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  • 1.
    Agić, Heda
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Palaeobiology.
    Moczydłowska, Małgorzata
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Palaeobiology.
    Canfield, Donald
    University of Southern Denmark .
    Reproductive cyst and operculum formation in the Cambrian-Ordovician galeate-plexus microfossils2016In: GFF, ISSN 1103-5897, E-ISSN 2000-0863, Vol. 138, no 2, p. 278-294Article in journal (Refereed)
    Abstract [en]

    Unicellular organic-walled microfossils from the Cambrian-Ordovician transition in Estonia (ca. 490-480 million years ago) exhibit rare characters reflecting their function as reproductive algal cysts. The studied assemblages record the evolutionary history of phytoplankton in the early Paleozoic Era: novel morphologies appearing through the Cambrian and subsequently diversifying in the Ordovician. Well preserved specimens were extracted following a standard palynological method and studied by light transmitted microscopy. The galeate plexus acritarchs Caldariola, Priscogalea and Stelliferidium have revealed exceptionally preserved morphological elements and a rare structure among both fossil and extant protists – an opening with operculum (lid) in reproductive cysts, in addition to lavish vesicle ornamentation and sculpture. Analogous morphology is observed in the living dasycladalean alga Acetabularia (Chlorophyta), which possesses an intrinsic lid-forming apparatus used during organism’s reproductive stage. Based on the observations on the fossil material and studies on the Acetabularia lid-formation, we propose a model of operculum formation in the galeate plexus microorganisms. Due to strong morphological and ecological similarities between galeate fossils and dasycladalean cysts, and the antiquity of this algal order, galeates may be positioned within green algae, more specifically Dasycladales. Unique morphology of the operculum-bearing microbiota would have required a high degree of intracellular complexity for its development, suggesting that advanced intracellular machinery was present already in the early Paleozoic phytoplankton. Additionally, minute prasinophyte microfossils Reticella corrugata  are reported for the first time in the Upper Cambrian strata. 

  • 2.
    Alexanderson, Helena
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Sub-till glaciofluvial sediments at Hultsfred, South Swedish Upland2010In: GFF, ISSN 1103-5897, E-ISSN 2000-0863, Vol. 132, no 3&4, p. 153-159Article in journal (Refereed)
    Abstract [en]

    In a gravel pit near Hultsfred, at the eastern margin of the South Swedish Upland, gravelly, sandy and silty-sandy beds covered by a thick, strati?ed gravelly diamicton are exposed. Large folds and shear-planes indicate post-depositional deformation of the sorted sediments, which according to OSL dating have a maximum Middle Weichselian (,60 ka) age. The sand and gravel are interpreted as glacio?uvial sediments that were deposited laterally during a Middle Weichselian deglaciation, or possibly subglacially during the Late Weichselian. The large-scale deformation was due to glaciotectonics, caused by an overriding wet-based ice sheet during the last deglaciation. The subglacial hydrostatical pressure was high and led to the formation of downward-injected clastic dykes. A basal till, which forms the cover moraine in the area, caps the succession. The fairly frequent occurrence of sub-till sediments on the South Swedish Upland demonstrates the limited effect of glacial erosion in parts of this area. During the Last Glacial Maximum, the South Swedish Upland was an ‘island’ of slow-moving, polythermal and at least partly non-erosive ice, surrounded by faster ice-streams in the Baltic and in the Skagerrak. The ice sheet may have left its main impact on the landscape during short periods during advance and deglaciation only.

  • 3.
    Andersson, Stefan
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Mineralogy Petrology and Tectonics. Univ Helsinki, Dept Geosci & Geog, FI-00014 Helsinki, Finland.
    Jonsson, Erik
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Mineralogy Petrology and Tectonics. Geol Survey Sweden, Dept Mineral Resources, Uppsala, Sweden.
    Högdahl, Karin
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Mineralogy Petrology and Tectonics.
    Metamorphism and deformation of a Palaeoproterozoic polymetallic sulphide-oxide mineralisation: Hornkullen, Bergslagen, Sweden2016In: GFF, ISSN 1103-5897, E-ISSN 2000-0863, Vol. 138, no 3, p. 410-423Article in journal (Refereed)
    Abstract [en]

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

  • 4.
    Andren, Thomas
    et al.
    Stockholm University, Faculty of Science, Department of Geology and Geochemistry.
    Andren, Elinor
    Berglund, Bjorn E.
    Yu, Shi-Yong
    New insights on the Yoldia Sea low stand in the Blekinge archipelago, southern Baltic Sea2007In: GFF, ISSN 1103-5897, E-ISSN 2000-0863, Vol. 129, p. 277-285Article in journal (Refereed)
    Abstract [en]

    One sediment core from the Jarnavik bay in Blekinge archipelago has been investigated for its content of pollen and diatoms and its chemical properties. Two levels were also dated by radiocarbon. Based on the results the sediment sequence analysed has been divided into three environmental units largely corresponding to the lithology of the sequence. A lowermost unit consisting of weakly varved and homogeneous clay was deposited during the end of the brackish phase of the Yoldia Sea at a moderate water depth. On top of this unit a gyttja-clay unit was deposited. The onset of the deposition of this unit has been dated to c. 11 100 cal. yrs. BP. An increasing organic production and increased terrestrial influence is recorded in the chemical data and a very shallow water depth is indicated in the pollen and diatom flora. These results point to conditions in a bay probably isolated from the Yoldia Sea. A local tentative shore displacement curve have been constructed and it is proposed that this unit represents the low stand at c. -18 m during the Yoldia Sea stage in this part of the Baltic Sea basin. The uppermost unit consists of homogeneous clay with a low content of organic carbon. An increasing water depth is indicated by the composition of both pollen and diatoms. The diatom flora also displays an increase in freshwater species. This environmental change was probably the result of a transgression in the beginning of the Ancylus Lake stage.

  • 5. Andréasson, Per-Gunnar
    et al.
    Allen, Ann
    Aurell, Oskar
    Boman, Daniel
    Ekestubbe, Jonas
    Goerke, Ute
    Lundgren, Anders
    Nilsson, Patrik
    Sandelin, Stefan
    Seve terranes of the Kebnekaise Mts., Swedish Caledonides, and their amalgamation, accretion and affinity2018In: GFF, ISSN 1103-5897, E-ISSN 2000-0863, Vol. 140, no 3, p. 264-291Article in journal (Refereed)
    Abstract [en]

    A major allochthon of the Scandinavian Caledonides, the Seve belt has traditionally been considered to be derived from the rifted margin and continent-ocean transition (COT) of Baltica. However, geochronological results obtained from its inferred northern equivalent, the Kalak Nappe Complex (KNC), have been taken to indicate an exotic affinity of this complex and of also Seve terranes, an interpretation adopted in recent palaeogeographic models. In the Kebnekaise Mts., the COT is represented by the Kebnekaise terrane composed of amphibolitized dykes of gabbro and dolerite of depleted magma source and rare felsic and ultramafic rocks. Coronitic dolerite and gabbro with abundant rutile suggest high pressures before or during amalgamation with the underlying Mårma terrane, composed of quartzofeldspathic gneisses intruded by mafic and granitic rocks, the latter including a previously dated c. 845 Ma-old granite. The granite mingled with mildly alkaline dolerites chemically similar to transitional basalts of continental rifts. Following emplacement at shallow (andalusite stability) crustal levels, the igneous complex and host rocks underwent extensive deformation, metamorphism within the sillimanite-kyanite stability field and local migmatization. The Kebnekaise and Mårma terranes amalgamated in early Ordovician as indicated by the U-Pb age of 487±7 Ma obtained from titanite fabrics of deformed granite in thrust vicinity, and by 40Ar-39Ar results. The pressure increase in both terranes suggests that amalgamation occurred during initial subduction and imbrication. Correlation of the Mårma terrane with the KNC is discussed. Results obtained in this study give no reason to ascribe an exotic affinity to the Seve terranes of the Kebnekaise Mts.

  • 6.
    Andrén, Thomas
    et al.
    Stockholm University.
    Andrén, Elinor
    Södertörn University, School of Life Sciences.
    Berglund, Björn E.
    Lund University.
    Yu, Shi-Yong
    University of Minnesota.
    New insights on the Yoldia Sea low stand in the Blekinge archipelago, southern Baltic Sea2007In: GFF, ISSN 1103-5897, E-ISSN 2000-0863, Vol. 129, no 4, p. 277-285Article in journal (Refereed)
    Abstract [en]

    One sediment core from the Jarnavik bay in Blekinge archipelago has been investigated for its content of pollen and diatoms and its chemical properties. Two levels were also dated by radiocarbon. Based on the results the sediment sequence analysed has been divided into three environmental units largely corresponding to the lithology of the sequence. A lowermost unit consisting of weakly varved and homogeneous clay was deposited during the end of the brackish phase of the Yoldia Sea at a moderate water depth. On top of this unit a gyttja-clay unit was deposited. The onset of the deposition of this unit has been dated to c. 11 100 cal. yrs. BP. An increasing organic production and increased terrestrial influence is recorded in the chemical data and a very shallow water depth is indicated in the pollen and diatom flora. These results point to conditions in a bay probably isolated from the Yoldia Sea. A local tentative shore displacement curve have been constructed and it is proposed that this unit represents the low stand at c. -18 m during the Yoldia Sea stage in this part of the Baltic Sea basin. The uppermost unit consists of homogeneous clay with a low content of organic carbon. An increasing water depth is indicated by the composition of both pollen and diatoms. The diatom flora also displays an increase in freshwater species. This environmental change was probably the result of a transgression in the beginning of the Ancylus Lake stage.

  • 7.
    Arvestål, Emma
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Palaeobiology.
    Streng, Michael
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Palaeobiology.
    Cyrtograptids from the Telychian (upper Llandovery) of Kinnekulle Mountain, southern Sweden2013In: GFF, ISSN 1103-5897, E-ISSN 2000-0863, Vol. 135, no 1, p. 45-56Article in journal (Refereed)
    Abstract [en]

    The late Llandovery graptolite fauna of the Retiolites Shales on Kinnekulle Mountain in the province of Västergötland has long been known but never illustrated or studied in detail. New collections of graptolites from an interval at the very top of the exposed succession confirm previous reports of cyrtograptids, which make the shales on Kinnekulle the youngest preserved Palaeozoic rocks in the area. The co-occurrence of Oktavites spiralis and Cyrtograptus lapworthi constrains the strata to the lower lapworthi Biozone of the upper Telychian. The associated graptolite fauna comprises numerous monograptids and Retiolites angustidens as well as Cyrtograptus kinnekullensis n. sp., characterised by its open coiling and the presence of a second-order cladium on the second thecal cladium. This early occurrence of a cyrtograptid species with a second-order cladium on Baltica matches evolutionary patterns observed in Laurentia, suggesting that the ability to grow cladia of both first and higher order evolved approximately, synchronously and at the very beginning of cyrtograptid evolution.

  • 8. 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.

  • 9.
    Bark, Glenn
    et al.
    Luleå tekniska universitet, Geovetenskap och miljöteknik.
    Broman, Curt
    Stockholms Universitet.
    Weihed, Pär
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences.
    Fluid chemistry of the Palaeoproterozoic Fäboliden hypozonal orogenic gold deposit, northern Sweden: evidence from fluid inclusions2007In: GFF, ISSN 1103-5897, E-ISSN 2000-0863, Vol. 129, no 3, p. 197-210Article in journal (Refereed)
    Abstract [en]

    A new ore province, the Gold Line, southwest of the Skellefte District, northern Sweden, is currently under exploration. The largest known deposit in the Gold Line is the hypozonal Fäboliden orogenic gold deposit. The mineralization is hosted by arsenopyrite-bearing quartz veins, within a steep shear zone in amphibolite facies metagreywacke host rocks. Gold occur in fractures and as intergrowths in arsenopyrite-löllingite, and as free grains in the silicate matrix of the host rock. The hydrothermal mineral assemblage in the proximal alteration zone is diopside, calcic amphibole, biotite, and minor andalusite and tourmaline. Primary fluid inclusions in the Fäboliden quartz veins show a CO2-CH4 or a H2S (±CH4) composition (the latter recognized for the first time in a Swedish ore deposit). The primary fluid inclusions are associated with arsenopyrite-löllingite (+gold) and the CO2-CH4 fluid was also involved in precipitation of graphite. A prevalence of carbonic over aqueous fluid inclusions is characteristic for a number of hypozonal high-temperature orogenic gold deposits. The Fäboliden deposit, thus, shows fluid compositions similar to other hypozonal orogenic gold deposits. The proposed main mechanism for precipitation of gold from the fluids, is a mixing between H2S-rich and H2O?-CO2±CH4 fluids. Fluid inclusion data indicate arsenopyrite-löllingite and graphite deposition at a pressure condition of about 4 kbar. Graphite thermometry indicates maximum temperatures of 520-560°C for the hydrothermal alteration at Fäboliden, suggesting that at least the late stages of the mineralizing event took place shortly after peak-metamorphism in the area, i.e. at c. 1.80 Ga.

  • 10.
    Bark, Glenn
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Broman, Curt
    Stockholms Universitet.
    Weihed, Pär
    Fluid chemistry of the Palaeoproterozoic Fäboliden hypozonal orogenic gold deposit, northern Sweden: evidence from fluid inclusions2007In: GFF, ISSN 1103-5897, E-ISSN 2000-0863, Vol. 129, no 3, p. 197-210Article in journal (Refereed)
    Abstract [en]

    A new ore province, the Gold Line, southwest of the Skellefte District, northern Sweden, is currently under exploration. The largest known deposit in the Gold Line is the hypozonal Fäboliden orogenic gold deposit. The mineralization is hosted by arsenopyrite-bearing quartz veins, within a steep shear zone in amphibolite facies metagreywacke host rocks. Gold occur in fractures and as intergrowths in arsenopyrite-löllingite, and as free grains in the silicate matrix of the host rock. The hydrothermal mineral assemblage in the proximal alteration zone is diopside, calcic amphibole, biotite, and minor andalusite and tourmaline. Primary fluid inclusions in the Fäboliden quartz veins show a CO2-CH4 or a H2S (±CH4) composition (the latter recognized for the first time in a Swedish ore deposit). The primary fluid inclusions are associated with arsenopyrite-löllingite (+gold) and the CO2-CH4 fluid was also involved in precipitation of graphite. A prevalence of carbonic over aqueous fluid inclusions is characteristic for a number of hypozonal high-temperature orogenic gold deposits. The Fäboliden deposit, thus, shows fluid compositions similar to other hypozonal orogenic gold deposits. The proposed main mechanism for precipitation of gold from the fluids, is a mixing between H2S-rich and H2O?-CO2±CH4 fluids. Fluid inclusion data indicate arsenopyrite-löllingite and graphite deposition at a pressure condition of about 4 kbar. Graphite thermometry indicates maximum temperatures of 520-560°C for the hydrothermal alteration at Fäboliden, suggesting that at least the late stages of the mineralizing event took place shortly after peak-metamorphism in the area, i.e. at c. 1.80 Ga.

  • 11. Bassett-Butt, Lewis
    Systematics, biostratigraphy and biogeography of brachiopods and other fossils from the Middle Cambrian Nelson Limestone, Antarctica2016In: GFF, ISSN 1103-5897, E-ISSN 2000-0863, Vol. 138, no 3, p. 377-392Article in journal (Refereed)
    Abstract [en]

    An assemblage dominated by acrotretid brachiopods (Prototreta millsi Brock and Percival, 2006) is described from the Nelson Limestone of the Transantarctic Mountains, Antarctica. The formation also includes paterinids (Micromitra sp. cf. M. nerranubawu Kruse, 1990 and Dictyonina australis Roberts, 1990), lingulids (Oepikites haimantensis Reed, 1910)and acrothelids (Acrothele sp. cf. A. vertex Reed, 1910). The macrofauna also contains orthids (Diraphora dyunyin Kruse, 1990). The associated fauna include sponge spicules present in vast abundance. Other recognisable small shelly fossils (including chancelloriids and hyolithelminths) make up a small section of the fauna. Trilobites (including Nelsonia schesis Palmer and Gatehouse, 1972 and Solenopleura pruina Palmer and Gatehouse, 1972) belong to taxa previously described from the Nelson Limestone and support the Drumianage proposed for the formation. Palaeobiogeographic analysis indicates that the brachiopod fauna corroborates previously described strong links with Australasia and also suggests a strong link to Indian material, corroborating previous evidence for an East Gondwanan faunal province in the Middle Cambrian.

  • 12. Bauert, Heikki
    et al.
    Isozaki, Yukio
    Holmer, Lars Erik
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Palaeobiology.
    Aoki, Kazumasa
    Sakata, Shuhei
    Hirata, Takafumi
    New U-Pb zircon ages of the Sandbian (Upper Ordovician) "Big K-bentonite" in Baltoscandia (Estonia and Sweden) by LA-ICPMS2014In: GFF, ISSN 1103-5897, E-ISSN 2000-0863, Vol. 136, no 1, p. 30-33Article in journal (Refereed)
    Abstract [en]

    Oscillatory-zoned euhedral single zircons from the upper Sandbian (Upper Ordovician) Kinnekulle K-bentonite exposed in a hillock at Paaskula in Estonia and at the type locality on Mt Kinnekulle in Sweden were dated in a grain-by-grain manner by laser ablation-inductively coupled plasma mass spectrometer. The U-Pb (weighed mean) ages of the 25 grains from Mt Kinnekulle and 24 grains from Paaskula are 453.4 +/- 6.6 and 454.9 +/- 4.9Ma, respectively. This study provides the first ca. 454Ma (late Sandbian) age for the Ordovician K-bentonite in northern Estonia and confirmed its correlation with the type Kinnekulle bed across the Baltic Sea.

  • 13.
    Berglund, Mikael
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Litorina Sea shore displacement and pollen analytical indications of forest succession during the Mid-Holocene in Gästrikland, east central Sweden2010In: GFF, ISSN 1103-5897, E-ISSN 2000-0863, Vol. 132, no 3, p. 213-226Article in journal (Refereed)
    Abstract [en]

    This paper deals with the mid-Holocene shore level history and vegetation development in Gästrikland, east-central Sweden. This is investigated using sediment and microfossil records and 14C datings. The time span covered is c. 8000-5000 cal yr BP. Vegetation history during this time includes an increase in Tilia pollen 6500-6300 cal yr BP and a decrease in Ulmus and Corylus c. 5500 cal yr BP. The former change coincides with a sharp drop in relative sea level (RSL) of some 5 m; this RSL drop can be correlated to the regression from the L3 transgression of the Litorina Sea, identified in other areas around the Baltic Sea. The possible connections between RSL and climate (in particular changes on a maritime-continental continuum), as indicated by new pollen data and other records, are investigated. The new material shows, in comparison to other pollen records from southern and central Scandinavia, unusually high percentages of Tilia, Ulmus and Corylus pollen, but less Quercus. The change in pollen spectra around 5500 cal yr BP can be correlated to the northern European “elm decline”. A regional cooling is recorded in widespread data for this time, but observations suggest that other factors must be considered here, including disease and change in the physical landscape due to the ongoing land uplift.

  • 14.
    Berglund, Mikael
    Dalarna University, School of Education and Humanities, Geography.
    Litorina Sea shore displacement and pollen analytical indications of forest succession during the Mid-Holocene in Gästrikland, east central Sweden2010In: GFF, ISSN 1103-5897, E-ISSN 2000-0863, Vol. 132, p. 213-226Article in journal (Refereed)
    Abstract [en]

    This paper deals with the mid-Holocene shore level history and vegetation development in Gästrikland, east-central Sweden. This is investigated using sediment and microfossil records and 14C datings. The time span covered is c. 8000–5000 cal yr BP. Vegetation history during this time includes an increase in Tilia pollen 6500–6300 cal yr BP and a decrease in Ulmus and Corylusc. 5500 cal yr BP. The former change coincides with a sharp drop in relative sea level (RSL) of some 5 m; this RSL drop can be correlated to the regression from the L3 transgression of the Litorina Sea, identified in other areas around the Baltic Sea. The possible connections between RSL and climate (in particular changes on a maritime-continental continuum), as indicated by new pollen data and other records, are investigated. The new material shows, in comparison to other pollen records from southern and central Scandinavia, unusually high percentages of Tilia,Ulmus and Corylus pollen, but less Quercus. The change in pollen spectra around 5500 cal yr BP can be correlated to the northern European “elm decline”. A regional cooling is recorded in widespread data for this time, but observations suggest that other factors must be considered here, including disease and change in the physical landscape due to the ongoing land uplift.

  • 15.
    Berglund, Mikael
    et al.
    Dalarna University, School of Education, Health and Social Studies, Geography.
    Dahlström, Niklas
    Post-glacial fault scarps in Jämtland, central Sweden2015In: GFF, ISSN 1103-5897, E-ISSN 2000-0863, Vol. 137, no 4, p. 339-343Article in journal (Refereed)
    Abstract [en]

    Analysis of a light detection and ranging-derived digital elevation model has revealed previously unknown fault scarps in central Jämtland, Sweden. These are interpreted to have been formed by earthquakes at the time of deglaciation, c. 10 ka BP, in an area with current low-magnitude seismicity. The dating is based upon morphology and comparison with similar features at other locations in Sweden but not supported by independent dating. Observed scarps are 0.4–6 km long, 2–8 m high, trending SSW–NNE to WSW–ENE, the northern and western sides uplifted. The dimensions of the scarps suggest an approximate moment magnitude M 7 of the strongest corresponding earthquakes.

  • 16.
    Berg-Madsen, Vivianne
    et al.
    Uppsala University, Music and Museums, Museum of Evolution.
    Ebbestad, Jan Ove R.
    Uppsala University, Music and Museums, Museum of Evolution.
    The Bromell fossil collection at Uppsala University, Sweden: its history and the people behind it2013In: GFF, ISSN 1103-5897, E-ISSN 2000-0863, Vol. 135, no 1, p. 3-17Article in journal (Refereed)
    Abstract [en]

    Remains of 17(th) century cabinets of curiosity collections are held at the Museum of Evolution, Uppsala University, Sweden. Some of the oldest date back to the 1650s, and were included in the collection of Archiater, i.e. physician to the Crown, von Bromell (1679-1731). He is also known for publishing the first series of papers in Sweden to exclusively deal with palaeontology. Throughout his life he acquired specimens by collecting, buying or receiving in exchange to add to those he inherited from his father Olaus Bromelius, a famous botanist and physician. Information on the labels gives a glimpse of his network of friends, colleagues and fellow collectors, such as Kilian Stobaeus, Lars Roberg, Emanuel Swedenborg, Elias Brenner and Johan Dobelius. When Bromell died, his vast collections of books, coins, furniture, conchs, stuffed animals, minerals and fossils were sold off. The minerals and fossils were split up and owned by various persons during the following century. Parts owned by A. Lagerberg between the years 1746 and 1776 were bought in 1796 by Johan Afzelius and donated to Uppsala University at his death. Fossils and minerals earlier described by Bromell were in the care of The Royal Society of Science in Uppsala at least by 1791. Through the Institute of Geology, fossils accumulated over the centuries at Uppsala University eventually came together under the same roof in 1932, under professor Carl Wiman's care at the then newly erected Palaeontology museum building. Today, about 300 fossils from the Bromell collection are preserved at the museum.

  • 17.
    Berg-Madsen, Vivianne
    et al.
    Uppsala University, Music and Museums, Museum of Evolution.
    Valent, Martin
    Natl Museum, Dept Palaeontol, Cirkusova, Horni Pocernice, Czech Republic.
    Ebbestad, Jan Ove R.
    Uppsala University, Music and Museums, Museum of Evolution.
    An orthothecid hyolith with a digestive tract from the early Cambrian of Bornholm, Denmark2018In: GFF, ISSN 1103-5897, E-ISSN 2000-0863, Vol. 140, no 1, p. 25-37Article in journal (Refereed)
    Abstract [en]

    The hyolith assemblage from the early Cambrian of Bornholm, Denmark, shows a higher diversity than contemporary assemblages in Baltoscandia. The most common species in the Green Shales (Laesa Formation, Norretorp Member, Cambrian Stage 3), is Hyolithes [=Hyolithus] (Orthotheca) johnstrupi Holm, 1893. A specimen of this species shows a well-preserved and almost complete digestive tract, folded into an approximately 22mm long chevron-like structure comprised of at least 20 arcuate loops on the ventral side and a flattened, gently sinuous to straight anal tube on the dorsal side. The thin, phosphatic outer shell layer of the conch is crushed under the digestive tract due to compaction while the digestive tract is preserved in three dimensions and appears undisturbed. The shape of the digestive tract is similar to that of the middle Cambrian Guduguwan hardmani (Etheridge) from Australia and the lower Cambrian specimens from Russia described by Mekova & Sysoev. The Danish specimen is probably an adult, lending support to the idea that the orthothecid digestive tract becomes more complex during ontogeny. Hyolithus (Orthotheca) johnstrupi is revised and here referred to Circotheca Sysoev, 1958.

  • 18.
    Bergström, Jan
    et al.
    Swedish Museum of Natural History, Department of Paleobiology.
    Hou, Xian-Guang
    Yunnan University, Kunming.
    Hålenius, Ulf
    Swedish Museum of Natural History, Department of Geology.
    Gut contents and feeding in the Cambrian arthropod Naraoia2007In: GFF, ISSN 1103-5897, E-ISSN 2000-0863, Vol. 129, p. 71-76Article in journal (Refereed)
  • 19.
    Billström, Kjell
    et al.
    Swedish Museum of Natural History.
    Bergman, Stefan
    Geological Survey of Sweden.
    Martinsson, Olof
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Post-1.9 Ga metamorphic, mineralization and hydrothermal events in northern Sweden2002In: GFF, ISSN 1103-5897, E-ISSN 2000-0863, Vol. 124, no 4, p. 228-228Article in journal (Refereed)
  • 20.
    Björklund, Lennart
    et al.
    Gothenburg University.
    Weihed, Pär
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences. Luleå tekniska universitet.
    Geochemistry and tectonic setting of the Orvar Hill mafic volcanic rocks of the Tiveden area, south-central Sweden1997In: GFF, ISSN 1103-5897, E-ISSN 2000-0863, Vol. 119, no 2, p. 127-134Article in journal (Refereed)
    Abstract [en]

    The Orvar Hill formation in Tiveden, south-central Sweden, constitutes a unique low-strain window of well preserved Svecofennian mafic volcanic rocks on the southwestern border of the Svecokarelian orogen. The area can be considered as the southwestern border of the Bergslagen region of the Svecokarelian orogen. The Orvar Hill formation consists of coherent pillowed and non-pillowed basalts alternating with mafic volcaniclastic racks in the lower part of the Lindberga supracrustal succession. Only minor felsic volcanic rocks occur in the upper part. Quartz-bearing metagreywackes comprise the top part of the Lindberga supracrustal succession. Geochemistry of lavas and volcaniclastic rocks suggests that the Orvar Hill mafic volcanic rocks were emplaced in a volcanic-are setting. This demonstrates that the Tiveden supracrustal units probably formed in response to volcanism related to subduction. The Tiveden area may thus represent a 1.89 Ga primitive, sediment-starved volcanic are at the margin of the continental volcanic are of the Bergslagen district. The relationship between Tiveden and Bergslagen at the time of formation is not clear and Tiveden may represent a remnant of an are that accreted to a continent at c. 1.88-1.86 Ga.

  • 21.
    Björklund, Lennart
    et al.
    Gothenburg University.
    Weihed, Pär
    Geochemistry and tectonic setting of the Orvar Hill mafic volcanic rocks of the Tiveden area, south-central Sweden1997In: GFF, ISSN 1103-5897, E-ISSN 2000-0863, Vol. 119, no 2, p. 127-134Article in journal (Refereed)
    Abstract [en]

    The Orvar Hill formation in Tiveden, south-central Sweden, constitutes a unique low-strain window of well preserved Svecofennian mafic volcanic rocks on the southwestern border of the Svecokarelian orogen. The area can be considered as the southwestern border of the Bergslagen region of the Svecokarelian orogen. The Orvar Hill formation consists of coherent pillowed and non-pillowed basalts alternating with mafic volcaniclastic racks in the lower part of the Lindberga supracrustal succession. Only minor felsic volcanic rocks occur in the upper part. Quartz-bearing metagreywackes comprise the top part of the Lindberga supracrustal succession. Geochemistry of lavas and volcaniclastic rocks suggests that the Orvar Hill mafic volcanic rocks were emplaced in a volcanic-are setting. This demonstrates that the Tiveden supracrustal units probably formed in response to volcanism related to subduction. The Tiveden area may thus represent a 1.89 Ga primitive, sediment-starved volcanic are at the margin of the continental volcanic are of the Bergslagen district. The relationship between Tiveden and Bergslagen at the time of formation is not clear and Tiveden may represent a remnant of an are that accreted to a continent at c. 1.88-1.86 Ga.

  • 22. Bogolepova, O. K.
    et al.
    Gubanov, A. P.
    Paris, F.
    The first Silurian chitinozoans from Severnaya Zemlya, Russian Arctic2012In: GFF, ISSN 1103-5897, E-ISSN 2000-0863, Vol. 134Article in journal (Refereed)
    Abstract [en]

    The chitinozoan Conochitina aff. emmastensis Nestor, 1982 has been identified from the Silurian Telychian Stage, Llandovery Series, of Severnaya Zemlya, the Russian Arctic. Its presence suggests an early to late Telychian age for the strata, which is in accordance with previous biostratigraphic dating based on graptolites and conodonts.

  • 23.
    Bogolepova, Olga
    et al.
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Social Sciences, Institute for Russian and Eurasian Studies.
    Donovan, Stephen K.
    Harper, David A. T.
    Suyarkova, Anna A.
    Yakupov, Rustem
    Gubanov, Alexander P.
    Uppsala University, Music and Museums, Museum of Evolution.
    New records of brachiopods and crinoids from the Silurian (Wenlock) of the southern Urals, Russia2018In: GFF, ISSN 1103-5897, E-ISSN 2000-0863Article in journal (Refereed)
    Abstract [en]

    Crinoids and brachiopods are described from the Silurian Uzyan Formation of the Zilair Zone in the southern Urals. The occurrence of the graptolites Coronograptus praedeubeli suggests a late Homerian (Wenlock) age for the strata. A new disparid crinoid, Cicerocrinus gracilis Donovan sp. nov., is the oldest known member of this genus. It has a long, flexible and homeomorphic column, and a tall bryozoan palaeontology terminology (IBr2) (second primibrachial) axillary. All species of Cicerocrinus described previously have been limited to the Ludlow of the British Isles, Sweden and Estonia, and the Pridoli of Estonia. The poorly preserved brachiopod fauna is represented by small atrypid (Atrypa? sp.) and dalmanellid brachiopods (Levenea? sp.). The reported assemblage generally inhabited deep-water environments.

  • 24.
    Broman, Curt
    et al.
    Stockholm University, Faculty of Science, Department of Geological Sciences.
    Sturkell, Erik
    Fallick, Anthony E.
    Oxygen isotopes and implications for the cavity-grown quartz crystals in the Lockne impact structure, Sweden2011In: GFF, ISSN 1103-5897, E-ISSN 2000-0863, Vol. 133, no 02-jan, p. 101-107Article in journal (Refereed)
    Abstract [en]

    Well-developed quartz crystals are found in open cavities in the intensely fractured crystalline basement of the marine-target impact structure at Lockne in central Sweden. The 458 Ma impact structure has a well-preserved crater in Precambrian granitic basement rock that is covered by resurge deposits composed of breccias and fine-grained sedimentary units of mixed Ordovician limestone, Cambrian black bituminous shales and the basement granite. Directly after the impact, the resurge deposits formed when the seawater rushed back into the crater. The residual heat from the impact facilitated a short-lived hydrothermal system accompanied by the inflowing seawater, which resulted in mineral growth in fractures and open cavities of the granite basement. The oxygen isotope values of the first-precipitated minerals, the cavity-grown quartz crystals, range from +15.2 to +16.2 parts per thousand (Vienna Standard Mean Ocean Water) and differ from those of the hosting granite basement rock with delta(18)O quartz between +10.1 and +11.7 parts per thousand. The delta(18)O values of the quartz are more consistent with derivation from a fluid of relatively high delta(18)O probably attributable to oxygen isotope exchange during seawater-rock interactions in the resurge deposits. The occurrence of organic matter in association with the cavity-grown quartz strongly indicates a relationship to the black bituminous shale in the matrix of the breccia that rests on the crater floor. Comparing the results with previously obtained oxygen data on fracture-grown calcite from Lockne shows that oxygen isotope composition of the cavity-grown quartz crystals is less variable and probably more accurately reflects the original fluid source.

  • 25.
    Chen, Donglei
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Evolution and Developmental Biology.
    Blom, Henning
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Evolution and Developmental Biology.
    Scale morphology and squamation of Andreolepis from the Late Silurian of Gotland, Sweden2011In: GFF, ISSN 1103-5897, E-ISSN 2000-0863, Vol. 133, no 1-2, p. 60-61p. 60-61Article in journal (Refereed)
  • 26. Clausen, Sebastien
    et al.
    Peel, John S.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Palaeobiology.
    Middle Cambrian echinoderm remains from the Henson Gletscher Formation of North Greenland2012In: GFF, ISSN 1103-5897, E-ISSN 2000-0863, Vol. 134, no 3, p. 173-200Article in journal (Refereed)
    Abstract [en]

    A Middle Cambrian (Series 3, Stage 5) echinoderm assemblage is described from the uppermost part of the Henson Gletscher Formation based on disarticulated material. This represents the first detailed echinoderm report from the Cambrian of North Greenland and one of the most diverse for that time. Recovered ossicles include a morphotype continuum between various biserial (brachiolar) and uniserial ("brachial") plates from pelmatozoan feeding appendages along with thecal insertion plates, pelmatozoan holomeric and the oldest known polymeric stem elements and holdfasts. Ambulacral flooring plates from two different edrioasteroids are also described. This assemblage illustrates a high plasticity and disparity in early echinoderm stem and feeding appendages, thereby placing stress on the usual definitions of blastozoans and crinozoans, generally considered as two pelmatozoan subphyla. Along with previous studies, it also raises the question as to how early echinoderms responded to the Agronomic Revolution (Substrate Revolution). Echinoderm remains first appear during Cambrian Series 2, Stage 3, well after the Substrate Revolution had affected the first few centimetres of substrate used by this low-level tiering animals to stabilize themselves. Contrary to previous ideas, it is suggested that echinoderms evolved quickly and in a nonlinear way in response to the abrupt establishment of a mosaic of substrate types during the early Cambrian. Finally, this study highlights the primary importance of disarticulated elements in the elucidation of the early evolution, diversity and disparity of the earliest echinoderms. Such elements are much more common and always appear earlier in the geological record than the complete articulated specimens on which echinoderm studies generally focus despite the taphonomic biases which often characterize their preservation.

  • 27.
    Dahlin, Peter
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Palaeoproterozoic metavolcanic and metasedimentary succession hostingthe Dannemora iron ore deposits, Bergslagen region, Sweden2012In: GFF, ISSN 1103-5897, E-ISSN 2000-0863, Vol. 134, no 2, p. 71-85Article in journal (Refereed)
    Abstract [en]

    The Dannemora supracrustal inlier is located in the north-eastern part of the Bergslagen regionin south-central Sweden and hosts the second largest iron ore deposit in the region. The metasupracrustalsuccession of the inlier consists of c. 1.9 Ga Palaeoproterozoic rocks that are mainly sub-alkaline, rhyoliticto dacitic, pyroclastic deposits, reworked pyroclastic deposits and metalimestone. It is c. 700–800-m thickand termed the Dannemora Formation. The formation is divided into lower and upper members and theformer is in turn subdivided into subunits 1 and 2. The great thickness of individual pyroclastic depositsindicates deposition within a caldera. The rocks show characteristics of a pyroclastic origin by containingabundant pumice, cuspate and Y-shaped former glass shards, and fragmented crystals of quartz andsubordinate feldspars. Scattered spherulites and lack of welding-compacted fiamme suggest that the lowermember was slightly welded, where as the upper member contains sericite-replaced glass shards withpreserved primary shapes indicating no welding. Undisturbed layers of ash-siltstone with normal gradingand fluid–escape structures are attributed to subaqueous deposition below storm wave base in the easternpart of the inlier, where as erosion channels and cross-bedding in some of the volcaniclastic deposits implydeposition and reworking above wave base in the central part of the inlier. Epidote spots, previouslyinterpreted as altered limestone fragments and an indicator for subaquatic deposition, are here reinterpretedas the result of selective alteration related to the intrusion of mafic dykes and to Ca release duringdolomitisation of limestone.

  • 28.
    Dahlin, peter
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Allen, R.
    Division of Geosciences and Environmental Engineering, Luleå University of Technology, Luleå, Sweden.
    Sjöström, Håkan
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    The Palaeoproterozoic metavolcanic and metasedimentary succession hosting the Dannemora iron ore deposits, Bergslagen region, Sweden.2012In: GFF, ISSN 1103-5897, E-ISSN 2000-0863, Vol. 134, no 2, p. 71-85Article in journal (Refereed)
    Abstract [en]

    The Dannemora supracrustal inlier is located in the north-eastern part of the Bergslagen region in south-central Sweden and hosts the second largest iron ore deposit in the region. The metasupracrustal succession of the inlier consists of c. 1.9 Ga Palaeoproterozoic rocks that are mainly sub-alkaline, rhyolitic to dacitic, pyroclastic deposits, reworked pyroclastic deposits and metalimestone. It is c. 700–800-m thick and termed the Dannemora Formation. The formation is divided into lower and upper members and the former is in turn subdivided into subunits 1 and 2. The great thickness of individual pyroclastic deposits indicates deposition within a caldera. The rocks show characteristics of a pyroclastic origin by containing abundant pumice, cuspate and Y-shaped former glass shards, and fragmented crystals of quartz and subordinate feldspars. Scattered spherulites and lack of welding-compacted fiamme suggest that the lower member was slightly welded, where as the upper member contains sericite-replaced glass shards with preserved primary shapes indicating no welding. Undisturbed layers of ash-siltstone with normal grading and fluid–escape structures are attributed to subaqueous deposition below storm wave base in the eastern part of the inlier, where as erosion channels and cross-bedding in some of the volcaniclastic deposits imply deposition and reworking above wave base in the central part of the inlier. Epidote spots, previously interpreted as altered limestone fragments and an indicator for subaquatic deposition, are here reinterpreted as the result of selective alteration related to the intrusion of mafic dykes and to Ca release during dolomitisation of limestone.

  • 29.
    Dahlin, Peter
    et al.
    Department of Earth Sciences, Uppsala University.
    Allen, Rodney
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Sjöström, Håkan
    Department of Earth Sciences, Uppsala University.
    Palaeoproterozoic metavolcanic and metasedimentary succession hosting the Dannemora iron ore deposits, Bergslagen region, Sweden2012In: GFF, ISSN 1103-5897, E-ISSN 2000-0863, Vol. 134, no 2, p. 71-85Article in journal (Refereed)
    Abstract [en]

    The Dannemora supracrustal inlier is located in the north-eastern part of the Bergslagen region in south-central Sweden and hosts the second largest iron ore deposit in the region. The metasupracrustal succession of the inlier consists of c. 1.9 Ga Palaeoproterozoic rocks that are mainly sub-alkaline, rhyolitic to dacitic, pyroclastic deposits, reworked pyroclastic deposits and metalimestone. It is c. 700-800-m thick and termed the Dannemora Formation. The formation is divided into lower and upper members and the former is in turn subdivided into subunits 1 and 2. The great thickness of individual pyroclastic deposits indicates deposition within a caldera. The rocks show characteristics of a pyroclastic origin by containing abundant pumice, cuspate and Y-shaped former glass shards, and fragmented crystals of quartz and subordinate feldspars. Scattered spherulites and lack of welding-compacted fiamme suggest that the lower member was slightly welded, where as the upper member contains sericite-replaced glass shards with preserved primary shapes indicating no welding. Undisturbed layers of ash-siltstone with normal grading and fluid-escape structures are attributed to subaqueous deposition below storm wave base in the eastern part of the inlier, where as erosion channels and cross-bedding in some of the volcaniclastic deposits imply deposition and reworking above wave base in the central part of the inlier. Epidote spots, previously interpreted as altered limestone fragments and an indicator for subaquatic deposition, are here reinterpreted as the result of selective alteration related to the intrusion of mafic dykes and to Ca release during dolomitisation of limestone.

  • 30.
    Ebbestad, Jan Ove R.
    et al.
    Uppsala University, Music and Museums, Museum of Evolution.
    Hogstrom, Anette E. S.
    Frisk, Åsa M.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Palaeobiology.
    Martma, Tonu
    Kaljo, Dimitri
    Kroger, Bjorn
    Parnaste, Helje
    Terminal Ordovician stratigraphy of the Siljan district, Sweden2015In: GFF, ISSN 1103-5897, E-ISSN 2000-0863, Vol. 137, no 1, p. 36-56Article, review/survey (Refereed)
    Abstract [en]

    Integration of new isotopic data and earlier biostratigraphic information from eight sections through the terminal Ordovician (Pirgu and Porkuni stages) of the Siljan district, Sweden, allows a more precise correlation of sections in terms of biostratigraphy and carbon isotope dating. Four levels with positive delta C-13 excursions are identified (from bottom) - the Moe, an unnamed excursion, Paroveja and Hirnantian Carbon Isotope Excursion (HICE). The delta C-13 values through the Boda Limestone are 1-2 parts per thousand higher than usual in Baltica, only the values for the HICE remains within what is expected. Background values increase from 1.5 parts per thousand in the bottom of the core of the Boda Limestone up to 3 parts per thousand in the top of it. The HICE is identified in five of eight sections and the main peak falls according to inferred correlation within the Metabolograptus persculptus Biozone, at or close to the Hindella beds in the Upper Boda Member. The late Katian (Pirgu) age of Holorhynchus in the Siljan district is clear and its co-occurrence with the chitinozoan Belonechitina gamachiana in Estonia supports a Katian age for this zone. The base of the Ozarkodina hassi Biozone may occur within units B-C of the Upper Boda Member and in the upper part of the Loka Formation and most likely is correlated with the M. persculptus Biozone. The Hirnantia-Dalmanitina faunas reported from the lowermost part of the Loka Formation and units B-D of the Upper Boda Member seem to range through all the Hirnantian, but detailed morphological studies allow to distinguish an older (=extraordinarius) and a younger (=persculptus) fauna.

  • 31.
    Ebbestad, Jan Ove R.
    et al.
    Uppsala University, Music and Museums, Museum of Evolution.
    Pour, Mansoureh Ghobadi
    Natl Museum Wales, Dept Geol, Cathays Pk, Cardiff CF10 3NP, S Glam, Wales.;Golestan Univ, Dept Geol, Fac Sci, Gorgan, Iran..
    Bassett, Michael G.
    Natl Museum Wales, Dept Geol, Cathays Pk, Cardiff CF10 3NP, S Glam, Wales..
    Popov, Leonid E.
    Natl Museum Wales, Dept Geol, Cathays Pk, Cardiff CF10 3NP, S Glam, Wales..
    First occurrence of Lesueurilla prima (Gastropoda) from the Middle Ordovician (Darriwilian) of Iran2016In: GFF, ISSN 1103-5897, E-ISSN 2000-0863, Vol. 138, no 4, p. 510-518Article in journal (Refereed)
    Abstract [en]

    The near planispiral euomphaloid gastropod Lesueurilla prima (Barrande in Perner) is a typical part of the cold water Mediterranean fauna in the Lower and Middle Ordovician. It is a signature species in strata of this age in the Prague Basin in the Czech Republic, Montagne Noire in France, and Central Morocco. The species is reported for the first time from the Darriwilian of Iran where it occurs in the upper part of the Shirgesht Formation of the Derenjal Mountains north of Tabas in east Central Iran. It occurs with a small species of the bellerophontoid gastropod Sinuites sp., as well as the calymenid trilobite Neseuretinus birmanicus (Reed) and the pliomerid trilobite Ovalocephalus kanlingensis (Zhang). The biogeographic distribution of Lesueurilla suggests that the genus had its origin in cold water, high-latitude peri-Gondwana areas during the Lower Ordovician, spreading to other peri-Gondwana areas and low-latitude areas of North China, Tarim, and finally Baltica, Laurentia and Australia in the late Middle and Upper Ordovician.

  • 32.
    Ebbestad, Jan Ove R.
    et al.
    Uppsala University, Music and Museums, Museum of Evolution. Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Palaeobiology.
    Rushton, Adrian W. A.
    Stein, Martin
    Weidner, Thomas
    A paradoxidid moult ensemble from the Cambrian of Sweden2013In: GFF, ISSN 1103-5897, E-ISSN 2000-0863, Vol. 135, no 1, p. 18-29Article in journal (Refereed)
    Abstract [en]

    A mass aggregation of 148 paradoxidid trilobites and associated specimens of the agnostoid Pentagnostus praecurrens is preserved on a surface of a split orsten lens from the Middle Cambrian Series 3 Acadoparadoxides pinus-P. praecurrens Zone in Jamtland, Sweden. Most specimens are complete or nearly complete, lying parallel to the sediment surface and seem unaffected by currents or sorting. The association is interpreted as a moult ensemble. Paradoxidid specimens are represented by two taxa, identified as paradoxidid sp. 1 (n=28 specimens) and Eccaparadoxides sp. 2 (n=45 specimens). The species are preserved both dorsum up and dorsum down, in about equal number, which may reflect a natural tendency to moult in either posture. They probably moulted by opening the cephalic sutures along the wide rostrum. The dorsal sutures are invariably open and the librigenae are very often displaced, commonly backwards in relation to the cranidium, but not symmetrically in relation to the axial shield. The glabella of the paradoxidids is often crushed, so that sometimes the underlying hypostome is outlined. Very few examples show the joint between the cranidium and the trunk being broken. Facies interpretation suggests deposition below storm wave base. Rapid burial, possibly by blanketing from hypopycnal flows followed by an extended period of slow sediment input (Type 1 facies of Brett et al. 2012) may explain the unusual preservation. The animals may have lived in an ex-aerobic environment, but evidence to support this is at the moment insubstantial.

  • 33. Edfelt, Åsa
    et al.
    Sandrin, Alessandro
    Luleå tekniska universitet.
    Evins, Paul
    EGRU, School of Earth Sciences, James Cook University.
    Jeffries, Teresa
    Natural History Museum, London.
    Storey, Craig
    Open University, Walton Hall, Milton Keynes.
    Elming, Sten-åke
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Martinsson, Olof
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Stratigraphy and tectonic setting of the host rocks to the Tjårrojåkka Fe-oxide Cu-Au deposits, Kiruna area, northern Sweden2006In: GFF, ISSN 1103-5897, E-ISSN 2000-0863, Vol. 128, no 3, p. 221-232Article in journal (Refereed)
    Abstract [en]

    The Tjårrojåkka area is located about 50 km WSW of Kiruna, northern Sweden, and hosts one of the best examples of spatially and possibly genetically related Fe-oxide and Cu-Au occurrences in the area. The bedrock is dominated by intermediate and basic extrusive and intrusive rocks. An andesite constrains the ages of these rocks with a U-Pb LA-ICPMS age of 1878±7 Ma. They are cut by dolerites, which acted as feeder dykes for the overlying basalts. Based on geochemistry and the obtained age the andesites and basaltic andesites can be correlated with the 1.9 Ga intermediate volcanic rocks of the Svecofennian Porphyrite Group in northern Sweden. They formed during subduction-related magmatism in a volcanic arc environment on the Archaean continental margin above the Kiruna Greenstone Group. Chemically the basalts and associated dolerites have the same signature, but cannot directly be related to any known basaltic unit in northern Sweden. The basalts show only minor contamination of continental crust and may represent a local extensional event in a subaquatic back arc setting with extrusion of mantle derived magma. The intrusive rocks range from gabbro to quartz-monzodiorite in composition. The area is metamorphosed at epidote-amphibolite facies and has been affected by scapolite, K-feldspar, epidote, and albite alteration that is more intense in the vicinity of deformation zones and mineral deposits. Three events of deformation have been distinguished in the area. D1 brittle-ductile deformation created NE-SW-striking steep foliation corresponding with the strike of the Tjårrojåkka-Fe and Cu deposits and was followed by the development of an E-W deformation zone (D2). A compressional event (D3), possible involving thrusting from the SW, produced folds in the central part of the area and a NNW-SSE striking deformation zone in NE.

  • 34.
    Egenhoff, Sven
    et al.
    Colorado State Univ, Dept Geosci, Ft Collins, CO 80523 USA.
    Maletz, Jörg
    Free Univ Berlin, Inst Geowissensch, Berlin, Germany.
    Ahlberg, Per
    Lund Univ, Dept Geol, Lund, Sweden.
    Mast, Allison
    Colorado State Univ, Dept Geosci, Ft Collins, CO 80523 USA.
    Frisk, Åsa
    Uppsala University, Music and Museums, Museum of Evolution.
    Ebbestad, Jan Ove R.
    Uppsala University, Music and Museums, Museum of Evolution.
    Newby, Warren
    Colorado State Univ, Dept Geosci, Ft Collins, CO 80523 USA;Total Oil & Gas, Houston, TX 77010 USA.
    Sedimentology of the Lower Ordovician (upper Tremadocian) Bjørkasholmen Formation at Flagabro, southern Sweden2018In: GFF, ISSN 1103-5897, E-ISSN 2000-0863, Vol. 140, no 1, p. 55-65Article in journal (Refereed)
    Abstract [en]

    The Lower Ordovician Bjørkasholmen Formation at Flagabro, Scania, southern Sweden, consists of a 0.8m thick succession of carbonates with three siliciclastic mudstones, 5, 1 and 100mm thick, intercalated in the central part of the unit. Carbonate and siliciclastic mudstone beds show both normal and inverse grading. The carbonates are mud-rich and subdivided into a mudstone, a wackestone and a packstone facies. Grain types in the carbonates are mostly shells and shell fragments of brachiopods and trilobites. The carbonate rocks are strongly bioturbated seen as in roundish burrows filled with mud and a clear cement; additionally, bioturbation is reflected in the random orientation of shells. The siliciclastic mudstones are subdivided into two facies; one contains large amounts of shells and is in part grain-supported, the other is matrix-dominated and laminated to massive. The succession reflects sedimentation on a low-inclined shelf equivalent to a mid-ramp to basinal setting. Most mud- and wackestones (facies 3 and 4) represent fair-weather sedimentation, and the intercalated wacke- and packstones (facies 4 and 5) represent concentration of shell debris during high-energy storm. The siliciclastic mudstones in the central part of the succession reflect deposition in a basinal setting. The entire BjOrkasholmen Formation at Flagabro is equivalent to a lowstand of third (?) order without a well-developed internal cyclicity and is in that respect similar to the Bjørkasholmen Formation of oland, but different from the age-equivalent Norwegian sections.

  • 35.
    Egerquist, Eva
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Palaeobiology, Palaeontology group.
    Holmer, Lars E.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Palaeobiology.
    Early-Middle Ordovician (Billingen-Volkhov stages) Orthide and Protorthide brachiopods from the East Baltic2006In: GFF, ISSN 1103-5897, E-ISSN 2000-0863, Vol. 128, no 4, p. 339-348Article in journal (Refereed)
    Abstract [en]

    Three new orthide species: Orthidium lavensis, Orthidium gambolovensis and Ranorthis rotunda, and one new protorthide species: Skenidioides minutus, are described from the Early-Middle Ordovician (Billingen-Volkhov stages) of Estonia and north-western Russia. This is the first record of Orthidium from Baltica, whereas Skenidioides was known previously only from the Keila and Oandu stages in Estonia.

  • 36.
    Einarsson, Elisabeth
    et al.
    Lund University.
    lindgren, Johan
    Lund University.
    Kear, Benjamin P.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Palaeobiology.
    Siverson, Mikael
    Western Australian Museum.
    Mosasaur bite marks on a plesiosaur propodial from the Campanian (Late Cretaceous) of southern Sweden2010In: GFF, ISSN 1103-5897, E-ISSN 2000-0863, Vol. 132, no 2, p. 123-128Article in journal (Refereed)
    Abstract [en]

    Although plesiosaurs and mosasaurs co-existed for about 35 million years at the end of the Cretaceous, the fossil record documenting interactions between these two groups of marine reptiles is meagre. The discovery of deeply incised scars on a limb bone of an immature polycotylid plesiosaur from the latest early Campanian (in the European two-fold division of the Campanian Stage) of the Kristianstad Basin, southern Sweden, is thus significant because it represents a rare example of predation or scavenging on an immature polycotylid plesiosaur by a large mosasaur.

  • 37.
    Einarsson, Elisabeth
    et al.
    Lund University.
    Lindgren, Johan
    Lund University.
    Kear, Benjamin P.
    Uppsala University.
    Siverson, Mikael
    Australia.
    Mosasaur bite marks on a plesiosaur propodial from the Campanian (Late Cretaceous) of southern Sweden2010In: GFF, ISSN 1103-5897, E-ISSN 2000-0863, Vol. 132, no 2, p. 123-128Article in journal (Refereed)
    Abstract [en]

    Although plesiosaurs and mosasaurs co-existed for about 35 million years at the end of the Cretaceous, the fossil record documenting interactions between these two groups of marine reptiles is meagre. The discovery of deeply incised scars on a limb bone of an immature polycotylid plesiosaur from the latest early Campanian (in the European two-fold division of the Campanian Stage) of the Kristianstad Basin, southern Sweden, is thus significant because it represents a rare example of predation or scavenging on an immature polycotylid plesiosaur by a large mosasaur.

  • 38.
    Elming, Sten-åke
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Mattsson, Håkan J.
    Luleå tekniska universitet.
    A paleomagnetic and AMS study of the Rätan granite of the Transscandinavian Igneous Belt, central Sweden2001In: GFF, ISSN 1103-5897, E-ISSN 2000-0863, Vol. 123, no 4, p. 205-215Article in journal (Refereed)
    Abstract [en]

    The 1.85-1.67 Ga Transscandinavian Igneous Belt (TIB) forms a major Paleoproterozoic igneous complex in the western part of the Fennoscandian Shield. Different tectonic models propose that the TIB was formed in a tectonic regime governed either by compression or by extension. This paper presents an analysis of anisotropy of magnetic susceptibility (AMS) and paleomagnetic data from the Rätan granite (1.70 Ga), which forms a large pluton in the central part of the TIB. The major aim of the study is to test the existing tectonic models and to define a paleomagnetic pole position for the Rätan granite. Three contrasting magnetic fabric domains are identified. In the eastern and western domains the AMS fabric is characterized by NW-SE to N-S trending subvertical foliation planes and a girdle distribution of the maximum and intermediate anisotropy axes. The central domain is characterized by subhorizontal magnetic foliation planes and lineations that cluster in a NW-SE trending direction. We suggest that the Rätan granite was emplaced in a tectonic regime governed by NW-SE directed extension and that the pluton was fed obliquely with a magma source situated to the present northwest. A positive baked contact test is demonstrated for a basic dyke suggesting that the Rätan granite has not been remagnetized since c. 1.6 Ga. A paleomagnetic formation mean direction is defined for the granite (decl. = 2°, incl. = 59°) that yields a paleopole position of Plat = 67° and Plon = 190°.

  • 39.
    Elming, Sten-åke
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Moakhar, Mohsen Oveisy
    Razi University, Kermanshah.
    Martinsson, Olof
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    A palaeomagnetic and geochemical study of basic intrusions in northern Sweden2004In: GFF, ISSN 1103-5897, E-ISSN 2000-0863, Vol. 126, no 2, p. 243-252Article in journal (Refereed)
    Abstract [en]

    A palaeomagnetic and geochemical study has been performed on basic dykes in northern Sweden. The dykes and a gabbro formation were sampled in 28 sites and characteristic magnetizations could be defined in 23 of them. The dykes form a part of a swarm that trends in NE-SW to E-W. From differences in palaeomagnetic signatures and composition it is concluded that this swarm is composed of two generations of dykes, group A and B, trending in similar directions. The dykes of group A have compositions that are similar to rapakivi related dykes, while those of group B are different from most rapakivi dykes in Fennoscandia. The calculated pole positions may suggest that the group B dykes are older than those of group A and both groups intruded within the time span 1.77 Ga to 1.50 Ga. The trend of the dykes is more or less parallell to a palaeo-compressional stress field that may be expected from the collisional tectonics related to the Gothian orogeny. The intrusion of the rapakivi formations in Fennoscandia has been suggested to be related with the Gothian orogeny and the intrusion of the dykes may thus be guided by the stress field generated by the collisional tectonics.

  • 40.
    Elming, Sten-åke
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Törne, Anders
    The blue road geotraverse: a magnetic ground survey and the interpretation of magnetic anomalies1976In: GFF, ISSN 1103-5897, E-ISSN 2000-0863, Vol. 98, p. 264-270Article in journal (Refereed)
    Abstract [en]

    Ground measurements of the magnetic field were carried out along a 20-km-wide zone along the Blue Road Geotraverse. In addition, a profile of high precision was measured. A large positive anomaly within the mountain area cannot be explained by anomalous magnetization of surface rocks. Optimization of theoretical models shows that it may have its origin at a depth of 30 km, indicating a rise of the Curie isothermal surface from the mountain area to the Baltic shield. The rise of the isotherm may be connected with the land uplift. Interpretation of smaller anomalies reveals the thickness of sedimentary layers

  • 41.
    Eriksson, Mats E.
    et al.
    Department of Geology, Lund University.
    Hints, Olle
    Institute of Geology at Tallinn University of Technology.
    Bergman, Claes F.
    Kristianstad University, School of Education and Environment.
    Kingnites diamondi gen. et sp. nov., an exceptionally large Silurian paulinitid (Annelida; Polychaeta) from shallow marine settings of Baltoscandia2012In: GFF, ISSN 1103-5897, E-ISSN 2000-0863, Vol. 134, no 3, p. 217-224Article in journal (Refereed)
    Abstract [en]

    The polychaete annelid Kingnites diamondi, a new paulinitid genus and species, is described from the Silurian of Baltoscandia. Its large maxillae differ morphologically from those of all other known paulinitids, particularly in being very elongate and having conspicuous myocoele openings and posterior portions of the first maxillae (MI). Albeit rare, this polychaete taxon is highly characteristic and appears to be confined to the Wenlock?Ludlow transitional interval on Gotland, Sweden, and ranges into the upper Ludlow on Saaremaa, Estonia. All samples yielding this species derive from strata formed in proximal carbonate platform environments. The temporal and geographical distribution indicates that it first appeared in Gotland and subsequently spread north-eastwards to the present-day Saaremaa. Kingnites diamondi adds to the list of known members of the Paulinitidae and reinforces the importance of this family, in terms of abundance and diversity, in Silurian polychaete faunas of Baltica. This is the biggest paulinitid recorded from the Silurian with an inferred body length of approximately half a metre and its diagnostic jaws may serve as a proxy for shallow water, backreef (marginal marine to lagoonal) environments.

  • 42.
    Ernst, Andrej
    et al.
    Hamburg University.
    Bogolepova, Olga
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Social Sciences, Uppsala Centre for Russian and Eurasian Studies.
    Gubanov, Alexander P.
    Uppsala University, Music and Museums, Museum of Evolution.
    Two bryozoan assemblages from the Ordovician of the Russian Arctic2017In: GFF, ISSN 1103-5897, E-ISSN 2000-0863, Vol. 139, no 3, p. 205-215Article in journal (Refereed)
    Abstract [en]

    Two assemblages from the Ordovician rocks of the Arctic region contain exclusively trepostome bryozoans. The first assemblage from the Yunoyaga Formation (Middle Ordovician) of Maly Oleniy Island, Novaya Zemlya, contains Monticulipora mammulata d’Orbigny, 1850 and Nicholsonella vaupeliformis Modzalevskaya, 1955. Both species possess thick-branched ramose colonies characteristic for rather high energy environments. The second assemblage comes from two localities of the Stroinaya Formation (Upper Ordovician) of the October Revolution Island containing the single species Amplexopora angusta Astrova, 1965. The monospecific bryozoan fauna of branched, rarely encrusting growth forms and sedimentological characteristics of embedding rocks (floatstone) suggest low energy conditions in deeper environments, apparently accompanied by high salinity conditions.

  • 43.
    Frisk, Åsa M.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Palaeobiology.
    Ebbestad, Jan Ove R.
    Uppsala University, Music and Museums, Museum of Evolution. Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
    Paragastropoda, Tergomya and Gastropoda (Mollusca) from the Upper Ordovician Dalby Limestone, Sweden2007In: GFF, ISSN 1103-5897, E-ISSN 2000-0863, Vol. 129, no 2, p. 83-99Article in journal (Refereed)
    Abstract [en]

    A fauna of 12 species of paragastropods, tergomyans and gastropods is described from the Upper Ordovician (Kukruse Stage to Idavare substage) Dalby Limestone of Tvären, Lockne, and Fjäcka (Sweden), presenting a higher diversity than previously recognized. The presence of Mimospira, Laeogyra, Sarkanella epelys n. sp. indicates a strong faunal connection with Bohemia, Czech Republic. Sarkanella is reported from outside Bohemia for the first time. Bucania erratica n. sp. represents one of the earliest records of the genus in Baltoscandia. A single case of shell repair from failed predation is recorded in this species. Synonyms for Eccyliopterus princeps Remelé and E. regularis Remelé are proposed. The significance of Laeogyra, Eccyliopterus, and Deaechospira for regional correlation within the Upper Ordovician of Baltoscandia is confirmed.

  • 44.
    Frisk, Åsa M
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Palaeobiology.
    Ebbestad, Jan Ove R.
    Uppsala University, Music and Museums, Museum of Evolution.
    Trilobite bio and ecostratigraphy of the Tremadocian Djupvik and Köpingsklint formations (A. serratus trilobite Zone) on southern Öland, Sweden2008In: GFF, ISSN 1103-5897, E-ISSN 2000-0863, Vol. 130, no 3, p. 153-160Article in journal (Refereed)
    Abstract [en]

    Trilobites of the late Tremadocian Apatokephalus serratus trilobite Zone, the Ceratopyge fauna, are abundant and widely distributed across Baltoscandia. During the Tremadocian they occur in the initial stable carbonate deposits on the platform (the Bjørkåsholmen Formation in the west; Djupvik and Köpingsklint formations in the east). Two sections at Ottenby and Degerhamn, southern Öland, Sweden, were investigated for trilobite abundance distribution. At Degerhamn and Ottenby the fauna is restricted to 70 and 78 cm respectively. In the Degerhamn quarry the fauna appears in the Djupvik Formation. At both localities the abundance distributions are similar, with an initial dominance of Ceratopyge acicularis and Shumardia pusilla, followed by a marked shift to a dominance of nileid species (Symphysurus angustatus, Varvia longicauda, Nileus limbatus). Comparisons with the Oslo Region showed a remarkably similar distribution pattern, and three biofacies are recognized. In the Oslo Region the Ceratopyge-Shumardia biofacies, the Bienvillia biofacies, and the nileid biofacies are developed. Only two of these are present on Öland, where the short lived drowning represented by the Bienvillia biofacies in the Oslo Region is not recorded. Within the nileid biofacies, Nileus and Varvia are more frequent on Öland than in the Oslo Region. The three biofacies may be applied to other areas of the Baltoscandian platform where this facies is present and potentially be used to discriminate depth gradients.

  • 45.
    Fu, Dongjing
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Palaeobiology.
    Zhang, Xingliang
    Budd, Graham E.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Palaeobiology.
    The first dorsal-eyed bivalved arthropod and its significance for early arthropod evolution2014In: GFF, ISSN 1103-5897, E-ISSN 2000-0863, Vol. 136, no 1, p. 80-84Article in journal (Refereed)
    Abstract [en]

    A new bivalved arthropod Erjiecaris minusculo gen. et sp. nov. is described from the Lower Cambrian Chengjiang Lagerstatte, Yunnan, southwest China. It possesses mosaic features, such as the reduced shield that is dorsoventrally flattened, dorsally positioned eyes, ring-shaped somites and broad furcal rami. These provide an important link for assessing the evolutionary morphological gap between two distinctive Cambrian arthropod groups, crustaceanomorph and trilobite-like taxa. Thus, the new finding reported here in turn improves the understanding of the body plan of early arthropods and provides fresh insight into the evolution of the carapace/head shield and visual system.

  • 46. Gedda, B
    et al.
    Lemdahl, Geoffrey
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Gaillard, Marie-Jose
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Lateglacial and Early Holocene environments inferred from a tufa deposit at Fyledalen, S. Sweden1999In: GFF, ISSN 1103-5897, E-ISSN 2000-0863, Vol. 121, p. 33-41Article in journal (Refereed)
    Abstract [en]

    A reinvestigation of a tufa deposit in Skane, including a number of biostratigraphical methods and chronology was carried out. The tufa was formed in a paludal environment during the time period c. 9,500 to 8,000 BP. This period is characterised by exceptional low lake levels and high summer temperatures in southern Sweden. This may suggest that optimal conditions for tufa formation at the site coincided with warm and dry climate conditions, a low groundwater table, and high evaporation. During periods with colder conditions and/or higher groundwater table pear was deposited. The changes in the local environment at and around the site were inferred from the biostratigraphical records of pollen, plant macrofossils, molluscs, and insects. The results demonstrate a development from a dwarf shrub tundra during the Late-glacial, which turned to an open birch/pine woodland around 10,000 BP. Atc. 9,000 BP hazel and birch were probably the dominant tree species in the woodland. The mollusc record suggests that the woodland remained relatively open until c. 8,500 BP when tree taxa such as alder, oak and elm became established in the Fyledalen valley. The site remained a marsh throughout the studied period, however, the results indicate a succession of different marsh plant communities.

  • 47.
    Gee, David G.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Geophysics.
    Andreasson, Per-Gunnar
    Lund Univ, Dept Geol, Lund, Sweden..
    Li, Yuan
    MLR Inst Geol, Beijing, Peoples R China..
    Krill, Allan
    Norwegian Univ Sci & Technol, Dept Geol & Mineral Resources, Trondheim, Norway..
    Baltoscandian margin, Sveconorwegian crust lost by subduction during Caledonian collisional orogeny2017In: GFF, ISSN 1103-5897, E-ISSN 2000-0863, Vol. 139, no 1, p. 36-51Article in journal (Refereed)
    Abstract [en]

    Underthrusting of Laurentia by the continental margin of Baltica during Caledonian orogeny resulted in the lateral emplacement of Iapetus Ocean-related terranes of the Upper Allochthon at least 500 km onto Baltica. The underlying Lower and Middle allochthons of the Baltoscandian margin mostly comprise Cryogenian, Ediacaran and Cambro-Silurian sedimentary successions; basement to these formations are present only as minor, isolated fragments, except at the base of the Middle Allochthon and within the underlying windows. The upper parts of the Middle Allochthon are notable for the presence of early Ediacaran dyke-swarms and other components of the Baltoscandian continent-ocean transition zone (COT). New data are presented here on the c. 610 Ma age of the COT-related dolerites in the Kalak Nappe Complex in Northern Norway and also on detrital zircons in the underlying Laksefjord and Gaissa nappes. The former confirms that the Baltoscandian COT has a similar age along the length of the orogen; the latter shows that the detrital zircon signatures in the Lower and Middle allochthons are comparable throughout the orogen. These sedimentary rocks have dominating populations of Mesoproterozoic to latest Palaeoproterozoic zircons similar to those from southern parts of the orogen, where Sveconorwegian complexes comprise the basement to the Caledonides. Thus, they help define the probable character and age of the crystalline basement that existed along this outer margin of Baltica during the Neoproterozoic, continental lower crust that was partly subducted during Ordovician continent-arc collision and subsequently lost beneath Laurentia during the 50 million years of Scandian collisional orogeny.

  • 48.
    Gee, David G.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Geophysics.
    Juhlin, Christopher
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Geophysics.
    Pascal, Christophe
    Geological Survey of Norway.
    Robinson, Peter
    Geological Survey of Norway.
    Collisional Orogeny in the Scandinavian Caledonides (COSC)2010In: GFF, ISSN 1103-5897, E-ISSN 2000-0863, Vol. 132, no 1, p. 29-44Article in journal (Refereed)
    Abstract [en]

    The COSC project is focused on the mid Paleozoic Caledonide Orogen in Scandinavia in order to better understand orogenic processes, both in the past and in today's active mountain belts. It relates to two of ICDP's main themes - the fundamental physics of plate tectonics and heat, mass and fluid transfer through Earth's crust, and on improving interpretation of geophysical data used to determine the structure and properties of the Earth's crust. Lateral transport of Caledonian allochthons over distances of several hundreds of kilometers in the Scandes, by a combination of thrusting and ductile extrusion, is comparable to that recognized in the Himalayas. The Caledonides in Scandinavia provide special opportunities for understanding Himalayan-type orogeny and the Himalayan Orogen itself, thanks to the deep level of erosion and the paucity of superimposed post-Paleozoic deformation. The surface geology in combination with the seismic, magnetotelluric, magnetic and gravity data provide control of the geometry of the Caledonian structure, both of the allochthon and the underlying parautochthon-autochthon, and define the locations for drilling. The latter will investigate both the high-grade, ductile Caledonian nappes and the underlying allochthons and basement, with two c. 2.5km deep boreholes, located near re and Jarpen in western Jamtland. The two boreholes will also provide unique information about other important aspects of the Scandinavian bedrock, including the heat flow and potential for geothermal energy, mineralization in the Seve nappes and alum shales, the uplift history of the Scandes, the Holocene paleoclimatological changes and the deep biosphere.

  • 49. Grad, M.
    et al.
    Tiira, T.
    Olsson, Sverker
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
    Komminaho, K.
    Seismic lithosphere-asthenosphere boundary beneath the Baltic Shield2014In: GFF, ISSN 1103-5897, E-ISSN 2000-0863, Vol. 136, no 4, p. 581-598Article in journal (Refereed)
    Abstract [en]

    The problem of the existence of the asthenosphere for old Precambrian cratons is still discussed. In order to study the seismic lithosphere-asthenosphere boundary (LAB) beneath the Baltic Shield, we used records of nine local earthquakes with magnitudes ranging from 2.7 to 5.9. To model the LAB, original data were corrected for topography and Moho depth using a reference model with a 46-km-thick crust. For two northern events at Spitsbergen and Novaya Zemlya, we observe a low-velocity layer, 60-70-km-thick asthenosphere, and the LAB beneath Barents Sea was found at depth of c. 200km. Sections for other events show continuous first arrivals of P-waves with no evidence for "shadow zone" in the whole range of registration, which could either be interpreted as the absence of the asthenosphere beneath the central part of the Baltic Shield, or that the LAB in this area occurs deeper (>200km). The relatively thin low-velocity layer found beneath southern Sweden, 15km below the Moho, could be interpreted as small-scale lithospheric heterogeneities, rather than asthenosphere. Differentiation of the lower lithosphere velocities beneath the Baltic Shield could be interpreted as regional heterogeneity or as anisotropy of the Baltic Shield lithosphere, with high velocities approximately in the east-west direction, and slow velocities approximately in the south-north direction.

  • 50.
    Greenwood, Sarah L.
    et al.
    Stockholm University, Faculty of Science, Department of Geological Sciences.
    Clason, Caroline C.
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Mikko, Henrik
    Nyberg, Johan
    Peterson, Gustaf
    Smith, Colby A.
    Integrated use of LiDAR and multibeam bathymetry reveals onset of ice streaming in the northern Bothnian Sea2015In: GFF, ISSN 1103-5897, E-ISSN 2000-0863, Vol. 137, no 4, p. 284-292Article in journal (Refereed)
    Abstract [en]

    Geomorphological mapping from the new LiDAR (Light Detection and Ranging)-derived digital elevation model for Sweden and a high-resolution multibeam bathymetry data-set for the Gulf of Bothnia reveals a continuous system of glacial landforms crossing the transition between the modern terrestrial and marine environments. A palaeo-ice stream in the northern Bothnian Sea is reconstructed, with an onset tributary over the present-day angstrom ngermanland-Vasterbotten coastline. Systematic contrasts in landform morphology and lineation length indicate that this ice stream comprised a relatively narrow (approximate to 40km) corridor of fast flow, flowing first SW then S, and likely fed by converging flow around the upper Bothnian Sea. The geometry and landform associations of this system imply that ice, at the time period represented here, did not flow across the Gulf of Bothnia: SSE-ward ice flow indicators on the northern Swedish coast do not correspond directly with landform assemblages of the large SE-oriented Finnish deglacial lobes. Instead, we suggest they may contribute to a late-stage fast-flow event to the S and SW. Multibeam bathymetry data offer entirely new access into the rich, landform-scale geomorphological record on the seafloor of the Gulf of Bothnia. The combination of offshore multibeam with the new terrestrial LiDAR data provides unprecedented insight into and renewed understanding of the glacial dynamics of the Bothnian Sea sector of the Fennoscandian Ice Sheet, hitherto interpreted over large areas of unmapped ice sheet bed.

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