uniserial rows of large cells and grows through diffusely distributed septation. Each cell has a centrally suspended, conspicuous rhomboidal disk interpreted as a pyrenoid. The septa between the cells have central structures that may represent pit connections and pit plugs. Another filamentous form, Denaricion mendax n. gen., n. sp., has coin-like cells reminiscent of those in large sulfur-oxidizing bacteria but much more recalcitrant than the liquid-vacuole-filled cells of the latter. There are also resemblances with oscillatoriacean cyanobacteria, although cell volumes in the latter are much smaller. The wider affinities of Denaricion are uncertain. Ramathallus lobatus n. gen., n. sp. is a lobate sessile alga with pseudoparenchymatous thallus, “cell fountains,” and apical growth, suggesting florideophycean affinity. If these inferences are correct, Rafatazmia and Ramathallus represent crown-group multicellular rhodophytes, antedating the oldest previously accepted red alga in the fossil record by about 400 million years.

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  • 31. Bennike, Ole
    et al.
    Hedenäs, Lars
    Swedish Museum of Natural History, Department of Botany.
    High, Kirsty
    Korshöj, Joakim S.
    Lemdahl, Geoffrey
    Penkman, Kirsty
    Preece, Richard C.
    Rosenlund, Knud
    Viehlberg, Finn A.
    New interglacial deposits from Copenhagen, Denmark:marine Isotope Stage 72018In: Boreas, ISSN 0300-9483, E-ISSN 1502-3885, Vol. 48, p. 107-118Article in journal (Refereed)
  • 32. Bergemann, Christian A
    et al.
    Gnos, Edwin
    Berger, Alfons
    Janots, Emilie
    Whitehouse, Martin J.
    Swedish Museum of Natural History, Department of Geology.
    Dating tectonic activity in the Lepontine Dome and Rhone-Simplon Fault regions through hydrothermal monazite-(Ce)2020In: Solid Earth, ISSN 1869-9510, E-ISSN 1869-9529, Vol. 11, no 1, p. 199-222Article in journal (Refereed)
  • 33. Bernardi, Francesco
    et al.
    Skogby, Henrik
    Swedish Museum of Natural History, Department of Geology.
    Lenaz, Davide
    University of Trieste.
    OH-Defects in Detrital Quartz Grains from the Julian Basin (NE Italy and Slovenia): A Fourier Transform Infrared Study2022In: Geosciences, E-ISSN 2076-3263, Vol. 12, article id 90Article in journal (Refereed)
  • 34. Betts, Marissa, J.
    et al.
    Claybourn, Thomas M.
    Brock, Glenn, A.
    Jago, James, B.
    Skovsted, Christian
    Swedish Museum of Natural History, Department of Paleobiology.
    Paterson, John, R.
    Shelly fossils from the lower Cambrian White Point Conglomerate, Kangaroo Island, South Australia2019In: Acta Palaeontologica Polonica, ISSN 0567-7920, E-ISSN 1732-2421, Vol. 64, no 3, p. 489-522Article in journal (Refereed)
    Abstract [en]

    The lower Cambrian (Series 2) White Point Conglomerate (WPC) on Kangaroo Island, South Australia contains exoticclasts representing a diverse array of lithologies, including metamorphics, chert, sandstone, and abundant carbonates,notably archaeocyath-rich bioclastic limestone. Acetic acid digestion of the WPC bioclastic limestone clasts reveals adiverse shelly fauna. This assemblage includes abundant organophosphatic brachiopods such as Cordatia erinae Brockand Claybourn gen. et sp. nov., Curdus pararaensis, Eodicellomus elkaniformiis, Eohadrotreta sp. cf. E. zhenbaensis,Eoobolus sp., Kyrshabaktella davidii, and Schizopholis yorkensis. Additional shelly taxa include the solenopleurid trilobiteTrachoparia? sp., the tommotiids Dailyatia odyssei, Dailyatia decobruta Betts sp. nov., Kelanella sp., and Lapworthellafasciculata, spines of the bradoriid arthropod Mongolitubulus squamifer, and several problematica, such as Stoibostrombuscrenulatus and a variety of tubular forms. The upper age limit for the WPC is constrained by biostratigraphic data fromthe overlying Marsden Sandstone and Emu Bay Shale, which are no younger than the Pararaia janeae Trilobite Zone(Cambrian Series 2, Stage 4). The shelly fossil assemblage from the WPC limestone clasts indicates an upper Dailyatiaodyssei Zone (= Pararaia tatei to lower P. janeae trilobite zones), equivalent to the Atdabanian–early Botoman of theSiberian scheme. This contrasts with the previously suggested late Botoman age for the limestone clasts, based on the diversearchaeocyath assemblage. The minor age difference between the WPC and its fossiliferous limestone clasts suggestsrelatively rapid reworking of biohermal buildups during tectonically-active phases of deposition in the Stansbury Basin.

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  • 35. Betts, Marissa, J.
    et al.
    Paterson, John, R.
    Jacquet, Sarah, M.
    Andrew, Anita S.
    Hall, Philip A.
    Jago, James, B.
    Jagodzinski, Elisabeth A.
    Preiss, Wolfgang V.
    Crowley, James L.
    Brougham, Tom
    Mathewson, Ciaran P.
    Garcia-Bellido, Diego C.
    Topper, Timothy, P.
    Skovsted, Christian
    Swedish Museum of Natural History, Department of Paleobiology.
    Brock, Glenn, A.
    Early Cambrian chronostratigraphy and geochronology of South Australia2018In: Earth-Science Reviews, ISSN 0012-8252, E-ISSN 1872-6828, Vol. 185, p. 498-543Article in journal (Refereed)
    Abstract [en]

    The most successful chronostratigraphic correlation methods enlist multiple proxies such as biostratigraphy and chemostratigraphy to constrain the timing of globally important bio- and geo-events. Here we present the first regional, high-resolution shelly fossil biostratigraphy integrated with δ13C chemostratigraphy (and corresponding δ18O data) from the traditional lower Cambrian (Terreneuvian and provisional Cambrian Series 2) of South Australia. The global ZHUCE, SHICE, positive excursions II and III and the CARE are captured in lower Cambrian successions from the Arrowie and Stansbury basins. The South Australian shelly fossil biostratigraphy has a consistent relationship with the δ13C results, bolstering interpretation, identification and correlation of the excursions. Positive excursion II straddles the boundary between the Kulparina rostrata and Micrina etheridgei zones, and the CARE straddles the boundary between the M. etheridgei and Dailyatia odyssei zones, peaking in the lower parts of the latter zone. New CA-TIMS zircon dates from the upper Hawker Group and Billy Creek Formation provide geochronologic calibration points for the upper D. odyssei Zone and corresponding chemostratigraphic curve, embedding the lower Cambrian successions from South Australia into a global chronostratigraphic context. This multi-proxy investigation demonstrates the power of integrated methods for developing regional biostratigraphic schemes and facilitating robust global correlation of lower Cambrian successions from South Australia (part of East Gondwana) with coeval terranes on other Cambrian palaeocontinents, including South and North China, Siberia, Laurentia, Avalonia and West Gondwana.

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  • 36. Betts, Marissa, J.
    et al.
    Paterson, John, R.
    Jago, James, B.
    Jacquet, Sarah, M.
    Skovsted, Christian
    Swedish Museum of Natural History, Department of Paleobiology.
    Topper, Timothy, P.
    Brock, Glenn, A.
    A new lower Cambrian shelly fossil biostratigraphy for South Australia:Reply2017In: Gondwana Research, ISSN 1342-937X, E-ISSN 1878-0571, Vol. 44, p. 262-264Article in journal (Refereed)
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  • 37.
    Betts, Marissa, J.
    et al.
    Department of Biological Sciences, Macquarie University, Sydney, 2109, Australia.
    Paterson, John, R.
    Palaeoscience Research Centre, School of Environmental and Rural Science, University of New England, Armidale, New South Wales 2351, Australia.
    Jago, James, B.
    School of Natural and Built Environments, University of South Australia, Mawson Lakes, South Australia 5095, Australia.
    Jacquet, Sarah, M.
    Department of Biological Sciences, Macquarie University, Sydney, 2109, Australia.
    Skovsted, Christian
    Swedish Museum of Natural History, Department of Paleobiology.
    Topper, Timothy, P.
    Palaeoecosystems Group, Department of Earth Sciences, Durham University, Durham, DH1 3LE, UK.
    Brock, Glenn, A.
    Department of Biological Sciences, Macquarie University, Sydney, 2109, Australia.
    Global correlation of the early Cambrian of South Australia: Shelly faunaof the Dailyatia odyssei Zone2017In: Gondwana Research, ISSN 1342-937X, E-ISSN 1878-0571, Vol. 46, p. 240-279Article in journal (Refereed)
    Abstract [en]

    A lack of well resolved biostratigraphic data has prevented robust regional and global correlation of lower Cambriansuccessions from South Australia. A new early Cambrian biostratigraphy, based on data derived from 21measured stratigraphic sections and drill cores (11 described herein) reveals the abundance and diversity ofshelly fauna from the Arrowie Basin, and the value of early Cambrian “small shelly fossils” (SSF) for biostratigraphicstudies. Here we examine shelly fauna associated with the youngest of three recently establishedbiozones, the Dailyatia odyssei Taxon Range Zone (hereafter D. odyssei Zone), and their correlative potential.The D. odyssei Zone features a diverse suite of tommotiids, organophosphatic brachiopods, bradoriid arthropods,molluscs and phosphatic problematica. This fauna permits strong correlation (often at species-level) with othermajor early Cambrian terranes, particularly Antarctica, South China and Laurentia, and suggest a Cambrian Series2, Stages 3–4 age for the D. odyssei Zone. Bradoriids have proven to be useful biostratigraphic tools. Four newspeciesand three new genera are described herein: Acutobalteus sinuosus gen. et sp. nov., Eozhexiella adnyamathanha gen. etsp. nov., Manawarra jonesi gen. et sp. nov. and Mongolitubulus descensus sp. nov. The description of Eohadrotreta sp.cf. zhenbaensis represents the first occurrence of the acrotretoid brachiopod Eohadrotreta from Australia.

  • 38.
    Betts, Marissa J.
    et al.
    Macquarie University, Sydney, Australia.
    Topper, Timothy P.
    Geological Museum, Copenhagen.
    Valentine, James L.
    Macquarie University, Sydney, Australia.
    Skovsted, Christian
    Swedish Museum of Natural History, Department of Paleobiology.
    Brock, Glenn A.
    Macquarie university, Australia.
    A new early Cambrian bradoriid (Arthropoda) assemblage from the northern Flinders Ranges, South Australia2014In: Gondwana Research, ISSN 1342-937X, E-ISSN 1878-0571, Vol. 25, p. 420-437Article in journal (Refereed)
    Abstract [en]

    A new assemblage of early Cambrian bivalved arthropods (Bradoriida) is described from the Arrowie Syncline in the northern Flinders Ranges, South Australia. The well preserved, largely endemic fauna comprises a total of six taxa (including five new species): Jiucunella phaseloa sp. nov., Jixinlingella daimonikoa sp. nov., Mongolitubulus anthelios sp. nov., Neokunmingella moroensis sp. nov., Phasoia cf. spicata ( Öpik, 1968), and Sinskolutella cuspidata sp. nov. This assemblage is derived from a carbonate sedimentary package representing a high energy, shallow water archaeocyath-Renalcis biohermal facies of Terreneuvian, Stage 2 age which transitions up-section to a more restricted, low energy, intra-shelf lagoonal environment that correlates with a Cambrian Series 2, Stage 3 age. The new taxon J. phaseloa sp. nov., has a first appearance datum (FAD) in shallow water biohermal facies of the Hideaway Well Member of the Wilkawillina Limestone at a level 47 m below the FAD of Pelagiella subangulata which is taken to approximate the base of Series 2, Stage 3 in South Australia. Along with Liangshanella circumbolina, this makes J. phaseloa sp. nov. amongst the oldest bivalved arthropods in South Australia and potentially greater Gondwana. The presence of 25 bradoriid taxa from the early Cambrian of South Australia suggests East Gondwana represents a major centre of origin for the Bradoriida.

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  • 39. Bezenjani, R. Nasiri
    et al.
    Pease, V.
    Whitehouse, Martin J.
    Swedish Museum of Natural History, Department of Geology.
    Shalaby, M. H.
    Kadi, K. A.
    Kozdroj, W.
    Detrital zircon geochronology and provenance of the Neoproterozoic Hammamat Group (Igla Basin), Egypt and the Thalbah Group, NW Saudi Arabia: Implications for regional collision tectonics2014In: Precambrian Research, ISSN 0301-9268, E-ISSN 1872-7433, Vol. 245, p. 225-243Article in journal (Refereed)
  • 40.
    Biagioni, Cristian
    University of Pisa.
    Pasero, Marco
    University of Pisa.
    Bonaccorsi, Elena
    Lepore, Giovanni Orazio
    Zaccarini, Federica
    University of Leoben.
    Skogby, Henrik
    Swedish Museum of Natural History, Department of Geology.
    Crystal-chemistry of sulfates from the Apuan Alps (Tuscany, Italy). VI. Tl-bearingalum-(K) and voltaite from the Fornovolasco mining complex2020In: American Mineralogist, ISSN 0003-004X, E-ISSN 1945-3027, Vol. 105, p. 1088-1098Article in journal (Refereed)
  • 41. Biagioni, Cristian
    et al.
    Bosi, Ferdinando
    Mauro, Daniela
    Skogby, Henrik
    Swedish Museum of Natural History, Department of Geology.
    Dini, Andrea
    Zaccarini, Federica
    Dutrowite, Na(Fe2+2.5Ti0.5)Al6(Si6O18)(BO3)3(OH)3O, a new mineral from the Apuan Alps (Tuscany, Italy): the first member of the tourmaline supergroup with Ti as a species-forming chemical constituent2023In: European journal of mineralogy, ISSN 0935-1221, E-ISSN 1617-4011, Vol. 35, no 1, p. 81-94Article in journal (Refereed)
  • 42. Bicknell, Russell D.C.
    et al.
    Paterson, John, R.
    Caron, Jean-Bernhard
    Skovsted, Christian
    Swedish Museum of Natural History, Department of Paleobiology.
    The gnathobasic spine microstructure of recent and Silurian chelicerates and the Cambrian artiopodan Sidneyia: Functional and evolutionary implications2018In: Arthropod structure & development, ISSN 1467-8039, E-ISSN 1873-5495, Vol. 47, p. 12-24Article in journal (Refereed)
    Abstract [en]

    Gnathobasic spines are located on the protopodal segments of the appendages of various euarthropod taxa, notably chelicerates. Although they are used to crush shells and masticate soft food items, the microstructure of these spines are relatively poorly known in both extant and extinct forms. Here we compare the gnathobasic spine microstructures of the Silurian eurypterid Eurypterus tetragonophthalmus from Estonia and the Cambrian artiopodan Sidneyia inexpectans from Canada with those of the Recent xiphosuran chelicerate Limulus polyphemus to infer potential variations in functional morphology through time. The thickened fibrous exocuticle in L. polyphemus spine tips enables effective prey mastication and shell crushing, while also reducing pressure on nerve endings that fill the spine cavities. The spine cuticle of E. tetragonophthalmus has a laminate structure and lacks the fibrous layers seen in L. polyphemus spines, suggesting that E. tetragonophthalmus may not have been capable of crushing thick shells, but a durophagous habit cannot be precluded. Conversely, the cuticle of S. inexpectans spines has asimilar fibrous microstructure to L. polyphemus, suggesting that S. inexpectans was a competent shell crusher. This conclusion is consistent with specimens showing preserved gut contents containing various shelly fragments. The shape and arrangement of the gnathobasic spines is similar for both L. polyphemusand S. inexpectans, with stouter spines in the posterior cephalothoracic or trunk appendages, respectively.This differentiation indicates that crushing occurs posteriorly, while the gnathobases on anterior appendages continue mastication and push food towards and into the mouth. The results of recent phylogenetic analyses that considered both modern and fossil euarthropod clades show that xiphosurans and eurypterids are united as crown-group euchelicerates, with S. inexpectans placed within more basalartiopodan clades. These relationships suggest that gnathobases with thickened fibrous exocuticle, if not homoplasious, may be plesiomorphic for chelicerates and deeper relatives within Arachnomorpha. This study shows that the gnathobasic spine microstructure best adapted for durophagy has remained remarkably constant since the Cambrian.

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  • 43. Biel, Christina
    et al.
    Subias, Ignacio
    Billström, Kjell
    Swedish Museum of Natural History, Department of Geology.
    Acevedo, Rogelio
    Multi-isotope approach for the identification of metal and fluid sources of the Arroyo Rojo VMS deposit, Tierra del Fuego, Argentina2016In: Ore Geology Reviews, ISSN 0169-1368, E-ISSN 1872-7360Article in journal (Refereed)
  • 44.
    Billström, Kjell
    et al.
    Swedish Museum of Natural History, Department of Geology.
    Broman, Curt
    Larsson, Alfred
    Schersten, Anders
    Schmitt, Melanie
    Swedish Museum of Natural History, Department of Geology.
    Sandstone-hosted Pb-Zn deposits along the margin of the Scandinavian Caledonides and their possible relationship with nearby Pb-Zn vein mineralisation2020In: Ore Geology Reviews, ISSN 0169-1368, E-ISSN 1872-7360Article in journal (Refereed)
    Abstract [en]

    Numerous sandstone-hosted Pb-Zn deposits occur along the present-day erosional front of the eastern Scandinavian Caledonides. The largest deposit is Laisvall (64.3 Mt at 4.0% Pb, 0.6% Zn and 9.0g/t Ag) and since mineralisations generally share similar characteristics (reminding of both SEDEX and MVT-style) the term Laisvall-type has often been used. Typically, mineralised zones occur along sedimentary bedding and consist of disseminated galena and sphalerite and lesser amounts of calcite, fluorite, baryte, pyrite and sericite forming a cement that fill interstitial pores in Neoproterozoic/Eocambrian (e.g. Laisvall) to Cambrian (e.g. Vassbo) sandstones.

    Deposits occur both in autochtonous and allochtonous sedimentary rocks, and a broad consensus exists about their epigenetic nature, their spatial relationships to syn-sedimentary faults and that ore fluids have scavenged metals from the crystalline basement. However, the detailed ore depositional history and the timing of ore deposition have remained more controversial. New analyses aimed to complement earlier Rb-Sr data (crush-leach technique using sphalerite) fail to support a published three-point isochron age of 467±5 Ma. This is probably due to syn-ore mixing between fluids carrying isotopically variable strontium and inherited problems to analyse sphalerite grains that strictly were deposited from a single ore pulse. Tentatively, strontium in the ores originate from a mix of components derived from the basement, seawater and the local sedimentary host sequences. The lead component has highly radiogenic compositions, and data define sub-parallel linear arrays interpreted to essentially represent mixing of isotopically different types of lead released from regional basement rocks.

    There are obvious similarities when comparing features of deposits representing two Pb-Zn ore styles, the sandstone-hosted dissemination and the fracture-controlled mineralisation in the granite-dominated basement occurring further east of the Caledonian margin. These include low temperature brines responsible for mineral deposition, the mineralogy and the nature of Rb-Sr and Pb isotope data. We suggest that these types of mineralisation have a common origin and time of emplacement, but it is elusive to propose a well-constrained age. Nonetheless, field observations and other evidence suggest that ore formation is due to large-scale fluid flow triggered by the transition from an extensional to compressional tectonic setting at about 500 Ma. Connected to this mid-Cambrian stage was the development of syn-sedimentary faults and fractures in the basement and in overlying consolidated sandstones. 

  • 45.
    Billström, Kjell
    et al.
    Swedish Museum of Natural History, Department of Geology. Department of Geological Sciences, Swedish Museum of Natural History, Stockholm, Sweden.
    Söderhielm, Johan
    Geological Survey of Sweden, Malå Office, Uppsala, Sweden.
    Broman, Curt
    Department of Geological Sciences, Stockholm University, Stockholm, Sweden.
    Sundblad, Krister
    Institute of Earth Sciences, Saint Petersburg State University, St Petersburg, Russia.
    Solstad, a Co-Se-bearing copper ore in the Västervik quartzites, Sweden2022In: GFF, ISSN 1103-5897, E-ISSN 2000-0863, p. 1-14Article in journal (Refereed)
  • 46.
    Bindi, Luca
    et al.
    Università degli Studi di Firenze.
    Holtstam, Dan
    Swedish Museum of Natural History, Department of Geology.
    Fantappiè, Giulia
    Università degli Studi di Firenze.
    Andersson, Ulf B
    Luossavaara-Kiirunavaara AB.
    Bonazzi, Paola
    Università degli Studi di Firenze.
    Ferriperbøeite-(Ce), [CaCe3]å=4[Fe3+Al2Fe2+]å=4[Si2O7][SiO4]3O(OH)2, a new mineral of the gatelite supergroup, from the Nya Bastnäs Fe-Cu-REE deposit, Västmanland, Sweden.2018In: European journal of mineralogy, ISSN 0935-1221, E-ISSN 1617-4011, Vol. 30, p. 537-544Article in journal (Refereed)
  • 47.
    Bing, Pan
    et al.
    Nanjing Institute of Geology & Palaeontology.
    Skovsted, Christian
    Swedish Museum of Natural History, Department of Paleobiology.
    Brock, Glenn, A.
    Macquarie University.
    Topper, Timothy, P.
    Swedish Museum of Natural History, Department of Paleobiology.
    Holmer, Lars, E.
    Uppsala Universitet.
    Li, Luoyang
    Swedish Museum of Natural History, Department of Paleobiology.
    Li, Guoxiang
    Nanjing Institute of Geology and Palaeontology.
    Early Cambrian organophosphatic brachiopods from the Xinji Formation, at Shuiyu section, Shanxi Province, North China2020In: Palaeoworld, ISSN 1871-174X, E-ISSN 1875-5887, Vol. 29, p. 512-533Article in journal (Refereed)
    Abstract [en]

    Abundant and diverse small shelly fossils have been reported from Cambrian Series 2 in North China, but the co-occurring brachiopods are still poorly known. Herein, we describe seven genera, five species and two undetermined species of organophosphatic brachiopods including one new genus and new species from the lower Cambrian Xinji Formation at Shuiyu section, located on the southern margin of North China Platform. The brachiopod assemblage comprises one mickwitziid (stem group brachiopoda), Paramickwitzia boreussinaensis n. gen. n. sp., a paterinide, Askepasma toddense Laurie, 1986, an acrotretoid, Eohadrotreta cf. zhenbaensis Li and Holmer, 2004, a botsfordiid, Schizopholis yorkensis (Holmer and Ushatinskaya in Gravestock et al., 2001) and three linguloids, Spinobolus sp., Eodicellomus cf. elkaniiformis Holmer and Ushatinskaya in Gravestock et al., 2001 and Eoobolus sp. This brachiopod assemblage suggests a late Age 3 to early Age 4 for the Xinji Formation and reveals a remarkably strong connection with coeval faunas from East Gondwana, particularly the Hawker Group in South Australia. The high degree of similarity (even at species level) further supports a close palaeogeographic position between the North China Platform and Australian East Gondwana during the early Cambrian as indicated by small shelly fossil data.

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  • 48. Bing, Pan
    et al.
    Skovsted, Christian
    Swedish Museum of Natural History, Department of Paleobiology.
    Sun, Haijing
    Li, Guoxiang
    Biostratigraphical and palaeogeographical implications of Early Cambrian hyoliths from the North China Platform2019In: Alcheringa, ISSN 0311-5518, E-ISSN 1752-0754, Vol. 43, p. 351-380Article in journal (Refereed)
    Abstract [en]

    A succession of diverse hyolith assemblages comprising 10 genera and 14 species are reported from the lower Cambrian Shangwan and Sanjianfang sections of the Xinji Formation, and Xiaomeiyao section of the Houjiashan Formation, which crop out along the southern margin of the North China Platform. Most of the specimens are represented by both conchs and opercula. The identified orthothecids include Conotheca australiensis, Cupitheca holocyclata, C. costellata, Neogloborilus applanatus, N. spinatus, Tegminites hymenodes, Triplicatella disdoma, T. xinjia sp. nov. and Paratriplicatella shangwanensis gen. et sp. nov. The hyolithids comprise Protomicrocornus triplicensis gen. et sp. nov., Microcornus eximius, M. petilus, Parkula bounites and Parakorilithes mammillatus. Some anomalous taxa possess characteristics of both Hyolithida and Orthothecida, such as C. australiensis, Neogloborilus and P. triplicensis. Protomicrocornus may constitute a sister group of other hyolithids. The teeth of Parkula bounites and clavicles of Parakorilithes mammillatus are documented for the first time. The hyolith assemblages from North China are probably coeval, and can be correlated with the Cambrian upper Stage 3–lower Stage 4. Many taxa are also globally distributed and have significant potential for biostratigraphical correlations. In accordance, the hyoliths from North China reveal closest compositional similarities to faunas from eastern Gondwana, and especially South Australia. However, some taxa are shared with Laurentian assemblages suggesting cosmopolitanism, and possibly planktonic larval dispersal.

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  • 49. Bingen, B.
    et al.
    Corfu, F.
    Stein, H.J.
    Whitehouse, Martin J.
    Swedish Museum of Natural History, Department of Geology.
    U-Pb geochronology of the syn-orogenic Knaben molybdenum deposits, Sveconorwegian orogen, Norway2015In: Geological Magazine, ISSN 0016-7568, E-ISSN 1469-5081, Vol. 152, p. 537-556Article in journal (Refereed)
    Abstract [en]

    Paired isotope dilution – thermal ionization mass spectrometry (ID-TIMS) and secondary ion mass spectrometry (SIMS) zircon U–Pb data elucidate geochronological relations in the historically important Knaben molybdenum mining district, Sveconorwegian Orogen, south Norway. This polyphase district provided c. 8.5 Mt of ore with a grade of 0.2%. It consists of mineralized quartz veins, silica-rich gneiss, pegmatites and aplites associated with a heterogeneous, locally sulphide-bearing, amphibolites facies gneiss called Knaben Gneiss, and hosted in a regional-scale monotonous, commonly weakly foliated, granitic gneiss. An augen gneiss at the Knaben I deposit yields a 1257±6 Ma magmatic zircon age, dating the pre-Sveconorwegian protolith of the Knaben Gneiss. Mineralized and non-mineralized granitic gneiss samples at the Knaben II and Kvina deposits contain some 1488–1164 Ma inherited zircon and yield consistent intrusion ages of 1032±4, 1034±6 and 1036±6 Ma. This age links magmatism in the district to the regional 1050–1020 Ma Sirdal I-type granite suite, corresponding to voluminous crustal melting during the Sveconorwegian orogeny. A high-U, low-Th/U zircon rim is present in all samples. It defines several age clusters between 1039±6 and 1009±7 Ma, peaking at c. 1016 Ma and overlapping with a monazite age of 1013±5 Ma. The rim records protracted hydrothermal activity, which started during the main magmatic event and outlasted it. This process was coeval with regional high-grade Sveconorwegian metamorphism. Molybdenum deposition probably started during this event when silica-rich mineralizing fluids or hydrous magmas were released from granite magma batches. An analogy between the Knaben district and shallow, short-lived porphyry Mo deposits is inappropriate.

  • 50. Bingen, B.
    et al.
    Solli, A.
    Viola, G.
    Torgersen, E.
    Sandstad, J.S.
    Whitehouse, Martin J.
    Swedish Museum of Natural History, Department of Geology.
    Røhr, T.
    Ganerød, M.
    Nasuti, A.
    Geochronology of the Palaeoproterozoic Kautokeino Greenstone Belt, Finnmark, Norway: Tectonic implications in a Fennoscandia context.2015In: Norwegian Journal of Geology, Vol. 95, p. 365-396Article in journal (Refereed)
    Abstract [en]

    Zircon U–Pb geochronological data in 18 samples from Finnmarksvidda and one sample from the Repparfjord Tectonic Window, northern Norway, constrain the evolution of the Palaeoproterozoic Kautokeino Greenstone Belt and neighbouring units in a Fennoscandia context. The Jergul Complex is an Archaean cratonic block of Karelian affinity, made of variably gneissic, tonalite–trondhjemite–granodiorite–granite plutonic rocks formed between 2975 ± 10 and 2776 ± 6 Ma. It is associated with the Archaean Goldenvárri greenstone–schist formation. At the base of the Kautokeino Greenstone Belt, the Masi Formation is a typical Jatulian quartzite, hosting a Haaskalehto-type, albite–magnetite-rich, mafic sill dated at 2220 ± 7 Ma. The Likčá and Čáskejas formations represent the main event of basaltic magmatism. A synvolcanic metagabbro dates this magmatism at 2137 ± 5 Ma. The geochemical and Nd isotopic signature of the Čáskejas Formation (eNd = +2.2 ± 1.7) is remarkably similar to coeval dykes intruding the Archaean Karelian Craton in Finland and Russia (eNd = +2.5 ± 1.0). The Čáskejas Formation can be correlated with the Kvenvik Formation in the Alta–Kvænangen Tectonic Window. Two large granite plutons yield ages of 1888 ± 7 and 1865 ± 8 Ma, and provide a maximum age for shearing along two prominent NNW–SSE-oriented shear zones recording Svecokarelian transpression. The Bidjovagge Au–Cu deposit formed around 1886 to 1837 Ma and is also related to this NNW–SSE-oriented shear system. The Ráiseatnu Complex is mainly composed of granitic gneisses formed between 1868 ± 13 and 1828 ± 5 Ma, and containing metasediment rafts and zircon xenocrysts ranging from c. 3100 to 2437 Ma. The Kautokeino Greenstone Belt and Ráiseatnu Complex are interpreted as Palaeoproterozoic, pericontinental, lithospheric domains formed during rifting between Archaean cratonic domains. They accommodated oblique convergence between the Karelian and the Norrbotten Archaean cratons during the Svecokarelian orogeny.

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