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  • Ivarsson, Magnus
    et al.
    Swedish Museum of Natural History, Department of Paleobiology. Nordic Center for Earth Evolution (NordCEE).
    Gustavsson, Lena
    Swedish Museum of Natural History, Department of Zoology.
    Hedenäs, Lars
    Swedish Museum of Natural History, Department of Botany.
    Kronestedt, Torbjörn
    Swedish Museum of Natural History, Department of Zoology.
    Lundberg, Johannes
    Swedish Museum of Natural History, Department of Botany.
    Norbäck Ivarsson, Lena
    Södertörn University.
    Sallstedt, Therese
    Swedish Museum of Natural History, Department of Paleobiology. Nordic Center for Earth Evolution (NordCEE).
    Scheuerer, Manuela
    Sweco Rail.
    Thureborn, Olle
    Stockholm University.
    Wedin, Mats
    Swedish Museum of Natural History, Department of Botany.
    Unikt ekosystem i tunnelbanan vid Kungsträdgården2017In: Fauna och flora : populär tidskrift för biologi, ISSN 0014-8903, Vol. 112, no 1, 2-9 p.Article in journal (Other (popular science, discussion, etc.))
  • Trezzi, Giada
    et al.
    Universitat Autonoma de Barcelona, Spain.
    Garcia-Orellana, Jordi
    Universitat Autonoma de Barcelona, Spain.
    Rodellas, Valentí
    Universitat Autonoma de Barcelona, Spain.
    Masque, Pere
    Universitat Autonoma de Barcelona, Spain.
    Garcia-Solsona, Ester
    Universitat de Barcelona, Spain.
    Andersson, Per
    Swedish Museum of Natural History, Department of Geology.
    Assessing the role of submarine groundwater discharge as a source of Sr to the Mediterranean Sea2017In: Geochimica et Cosmochimica Acta, ISSN 0016-7037, E-ISSN 1872-9533, Vol. 200, 42-54 p.Article in journal (Refereed)
    Abstract [en]

    Submarine groundwater discharge (SGD) has been identified as an

    important source of Sr to the ocean and the SGD-driven Sr flux to the

    global ocean has been recently re-evaluated (Beck et al. 2013). However,

    the uncertainty of this value is still high because of the uncertainties

    related to the determination of SGD flow rates and the paucity of

    87Sr/86Sr data in SGD end-members. As carbonates have high Sr

    concentrations and are subjected to intense heightened weathering, they

    might significantly influence the SGD input of Sr to the ocean. Here we

    present data on Sr concentrations and 87Sr/86Sr ratios in three carbonate

    dominated sites of the western area of the Mediterranean Sea, a semienclosed

    basin characterized by abundant coastal carbonates. The

    87Sr/86Sr ratios in groundwater were lower compared to modern seawater (~

    0.70916), as expected for areas dominated by carbonate lithologies.

    Concentrations of Sr and 87Sr/86Sr ratios in groundwater showed

    conservative mixing in the studied subterranean estuaries. By using SGD

    flow rates reported in the literature for the study areas, a meteoric

    SGD-driven Sr flux of (0.12 - 2.1)·103 mol d-1 km-1 was calculated for

    the region, with a fresh SGD end-member characterized by a Sr

    concentration of 27 - 30 μM and a 87Sr/86Sr ratio of 0.708020 - 0.707834.

    Integrating these Sr data with literature data (i.e. values of Sr

    concentration and 87Sr/86Sr ratio from other lithologies as well as SGD

    flow rates), we also calculated the fresh SGD-driven Sr flux to the

    entire Mediterranean Sea, obtaining a value of (0.34 - 0.83)·109 mol y-1,

    with a 87Sr/86Sr of 0.7086 - 0.7081. Thus, for the entire Mediterranean

    basin, SGD is globally a source of Sr less radiogenic compared to

    seawater. The SGD Sr flux to the Mediterranean Sea represents 5-6% of the

    SGD Sr flux to the global ocean and the Mediterranean SGD end-member has

    higher Sr concentration (5.0 - 12 μM) than the global SGD end-member (2.9

    μM). This confirms the significant role of carbonate lithologies on SGDdriven

    Sr fluxes to seawater.

    The fresh SGD-driven Sr flux to the Mediterranean Sea is about 20 - 50%

    of the riverine Sr input and significantly higher than the input through

    atmospheric dust deposition. Therefore SGD should be considered as an

    important continental source of Sr to the basin.

  • Grasse, P.
    et al.
    GEOMAR Helmholtz Centre for Ocean Research Kiel, Germany.
    Brezezinski, M.
    Marine Science Institute and the Department of Ecology, Evolution, and Marine Biology & University of California, USA.
    Cardinal, D.
    Sorbonne Universités, Paris, France.
    de Souza, G.F.
    ETH Zurich, Institute of Geochemistry and Petrology, Switzerland.
    Andersson, Per
    Swedish Museum of Natural History, Department of Geology.
    Closset, I.
    Sorbonne Universités, Paris, France.
    Cao, Z.
    State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, China.
    Dai, M.
    State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, China.
    Ehlert, C.
    Max Planck Research Group for Marine Isotope Geochemistry, University of Oldenburg, Germany.
    Estrade, N.
    University of British Columbia, Vancouver, British Columbia,.
    Francois, R.
    University of British Columbia, Vancouver, British Columbia,.
    Frank, M.
    GEOMAR, Helmholtz Centre for Ocean Research Kiel, Germany.
    Jiang, G.
    Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, China.
    Jones, J.L.
    Marine Science Institute and the Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara USA.
    Kooijman, E.
    Swedish Museum of Natural History, Department of Geology.
    Liu, Q.
    Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, China.
    Lu, D.
    Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, China.
    Pahnke, K.
    Institute for Chemistry and Biology of the Marine Environment, University of Oldenburg, Germany.
    Ponzevera, E.
    Unité de Recherche Géosciences Marines, IFREMER, Brest, France.
    Schmitt, M.
    Swedish Museum of Natural History, Department of Geology.
    Sun, S.
    Department of Environmental Science and Analytical Chemistry, Stockholm University, Sweden.
    Sutton, J.N.
    Universite de Brest, CNRS, IRD, IFREMER, LEMAR, IUEM, France.
    Thil, F.
    LSCE/IPSL - Laboratoire des Sciences du Climat et de l'Environnement, Gif sur Yvette, France.
    Weis, D.
    University of British Columbia Pacific Center for Isotopic and Geochemical Research, Vancouver, British Columbia,Canada .
    Wetzel, F.
    ETH Zurich, Institute of Geochemistry and Petrology, Switzerland.
    Zhang, A.
    State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai, China.
    Zhang, J.
    State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai, China.
    Zhang, Z.
    State Key Laboratory of Marine Environmental Science,Xiamen University,.
    GEOTRACES Intercalibration of the Stable Silicon Isotope Composition of Dissolved Silicic Acid in Seawater2017In: Journal of Analytical Atomic Spectrometry, ISSN ISSN 0267-9477, Vol. 32, 562-578 p.Article in journal (Refereed)
    Abstract [en]

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

  • Wortberg, Katharina
    et al.
    Luleå Technical University.
    Conrad, Sarah
    Luleå Technical University.
    Andersson, Per
    Swedish Museum of Natural History, Department of Geology.
    Ingri, Johan
    Luleå Technical University.
    Strontium Isotopes - A Tracer for River Suspended Iron Aggregates2017In: Applied Geochemistry, ISSN 0883-2927, E-ISSN 1872-9134, Vol. 95, 85-90 p.Article in journal (Refereed)
    Abstract [en]

    The Kalix River shows distinct temporal variations in the Sr-isotope ratio in filtered water (0.726 to 0.732). During base flow in winter the 87Sr/86Sr ratio is on average 0.730. When discharge increases and peaks during spring flood the 87Sr/86Sr ratio shows the most radiogenic (0.732) values. The temporal variations in the 87Sr/86Sr ratio in the Kalix River can be explained by mixing of water from the woodlands and the mountain areas.

    During high water discharge in May the 87Sr/86Sr ratios are more radiogenic in the suspended phase (1 kDa - 70 µm) compared to the truly dissolved phase (<1 kDa). The difference in 87Sr/86Sr ratio between the two phases (Δ 87Sr/86Sr) is linearly correlated with the suspended iron concentration. During spring flood Sr and Fe derived from an additional source, reach the river. Deep groundwater has a more radiogenic 87Sr/86Sr isotope ratio than the Kalix River during spring flood and thus, represents a possible source for the suspended Fe and the associated Sr. Strontium can be coprecipitated with and adsorbed to different types of Fe aggregates. We propose that the Sr-isotope ratio in the suspended phase reflects the isotopic composition of the water at the interface between anoxic groundwater and oxic stream water in the riparian zone, where the Fe aggregates are formed. These particles dominate the suspended phase in the river and the mixing with mountain waters, poor in Fe, produces the difference in the isotopic signature. The different signatures in suspended and truly dissolved fraction indicate that these aggregates are relatively stable during stream-river transport. As such the 87Sr/86Sr can be used to trace the origin of the non-detrital suspended phase.

  • Doguzhaeva, Larisa A.
    et al.
    Swedish Museum of Natural History, Department of Paleobiology.
    Bengtson, Stefan
    Swedish Museum of Natural History, Department of Paleobiology.
    Reguero, Marcello A.
    Mörs, Thomas
    Swedish Museum of Natural History, Department of Paleobiology.
    An Eocene orthocone from Antarctica shows convergent evolution of internally shelled cephalopods.2017In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 12, no 3, 1-20 p., e0172169Article in journal (Refereed)
    Abstract [en]

    Background

    The Subclass Coleoidea (Class Cephalopoda) accommodates the diverse present-day internally shelled cephalopod mollusks (Spirula, Sepia and octopuses, squids, Vampyroteuthis) and also extinct internally shelled cephalopods. Recent Spirula represents a unique coleoid retaining shell structures, a narrow marginal siphuncle and globular protoconch that signify the ancestry of the subclass Coleoidea from the Paleozoic subclass Bactritoidea. This hypothesis has been recently supported by newly recorded diverse bactritoid-like coleoids from the Carboniferous of the USA, but prior to this study no fossil cephalopod indicative of an endochochleate branch with an origin independent from subclass Bactritoidea has been reported.

    Methodology/Principal findings

    Two orthoconic conchs were recovered from the Early Eocene of Seymour Island at the tip of the Antarctic Peninsula, Antarctica. They have loosely mineralized organic-rich chitincompatible microlaminated shell walls and broadly expanded central siphuncles. The morphological, ultrustructural and chemical data were determined and characterized through comparisons with extant and extinct taxa using Scanning Electron Microscopy/Energy Dispersive Spectrometry (SEM/EDS).

    Conclusions/Significance

    Our study presents the first evidence for an evolutionary lineage of internally shelled cephalopods with independent origin from Bactritoidea/Coleoidea, indicating convergent evolution with the subclass Coleoidea. A new subclass Paracoleoidea Doguzhaeva n. subcl. is established for accommodation of orthoconic cephalopods with the internal shell associated with a broadly expanded central siphuncle. Antarcticerida Doguzhaeva n. ord., Antarcticeratidae Doguzhaeva n. fam., Antarcticeras nordenskjoeldi Doguzhaeva n. gen., n. sp. are described within the subclass Paracoleoidea. The analysis of organic-rich shell preservation of A. nordenskjoeldi by use of SEM/EDS techniques revealed fossilization of hyposeptal cameral soft tissues. This suggests that a depositional environment favoring soft-tissue preservation was the factor enabling conservation of the weakly mineralized shell of A. nordenskjoeldi.

  • Fransson, Thord
    et al.
    Swedish Museum of Natural History, Department of Environmental research and monitoring.
    Karlsson, Måns
    Kullberg, Cecilia
    Stach, Robert
    Barboutis, Christos
    Inability to regain normal body mass despite extensive refuelling in great reed warblers following the trans-Sahara crossing during spring migration2017In: Journal of Avian Biology, ISSN 0908-8857, E-ISSN 1600-048X, Vol. 48, 58-65 p.Article in journal (Refereed)
  • Trezzi, Giada
    et al.
    Universitat Autònoma de Barcelona.
    Garcia-Orellana, Jordi
    Universitat Autònoma de Barcelona.
    Rodellas, Valentí
    Universitat Autònoma de Barcelona.
    Masque, Pere
    Universitat Autònoma de Barcelona.
    Garcia-Solsona, Ester
    Universitat de Barcelona.
    Andersson, Per
    Swedish Museum of Natural History, Department of Geology.
    Assessing the role of submarine groundwater discharge as a source of Sr to the Mediterranean Sea2017In: Geochimica et Cosmochimica Acta, ISSN 0016-7037, E-ISSN 1872-9533, Vol. 200, 42-54 p.Article in journal (Refereed)
    Abstract [en]

    Submarine groundwater discharge (SGD) has been identified as an important source of Sr to the ocean and the SGD-driven Sr flux to the global ocean has been recently re-evaluated (Beck et al. 2013). However, the uncertainty of this value is still high because of the uncertainties related to the determination of SGD flow rates and the paucity of 87Sr/86Sr data in SGD end-members. As carbonates have high Sr concentrations and are subjected to intense heightened weathering, they might significantly influence the SGD input of Sr to the ocean. Here we present data on Sr concentrations and 87Sr/86Sr ratios in three carbonate dominated sites of the western area of the Mediterranean Sea, a semi-enclosed basin characterized by abundant coastal carbonates. The 87Sr/86Sr ratios in groundwater were lower compared to modern seawater (~ 0.70916), as expected for areas dominated by carbonate lithologies. Concentrations of Sr and 87Sr/86Sr ratios in groundwater showed conservative mixing in the studied subterranean estuaries. By using SGD flow rates reported in the literature for the study areas, a meteoric SGD-driven Sr flux of (0.12 – 2.1)·103 mol d-1 km-1 was calculated for the region, with a fresh SGD end-member characterized by a Sr concentration of 27 – 30 μM and a 87Sr/86Sr ratio of 0.708020 – 0.707834.

    Integrating these Sr data with literature data (i.e. values of Sr concentration and 87Sr/86Sr ratio from other lithologies as well as SGD flow rates), we also calculated the fresh SGD-driven Sr flux to the entire Mediterranean Sea, obtaining a value of (0.34 – 0.83)·109 mol y-1, with a 87Sr/86Sr of 0.7086 – 0.7081. Thus, for the entireMediterranean basin, SGD is globally a source of Sr less radiogenic compared toseawater. The SGD Sr flux to the Mediterranean Sea represents 5-6% of the SGD Sr flux to the global ocean and the Mediterranean SGD end-member has higher Sr concentration (5.0 – 12 μM) than the global SGD end-member (2.9 μM). This confirms the significant role of carbonate lithologies on SGD-driven Sr fluxes to seawater.

    The fresh SGD-driven Sr flux to the Mediterranean Sea is about 20 – 50% of the riverine Sr input and significantly higher than the input through atmospheric dust deposition. Therefore SGD should be considered as an important continental source of Sr to the basin.