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  • 151. Heathcote, A. J.
    et al.
    Hobbs, J. M. R.
    Anderson, N. J.
    Frings, Patrick J
    Swedish Museum of Natural History, Department of Geology.
    Engstrom, D. R.
    Downing, J. A.
    Diatom floristic change and lake paleoproduction as evidence of recent eutrophication in shallow lakes of the midwestern USA2015In: Journal of Paleolimnology, ISSN 0921-2728, E-ISSN 1573-0417, Vol. 53, no 1, p. 17-34Article in journal (Refereed)
    Abstract [en]

    Intensive agricultural practices can dramatically change the landscape, thereby increasing the concentrations and rates at which nutrients are delivered to aquatic ecosystems. In the United States, concerns about accelerating rates of lake eutrophication related to increases in nutrient loading require a method of quantifying ecological changes that have occurred since European settlement. Because the application of traditional quantitative total phosphorus transfer functions in paleolimnology has proven difficult in shallow, hypereutrophic lakes, we used several approaches in this study to assess ecosystem changes associated with eutrophication of 32 natural lakes in the state of Iowa, USA. In addition to traditional transfer function methods, we estimated changes in primary productivity from the flux of biogenic silica (BSi) and organic carbon accumulation rates (OC AR). Additionally, we compared pre-disturbance diatom communities to modern diatom communities, i.e. floristic change, using non-metric multi-dimensional scaling and square chord distance. OC AR and BSi fluxes increased over time and were positively correlated with the time period of agricultural intensification in the region (post-1940). Ninety-one percent of the lakes in this study showed evidence for eutrophication based on geochemical proxies, and 88 % of lakes showed major floristic change in the diatom community. Whereas geochemical indicators showed consistent increases in productivity across most lakes, floristic changes reflected more complex interactions between other environmental drivers. The magnitude of floristic change did not directly correlate to nutrient-driven increases in primary production, but was driven by ecological diatom assembly related to lake depth. Transfer functions consistently perform poorly, especially for shallow lakes, and other techniques that combine geochemistry and diatom ecology are recommended for reconstructions of eutrophication.

  • 152. Heinonen, A.
    et al.
    Andersen, T.
    Rämö, O.T.
    Whitehouse, Martin J.
    Swedish Museum of Natural History, Department of Geology.
    The source of Proterozoic anorthosite and rapakivi granite magmatism: evidence from combined in situ Hf–O isotopes of zircon in the Ahvenisto complex, southeastern Finland.2015In: Journal of the Geological Society, ISSN 0016-7649, E-ISSN 2041-479X, Vol. 172, p. 103-112Article in journal (Refereed)
    Abstract [en]

    The isotope compositions of massif-type anorthosites in Proterozoic anorthosite–mangerite–charnockite–granite (AMCG) complexes are commonly dominated by crustal values. Olivine-bearing anorthositic rocks in several AMCG suites have, however, been shown to display juvenile character, suggesting that variably depleted mantle reservoirs were involved in their genesis. A coupled in situ zircon Hf–O isotope dataset from the 1.64 Ga Ahvenisto AMCG complex in the 1.54–1.65 Ga Fennoscandian rapakivi granite–massif-type anorthosite province reveals correlated juvenile isotope signals (δ18Ozrn = 5.4–6.6‰; initial ϵHf = −1.1 to +3.4) in the most primitive gabbroic rock type of the suite suggesting a depleted mantle origin for the anorthositic rocks. This signal is not as prominent in the more evolved co-magmatic anorthositic rocks (δ18Ozrn = 6.3–7.8‰; initial ϵHf = −0.8 to +2.0), most probably owing to contamination of the mantle-derived primary magma by crustal material. A rapakivi granite associated with the anorthositic rocks has different isotope composition (δ18Ozrn = 7.4–8.6‰; initial ϵHf = −2.1 to +0.5) that points to a crustal source.

  • 153. Heinonen, Jussi S.
    et al.
    Luttinen, Arto V.
    Whitehouse, Martin J.
    Swedish Museum of Natural History, Department of Geology.
    Enrichment of 18O in the mantle sources of the Antarctic portion of the Karoo large igneous province2018In: Contributions to Mineralogy and Petrology, ISSN 0010-7999, E-ISSN 1432-0967, Vol. 173, no 3Article in journal (Refereed)
    Abstract [en]

    Karoo continental flood basalt (CFB) province is known for its highly variable trace element and isotopic composition, often attributed to the involvement of continental lithospheric sources. Here, we report oxygen isotopic compositions measured with secondary ion mass spectrometry for hand-picked olivine phenocrysts from ~ 190 to 180 Ma CFBs and intrusive rocks from Vestfjella, western Dronning Maud Land, that form an Antarctic extension of the Karoo province. The Vestfjella lavas exhibit heterogeneous trace element and radiogenic isotope compositions (e.g., εNd from − 16 to + 2 at 180 Ma) and the involvement of continental lithospheric mantle and/or crust in their petrogenesis has previously been suggested. Importantly, our sample set also includes rare primitive dikes that have been derived from depleted asthenospheric mantle sources (εNd up to + 8 at 180 Ma). The majority of the oxygen isotopic compositions of the olivines from these dike rocks (δ18O = 4.4–5.2‰; Fo = 78–92 mol%) are also compatible with such sources. The olivine phenocrysts in the lavas, however, are characterized by notably higher δ18O (6.2–7.5‰; Fo = 70–88 mol%); and one of the dike samples gives intermediate compositions (5.2‒6.1‰, Fo = 83–87 mol%) between the other dikes and the CFBs. The oxygen isotopic compositions do not correlate with radiogenic isotope compositions susceptible to crustal assimilation (Sr, Nd, and Pb) or with geochemical indicators of pyroxene-rich mantle sources. Instead, δ18O correlates positively with enrichments in large-ion lithophile elements (especially K) and 187Os. We suggest that the oxygen isotopic compositions of the Vestfjella CFB olivines primarily record large-scale subduction-related metasomatism of the sub-Gondwanan mantle (base of the lithosphere or deeper) prior to Karoo magmatism. The overall influence of such sources to Karoo magmatism is not known, but, in addition to continental lithosphere, they may be responsible for some of the geochemical heterogeneity observed in the CFBs.

  • 154.
    Henrik, Skogby
    et al.
    Swedish Museum of Natural History, Department of Geology.
    Janak, Marian
    Broska, Igor
    Water incorporation in omphacite: concentrations and compositional relations in ultrahigh-pressure eclogites from Pohorje, Eastern Alps2016In: European journal of mineralogy, ISSN 0935-1221, E-ISSN 1617-4011, Vol. 28, p. 631-639Article in journal (Refereed)
  • 155.
    Hirst, Catherine
    et al.
    Swedish Museum of Natural History, Department of Geology.
    Andersson, Per
    Swedish Museum of Natural History, Department of Geology.
    Shaw, Samuel
    University of Manchester.
    Burke, Ian
    University of Leeds.
    Kutscher, Liselott
    Swedish Museum of Natural History, Department of Geology.
    Murphy, Melissa
    Oxford University.
    Maximov, Trofim
    Institute for Biological Problems of the Cryolithozone, Siberian Branch of the Russian Academy of Sciences, Yakutsk.
    Pokrovsky, Oleg
    University of Toulouse.
    Mörth, Carl-Magnus
    Stockholm University.
    Porcelli, Don
    Oxford University.
    Characterisation of Fe-bearing particles and colloids in the Lena River basin, NE Russia2017In: Geochimica et Cosmochimica Acta, ISSN 0016-7037, E-ISSN 1872-9533, Vol. 213, p. 553-573Article in journal (Refereed)
    Abstract [en]

    Rivers are significant contributors of Fe to theocean. However, the characteristics of chemically reactive Fe remain poorly constrained, especially in large Arctic rivers, which drain landscapes highly susceptible to climate change and carbon cycle alteration. The aim of this study was a detailed characterisation (size, mineralogy, and speciation) of riverine Fe-bearing particles (> 0.22 µm) and colloids (1 kDa – 0.22 µm) and their association with organic carbon (OC), in the Lena River and tributaries, which drain a catchment almost entirely underlain by permafrost. Samples fromthe main channel and tributaries representing watersheds that span a wide rangein topography and lithology were taken after the spring flood in June 2013 and summer baseflow in July 2012. Fe-bearing particles were identified, usingTransmission Electron Microscopy, as large (200 nm – 1 µm) aggregates of smaller (20 nm - 30 nm) spherical colloids of chemically-reactive ferrihydrite.In contrast, there were also large (500 nm – 1 µm) aggregates of clay (illite) particles and smaller (100 - 200 nm) iron oxide particles (dominantly hematite) that contain poorly reactive Fe. TEM imaging and Scanning Transmission X-raymicroscopy (STXM) indicated that the ferrihydrite is present as discrete particles within networks of amorphous particulate organic carbon (POC) and attached to the surface of primary produced organic matter and clay particles.Together, these larger particles act as the main carriers of nanoscale ferrihydrite in the Lena River basin.  The chemically reactive ferrihydrite accounts for on average 70 ± 15 % of the total suspended Fe in the Lena River and tributaries. These observations place important constraints on Fe and OC cycling in the Lena River catchment area and Fe-bearing particle transport to the Arctic Ocean.

  • 156.
    Hode Vuorinen, Jaana
    et al.
    Stockholms universitet.
    Hålenius, Ulf
    Swedish Museum of Natural History, Department of Geology.
    Nb-, Zr- and LREE-rich titanite from the Alnö alkaline complex: Crystal chemistry and its importance as a petrogenetic indicator2005In: Lithos, ISSN 0024-4937, E-ISSN 1872-6143, Vol. 83, p. 128-142Article in journal (Refereed)
  • 157.
    Hode Vuorinen, Jaana
    et al.
    Stockholms universitet.
    Hålenius, Ulf
    Swedish Museum of Natural History, Department of Geology.
    Whitehouse, Martin J.
    Swedish Museum of Natural History, Department of Geology.
    Mansfeld, Joakim
    Stockholms universitet.
    Skelton, Alasdair D. L.
    Stockholms universitet.
    Compositional variations (major and trace elements) of clinopyroxene and Ti-andradite from pyroxenite, ijolite and nepheline syenite, Alnö Island, Sweden2005In: Lithos, ISSN 0024-4937, E-ISSN 1872-6143, Vol. 81, p. 55-77Article in journal (Refereed)
  • 158.
    Hogmalm, Johan K.
    et al.
    Department of Earth Science, University of Gothenburg, Gothenburg, Sweden.
    Zack, Thomas
    Department of Earth Science, University of Gothenburg, Gothenburg, Sweden.
    Karlsson, Andreas
    Swedish Museum of Natural History, Department of Geology.
    Sjökvist, Axel S.L.
    Department of Earth Science, University of Gothenburg, Gothenburg, Sweden.
    Garbe-Schönberg, Dieter
    CAU Kiel University, Institute of Geosciences, Ludewig-Meyn-Strasse 10, D-24118 Kiel, Germany .
    In situ Rb–Sr and K–Ca dating by LA-ICP-MS/MS: an evaluation of N2O and SF6 as reaction gases2017In: Journal of Analytical Atomic Spectrometry, ISSN 0267-9477, E-ISSN 1364-5544, Vol. 32, p. 305-313Article in journal (Refereed)
    Abstract [en]

    In situ dating of K-rich minerals, e.g. micas and K-feldspar, by the Rb–Sr isotopic system is a new development made possible by the ICP-MS/MS technique. Online chemical separation of Rb and Sr is possible in an O2-filled reaction cell, wherein a portion of the Sr reacts to SrO+ while simultaneously no RbO+ is formed. O2 reactions provide stable analytical conditions sufficient for precise and accurate determination of Rb/Sr and Sr/Sr isotopic ratios using 80 micron laser ablation spots. However, to date <10% of the Sr reacts with O2 as reaction gas, leaving room for improvement using more potent reaction gases. With a more efficient reactive transfer, it should be possible to obtain similar results with a smaller laser spot size, hence gaining higher spatial resolution. In this study, we have evaluated N2O and SF6 as reaction gases since they have previously been shown to react strongly with Sr+, without affecting Rb+. Analytical conditions, including cell parameters and reaction gas flow rate were optimized while ablating NIST SRM 610. The main reaction product is SrO+ for N2O reaction and SrF+ for SF6 reaction. Both gases show significantly higher reaction product formation compared to O2 with >85% of Sr reacting with N2O and >70% Sr reacting with SF6; Rb does not react with either gas. As a result, the sensitivity for Sr reaction products is ∼10 times higher with N2O and ∼8 times higher with SF6 compared to O2. With these more reactive gases, the error of mica isochron ages, calibrated against a newly developed nano-particulate pressed powder tablet of mica–Mg, is ∼1% using a 50 μm laser spot. Our tests show that both N2O and SF6 form interfering reaction products, e.g., SrOH (N2O), SiF3 and TiF3 (SF6) that are difficult to handle using single mass spectrometer instruments, but which can be overcome using MS/MS. Using SF6 combined with H2, it is possible to measure 40Ca+ as 40Ca19F+, free from interference of 40Ar+ and 40K+. This facilitates the dating of micas by the K–Ca isotopic system; we present the first in situ K–Ca age determination.

  • 159.
    Holtstam, Dan
    Swedish Museum of Natural History, Department of Geology.
    Vad betyder ett namn? Om beskrivningar och namngivning av mineral.2018In: Litofilen, ISSN 1651-6117, Vol. 34, no 4, p. 7-12Article in journal (Other (popular science, discussion, etc.))
  • 160.
    Holtstam, Dan
    et al.
    Swedish Museum of Natural History, Department of Geology.
    Andersson, Ulf B
    LKAB.
    Broman, Curt
    Stockholms universitet.
    Mansfeld, Joakim
    Stockholms universitet.
    Origin of REE mineralization in the Bastnäs-type Fe-REE-(Cu-Mo-Bi-Au) deposits, Bergslagen, Sweden2014In: Mineralium Deposita, ISSN 0026-4598, E-ISSN 1432-1866, Vol. 49, p. 933-966Article in journal (Refereed)
  • 161.
    Holtstam, Dan
    et al.
    Swedish Museum of Natural History, Department of Geology.
    Bindi, Luca
    Università di Firenze, Italy.
    Hålenius, Ulf
    Swedish Museum of Natural History, Department of Geology.
    Andersson, Ulf Bertil
    Luossavaara-Kiirunavaara AB, Kiruna, Sweden.
    Delhuyarite-(Ce) – Ce4Mg(Fe3+2W)□(Si2O7)2O6(OH)2 – a new mineral of the chevkinite group, from the Nya Bastnäs Fe–Cu–REE deposit, Sweden2017In: European journal of mineralogy, ISSN 0935-1221, E-ISSN 1617-4011, Vol. 29, no 5, p. 897-905Article in journal (Refereed)
    Abstract [en]

    Delhuyarite-(Ce) is a new mineral (IMA no. 2016-091) with ideal formula Ce4Mg(Fe3+2W)□(Si2O7)2O6(OH)2. It is named after Juan and Fausto de Elhuyar (Delhuyar), chemists and metallurgists, who in 1783 isolated tungsten metal for the first time.  Associated minerals in the only known sample, from the Nya Bastnäs Fe–Cu–REE deposit (Västmanland, Sweden), include cerite-(Ce), tremolite‒actinolite, percleveite-(Ce), bastnäsite-(Ce), ferriallanite-(Ce), törnebohmite-(Ce), magnetite, chalcopyrite, quartz and scheelite. Delhuyarite-(Ce), which forms subhedral crystals up to 0.3mm long, is brown–black with a dark brown streak and translucent with an adamantine lustre. It is pleochroic in black to rust red and optically biaxial (-). Calculated density and mean refractive index are 5.20 g·cm-3 and 1.94, respectively. Chemical analyses (electron microprobe) gave (in wt%) La2O3 14.58, Ce2O3 23.29, Pr2O1.89, Nd2O3 6.13, Sm2O3 0.74, Gd2O3 0.37, Dy2O3 0.03, Er2O3 0.04, Yb2O3 0.12, Y2O3 0.22, CaO 0.76, Fe2O3 12.86, MgO 2.43, Al2O3 0.73, SiO2 18.16, TiO2 0.09, WO3 15.53, H2Ocalc 1.33, F 0.05, Cl 0.03, O=(F, Cl) 0.03, sum 99.35, corresponding to an empirical formula: (Ce1.89La1.19Nd0.48Pr0.15Sm0.06Gd0.03Y0.03Ca0.18)Σ4.01(Fe3+2.14W0.89Mg0.80Al0.19Ti0.02)Σ4.04Si4.01O20(OH1.96F0.04)Σ2, based on 22 O atoms per formula unit (apfu). The presence of H2O is confirmed by IR-spectroscopy, from a strong absorption band at 3495 cm-1. Delhuyarite-(Ce) is monoclinic, space group C2/m, with unit-cell parameters a =13.6020(6)Å, b = 5.7445(3)Å, c = 10.9996(5)Å, β = 100.721(4)°, V = 844.47 (6)Å3 and Z = 2 (data for natural crystal). The crystal structure was refined to an R1 index of 3.9% (natural crystal) and 1.8% (annealed). Delhuyarite-(Ce) has the same structural topology as chevkinite subgroup minerals, e.g. chevkinite-(Ce). It is the only mineral of the group with a significant content of W6+ = 0.89 apfu. In delhuyarite-(Ce), Mg is dominant at the M1 site as in polyakovite-(Ce); the composition of the M2, M3 and M4 sites is [(Fe3+2W)□], with M2 being 50% vacant.

  • 162.
    Holtstam, Dan
    et al.
    Swedish Museum of Natural History, Department of Geology.
    Bindi, Luca
    Università di Firenze, Italy.
    Hålenius, Ulf
    Swedish Museum of Natural History, Department of Geology.
    Kolitsch, Uwe
    Naturhistorisches Museum, Wien, Austria.
    Mansfeld, Joakim
    Stockholm University, Sweden.
    Ulfanderssonite-(Ce), a new Cl-bearing REE silicate mineral species from the Malmkärra mine, Norberg, Sweden2017In: European journal of mineralogy, ISSN 0935-1221, E-ISSN 1617-4011, Vol. 29, no 6, p. 1015-1026Article in journal (Refereed)
    Abstract [en]

    Ulfanderssonite-(Ce) is a new mineral (IMA 2016-107) from the long-abandoned Malmkärra iron mine, one of the Bastnäs-type Fe-rare earth element (REE) deposits in the Bergslagen ore region, central Sweden. It is named for Ulf B. Andersson, a Swedish geologist and petrologist. In the type specimen, the mineral occurs with västmanlandite-(Ce), bastnäsite-(Ce), phlogopite, talc, magnetite, pyrite, fluorbritholite-(Ce) and scheelite. Ulfanderssonite-(Ce) forms pinkish, translucent subhedral grains, 100–300 mm, in aggregates up to 2 mm. Fracture is uneven, and there is an indistinct cleavage parallel (001). Mohs' hardness is 5−6, dcalc= 4.97 g·cm-3. Optically, ulfanderssonite-(Ce) is nonpleochroic, biaxial negative, with 2Vmeas =55° and ncalc=1.82. The ideal composition is Ce15CaMg2(SiO4)10(SiO3OH)(OH,F)5Cl3. EMP and LA-ICP-MS chemical analyses yielded (in wt%) La2O3 11.87, Ce2O3 30.98, Pr2O3 3.99, Nd2O3 17.14, Sm2O3 2.81, Eu2O3 0.18, Gd2O3 1.15, Dy2O3 0.30, Tb2O3 0.10, Y2O3 1.11, CaO 2.26, FeO 0.02, MgO 1.97, P2O5 0.08 SiO2 19.13, H2Ocalc 1.07, F 1.09, Cl 2.89, O=(F, Cl) -1.10, sum 97.04. The five strongest powder X-ray diffraction lines are [I (%) dobs(Å) (hkl)]: 100 2.948 (-421), 47 2.923 (204), 32 2.660 (-225), 26 3.524 (40-1), 25 1.7601 (6-23). Ulfanderssonite-(Ce) is monoclinic, Cm, with a =14.1403(8), b = 10.7430(7), c = 15.498(1) Å, β = 106.615(6)° and V = 2256.0(2) Å3 for Z = 2. The crystal structure has been solved by direct methods and refined to R1 = 2.97% for 5280 observed reflections. It consists of a regular alternation of two layers, designated A and B, along the c-axis: A (ca. 9 Å thickness), with composition [(Ce8Ca)MgSiO22(OH,F)4]8+, and B (ca. 6.5 Å), with composition [Ce7Mg­Si4O21(OH,F)2Cl3]8-; the A layer is topologically and chemically closely related to cerite-(Ce). A FTIR spectrum shows strong absorption in the region 2850−3650 cm-1, related to the presence of O-H stretching bands. Ulfanderssonite-(Ce) is interpreted as a primary mineral at the deposit, along with the more common fluorbritholite-(Ce), formed by a magmatic-hydrothermal fluid with REE, Si, F and Cl ion complexes reacting with dolomite marble. The presence of ulfanderssonite-(Ce) is direct evidence of a Cl-rich mineral-forming aqueous solution, normally not reflected in the composition of skarn minerals in Bastnäs-type deposits.

  • 163.
    Horst, Axel
    et al.
    Stockholm University.
    Holmstrand, Henry
    Stockholm University.
    Andersson, Per
    Swedish Museum of Natural History, Department of Geology.
    Thornton, Brett F
    Stockholm University.
    Wishkerman, Asher
    Max-Planck-Institute for Chemistry, Germany.
    Keppler, Frank
    Max-Planck-Institute for Chemistry, Germany.
    Gustafsson, Örjan
    Stockholm University.
    Stable bromine isotopic composition of methyl bromide released from plant matter2014In: Geochimica et Cosmochimica Acta, ISSN 0016-7037, E-ISSN 1872-9533, Vol. 125, p. 186-195Article in journal (Refereed)
  • 164.
    Hålenius, Ulf
    Swedish Museum of Natural History, Department of Geology.
    Absorption of light by exchange coupled pairs of tetrahedrally coordinated divalent manganese in the helvite-genthelvite solid solution2011In: Periodico di Mineralogia, ISSN 0369-8963, Vol. 80, p. 105-111Article in journal (Refereed)
  • 165.
    Hålenius, Ulf
    et al.
    Swedish Museum of Natural History, Department of Geology.
    Andreozzi, Giovanni B.
    Sapienza Università di Roma.
    Skogby, Henrik
    Swedish Museum of Natural History, Department of Geology.
    Structural relaxation around Cr3+ and the red-green color change in the spinel s.s.-magnesiochromite (MgAl2O4–MgCr2O4) and gahnite-zincochromite (ZnAl2O4–ZnCr2O4) solid solution series2010In: American Mineralogist, ISSN 0003-004X, E-ISSN 1945-3027, Vol. 95, p. 456-462Article in journal (Refereed)
  • 166.
    Hålenius, Ulf
    et al.
    Swedish Museum of Natural History, Department of Geology.
    Bosi, Ferdinando
    Swedish Museum of Natural History, Department of Geology.
    Cation ordering in Pb2+-bearing, Mn3+-rich pargasite from Långban, Sweden2012In: American Mineralogist, ISSN 0003-004X, E-ISSN 1945-3027, Vol. 97, p. 1635-1640Article in journal (Refereed)
  • 167.
    Hålenius, Ulf
    et al.
    Swedish Museum of Natural History, Department of Geology.
    Bosi, Ferdinando
    Swedish Museum of Natural History, Department of Geology.
    Color of Mn-bearing gahnite: A first example of electronic transitions in heterovalent exchange coupled IVMn2+-VIMn3+ pairs in minerals.2014In: American Mineralogist, ISSN 0003-004X, E-ISSN 1945-3027, Vol. 99, p. 261-266Article in journal (Refereed)
  • 168.
    Hålenius, Ulf
    et al.
    Swedish Museum of Natural History, Department of Geology.
    Bosi, Ferdinando
    Sapienza Università di Roma, Rome, Italy.
    Gatedalite, Zr(Mn2+2Mn3+4)SiO12, a new mineral species of the braunite group from Långban, Sweden2015In: Mineralogical magazine, ISSN 0026-461X, E-ISSN 1471-8022, Vol. 79, no 3, p. 625-634Article in journal (Refereed)
    Abstract [en]

    Gatedalite, Zr(Mn2+2Mn3+4)SiO12, is a new mineral of the braunite group. It is found in hausmannite impregnated skarn together with jacobsite, Mn-bearing calcite, tephroite, Mn-bearing phlogopite,långbanite, pinakiolite and oxyplumboroméite at the Långban Mn-Fe oxide deposit, Värmland, central Sweden. The mineral occurs as very rare, small ≤60 µm), grey, submetallic, irregularly rounded anhedral grains. Gatedalite has a calculated density of 4.783 g/cm3. It is opaque and weakly anisotropic with reflectivity in air varying between 17.1 and 20.8% in the visible spectral range. Gatedalite is tetragonal, space group I41/acd, with the unit-cell parameters a = 9.4668(6) Å , c = 18.8701(14) Å , V = 1691.1(2) Å3 and Z = 8. The crystal structure was refined to an R1 index of 5.09% using 1339 unique reflections collected with MoKa X-ray radiation. The five strongest powder X-ray diffraction lines [d in Å, (I), (hkl)] are: 2.730(100)(224), 2.367(12)(040), 1.6735(12)(440), 1.6707(29)(048) and 1.4267(16)(264). Gatedalite is a member of the braunite group (general formula AB6SiO12). It is related to braunite (Mn2+Mn3+6SiO12) through the net cation exchange (Zr4++Mn2+)➝2Mn3+, which results from the substitutions Zr4+ ➝ Mn2+ at the 8-fold coordinated site (A in the general formula) coupled with a 2Mn2+ ➝ 2Mn3+ substitution at the 6-fold coordinated sites (B in the general formula).

  • 169.
    Hålenius, Ulf
    et al.
    Swedish Museum of Natural History, Department of Geology.
    Bosi, Ferdinando
    Swedish Museum of Natural History, Department of Geology.
    Oxyplumboroméite, Pb2Sb2O7, a new mineral species of the pyrochlore supergroup from Harstigen Mine, Värmland, Sweden2013In: Mineralogical magazine, ISSN 0026-461X, E-ISSN 1471-8022, Vol. 77, no 7, p. 2931-2939Article in journal (Refereed)
  • 170.
    Hålenius, Ulf
    et al.
    Swedish Museum of Natural History, Department of Geology.
    Bosi, Ferdinando
    Swedish Museum of Natural History, Department of Geology.
    Gatedal, Kjell
    Nordmark Mining Museum.
    Crystal structure and chemistry of skarn-associated bismuthian vesuvianite2013In: American Mineralogist, ISSN 0003-004X, E-ISSN 1945-3027, Vol. 98, p. 566-573Article in journal (Refereed)
  • 171.
    Hålenius, Ulf
    et al.
    Swedish Museum of Natural History, Department of Geology.
    Bosi, Ferdinando
    Swedish Museum of Natural History, Department of Geology.
    Skogby, Henrik
    Swedish Museum of Natural History, Department of Geology.
    A first record of strong structural relaxation of TO4 tetrahedra in a spinel solid solution2011In: American Mineralogist, ISSN 0003-004X, E-ISSN 1945-3027, Vol. 96, p. 617-622Article in journal (Refereed)
  • 172.
    Hålenius, Ulf
    et al.
    Swedish Museum of Natural History, Department of Geology.
    Bosi, Ferdinando
    Swedish Museum of Natural History, Department of Geology.
    Skogby, Henrik
    Swedish Museum of Natural History, Department of Geology.
    Galaxite, MnAl2O4, a spectroscopic standard for tetrahedrally coordinated Mn2+ in oxygen-based mineral structures2007In: American Mineralogist, ISSN 0003-004X, E-ISSN 1945-3027, Vol. 92, p. 1225-1231Article in journal (Refereed)
  • 173.
    Hålenius, Ulf
    et al.
    Swedish Museum of Natural History, Department of Geology.
    Hatert, Frédéric
    Université de Liège, Belgium.
    Pasero, Marco
    Università di Pisa, Italy.
    Mills, Stuart
    Museum Victoria, Melbourne, Australia.
    IMA Commission in New Minerals, Nomenclature and Classification (CNMNC) Newsletter 272015In: Mineralogical magazine, ISSN 0026-461X, E-ISSN 1471-8022, Vol. 79, no 5, p. 1223-1230Article in journal (Other academic)
  • 174.
    Hålenius, Ulf
    et al.
    Swedish Museum of Natural History, Department of Geology.
    Hatert, Frédéric
    Université de Liegè, Belgium.
    Pasero, Marco
    Università degli Studi di Pisa, Italy.
    Mills, Stuart
    Museum Victoria, Melbourne, Australia.
    IMA Commission on New Minerals, Nomenclature and Classification (CNMNC) Newsletter 242015In: Mineralogical magazine, ISSN 0026-461X, E-ISSN 1471-8022, Vol. 79, no 2, p. 247-251Article in journal (Other academic)
  • 175.
    Hålenius, Ulf
    et al.
    Swedish Museum of Natural History, Department of Geology.
    Hatert, Frédéric
    Université de Liegè, Belgium.
    Pasero, Marco
    Università degli Studi di Pisa, Italy.
    Mills, Stuart
    Museum Victoria, Melbourne, Australia.
    IMA Commission on New Minerals, Nomenclature and Classification (CNMNC) Newsletter 252015In: Mineralogical magazine, ISSN 0026-461X, E-ISSN 1471-8022, Vol. 79, no 3, p. 529-535Article in journal (Other academic)
  • 176.
    Hålenius, Ulf
    et al.
    Swedish Museum of Natural History, Department of Geology.
    Hatert, Frédéric
    Université de Liegè, Belgium..
    Pasero, Marco
    Università degli Studi di Pisa, Italy..
    Mills, Stuart
    Museum Victoria, Melbourne, Australia..
    IMA Commission on New Minerals, Nomenclature and Classification (CNMNC) Newsletter 262015In: Mineralogical magazine, ISSN 0026-461X, E-ISSN 1471-8022, Vol. 79, no 4, p. 941-947Article in journal (Other academic)
  • 177.
    Hålenius, Ulf
    et al.
    Swedish Museum of Natural History, Department of Geology.
    Hatert, Frédéric
    Université de Liège, Belgium.
    Pasero, Marco
    Università di Pisa, Italy.
    Mills, Stuart
    Museum Victoria, Melbourne, Australia.
    IMA Commission on New Minerals, Nomenclature and Classification (CNMNC) Newsletter 282015In: Mineralogical magazine, ISSN 0026-461X, E-ISSN 1471-8022, Vol. 79, no 7, p. 1859-1864Article in journal (Other academic)
  • 178.
    Hålenius, Ulf
    et al.
    Swedish Museum of Natural History, Department of Geology.
    Hatert, Frédéric
    Université de Liège, Belgium.
    Pasero, Marco
    Università di Pisa, Italy.
    Mills, Stuart
    Museum Victoria, Melbourne, Australia.
    IMA Commission on New Minerals, Nomenclature and Classification (CNMNC) Newsletter 322016In: Mineralogical magazine, ISSN 0026-461X, E-ISSN 1471-8022, Vol. 80, no 5, p. 915-922Article in journal (Other academic)
  • 179.
    Hålenius, Ulf
    et al.
    Swedish Museum of Natural History, Department of Geology.
    Hatert, Frédéric
    Université de Liège, Belgium.
    Pasero, Marco
    Università di Pisa, Italy.
    Mills, Stuart J.
    Museum Victoria, Melbourne, Australia.
    IMA Commission on New Minerals, Nomenclature and Classification (CNMNC) Newsletter 292016In: Mineralogical magazine, ISSN 0026-461X, E-ISSN 1471-8022, Vol. 80, no 1, p. 199-205Article in journal (Other academic)
  • 180.
    Hålenius, Ulf
    et al.
    Swedish Museum of Natural History, Department of Geology.
    Hatert, Frédéric
    Université de Liège, Belgium.
    Pasero, Marco
    Università di Pisa, Italy.
    Mills, Stuart J.
    Museum Victoria, Melbourne, Australia.
    IMA Commission on New Minerals, Nomenclature and Classification (CNMNC) Newsletter 302016In: Mineralogical magazine, ISSN 0026-461X, E-ISSN 1471-8022, Vol. 80, no 2, p. 407-413Article in journal (Other academic)
  • 181.
    Hålenius, Ulf
    et al.
    Swedish Museum of Natural History, Department of Geology.
    Hatert, Frédéric
    Université de Liège, Belgium..
    Pasero, Marco
    Università di Pisa, Italy..
    Mills, Stuart J.
    Museum Victoria, Melbourne, Australia..
    IMA Commission on New Minerals, Nomenclature and Classification (CNMNC) Newsletter 312016In: Mineralogical magazine, ISSN 0026-461X, E-ISSN 1471-8022, Vol. 80, no 4, p. 691-697Article in journal (Other academic)
  • 182.
    Hålenius, Ulf
    et al.
    Swedish Museum of Natural History, Department of Geology.
    Hatert, Frédéric
    Université de Liège, Belgium..
    Pasero, Marco
    Università di Pisa, Italy..
    Mills, Stuart J.
    Museum Victoria, Melbourne, Australia..
    IMA Commission on New Minerals, Nomenclature and Classification (CNMNC) Newsletter 332016In: Mineralogical magazine, ISSN 0026-461X, E-ISSN 1471-8022, Vol. 80, no 6, p. 1135-1144Article in journal (Other academic)
  • 183.
    Hålenius, Ulf
    et al.
    Swedish Museum of Natural History, Department of Geology.
    Hatert, Frédéric
    Université de Liège, Belgium..
    Pasero, Marco
    Università di Pisa, Italy..
    Mills, Stuart J.
    Museum Victoria, Melbourne, Australia..
    IMA Commission on New Minerals, Nomenclature and Classification (CNMNC) Newsletter 342016In: Mineralogical magazine, ISSN 0026-461X, E-ISSN 1471-8022, Vol. 80, no 7, p. 1315-1321Article in journal (Other academic)
  • 184.
    Hålenius, Ulf
    et al.
    Swedish Museum of Natural History, Department of Geology.
    Hatert, Frédéric
    Université de Liège, Belgium..
    Pasero, Marco
    Università di Pisa, Italy..
    Mills, Stuart J.
    Museum Victoria, Melbourne, Australia..
    IMA Commission on New Minerals, Nomenclature and Classification (CNMNC) Newsletter 352017In: Mineralogical magazine, ISSN 0026-461X, E-ISSN 1471-8022, Vol. 81, no 1, p. 209-213Article in journal (Other academic)
  • 185.
    Hålenius, Ulf
    et al.
    Swedish Museum of Natural History, Department of Geology.
    Hatert, Frédéric
    Université de Liège, Belgium..
    Pasero, Marco
    Università di Pisa, Italy..
    Mills, Stuart J.
    Museum Victoria, Melbourne, Australia..
    IMA Commission on New Minerals, Nomenclature and Classification (CNMNC) Newsletter 362017In: Mineralogical magazine, ISSN 0026-461X, E-ISSN 1471-8022, Vol. 81, no 2, p. 403-409Article in journal (Other academic)
  • 186.
    Hålenius, Ulf
    et al.
    Swedish Museum of Natural History, Department of Geology.
    Hatert, Frédéric
    Université de Liège, Belgium..
    Pasero, Marco
    Università di Pisa, Italy..
    Mills, Stuart J.
    Museum Victoria, Melbourne, Australia..
    IMA Commission on New Minerals, Nomenclature and Classification (CNMNC) Newsletter 372017In: Mineralogical magazine, ISSN 0026-461X, E-ISSN 1471-8022, Vol. 81, no 3, p. 737-742Article in journal (Other academic)
  • 187.
    Hålenius, Ulf
    et al.
    Swedish Museum of Natural History, Department of Geology.
    Hatert, Frédéric
    Université de Liège, Belgium..
    Pasero, Marco
    Università di Pisa, Italy..
    Mills, Stuart J.
    Museum Victoria, Melbourne, Australia..
    IMA Commission on New Minerals, Nomenclature and Classification (CNMNC) Newsletter 382017In: Mineralogical magazine, ISSN 0026-461X, E-ISSN 1471-8022, Vol. 81, no 4, p. 1033-1038Article in journal (Other academic)
  • 188.
    Hålenius, Ulf
    et al.
    Swedish Museum of Natural History, Department of Geology.
    Hatert, Frédéric
    Université de Liège, Belgium..
    Pasero, Marco
    Università di Pisa, Italy..
    Mills, Stuart J.
    Museum Victoria, Melbourne, Australia..
    IMA Commission on New Minerals, Nomenclature and Classification (CNMNC) Newsletter 392017In: Mineralogical magazine, ISSN 0026-461X, E-ISSN 1471-8022, Vol. 81, no 5, p. 1279-1286Article in journal (Other academic)
  • 189.
    Hålenius, Ulf
    et al.
    Swedish Museum of Natural History, Department of Geology.
    Hatert, Frédéric
    Université de Liège, Belgium..
    Pasero, Marco
    Università di Pisa, Italy..
    Mills, Stuart J.
    Museum Victoria, Melbourne, Australia..
    IMA Commission on New Minerals, Nomenclature and Classification (CNMNC) Newsletter 402017In: Mineralogical magazine, ISSN 0026-461X, E-ISSN 1471-8022, Vol. 81, no 6, p. 1577-1581Article in journal (Other academic)
  • 190.
    Hålenius, Ulf
    et al.
    Swedish Museum of Natural History, Department of Geology.
    Hatert, Frédéric
    Université de Liège, Belgium..
    Pasero, Marco
    Università di Pisa, Italy..
    Mills, Stuart J.
    Museum Victoria, Melbourne, Australia..
    IMA Commission on New Minerals, Nomenclature and Classification (CNMNC) Newsletter 412018In: European journal of mineralogy, ISSN 0935-1221, E-ISSN 1617-4011, Vol. 30, no 1, p. 183-186Article in journal (Other academic)
  • 191.
    Hålenius, Ulf
    et al.
    Swedish Museum of Natural History, Department of Geology.
    Hatert, Frédéric
    Université de Liège, Belgium..
    Pasero, Marco
    Università di Pisa, Italy..
    Mills, Stuart J.
    Museum Victoria, Melbourne, Australia..
    IMA Commission on New Minerals, Nomenclature and Classification (CNMNC) Newsletter 422018In: Mineralogical magazine, ISSN 0026-461X, E-ISSN 1471-8022, Vol. 82, no 2, p. 445-451Article in journal (Other academic)
  • 192.
    Hålenius, Ulf
    et al.
    Swedish Museum of Natural History, Department of Geology.
    Hatert, Frédéric
    Université de Liège, Belgium..
    Pasero, Marco
    Università di Pisa, Italy..
    Mills, Stuart J.
    Museum Victoria, Melbourne, Australia..
    IMA Commission on New Minerals, Nomenclature and Classification (CNMNC) Newsletter 432018In: European journal of mineralogy, ISSN 0935-1221, E-ISSN 1617-4011, Vol. 30, no 3, p. 647-652Article in journal (Other academic)
  • 193.
    Hålenius, Ulf
    et al.
    Swedish Museum of Natural History, Department of Geology.
    Hatert, Frédéric
    Université de Liège, Belgium..
    Pasero, Marco
    Università di Pisa, Italy..
    Mills, Stuart J.
    Museum Victoria, Melbourne, Australia..
    IMA Commission on New Minerals, Nomenclature and Classification (CNMNC) Newsletter 442018In: Mineralogical magazine, ISSN 0026-461X, E-ISSN 1471-8022, Vol. 82, no 4, p. 1015-1021Article in journal (Other academic)
  • 194.
    Hålenius, Ulf
    et al.
    Swedish Museum of Natural History, Department of Geology.
    Hatert, Frédéric
    Université de Liège, Belgium..
    Pasero, Marco
    Università di Pisa, Italy..
    Mills, Stuart J.
    Museum Victoria, Melbourne, Australia..
    IMA Commission on New Minerals, Nomenclature and Classification (CNMNC) Newsletter 452018In: Mineralogical magazine, ISSN 0026-461X, E-ISSN 1471-8022, Vol. 82, no 5, p. 1225-1232Article in journal (Other academic)
  • 195.
    Hålenius, Ulf
    et al.
    Swedish Museum of Natural History, Department of Geology.
    Hatert, Frédéric
    Université de Liège, Belgium..
    Pasero, Marco
    Università di Pisa, Italy..
    Mills, Stuart J.
    Museum Victoria, Melbourne, Australia..
    IMA Commission on New Minerals, Nomenclature and Classification (CNMNC) Newsletter 462018In: European journal of mineralogy, ISSN 0935-1221, E-ISSN 1617-4011, Vol. 30, no 6, p. 181-189Article in journal (Other academic)
  • 196.
    Hålenius, Ulf
    et al.
    Swedish Museum of Natural History, Department of Geology.
    Häussermann, Ulrich
    Stockholms universitet.
    Harryson, Hans
    Uppsala universitet.
    Holtstamite, Ca3(Al,Mn3+)2(SiO4)3-x(H4O4)x, a new tetragonal hydrogarnet from Wessels Mine, South Africa2005In: European journal of mineralogy, ISSN 0935-1221, E-ISSN 1617-4011, Vol. 17, p. 375-382Article in journal (Refereed)
  • 197.
    Hålenius, Ulf
    et al.
    Swedish Museum of Natural History, Department of Geology.
    Libowitzky, Eugen
    Universität Wien.
    Wildner, Manfred
    Universität Wien.
    6th European Conference on Mineralogy and Spectroscopy: Preface2009In: European journal of mineralogy, ISSN 0935-1221, E-ISSN 1617-4011, Vol. 21, p. 7-7Article in journal (Other academic)
  • 198.
    Hålenius, Ulf
    et al.
    Swedish Museum of Natural History, Department of Geology.
    Skogby, Henrik
    Swedish Museum of Natural History, Department of Geology.
    Edén, Mattias
    Stockholm universitet.
    Nazzareni, Sabrina
    Università di Perugia.
    Kristiansson, Per
    Lunds universitet.
    Resmark, Jeppa
    Lunds universitet.
    Coordination of boron in nominally boron-free rock forming silicates: evidence for incorporation of BO3 groups in clinopyroxene2010In: Geochimica et Cosmochimica Acta, ISSN 0016-7037, E-ISSN 1872-9533, Vol. 74, p. 5672-5679Article in journal (Refereed)
  • 199.
    Ivarsson, Magnus
    et al.
    Swedish Museum of Natural History, Department of Paleobiology.
    Bengtson, Stefan
    Swedish Museum of Natural History, Department of Paleobiology.
    Skogby, Henrik
    Swedish Museum of Natural History, Department of Geology.
    Belivanova, Veneta
    Swedish Museum of Natural History, Department of Paleobiology.
    Marone, Federica
    Paul Scherrer Institute.
    Fungal colonies in open fractures of subseafloor basalt.2013In: Geo-Marine Letters, ISSN 0276-0460, E-ISSN 1432-1157, Vol. 33, no 4, p. 233-234Article in journal (Refereed)
    Abstract [en]

    The deep subseafloor crust is one of the few great frontiers of unknown biology on Earth and, still today, the notion of the deep biosphere is commonly based on the fossil record. Interpretation of palaeobiological information is thus central in the exploration of this hidden biosphere and, for each new discovery, criteria used to establish biogenicity are challenged and need careful consideration. In this paper networks of fossilized filamentous structures are for the first time described in open fractures of subseafloor basalts collected at the Emperor Seamounts, Pacific Ocean. These structures have been investigated with optical microscopy, environmental scanning electron microscope, energy dispersive spectrometer, X-ray powder diffraction as well as synchrotron-radiation X-ray tomographic microscopy, and interpreted as fossilized fungal mycelia.Morphological features such as hyphae, yeastlike growth and sclerotia were observed. The fossilized fungi are mineralized by montmorillonite, a process that probably began while the fungi were alive. It seems plausible that the fungi produced mucilaginous polysaccharides and/or extracellular polymeric substances that attracted minerals or clay particles, resulting in complete fossilization by montmorillonite. The findings are in agreement with previous observations of fossilized fungi in subseafloor basalts and establish fungi as regular inhabitants of such settings. They further show that fossilized microorganisms are not restricted to pore spaces filled by secondary mineralizations but can be found in open pore spaces as well. This challenges standard protocols for establishing biogenicity and calls for extra care in data interpretation.

  • 200.
    Ivarsson, Magnus
    et al.
    Swedish Museum of Natural History, Department of Paleobiology. University of Southern Denmark, Department of Biology and Nordic Center for Earth Evolution, Campusvej 55, Odense M, DK-5230, Denmark.
    Skogby, Henrik
    Swedish Museum of Natural History, Department of Geology.
    Phichaikamjornwut, Bongkot
    Gems and Jewelry Program, Faculty of Science, Srinakharinwirot University, Bangkok, Thailand .
    Bengtson, Stefan
    Swedish Museum of Natural History, Department of Paleobiology.
    Siljeström, Sandra
    RISE Research Institutes of Sweden, Bioscience and Materials/Chemistry and Materials, Stockholm, Sweden.
    Ounchanum, Prayote
    Department of Geological Sciences, Faculty of Science, Chiang Mai University, Chiang Mai, Thailand.
    Boonsong, Apichet
    Department of Geological Sciences, Faculty of Science, Chiang Mai University, Chiang Mai, Thailand.
    Kruachanta, M
    Department of Geological Sciences, Faculty of Science, Chiang Mai University, Chiang Mai, Thailand .
    Marone, Federica
    Swiss Light Source, Paul Scherrer Institute, Villigen, Switzerland.
    Belivanova, Veneta
    Swedish Museum of Natural History, Department of Paleobiology.
    Sara, Holmström
    Stockholm University, Department of Geological Sciences, Stockholm, Sweden.
    Intricate tunnels in garnets from soils and rivere sediments in Thailand - possible endolithic microborings2018In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 13, no 8, article id e0200351Article in journal (Refereed)
    Abstract [en]

    Garnets from disparate geographical environments and origins such as oxidized soils and river sediments in Thailand host intricate systems of microsized tunnels that significantly decrease the quality and value of the garnets as gems. The origin of such tunneling has previously been attributed to abiotic processes. Here we present physical and chemical remains of endolithic microorganisms within the tunnels and discuss a probable biological origin of the tunnels. Extensive investigations with synchrotron-radiation X-ray tomographic microscopy (SRXTM) reveal morphological indications of biogenicity that further support a euendolithic interpretation. We suggest that the production of the tunnels was initiated by a combination of abiotic and biological processes, and that at later stages biological processes came to dominate. In environments such as river sediments and oxidized soils garnets are among the few remaining sources of bio-available Fe2+, thus it is likely that microbially mediated boring of the garnets has trophic reasons. Whatever the reason for garnet boring, the tunnel system represents a new endolithic habitat in a hard silicate mineral otherwise known to be resistant to abrasion and chemical attack.

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