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  • 251. Holtstam, D
    et al.
    Grins, J
    Nysten, Per
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Earth Sciences, Department of Earth Sciences. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Håleniusite-(La) from the Bastnäs deposit, Västmanland, Sweden: a new REE oxyflouride mineral species2004In: The canadian mineralogist, ISSN 0008-4476, Vol. 42, no 4, p. 1097-1104Article in journal (Refereed)
  • 252. Holtstam, D
    et al.
    Kolitsch, U
    Andersson, U.B
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Earth Sciences, Department of Earth Sciences. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Västmanlandite-(Ce) - a new REE- and F-bearing sorosilicate mineral from Västmanland, Sweden2005In: Eur. J. Miner., Vol. 177, p. 129-141Article in journal (Refereed)
  • 253. Hooey, L
    et al.
    Zarins, K
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Earth Sciences, Department of Earth Sciences. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Dahlstedt, A
    Annersten, H
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Behaviour of Kaolinite coated olivine pellets in Blast Furnace2004In: Ironmaking and Steelmaking, Vol. 31, p. 333-341Article in journal (Refereed)
  • 254.
    Hosseini-Barzi, M
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Earth Sciences, Department of Earth Sciences. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Talbot C.J,
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Earth Sciences, Department of Earth Sciences. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Earth Sciences, Department of Earth Sciences, Solid Earth Geology. berggrundsgeologi.
    A Tectonic pulse in the Makran accretionary prism recorded in Iranian coastal sediments2003In: J. Geol Soc London, Vol. 160, p. 903-910Article in journal (Refereed)
  • 255.
    Hudl, Matthias
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Mathieu, Roland
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Nordblad, Peter
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Ivanov, Sergey
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Bazuev, G.V.
    nstitute of Solid-State Chemistry, Ural Branch of the Russian Academy of Science, Ekaterinburg, Russia.
    Lazor, Peter
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Investigation of the magnetic phase transition and magnetocaloric properties of the Mn2FeSbO6 ilmenite2013In: Journal of Magnetism and Magnetic Materials, ISSN 0304-8853, E-ISSN 1873-4766, Vol. 331, p. 193-197Article in journal (Refereed)
    Abstract [en]

    The magnetic phase transition and magnetocaloric properties of both mineral and synthetic melanostibite Mn2FeSbO6 with ilmenite-type structure have been studied. Mn2FeSbO6 orders ferrimagnetically below 270 K and is found to undergo a second-order magnetic phase transition. The associated magnetic entropy change was found to be 1.7 J/kg K for the mineral and 1.8 J/kg K for the synthetic melanostibite for 5 T field change. For the synthetic Mn2FeSbO6 the adiabatic temperature change was estimated from magnetic- and specific heat measurements and amounts to 0.2 K in 1 T field change. Perspectives of the functional properties of Mn2FeSbO6-based materials are discussed.

  • 256. Hålenius, U
    et al.
    Häusserman, U
    Harrysson, H
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Earth Sciences, Department of Earth Sciences. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Holtstamite, Ca3(Al,Mn3+)2(SiO4)3-x(H4O4)x A new tetragonal hydrogarnet from Wessels Mine, South Africa.2005In: Eur. J. Min, Vol. 177, p. 375-382Article in journal (Refereed)
  • 257.
    Högdahl, K
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Ahl, M
    Granite age and some problems of rock classification2004In: The Transscandinavian Igneous Belt (TIB) in Sweden; a review of its character and evolution, 2004, p. 86-89Chapter in book (Refereed)
  • 258. Högdahl, K
    et al.
    Andersson, U.B
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Earth Sciences, Department of Earth Sciences. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Eklund, O
    The Transscandinavian igneous belt in Sweden: a review of its character and evolution2004Book (Refereed)
  • 259. Högdahl, K
    et al.
    Andersson, U.B.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Earth Sciences, Department of Earth Sciences. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Sjöström, H
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Earth Sciences, Department of Earth Sciences. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Ahl, M
    The Ljusdal Batholith and related rocks, central Svecofennian Domain2006In: 27th Nordic geological Wintermeeting: Abstracts, 2006Conference paper (Refereed)
  • 260.
    Högdahl, K., K.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Sjöström, H.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Relation between partial melting, metamorphism and deformation in the  area between the Ljusdal Batholith and the Bothnian Basin, central Sweden2009Report (Other (popular science, discussion, etc.))
  • 261. Högdahl, K
    et al.
    Sjöström, H
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Earth Sciences, Department of Earth Sciences. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    The Hassela Shear Zone – a link between migmatites and the contemporaneous Ljusdahl Batholith?2006In: 27th Nordic geological Wintermeeting: Abstracts, 2006Conference paper (Refereed)
  • 262. Högdahl, K
    et al.
    Sjöström, H
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Earth Sciences, Department of Earth Sciences. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Andersson, U.B.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Earth Sciences, Department of Earth Sciences. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Contemporaneous arc-related magmatism and migmatization in the central part of the Svecofennian domain in Sweden2006In: European Geosciences Union: Abstracts, 2006Conference paper (Refereed)
  • 263. Högdahl, K
    et al.
    Sjöström, H
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Earth Sciences, Department of Earth Sciences. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Andersson, U.B.
    Tectonic units and correlation problematics in the central Svecofennian domain2006Report (Other (popular scientific, debate etc.))
  • 264.
    Högdahl, K.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Sjöström, H.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Bergman, S.
    Ductile shear zones related to crustal shortening and  domain boundary evolution in the central Fennoscandian Shield2009In: Tectonics, ISSN 0278-7407, E-ISSN 1944-9194, Vol. 28, p. TC1003-Article in journal (Refereed)
    Abstract [en]

    The Paleoproterozoic part of the Fennoscandian Shield is composed of crustal components formed in different tectonic settings and generally separated by well-defined shear zone systems. An anomalous transitional boundary has been investigated by integrating structural analysis and geochronology with published geophysical data. The nature of this boundary is interpreted to be a consequence of an apparent stacking in the lower and middle crust initiating 1.87–1.86 Ga dextral shear along the Gävle-Rättvik Zone (GRZ) and adjacent shear zones, resulting in an arcuate northern boundary of the Bergslagen province. This boundary coincides with geophysical anomalies and temporal and metamorphic breaks. Owing to continuous convergence the pure-shear overprint component increased on the GRZ and caused a shift of dextral shear to the Hagsta Gneiss Zone with recorded shear at 1809 ± 2 Ma. Most likely, both these structures are related to coeval shear zones farther to the east as a part of an ∼1500 km long crustal, or possibly terrane, boundary.

  • 265.
    Högdahl, Karin
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Majka, Jaroslaw
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Nilsson, K.P.
    Sjöström, Håkan
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Claesson, S.
    Multiple monazite generations in migmatites and leucogranites in east central Sweden2010In: NGF, 2010, p. 79-Conference paper (Refereed)
  • 266.
    Högdahl, Karin
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Majka, Jaroslaw
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Sjöström, Håkan
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Persson Nilsson, Katarina
    Geol Survey Sweden, S-75328 Uppsala, Sweden.
    Claesson, Stefan
    Swedish Museum Nat Hist, Lab Isotope Geol, S-10405 Stockholm, Sweden.
    Konecny, Patrik
    Geol Survey Slovak Republ, Bratislava 81704, Slovakia.
    Reactive monazite and robust zircon growth in diatexitesand leucogranites from a hot, slowly cooled orogen: implicationsfor the Palaeoproterozoic tectonic evolution of the central Fennoscandian Shield, Sweden2012In: Contributions to Mineralogy and Petrology, ISSN 0010-7999, E-ISSN 1432-0967, Vol. 163, no 1, p. 167-188Article in journal (Refereed)
    Abstract [en]

    Monazite in melt-producing, poly-metamorphic terranes can grow, dissolve or reprecipitate at different stages during orogenic evolution particularly in hot, slowly cooling orogens such as the Svecofennian. Owing to the high heat flow in such orogens, small variations in pressure, temperature or deformation intensity may promote a mineral reaction. Monazite in diatexites and leucogranites from two Svecofennian domains yields older, coeval and younger U–Pb SIMS and EMP ages than zircon from the same rock. As zircon precipitated during the melt-bearing stage, its U–Pb ages reflect the timing of peak metamorphism, which is associated with partial melting and leucogranite formation. In one of the domains, the Granite and Diatexite Belt, zircon ages range between 1.87 and 1.86 Ga, whereas monazite yields two distinct double peaks at 1.87–1.86 and 1.82–1.80 Ga. The younger double peak is related to monazite growth or reprecipitation during subsolidus conditions associated with deformation along late-orogenic shear zones. Magmatic monazite in leucogranite records systematic variations in composition and age during growth that can be directly linked to Th/U ratios and preferential growth sites of zircon, reflecting the transition from melt to melt crystallisation of the magma. In the adjacent Ljusdal Domain, peak metamorphism in amphibolite facies occurred at 1.83–1.82 Ga as given by both zircon and monazite chronology. Pre-partial melting, 1.85 Ga contact metamorphic monazite is preserved, in spite of the high-grade overprint. By combining structural analysis, petrography and monazite and zircon geochronology, a metamorphic terrane boundary has been identified. It is concluded that the boundary formed by crustal shortening accommodated by major thrusting.

  • 267.
    Högdahl, Karin
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Sjöström, Håkan
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Deep drilling in a Palaeoproterozoic hot orogen – potential for  deciphering the  orogenic accretion and physical properties of a tectonically layered crust2010In: GFF, ISSN 1103-5897, E-ISSN 2000-0863, Vol. 132, no 1, p. 55-63Article in journal (Refereed)
    Abstract [en]

    The Svecofennian is a large hot orogen composed of different accreted crustal units. The boundaries between these units are often characterised by major, steeply dipping shear zones with post-accretionary signatures. However, some of these shear zones have recorded an earlier and long-lived activity related to the accretionary episode, so have moderately eastward dipping shear zones identified in the eastern part of the Ljusdal Domain in the central part of the orogen. These shear zones, repeated at multiple lithostratigraphical levels, are associated with west verging asymmetric F2-folds indicating thrusting with imbricate slices in thickness comparable to those in the Caledonides. In the Ljusdal Domain these structures have been recognised in rock of significantly different metamorphic grade indicating thick-skin thrusting on the crustal scale possibly accompanied by channel flow. Information from deep drilling through these stacked units would shed light on the tectonostratigraphy and consequently the accretionary to post-accretionary evolution of hot orogens. In addition, information about groundwater circulation, geothermal energy potential and reservoir quality of tectonically layered rocks for e.g. CO2 sequestration experiments in crystalline rocks would be gained.

  • 268. Högdahl, Karin
    et al.
    Sjöström, Håkan
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Andersson, Ulf B.
    Ahl, Martin
    Continental margin magmatism and migmatisation in the west-central Fennoscandian Shield2008In: Lithos, ISSN 0024-4937, E-ISSN 1872-6143, Vol. 102, no 3-4, p. 435-459Article in journal (Refereed)
    Abstract [en]

    The Ljusdal Batholith (LjB) is a major component of the central Svecofennian Domain in Sweden. It is separated from the Bothnian Basin to the north by the 1.82-1.80 Cia crustal-scale Hassela Shear Zone (HSZ). The LjB has emplacement ages of 1.86-1.84 Cia, is mainly alkali-calcic, metaluminous, has epsilon(Nd) values between -0.3 and + 1.2 and was formed in a magmatic arc setting.

    During the Svecokarelian orogeny the LjB was affected by at least three fold episodes. Large-scale folded screens of migmatised metasedimentary rocks occur in the eastern part of the batholith, and to the north of the HSZ, there is a 50 km wide diatexite belt. The Transition Belt (TrB), consisting of 1.88-1.85 Ga granitoids, is located at the northwestern extension of this belt. A calc-alkaline and peraluminous composition combined with negative epsilon(Nd) values (- 1.7 to -0.8) indicates a large proportion of metasediments in the source for these granitoids.

    U-Pb SIMS data on zircon rims from migmatites and leucogranites to the north and east of LjB yield ages of 1.87-1.86 Ga, i.e. coeval with the granitoids of the LjB and the TrB. There is thus a close relationship between the LjB, the TrB and the migmatites in both space and time. Syn-migmatitic shearing along the HSZ indicates that a proto-HSZ was initiated already at c. 1.86 Ga, and the location of the proto-HSZ is inferred to be controlled by two older nuclei present in the lower parts of the crust. As crustal-scale shear zone systems are known to act as ascent pathways for sheet-like flow in active orogenies the TrB may represents accumulations of melts that were attracted and extracted by the proto-HSZ and intruded in a block that was not pervasively affected by subsequent shear along the HSZ.

    An active continental margin setting for the LjB implies subduction at c. 1.86 Ga, and provides a heat source for both the migmatites and the TrB.

    A later migmatisation at 1.82 Ga has been recorded to the south of the HSZ. Within the LjB the 1.82 Ga stromatic migmatites are folded by F-2 folds, and the fabric is truncated by 1.80 Cia pegmatites.

  • 269. Högdahl, Karin
    et al.
    Sjöström, Håkan
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Gromet, L.P.
    Character and timing of Svecokarelian, late-orogenic ductile deformation zones in Jämtland, west central sweden2001In: GFF, ISSN 1103-5897, E-ISSN 2000-0863, Vol. 123, no 4, p. 225-236Article in journal (Refereed)
    Abstract [en]

    An anastomosing pattern of NW-SE to NNW-SSE trending, ductile shear zones have affected the Precambrian bedrock in central Jämtland. Spatially these structures are related to two major shear zone systems, the Storsjön-Edsbyn Deformation Zone (SEDZ) and the Hassela Shear Zone (HSZ). Several of the local zones occur between Lake Näkten and Lake Locknesjön and coincide with linear magnetic anomalies. The dextral kinematics recorded are emphasised by clockwise rotation of early Svecofennian rocks, that partly are arranged in a large-scale C/S pattern. Three different, ductile shear zones yield U-Pb titanite ages of 1801±1, 1799±7, and 1794±3 Ma, interpreted to date the deformation. Pale titanite overgrowths, colourless titanite, and apatite yield younger U-Pb ages (c. 1.75 Ga) which argue for a tectonic reactivation of the zones, or a later thermal and/or hydrothermal event, as indicated by intrusions of cross-cutting pegmatites and felsic dykes. A hydrothermal activity during the Caledonian orogeny is recorded in one of the deformation zones. This is shown by an altered fabric containing titanites with pale outer parts which are severely discordant in a U-Pb concordia diagram with a Palaeozoic lower intercept. Sm-Nd analyses on re-precipitated zircon grains also deviate considerably from a Palaeoproterozoic trend given by other minerals in the assemblage.

  • 270. Högdahl, Karin
    et al.
    Sjöström, Håkan
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Earth Sciences, Department of Earth Sciences. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Earth Sciences, Department of Earth Sciences, Solid Earth Geology. Berggrundsgeologi.
    Gromet, Peter
    Character and timing of Svekokarelian, late-orogenic, ductile deformation zones in Jämtland, west central Sweden2001In: GFF: Timing of Svecokarelian, late-orogenic, ductile deformation zones in Jämtland, west central Sweden, Vol. 123, p. 225-236Article in journal (Refereed)
  • 271.
    Högdahl, Karin
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Troll, Valentin
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Nilsson, K.P.
    Jonsson, Erik
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Structural evolution of the apatite-iron oxide deposit at Grängesberg, Bergslagen, Sweden2013In: Mineral deposit research for a high-tech world, p. 1650-1553Article in journal (Refereed)
  • 272. Ismail-Zadeh, A
    et al.
    Naimark, B
    Talbot, C
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Earth Sciences, Department of Earth Sciences. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Reconstruction of the history of the movement of layered geostructures: Inverse problem of gravitational stability2004In: Comput. Seis. Geodyn, Vol. 6, p. 27-32Article in journal (Refereed)
  • 273. Ismail-Zadeh, A
    et al.
    Tsepelev, I.A
    Talbot, C
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Earth Sciences, Department of Earth Sciences. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Oster, P
    Three-dimensional modeling of salt diapirism: A numerical approach and algorithm of parallel calculations2004In: Comput. Seis. Geodyn, Vol. 6, p. 33-41Article in journal (Refereed)
  • 274. Ivarsson, M.
    et al.
    Bengtson, S.
    Skogby, H.
    Lazor, Peter
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Belivanova, V.
    Marone, F.
    Extensive bioweathering of secondary minerals in subseafloor basalts2014In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203Article in journal (Other academic)
  • 275. Jakobsson, Martin
    et al.
    Björck, Svante
    O'Regan, Matt
    Floden, Tom
    Greenwood, Sarah L.
    Swärd, Henrik
    Lif, Arne
    Ampel, Linda
    Koyi, Hemin
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Skelton, Alasdair
    Major earthquake at the Pleistocene-Holocene transition in Lake Vattern, southern Sweden2014In: Geology, ISSN 0091-7613, E-ISSN 1943-2682, Vol. 42, no 5, p. 379-382Article in journal (Refereed)
    Abstract [en]

    Lake Vattern, Sweden, is within a graben that formed through rifting along the boundary between two Precambrian terrains. Geophysical mapping and geological coring show that substantial tectonic movements along the Lake Vattern graben occurred at the very onset of the Holocene. This is evident from deformation structures in the soft sediment accumulated on the lake floor. Our interpretation of these structures suggests as much as 13 m of vertical tectonic displacements along sections of a >80-km-long fault system. If these large displacements are from one tectonic event, Lake Vattern must have had an earthquake with seismic moment magnitudes to 7.5. In addition, our geophysical mapping shows large landslides along sections of the steep lake shores. Pollen analysis of sediment infillings of some of the most prominent sediment deformation structures places this major seismic event at the Younger Dryas-Preboreal transition, ca. 11.5 ka. We suggest that this event is mainly related to the rapid release of ice-sheet load following the deglaciation. This paleoseismic event in Lake Vattern ranks among the larger known intraplate tectonic events in Scandinavia and attests to the significance of glacio-isostatic unloading.

  • 276.
    Jamshidi, K.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Ghasemi, H.
    Troll, Valentin
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Mineralogy Petrology and Tectonics.
    Sadeghian, M.
    Dahrén, Börje
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Mineralogy Petrology and Tectonics.
    Magma storage and plumbing of adakite-type post-ophiolite intrusions in the Sabzevar ophiolitic zone, northeast Iran2015In: Solid Earth, ISSN 1869-9510, E-ISSN 1869-9529, Vol. 6, no 1, p. 49-72Article in journal (Refereed)
    Abstract [en]

    Subduction-related adakite-type intrusive rocks emplaced into the late Cretaceous-Paleocene Sabzevar ophiolite zone, northeast Iran, range from Mg-andesite to rhyodacite in composition. Here we investigate the magma supply system to these subvolcanic intrusive rocks by applying thermobarometric mineral and mineral-melt equilibrium models, including amphibole thermobarometry, plagioclase-melt thermobarometry and clinopyroxene-melt barometry. Based on the results of these thermobarometric models, plagioclase crystallized dominantly at pressures of similar to 350 (130 to 468) MPa, while amphiboles record both low pressures (similar to 300 MPa) and very high pressures (> 700 MPa) of crystallization. The latter is supported by the calculated pressures for clinopyroxene crystallization (550 to 730 MPa). The association of amphibole with clinopyroxene and no plagioclase in the most primitive samples (Mg-andesites) is consistent with amphibole fractionation from very hydrous magmas at deep crustal levels of the plumbing system, which may have been a key process in intensifying adakite-type affinities in this rock suite. Barometry, combined with frequent disequilibrium features such as oscillatory-zoned and sieve-textured plagioclase crystals with An-rich overgrowths in more evolved samples, implies that final magma differentiation occurred in an open upper crustal magma system that developed progressively stronger compositional modifications during high-level magma storage.

  • 277.
    Janák, Marian
    et al.
    eological Institute, Slovak Academy of Sciences, Bratislav, Slovak Republic.
    van Roermund, Herman
    Structural Geology and Tectonics, Department of Earth Sciences, Utrecht University, The Netherlands.
    Majka, Jaroslaw
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Gee, David G.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Geophysics.
    UHP metamorphism recorded by kyanite-bearing eclogite in the Seve Nappe Complex of northern Jämtland, Swedish Caledonides2013In: Gondwana Research, ISSN 1342-937X, E-ISSN 1878-0571, Vol. 23, no 3, p. 865-879Article in journal (Refereed)
    Abstract [en]

    The first evidence for ultrahigh-pressure (UHP) metamorphism in the Seve Nappe Complex of the Scandinavian Caledonides is recorded by kyanite-bearing eclogite, found in a basic dyke within a garnet peridotite body exposed close to the lake Friningen in northern Jämtland (central Sweden). UHP metamorphic conditions of ~ 3 GPa and 800 °C, within the stability field of coesite, are constrained from geothermobarometry and calculated phase equilibria for the peak-pressure assemblage garnet + omphacite + kyanite + phengite. A prograde metamorphic evolution from a lower P–T (1.5–1.7 GPa and 700–750 °C) stage during subduction is inferred from inclusions of pargasitic amphibole, zoisite and kyanite in garnet cores. The post-UHP evolution is constrained from breakdown textures, such as exsolutions of kyanite and silica from the Ca-Eskola clinopyroxene. Near isothermal decompression of eclogite to lower crustal levels (~ 0.8–1.0 GPa ) led to formation of sapphirine, spinel, orthopyroxene and diopside at granulite facies conditions. Published age data suggest a Late Ordovician (460–445 Ma) age of the UHP metamorphism, interpreted to be related to subduction of Baltoscandian continental margin underneath an outboard terrane, possibly outermost Laurentia, during the final stages of closure of the Iapetus Ocean. The UHP rocks were emplaced from the hinterland collision zone during Scandian thrusting of the nappes onto the Baltoscandian foreland basin and platform. The record of P–T conditions and geochonological data from UHP rocks occurring within the allochthonous units of the Scandinavian Caledonides indicate that Ordovician UHP events may have affected much wider parts of the orogen than previously thought, involving deep subduction of the continental crust prior to final Scandian collision between Baltica and Laurentia.

  • 278. Jastrzebski, Miroslaw
    et al.
    Zelazniewicz, Andrzej
    Majka, Jaroslaw
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Murtezi, Mentor
    Bazarnik, Jakub
    Kapitonov, Igor
    Constraints on the Devonian-Carboniferous closure of the Rheic Ocean from a multi-method geochronology study of the Staré Město Belt in the Sudetes (Poland and the Czech Republic)2013In: Lithos, ISSN 0024-4937, E-ISSN 1872-6143, Vol. 170-171, p. 54-72Article in journal (Refereed)
    Abstract [en]

    This paper attempts to clarify the complex nature of how and when the Rheic Ocean closed in what is now Central Europe and, with respect to the various terranes that were involved, offer a regional chronology for the associated structural, metamorphic and igneous processes that accompanied and followed this closure. The Variscan orogen in Europe originated from the multiple collisions of Gondwana-derived terranes (the Armorican Terrane Assemblage) with Laurussia: however, many important structural details on the timing of these collision-related events remain obscure. In the Sudetes, the Stare Mesto Belt represents a WNW-dipping part of the Rheic suture that developed from the continental collision of the eastern terranes of the Armorican Terrane Assemblage (now in the Bohemian Massif) with the Brunovistulian Terrane (a part of Laurussia/Old Red Continent). In this study, the results of monazite Th-U-total Pb, garnet Lu-Hf and zircon U-Pb geochronology were integrated into a newly established D1-D3 tectonometamorphic sequence. A Th-U-total Pb age of similar to 368 Ma from a monazite that grew concurrently with D2 metasedimentary garnet, as well as Lu-Hf ages of similar to 361 Ma and similar to 355 Ma obtained from D2 metasedimentaly garnets, implies that the regional contractional deformation and progressive metamorphism of D2 took place mainly during the Famennian (Late Devonian) and extended into the Visean (Middle Mississippian of the Early Carboniferous). The ion probe U-Pb zircon ages of similar to 355 Ma and similar to 359 Ma obtained from leucocratic neosomes in migmatized amphibolites confirmed a lag in the peak temperature that followed crustal thickening during D1-D2. Metamorphic monazites dated at similar to 340 Ma provide a time for the subsequent D3 dextral transpressional regime. The closure of the Stare Mesto Belt segment of the Rheic Ocean probably resulted from a head-on hard collision between the westerly subducting Brunovistulian promontory of Laurussia and the eastern members of the Armorican Terrane Assemblage. Thus, the Rheic Ocean closed during the Late Devonian at similar to 370-360 Ma and preceded the collision of the Armorican Terrane Assemblage with East Avalonia at the western margin of what is now the Bohemian Massif. Following ocean closure, the Rheic slab may have broken off, resulting in the suture zone becoming dominated by lateral "tectonic escape" movements of the colliding terranes at similar to 340-330 Ma (Visean). Syntectonic D3 intrusions of granodiorite/tonalite magma acted as a hot lubricant and stitched the suture zone together. 

  • 279. Jaxybulatov, Kairly
    et al.
    Koulakov, Ivan
    Ibs-von Seht, Malte
    Klinge, Klaus
    Reichert, Christian
    Dahrén, Börje
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Troll, Valentin R.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Evidence for high fluid/melt content beneath Krakatau volcano (Indonesia) from local earthquake tomography2011In: Journal of Volcanology and Geothermal Research, ISSN 0377-0273, E-ISSN 1872-6097, Vol. 206, no 3-4, p. 96-105Article in journal (Refereed)
    Abstract [en]

    Within the KRAKMON project for multiparameter monitoring of Anak Krakatau volcano (Indonesia), a network of temporary stations was installed on the islands of the Krakatau complex as well as in the surrounding areas of the Sunda Strait, Sumatra and Java. The network was operated from June 2005 until January 2006. More than 700 local events were recorded during this experiment, and travel times from these events were used to perform a tomographic inversion for P and S velocities and for the Vp/Vs ratio. In this study, special attention was paid to the validation of the computed model based on different tests, such as inversion of independent data subsets and synthetic modeling. Although the network configuration and the distribution of the events are not favorable for high-quality tomographic imaging, we have obtained some important and robust features which give information about sources of volcanic activity in the Krakatau complex. The most interesting feature of this study is a zone of high Vp/Vs ratio beneath the Krakatau complex. At depths down to 4 km depth we observe anticorrelation of higher P- and lower S-velocities that leads to Vp/Vs ratio higher than 2. This is a probable indicator of the presence of partially molten and/or with high fluid content material with a composition corresponding to deeper layers. It is important that the anomaly of high Vp/Vs ratio beneath the Krakatau complex appears to be separated in two parts at a depth of 5-6 km. This fits to results of geobarometric analysis that presume the existence of several levels of magma chambers beneath Anak Krakatau.

  • 280.
    Jeffery, Adam J.
    et al.
    School of Physical and Geographical Sciences, Keele University, UK.
    Gertisser, Ralf
    School of Physical and Geographical Sciences, Keele University, UK.
    Troll, Valentin R.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Jolis, Ester M.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Dahrén, Börje
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Harris, Chris
    University of Cape Town, South Africa.
    Tindle, Andrew G.
    CEPSAR (Centre for Earth, Planetary, Space and Astronomy Research), The Open University, UK.
    Preece, Katie
    University of East Anglia.
    O'Driscoll, Brain
    Humaida, Hanik
    Balai Penyelidikan dan Pengembangan Teknologi, Indonesia.
    Chadwick, Jane P.
    Science Gallery, Trinity College Dublin, Dublin.
    The pre-eruptive magma plumbing system of the 2007–2008 dome-forming eruption of Kelut volcano, East Java, Indonesia2013In: Contributions to Mineralogy and Petrology, ISSN 0010-7999, E-ISSN 1432-0967, Vol. 166, no 1, p. 275-308Article in journal (Refereed)
    Abstract [en]

    Kelut volcano, East Java, is an active volcanic complex hosting a summit crater lake that has been the source of some of Indonesia’s most destructive lahars. In November 2007, an effusive eruption lasting approximately 7 months led to the formation of a 260-m-high and 400-m-wide lava dome that displaced most of the crater lake. The 2007–2008 Kelut dome comprises crystal-rich basaltic andesite with a texturally complex crystal cargo of strongly zoned and in part resorbed plagioclase (An47–94), orthopyroxene (En64–72, Fs24–32, Wo2–4), clinopyroxene (En40–48, Fs14–19, Wo34–46), Ti-magnetite (Usp16–34) and trace amounts of apatite, as well as ubiquitous glomerocrysts of varying magmatic mineral assemblages. In addition, the notable occurrence of magmatic and crustal xenoliths (meta-basalts, amphibole-bearing cumulates, and skarn-type calc-silicates and meta-volcaniclastic rocks) is a distinct feature of the dome. New petrographical, whole rock major and trace element data, mineral chemistry as well as oxygen isotope data for both whole rocks and minerals indicate a complex regime of magma-mixing, decompression-driven resorption, degassing and crystallisation and crustal assimilation within the Kelut plumbing system prior to extrusion of the dome. Detailed investigation of plagioclase textures alongside crystal size distribution analyses provide evidence for magma mixing as a major pre-eruptive process that blends multiple crystal cargoes together. Distinct magma storage zones are postulated, with a deeper zone at lower crustal levels or near the crust-mantle boundary (>15 km depth), a second zone at mid-crustal levels (~10 km depth) and several magma storage zones distributed throughout the uppermost crust (<10 km depth). Plagioclase-melt and amphibole hygrometry indicate magmatic H2O contents ranging from ~8.1 to 8.6 wt.% in the lower crustal system to ~1.5 to 3.3 wt.% in the mid to upper crust. Pyroxene and plagioclase δ18O values range from 5.4 to 6.7 ‰, and 6.5 to 7.6 ‰, respectively. A single whole rock analysis of the 2007–2008 dome lava gave a δ18O value of 7.6 ‰, whereas meta-basaltic and calc-silicate xenoliths are characterised by δ18O values of 6.2 and 10.3 ‰, respectively. Magmatic δ18O values calculated from individual pyroxene and plagioclase analyses range from 5.7 to 7.0 ‰, and 6.2 to 7.4 ‰, respectively. This range in O-isotopic compositions is explained by crystallisation of pyroxenes in the lower to mid-crust, where crustal contamination is either absent or masked by assimilation of material having similar δ18O values to the ascending melts. This population is mixed with isotopically distinct plagioclase and pyroxenes that crystallised from a more contaminated magma in the upper crustal system. Binary bulk mixing models suggest that shallow-level, recycled volcaniclastic sedimentary rocks together with calc-silicates and/or limestones are the most likely contaminants of the 2007–2008 Kelut magma, with the volcaniclastic sediments being dominant.

  • 281. Jerram, D.A.
    et al.
    Goodenough, K.
    Troll, V.R.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Introduction: from the British Tertiary into the future – modern perspectives on the British Palaeogene and North Atlantic Igneous provinces2009In: Geological Magazine, ISSN 0016-7568, E-ISSN 1469-5081, Vol. 146, no 3, p. 305-308Article in journal (Refereed)
    Abstract [en]

    The study of volcanic rocks and igneous centres has long been a classic part of geological research. Despite the lack of active volcanism, the British Isles have been a key centre for the study of igneous rocks ever since ancient lava flows and excavated igneous centres were recognized there in the 18th century (Hutton, 1788). This led to some of the earliest detailed studies of petrology. The starting point for many of these studies was the British Palaeogene Igneous Province (BPIP; formerly known as the ‘British Tertiary’ (Judd, 1889), and still recognized by this name by many geologists around the globe). This collection of lavas, volcanic centres and sill/dyke swarms covers much of the west of Scotland and the Antrim plateau of Northern Ireland, and together with similar rocks in the Faroe Islands, Iceland and Greenland forms a world-class Large Igneous Province. This North Atlantic Igneous Province (NAIP) began to form through continental rifting above a mantle plume at c. 60 Ma, and subsequently evolved as North America separated from Europe, creating the North Atlantic Ocean.

  • 282.
    Jiao, Jingjing
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Petrography and geochemistry of a section through the Blötbergetapatite-iron oxide deposit, Bergslagen, south central Sweden2011Independent thesis Advanced level (degree of Master (One Year)), 40 credits / 60 HE creditsStudent thesis
    Abstract [en]

    The Blötberget apatite-iron oxide ores are situated in the Grängesberg mining district (GMD). This is located in the famous Bergslagen ore province, within the southern part of the Svecokarelian domain in Sweden. Apatite-iron oxide ores of comparable type are generally known as „Kiruna-type‟ deposits; they are economically important, geologically interesting and genetically controversial.This study utilizes petrography and geochemistry to characterize and in part investigate the genesis of apatite-iron oxide ores and their host rocks in Blötberget. The ores are dominated by massive and banded magnetite and hematite with variable contents of phosphorous. Disseminated iron oxides are also present in the rock units close to the ores. The Palaeoproterozoic host rocks are mainly intermediate to felsic metavolcanic to meta-subvolcanic rocks, geochemically ranging between dacitic and rhyolitic in composition, accompanied by localized phyllosilicate-rich and amphibole-bearing units. The host rocks also include large amounts of cross-cutting older granitoids as well as younger granite-aplite-pegmatite.Fluorapatite, being one of the most important non-oxide mineral in the ores, is responsible for the high contents of REE in apatite-rich ores. The studied apatite-rich ore samples have highest ΣREE contents, and the ΣREE contents for all ores analyzed range between 195 ppm and 3009 ppm, while the host rocks range between 58 ppm and 366 ppm. Adding to the dominant role of apatite influencing the ΣREE contents, monazite-(Ce), xenotime-(Y) and allanite-(Ce) are locally important REE carriers. The REE patterns in the ores, and the phyllosilicate-rich and amphibole-bearing assemblages exhibit clear similarities, indicating a similar genetic origin. Furthermore, similarities in REE patterns and ferride geochemistry between Blötberget and other apatite-iron oxide ores, including Grängesberg and Kiruna, lend support to the fact that apatite-iron oxide ores in Blötberget belong to the Kiruna-type deposit class.The metavolcanic to metasubvolcanic rocks in the studied ores at Blötberget show regional K-(Na) alteration, similar to many volcanic and subvolcanic rocks in central and southern Sweden. In contrast, the phyllosilicate-rich (mainly biotite) and amphibole-bearing units spatially close to the ores show enrichment in Mg-(K), which is suggested to be a result of localized and comparatively small-scale hydrothermal alteration. They also share systematic similarities in major and trace elements geochemistry with the ores, thus indicating that they are genetically related. Furthermore, disseminated iron oxides occur within the localized alteration assemblages, highlighting the fact that ores and alteration units are closely related. Nevertheless, the presence of hydrothermal alteration does not exclude a main process of orthomagmatic ore formation. Not least, the presences of structures such as magnetite ore breccias are indications of an orthomagmatic origin.

  • 283.
    Jolis, E. M.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Troll, V. R.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Deegan, F. M.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Blythe, L. S.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Harris, C.
    Freda, C.
    Hilton, D.
    Chadwick, J.
    van Helden, M.
    Tracing crustal contamination along the Java segment of the Sunda Arc, Indonesia2012Conference paper (Refereed)
    Abstract [en]

    Arc magmas typically display chemical and petrographic characteristics indicative of crustal input. Crustal contamination can take place either in the mantle source region or as magma traverses the upper crust (e.g. [1]). While source contamination is generally considered the dominant process (e.g. [2]), late-stage crustal contamination has been recognised at volcanic arcs too (e.g. [3]). In light of this, we aim to test the extent of upper crustal versus source contamination along the Java segment of the Sunda arc, which, due its variable upper crustal structure, is an exemplary natural laboratory. We present a detailed geochemical study of 7 volcanoes along a traverse from Anak-Krakatau in the Sunda strait through Java and Bali, to characterise the impact of the overlying crust on arc magma composition. Using rock and mineral elemental geochemistry, radiogenic (Sr, Nd and Pb) and, stable (O) isotopes, we show a correlation between upper crustal composition and the degree of upper crustal contamination. We find an increase in 87Sr/86Sr and δ18O values, and a decrease in 143Nd/144Nd values from Krakatau towards Merapi, indicating substantial crustal input from the thick continental basement present. Volcanoes to the east of Merapi and the Progo-Muria fault transition zone, where the upper crust is thinner, in turn, show considerably less crustal input in their isotopic signatures, indicating a stronger influence of the mantle source. Our new data represent a systematic and high-resolution arc-wide sampling effort that allows us to distinguish the effects of the upper crust on the compositional spectrum of individual volcanic systems along the Sunda arc. [1] Davidson, J.P, Hora, J.M, Garrison, J.M & Dungan, M.A 2005. Crustal Forensics in Arc Magmas. J. Geotherm. Res. 140, 157-170; [2] Debaille, V., Doucelance, R., Weis, D., & Schiano, P. 2005. Geochim. Cosmochim. Acta, 70,723-741; [3] Gasparon, M., Hilton, D.R., & Varne, R. 1994. Earth Planet. Sci. Lett., 126, 15-22.

  • 284.
    Jolis, E. M.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Troll, V. R.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Deegan, F. M.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Blythe, L. S.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Harris, C
    Freda, C
    Hilton, D.
    Chadwick, J.
    van Helden, M.
    Tracing crustal contamination along the Java segment of the Sunda Arc, Indonesia2012Conference paper (Refereed)
    Abstract [en]

    Arc magmas typically display chemical and petrographic characteristics indicative of crustal input. Crustal contamination can take place either in the mantle source region or as magma traverses the crust (e.g. [1]). While source contamination is generally considered the dominant process (e.g. [2, 3, 4]), crustal contamination in high level magma chambers has also been recognised at volcanic arcs (e.g. [5, 6]). In light of this, we aim to test the extent of upper crustal versus source contamination along the Java segment of the Sunda arc, which, because of its variable upper crustal structure, is ideal for the task.

    We present a detailed geochemical study of 7 volcanoes along a traverse from Anak-Krakatau in the Sunda strait through Java (Gede, Slamet, Merapi, Kelut, Kawah-Ijen) and Bali (Batur). Using rock and mineral elemental geochemistry and radiogenic (Sr, Nd and Pb) and, stable (O) isotopes, we show a correspondence between changes in composition of the upper crust and the apparent degree of upper crustal contamination. There is an increase in 87Sr/86Sr and δ18O, and a decrease in 143Nd/144Nd from Krakatau towards Merapi, indicating substantial input from the thick quasi-continental basement beneath East and Central Java. Volcanoes to the east of Merapi, and the Progo-Muria fault zone, where the upper crust is thinner and increasingly oceanic in nature have lower 87Sr/86Sr and δ18O, and higher 143Nd/144Nd indicating a stronger influence of the mantle source [7]. Our new data represent a systematic and high-resolution arc-wide sampling effort that allows us to distinguish the effects of the upper crust on the compositional spectrum of individual volcanic systems along the Sunda arc.

     

     

    [1] Davidson, J.P, Hora, J.M, Garrison, J.M & Dungan, M.A (2005), J. Geotherm. Res., 140, 157-170.

    [2] Hilton, D.R., Fischer, T.P. & Marty, B. (2002), Rev. Mineral. Geochem., 47, 319-370.

    [3] Gertisser, R. & Keller, J. (2003). J. Petrol., 44, 457-489

    [4] Debaille, V., Doucelance, R., Weis, D., & Schiano, P. (2005), Geochim. Cosmochim. Acta, 70,723-741.

    [5] Gasparon, M., Hilton, D.R., & Varne, R. (1994), Earth Planet. Sci. Lett., 126, 15-22.

    [6] Chadwick, J.P., Troll, V.R., Ginibre, C., Morgan, D., Gertisser, R., Waight, T.E. & Davidson, J.P. (2007), J. Petrol., 48, 1793-1812.

    [7] Whitford, D.J. (1975), Geochim. Cosmochim. Acta, 39, 1287-1302.

  • 285.
    Jolis, Ester M.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Magma-Crust Interaction at Subduction Zone Volcanoes2013Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The focus of this work is magma-crust interaction processes and associated crustal volatile release in subduction zone volcanoes, drawing on rock, mineral, and gas geochemistry as well as experimental petrology. Understanding the multitude of differentiation processes that modify an original magma during ascent to the surface is vital to unravel the contributions of the various sources that contribute to the final magmas erupted at volcanoes. In particular, magma-crust interaction (MCI) processes have been investigated at a variety of scales, from a local scale in the Vesuvius, Merapi, and Kelut studies, to a regional scale, in the Java to Bali segment of the Sunda Arc.

     The role of crustal influences is still not well constrained in subduction systems, particulary in terms of the compositional impact of direct magma crust interplay. To address this shortcoming, we studied marble and calc-silicate (skarn) xenoliths, and used high resolution short timescale experimental petrology at Vesuvius volcano. The marbles and calc-silicates help to identify different mechanisms of magma-carbonate and magma-xenolith interaction, and the subsequent effects of volatile release on potential eruptive behaviour, while sequential short-duration experiments simulate the actual processes of carbonate assimilation employing natural materials and controlled magmatic conditions. The experiments highlight the efficiency of carbonate assimilation and associated carbonate-derived CO2 liberated over short timescales.

    The findings at Merapi and Kelut demonstrate a complex magmatic plumbing system underneath these volcanoes with magma residing at different depths, spanning from the mantle-crust boundary to the upper crust. The erupted products and volcanic gas emissions enable us to shed light on MCI-processes and associated volatile release in these systems. The knowledge gained from studying individual volcanoes (e.g., Merapi and Kelut) is then tested on a regional scale and applied to the entire Java and Bali arc segment. An attempt is presented to distinguish the extent of source versus crustal influences and establish a quantitative model of late stage crustal influence in this arc segment.

    This thesis therefore hopes to contribute to our knowledge of magma genesis and magma-crust interaction (MCI) processes that likely operate in subduction zone systems worldwide.

     

    List of papers
    1. C and O isotopes of marble and skarn xenoliths from Vesuvius, Italy: implications for syn-eruptive CO2 release
    Open this publication in new window or tab >>C and O isotopes of marble and skarn xenoliths from Vesuvius, Italy: implications for syn-eruptive CO2 release
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    (English)Manuscript (preprint) (Other academic)
    National Category
    Earth and Related Environmental Sciences Geochemistry Geology Other Earth and Related Environmental Sciences
    Identifiers
    urn:nbn:se:uu:diva-198037 (URN)
    Available from: 2013-04-08 Created: 2013-04-08 Last updated: 2013-08-30
    2. Experimental simulation of magma-carbonate interaction beneath Mt. Vesuvius, Italy
    Open this publication in new window or tab >>Experimental simulation of magma-carbonate interaction beneath Mt. Vesuvius, Italy
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    2012 (English)In: Annual Report 2012, HP-HT Laboratory of experimental Volcanology and Geophysics, p. 163-166Article in journal (Refereed) Published
    Place, publisher, year, edition, pages
    Department of Seismology and Tectonophysics, Istituto Nazionale di Geofisica e Vulcanologia, 2012
    National Category
    Geology Geochemistry
    Identifiers
    urn:nbn:se:uu:diva-198050 (URN)
    Available from: 2013-04-08 Created: 2013-04-08 Last updated: 2013-08-30Bibliographically approved
    3. Crustal CO2 liberation during the 2006 eruption and earthquake events at Merapi volcano, Indonesia
    Open this publication in new window or tab >>Crustal CO2 liberation during the 2006 eruption and earthquake events at Merapi volcano, Indonesia
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    2012 (English)In: Geophysical Research Letters, ISSN 0094-8276, E-ISSN 1944-8007, Vol. 39, p. L11302-Article in journal (Refereed) Published
    Abstract [en]

    High-temperature volcanic gas is widely considered to originate from ascending, mantle-derived magma. In volcanic arc systems, crustal inputs to magmatic gases mainly occur via subducted sediments in the mantle source region. Our data from Merapi volcano, Indonesia imply, however, that during the April-October 2006 eruption significant quantities of CO2 were added from shallow crustal sources. We show that prior to the 2006 events, summit fumarole gas delta C-13((CO2)) is virtually constant (delta C-13(1994-2005) = -4.1 +/- 0.3 parts per thousand), but during the 2006 eruption and after the shallow Yogyakarta earthquake of late May, 2006 (M6.4; hypocentres at 10-15 km depth), carbon isotope ratios increased to -2.4 +/- 0.2 parts per thousand. This rise in delta C-13 is consistent with considerable addition of crustal CO2 and coincided with an increase in eruptive intensity by a factor of similar to 3 to 5. We postulate that this shallow crustal volatile input supplemented the mantle-derived volatile flux at Merapi, intensifying and sustaining the 2006 eruption. Late-stage volatile additions from crustal contamination may thus provide a trigger for explosive eruptions independently of conventional magmatic processes.

    National Category
    Earth and Related Environmental Sciences
    Research subject
    Earth Science with specialization in Mineral Chemistry, Petrology and Tectonics
    Identifiers
    urn:nbn:se:uu:diva-176812 (URN)10.1029/2012GL051307 (DOI)000304772800002 ()
    Available from: 2012-06-27 Created: 2012-06-26 Last updated: 2017-12-07Bibliographically approved
    4. Magmatic differentiation processes at Merapi Volcano: inclusion petrology and oxygen isotopes
    Open this publication in new window or tab >>Magmatic differentiation processes at Merapi Volcano: inclusion petrology and oxygen isotopes
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    2013 (English)In: Journal of Volcanology and Geothermal Research, ISSN 0377-0273, E-ISSN 1872-6097, Vol. 261, no SI, p. 38-49Article in journal (Refereed) Published
    Abstract [en]

    Indonesian volcano Merapi is one of the most hazardous volcanoes on the planet and is characterised by periods of active dome growth and intermittent explosive events. Merapi currently degasses continuously through high temperature fumaroles and erupts basaltic-andesite dome lavas and associated block-and-ash-flows that carry a large range of magmatic, coarsely crystalline plutonic, and meta-sedimentary inclusions. These inclusions are useful in order to evaluate magmatic processes that act within Merapi's plumbing system, and to help an assessment of which phenomena could trigger explosive eruptions. With the aid of petrological, textural, and oxygen isotope analysis we record a range of processes during crustal magma storage and transport, including mafic recharge, magma mixing, crystal fractionation, and country rock assimilation. Notably, abundant calc-silicate inclusions (true xenoliths) and elevated δ18O values in feldspar phenocrysts from 1994, 1998, 2006, and 2010 Merapi lavas suggest addition of limestone and calc-silicate materials to the Merapi magmas. Together with high δ13C values in fumarole gas, crustal additions to mantle and slab-derived magma and volatile sources are likely a steady state process at Merapi. This late crustal input could well represent an eruption trigger due to sudden over-pressurisation of the shallowest parts of the magma storage system independently of magmatic recharge and crystal fractionation. Limited seismic precursors may be associated with this type of eruption trigger, offering a potential explanation for the sometimes erratic behaviour of Merapi during volcanic crises.

    Place, publisher, year, edition, pages
    Elsevier, 2013
    Keywords
    Merapi Volcano; Magmatic and crustal inclusions; Oxygen isotopes; Crustal contamination
    National Category
    Earth and Related Environmental Sciences Geochemistry
    Research subject
    Earth Science with specialization in Mineral Chemistry, Petrology and Tectonics
    Identifiers
    urn:nbn:se:uu:diva-188483 (URN)10.1016/j.jvolgeores.2012.11.001 (DOI)000324154400004 ()
    Available from: 2012-12-17 Created: 2012-12-17 Last updated: 2017-12-06Bibliographically approved
    5. The pre-eruptive magma plumbing system of the 2007–2008 dome-forming eruption of Kelut volcano, East Java, Indonesia
    Open this publication in new window or tab >>The pre-eruptive magma plumbing system of the 2007–2008 dome-forming eruption of Kelut volcano, East Java, Indonesia
    Show others...
    2013 (English)In: Contributions to Mineralogy and Petrology, ISSN 0010-7999, E-ISSN 1432-0967, Vol. 166, no 1, p. 275-308Article in journal (Refereed) Published
    Abstract [en]

    Kelut volcano, East Java, is an active volcanic complex hosting a summit crater lake that has been the source of some of Indonesia’s most destructive lahars. In November 2007, an effusive eruption lasting approximately 7 months led to the formation of a 260-m-high and 400-m-wide lava dome that displaced most of the crater lake. The 2007–2008 Kelut dome comprises crystal-rich basaltic andesite with a texturally complex crystal cargo of strongly zoned and in part resorbed plagioclase (An47–94), orthopyroxene (En64–72, Fs24–32, Wo2–4), clinopyroxene (En40–48, Fs14–19, Wo34–46), Ti-magnetite (Usp16–34) and trace amounts of apatite, as well as ubiquitous glomerocrysts of varying magmatic mineral assemblages. In addition, the notable occurrence of magmatic and crustal xenoliths (meta-basalts, amphibole-bearing cumulates, and skarn-type calc-silicates and meta-volcaniclastic rocks) is a distinct feature of the dome. New petrographical, whole rock major and trace element data, mineral chemistry as well as oxygen isotope data for both whole rocks and minerals indicate a complex regime of magma-mixing, decompression-driven resorption, degassing and crystallisation and crustal assimilation within the Kelut plumbing system prior to extrusion of the dome. Detailed investigation of plagioclase textures alongside crystal size distribution analyses provide evidence for magma mixing as a major pre-eruptive process that blends multiple crystal cargoes together. Distinct magma storage zones are postulated, with a deeper zone at lower crustal levels or near the crust-mantle boundary (>15 km depth), a second zone at mid-crustal levels (~10 km depth) and several magma storage zones distributed throughout the uppermost crust (<10 km depth). Plagioclase-melt and amphibole hygrometry indicate magmatic H2O contents ranging from ~8.1 to 8.6 wt.% in the lower crustal system to ~1.5 to 3.3 wt.% in the mid to upper crust. Pyroxene and plagioclase δ18O values range from 5.4 to 6.7 ‰, and 6.5 to 7.6 ‰, respectively. A single whole rock analysis of the 2007–2008 dome lava gave a δ18O value of 7.6 ‰, whereas meta-basaltic and calc-silicate xenoliths are characterised by δ18O values of 6.2 and 10.3 ‰, respectively. Magmatic δ18O values calculated from individual pyroxene and plagioclase analyses range from 5.7 to 7.0 ‰, and 6.2 to 7.4 ‰, respectively. This range in O-isotopic compositions is explained by crystallisation of pyroxenes in the lower to mid-crust, where crustal contamination is either absent or masked by assimilation of material having similar δ18O values to the ascending melts. This population is mixed with isotopically distinct plagioclase and pyroxenes that crystallised from a more contaminated magma in the upper crustal system. Binary bulk mixing models suggest that shallow-level, recycled volcaniclastic sedimentary rocks together with calc-silicates and/or limestones are the most likely contaminants of the 2007–2008 Kelut magma, with the volcaniclastic sediments being dominant.

    Keywords
    Kelut volcano, Sunda arc, Lava dome, CSD, Oxygen isotopes, Magma mixing, Crustal contamination, Volcanic hazards
    National Category
    Geology Geochemistry
    Research subject
    Earth Science with specialization in Mineral Chemistry, Petrology and Tectonics
    Identifiers
    urn:nbn:se:uu:diva-198047 (URN)10.1007/s00410-013-0875-4 (DOI)000320655900014 ()
    Available from: 2013-04-08 Created: 2013-04-08 Last updated: 2017-12-06Bibliographically approved
    6. Tracing crustal contamination along the Java-Bali segment of the Sunda Arc
    Open this publication in new window or tab >>Tracing crustal contamination along the Java-Bali segment of the Sunda Arc
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    (English)Manuscript (preprint) (Other academic)
    National Category
    Geochemistry Geology Geosciences, Multidisciplinary
    Identifiers
    urn:nbn:se:uu:diva-198043 (URN)
    Available from: 2013-04-08 Created: 2013-04-08 Last updated: 2013-08-30
    7. Crustal volatile release at Merapi volcano; the 2006 earthquake and eruption events
    Open this publication in new window or tab >>Crustal volatile release at Merapi volcano; the 2006 earthquake and eruption events
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    2013 (English)In: Geology Today, ISSN 0266-6979, E-ISSN 1365-2451, Vol. 29, no 3, p. 96-101Article in journal (Other (popular science, discussion, etc.)) Published
    National Category
    Geosciences, Multidisciplinary
    Identifiers
    urn:nbn:se:uu:diva-198051 (URN)10.1111/gto.12008 (DOI)
    Available from: 2013-04-08 Created: 2013-04-08 Last updated: 2017-12-06Bibliographically approved
  • 286.
    Jolis, Ester M.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Freda, Carmela
    Istituto Nazionale di Geofisica e Vulcanologia, INGV, Rome.
    Troll, Valentin R
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Deegan, Frances M.
    Dept. of Geoscience, Swedish Museum of Natural History, Stockholm.
    Blythe, Lara
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    McLeod, Claire L.
    University of Houston.
    Davidson, Jon P.
    Durham University.
    Experimental simulation of magma-carbonate interaction beneath Mt. Vesuvius, Italy2012In: Annual Report 2012, HP-HT Laboratory of experimental Volcanology and Geophysics, p. 163-166Article in journal (Refereed)
  • 287.
    Jolis, Ester Muñoz
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Freda, C.
    Troll, Valentin R.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Deegan, Frances M.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Blythe, Lara S.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    McLeod, C. L.
    Davidson, J. P.
    Experimental simulation of magma-carbonate interaction beneath Mt. Vesuvius, Italy2013In: Contributions to Mineralogy and Petrology, ISSN 0010-7999, E-ISSN 1432-0967, Vol. 166, no 5, p. 1335-1353Article in journal (Refereed)
    Abstract [en]

    We simulated the process of magma-carbonate interaction beneath Mt. Vesuvius in short duration piston-cylinder experiments under controlled magmatic conditions (from 0 to 300 s at 0.5 GPa and 1,200 A degrees C), using a Vesuvius shoshonite composition and upper crustal limestone and dolostone as starting materials. Backscattered electron images and chemical analysis (major and trace elements and Sr isotopes) of sequential experimental products allow us to identify the textural and chemical evolution of carbonated products during the assimilation process. We demonstrate that melt-carbonate interaction can be extremely fast (minutes), and results in dynamic contamination of the host melt with respect to Ca, Mg and Sr-87/Sr-86, coupled with intense CO2 vesiculation at the melt-carbonate interface. Binary mixing between carbonate and uncontaminated melt cannot explain the geochemical variations of the experimental charges in full and convection and diffusion likely also operated in the charges. Physical mixing and mingling driven by exsolving volatiles seems to be a key process to promote melt homogenisation. Our results reinforce hypotheses that magma-carbonate interaction is a relevant and ongoing process at Mt. Vesuvius and one that may operate not only on a geological, but on a human timescale.

  • 288.
    Jonsson, Erik
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Malmgeologiskt mästerverk firar 100 år2013Other (Other (popular science, discussion, etc.))
  • 289.
    Jonsson, Erik
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Mineral deposit research for a high-tech world2013Conference proceedings (editor) (Other academic)
  • 290.
    Jonsson, Erik
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Sista ordet: alternativa energikällor kräver mer än sol och vind2012In: Geologiskt forum, ISSN 1104-4721, no 76, p. 31-Article in journal (Other (popular science, discussion, etc.))
  • 291.
    Jonsson, Erik
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    The Norra Kärr REE-Zr project and the birthplace of the light REEs. SGA Excursion guidebook SWE3, SWE6 & SWE72013Other (Other academic)
  • 292.
    Jonsson, Erik
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Högdahl, Karin
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    New evidence for the timing of formation of Bastnäs-type REE mineralisation in Bergslagen, Sweden2013In: Mineral deposit research for a high-tech world, p. 1724-1727Article in journal (Refereed)
  • 293.
    Jonsson, Erik
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Högdahl, Karin
    Uppsala University, Disciplinary Domain of Science and Technology, E