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  • 1. Aaro, Sven
    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.
    Airborne and ground geophysics used for regional tectonic analysis2003In: IUGG 2003, Sapporo, Japan: No GAV.06/10P/A11-004, B260., 2003Conference paper (Refereed)
  • 2.
    Abdu, Yassir
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
    Annersten, Hans
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Ericsson, Tore
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
    Nordblad, Per
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy.
    Field induced local magnetic moments in gamma-fcc Fe-Ni anti-Invar alloys2004In: Journal of Magnetism and Magnetic Materials, ISSN 0304-8853, E-ISSN 1873-4766, Vol. 280, 243-250 p.Article in journal (Refereed)
    Abstract [en]

    Mössbauer spectroscopy in longitudinal external fields (up to 7 T) and SQUID magnetometry (up to 5 T)measurements have been carried out on mechanically alloyed (MA) g (FCC) Fe100xNix (x ¼ 21; 24, and 27 at%) alloysat room temperature. The zero-field M.ossbauer spectra of these alloys show only singlets. The high field M.ossbauerresults indicate that large amounts of the material is in the paramagnetic state, giving rise to two spectral componentswith their effective fields almost linearly depend on the external field, but with slopes that are smaller than unity. The infieldM.ossbauer spectra of the x ¼ 27 at% alloy show an additional component with a hyperfine field of E21 T, whichis attributed to Ni-rich (>30 at% Ni) clusters (domains) of ferromagnetically ordered HM phase that behavessuperparamagnetically at room temperature and shows a non-linear character in the magnetization (M–H) curves atlow fields. This HM phase is also present in the x ¼ 21 and 24 at% samples but with smaller amounts. The resultssuggest induced hyperfine fields and hence induced moments in the paramagnetic components, which increases withincreasing Ni contents. Taenite-enriched samples from the metal particles of two stony meteorites, Al Kidirate (H6)and New Halfa (L4), are also studied by high field M.ossbauer spectroscopy and the results are compared to that ofMA samples.

  • 3. Abouessa, A.
    et al.
    Morad, S.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    An integrated study of diagenesis and depositional facies in tidal sandstones: Hawaz Formation (middle Ordovician), Murzuq Basin, Libya2009In: Journal of Petroleum Geology, ISSN 0141-6421, E-ISSN 1747-5457, Vol. 32, no 1, 39-65 p.Article in journal (Refereed)
  • 4. Aftabi, Pedram
    et al.
    Roustaie, Mahasa
    Alsop, G.Ian
    Talbot, Christopher J.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    InSAR mapping and modelling of an active Iranian salt extrusion2010In: Journal of the Geological Society, ISSN 0016-7649, E-ISSN 2041-479X, Vol. 167, no 1, 155-170 p.Article in journal (Refereed)
    Abstract [en]

    Interferometric synthetic aperture radar (InSAR) imaging is a powerful technique that is increasingly used to extract detailed 3D information on Earth surface structures, including exposed diapiric surfaces. We have used InSAR to map, for the first time, the cumulative surface deformation in a 6 km × 3 6 km region surrounding an active salt diapir (Syahoo) and its associated surface salt flow (or namakier) exposed in the Zagros Mountains of southern Iran. Images provided by the European Space Agency were acquired in 12 increments (ranging in length between 35 and 1248 days) over a 14 year interval between July 1992 and May 2006. The deformation of the salt surface is non-steady, with (extrapolated) rates of displacement varying between surficial uplifts of +1.4 mm day-1 (+511 mm a-1) and subsidence of -2.2 mm day-1 (-803 mm a-1). Growth of a central topographic dome occurs following short wet intervals to create a salt fountain morphology, which then slowly decays during the intervening long dry periods. Salt associated with dynamic 'bulging' of the central dome during wet intervals may flow laterally via gravity spreading into the surrounding salt sheet, resulting in deflation and subsidence of the dome, which is counteracted by growth and inflation of the adjacent namakiers. Salt 'bulges' that migrate down the namakier, resulting in local inflationary and deflationary cycles of the surface, may be regarded as episodic pulses of gravity spreading. Areas of inflation and deflation are also observed to commonly reverse during dry to wet periods, as the overall salt system effectively self regulates as it continually strives for dynamic equilibrium. As long as the source of salt remains undepleted, gravity spreading of the dome ultimately results in more buoyancy-driven salt flowing up the diapiric neck to replenish and feed the extrusion and maintain the gross fountain morphology.

  • 5. Ahl, M
    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.
    Lundqvist, Th
    Sundblad, K
    The Dala granitoids2004In: The Transscandinavian Igneous Belt (TIB) in Sweden; a review of its character and evolution, 2004, 70-74 p.Chapter in book (Refereed)
  • 6.
    Aldahan, Ala Adin
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Morad, Sadoon
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Possnert, Göran
    Uppsala University, Disciplinary Domain of Science and Technology, För teknisk-naturvetenskapliga fakulteten gemensamma enheter, Tandem Laboratory. Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Ion Physics.
    Sturesson, Ulf
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Palaeobiology.
    ElSaiy, A.
    10Be in rhodochrosite nodules from Neogene sediments along the Galapagos Ridge, equatorial Pacific2010In: Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, ISSN 0168-583X, E-ISSN 1872-9584, Vol. 268, no 7-8, 1253-1256 p.Article in journal (Refereed)
    Abstract [en]

    Microcrystalline, calcian rhodochrosite occurs as nodules around burrows in late Neogene pelagic sediments from the Galapagos Ridge in the Guatemala Basin, eastern equatorial Pacific (DSDP Leg 68; Site 503). Be-10 isotope revealed that the rhodochrosite nodules have formed under growth conditions much faster than those reported for Fe-Mn nodules. The overall REE patterns of the nodules and host pelagic sediments indicate element derivation mainly from marine pore water. However, variations in the shale normalised Eu values suggest influx of hydrothermal fluids into mounds area at Galapagos, which is also evidenced by the similar minor and major element contents in the nodules and host sediments.

  • 7.
    Aleklett, Kjell
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Physics, Department of Nuclear and Particle Physics. Earth Sciences, Department of Earth Sciences, Solid Earth Geology. Kärnfysik.
    Tänk om det säger "slurp" i oljeröret2004In: Brännpunkt, Vol. 2 maj 2004Article in journal (Other (popular scientific, debate etc.))
    Abstract [en]

    Shell har nu skrivit ner sina oljereserver med 20 procent, men i Oman i Mellanöstern med 40 procent. Nedskrivningarna i Oman är till volymen inte de största men på sikt för världen kanske de allvarligaste.

    Det rör sig om överdrivna förväntningar på ny avancerad utvinningsteknik, horisontell borrning, den teknik som många hoppas ska vara avgörande för en ökad global oljeproduktion

  • 8.
    Ali Kalefa El-ghali, Mohamed
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Morad, Sadoon
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Mansurbeg, Howri
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Caja, Miguel A.
    Sirat, M.
    Ogle, N.
    Diagenetic alterations related to marine transgression and regression in fluvial deltaic and shallow marine sandstones of the Triassic Buntsandstein and Keuper formations, the Paris Basin, France2009In: Marine and Petroleum Geology, ISSN 0264-8172, E-ISSN 1873-4073, Vol. 26, no 3, 289-309 p.Article in journal (Refereed)
    Abstract [en]

    The distribution of diagenetic alterations in Triassic fluvio-deltaic, quartzarenitic to sublitharenitic, lowstand systems tract (LST) sandstones of the Grès á Voltzia Formation, anastomosing fluvial, quartzarenitic transgressive systems tract (TST) sandstones of the Grès á Roseaux Formation, and shallow marine, quartzarenitic to sublitharenitic, TST sandstones of the Grès Coquiller Formation, the Paris Basin (France), can be linked to transgression and regression events, and thus to the sequence stratigraphic context. Near-surface eogenetic alterations, which display a fairly systematic link to the depositional facies and sequence stratigraphic framework, include: (i) cementation by meteoric water calcite (δ18O=−8.9‰ and δ13C=−9.1‰) in the fluvio-deltaic, LST sandstones, (ii) cementation by mixed marine–meteoric calcite (δ18O=−5.3‰ to −2.6‰ and δ13C=−3.9‰ to −1.3‰) and dolomite (δ18O=−4.6‰ to −2.6‰ and δ13C=−2.9‰ to −2.3‰) in the foreshore, TST sandstones and below parasequence boundaries (PB), and transgressive surface (TS), and in the shoreface, TST sandstones below maximum flooding surfaces (MFS), being facilitated by the presence of carbonate bioclasts, (iii) dissolution of detrital silicates and precipitation of K-feldspar overgrowths and kaolinite, particularly in the fluvio-deltaic, LST sandstones owing to effective meteoric water circulation, and (vi) formation of autochthonous glauconite, which is increases in abundance towards the top of the fluvio-deltaic, LST sandstones, and along TS, and in the shoreface, TST sandstones, by alteration of micas owing to the flux of seawaters into the sandstones during transgression, whereas parautochthonous glauconite is restricted to the TS sandstones owing to marine reworking. Mesogenetic alterations, which include cementation by quartz overgrowths and illite, display fairly systematic link to fluvio-deltaic, LST sandstones. This study has revealed that linking of diagenesis to transgression and regression events enables a better understanding of the parameters that control the spatial and temporal distribution of diagenetic alterations in sandstones and of their impact on reservoir quality evolution.

  • 9. Al-Qayim, Basim
    et al.
    Omer, Azad
    Koyi, Hemin
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Tectonostratigraphic overview of the Zagros Suture Zone, Kurdistan Region, Northeast Iraq2012In: GeoArabia, ISSN 1025-6059, Vol. 17, no 4, 109-156 p.Article in journal (Refereed)
    Abstract [en]

    The northwestern segment of the Zagros Orogenic Belt of the Kurdistan Region of Iraq includes the Zagros Suture Zone which is consisting of allochthonous Tethyan Triassic-Eocene thrust sheets. The zone is bounded by the Zagros Main Reverse Fault in the northeast, and the Zagros Thrust Front in the southwest. Parts of this zone's rocks are represented by stacks of thrust mega-sheets obducted over the autochthonous Cretaceous-Cenozoic sequence of the Arabian Plate margin. Each sheet represents a specific Tethyan tectonostratigraphic facies, and includes (from older to younger): isolated Triassic carbonate platforms (Avroman Limestone), Jurassic carbonate imbricates (Chia Gara, Sargelu and other formations), radiolarites (Qulqula Group), sedimentary melange (sedimentary-volcanic units of the Qulqula Group), ophiolites (Mawat and Penjwin ultramafics complexes), and Cenozoic fore-arc volcano-sedimentary sequences (Walash Group). Petrography, facies interpretation and lithostratigraphic correlation of these allochthons along four traverses across the Zagros Suture Zone of the examined area indicate that they evolved during the closure of the Neo-Tethys Ocean. Their stacking pattern and tectonic association resulted from two important events: the Late Cretaceous obduction processes, and the Late Miocene Pliocene collision, uplift, folding and suturing between the Arabian Plate and the Sanandaj-Sirjan Block of Iran. Based on these field observations and by using the model of the Iranian Zagros evolution, a tectonic scenario is proposed to explain the history and evolution of the Zagros Suture Zone in this area.

  • 10.
    Amini, Samar
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Geophysics.
    Shomali, Z. Hossein
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Geophysics.
    Koyi, Hemin
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Roberts, Roland G.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Geophysics.
    Tomographic upper-mantle velocity structure beneath the Iranian Plateau2012In: Tectonophysics, ISSN 0040-1951, E-ISSN 1879-3266, Vol. 554-557, 42-49 p.Article in journal (Refereed)
    Abstract [en]

    The Iranian plateau is one of the most structurally complex and tectonically inhomogeneous regions in the world. In this study, we analyze Pn arrival-times from regional seismicity in order to resolve lateral velocity variations within the uppermost-mantle under the Iranian Plateau. More than 48,000 Pn first arrival times selected from the EHB catalog were used with epicentral distances of 200 to 1600 km. We used regularized isotropic and anisotropic damped least-squares inversion to image lateral velocity variations in the upper mantle. Our velocity model, with high lateral resolution, shows positive anomalies in the Zagros mountain belt with a distinct transition approximately along the Main Zagros Thrust to the lower mantle velocity zone of Central Iran. Anomalously low velocities are observed predominantly beneath NW Iran and eastern Turkey, suggesting a zone of relatively weak mantle. Low velocity region under the Damavand volcano reveals the hot upper mantle beneath the central Alborz mountains.

  • 11.
    Andersson, Magnus
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Geophysics.
    Malehmir, Alireza
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Geophysics.
    Troll, Valentin R.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Dehghannejad, Mahdieh
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Geophysics.
    Juhlin, Christopher
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Geophysics.
    Ask, Maria
    Carbonatite ring-complexes explained by caldera-style volcanism2013In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 3, 1677- p.Article in journal (Refereed)
    Abstract [en]

    Carbonatites are rare, carbonate-rich magmatic rocks that make up a minute portion of the crust only, yet they are of great relevance for our understanding of crustal and mantle processes. Although they occur in all continents and from Archaean to present, the deeper plumbing system of carbonatite ring-complexes is usually poorly constrained. Here, we show that carbonatite ring-complexes can be explained by caldera-style volcanism. Our geophysical investigation of the Alno carbonatite ring-complex in central Sweden identifies a solidified saucer-shaped magma chamber at similar to 3 km depth that links to surface exposures through a ring fault system. Caldera subsidence during final stages of activity caused carbonatite eruptions north of the main complex, providing the crucial element to connect plutonic and eruptive features of carbonatite magmatism. The way carbonatite magmas are stored, transported and erupt at the surface is thus comparable to known emplacement styles from silicic calderas.

  • 12.
    Andersson, Staffan
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Physics Didactics.
    Andersson Chronholm, Jannika
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Physics Didactics.
    Jakobsson, Tobias
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Biology Education Centre.
    Larsson, Johan
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Physics Didactics.
    Sjöström, Håkan
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Koyi, Hemin
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Eriksson, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Materials Chemistry, Structural Chemistry.
    Elmgren, Maja
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical and Analytical Chemistry.
    Rangordningsövningar i naturvetenskap2011Book (Other academic)
  • 13.
    Andersson, Stefan
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Malmmikroskopering - en studie av sulfidmineral från Långbantrakten, Bergslagen, Sverige2011Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The small sulphide mines, Näset and Getberget that have been investigated are located just outside the main mineralization of Långban, near the city of Filipstad in Värmland County. Opaque minerals have been studied in reflected light microscopy and with an electron microprobe analysis to describe the mineralogy. Both areas are dominated by various (Cu-Fe-Pb-Zn)-sulphides, Näset with chalcopyrite (CuFeS2), galena (PbS) and sphalerite ((Zn,Fe)S) and Getberget with, galena, sphalerite, cubanite (CuFe2S3) and pyrrhotite (Fe1-xS). The sulphides are also accompanied by various accessory minerals, in Näset by two different phases of Co-pentlandite (on rich in nickel and one without), native Sb and Bi, a (Ni-Co)-sulphide, breithauptite (NiSb) and pyrrhotite. Cubanite is also a very important mineral that reflects the formation of the mineralization. In Getberget there are similar accessory minerals, chalcopyrite, nickel rich Co-pentlandite, native Bi and Sb, acanthite (Ag2S), breithauptite and magnetite (Fe3O4). A late precipitation of cubanite has occurred in both areas, suggesting that the mineralizations has been formed in similar conditions. This also holds true when comparing the mineralogy, which also is similar.

  • 14. Andersson, U. B.
    et al.
    Begg, G. C.
    Griffin, W. L.
    Högdahl, Karin
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Ancient and juvenile components in the continental crust and mantle: Hf isotopes in zircon from Svecofennian magmatic rocks and rapakivi granites in Sweden2011In: Lithosphere, ISSN 1941-8264, E-ISSN 1947-4253, Vol. 3, no 6, 409-419 p.Article in journal (Refereed)
    Abstract [en]

    The sources of igneous rocks in the continental crust are elusive, but they may be traced by radiogenic isotopes, which convey a message about the age and composition of the concealed parts of the continent. We investigated the Hf-isotope composition of zircon in ten rocks from central and southern Sweden. Two felsic metavolcanic rocks and two metagabbros (ca. 1.89 Ga) from Bergslagen, southern Sweden, show epsilon(Hf)(t) ranges of -1.8 to +5.1 and +2.6 to +6.8, respectively, suggesting that juvenile sources have contributed to both. A 1.85 Ga granite from southern Bergslagen shows a epsilon(Hf)(t) range of -2.6 to +4.6 for magmatic zircons, but both highly negative and positive values for inherited grains, providing evidence for both Archean and juvenile crustal sources. These and previous data confirm the existence of juvenile proto-Svecofennian crust (<2.2-1.9 Ga) with a minor Archean component, from which later crustal magmas were generated. The Hf-isotope evolution curve for this crust can be approximated by epsilon(Hf)(1.90) = 3 +/- 3 and (176)Lu/(177)Hf = 0.018. Similarly, the present data, together with data for younger mafic intrusions, can be used to infer the presence of a "mildly depleted" sub-Svecofennian mantle evolution curve with epsilon(Hf)(1.90) = 4.5 +/- 2.5 and (176)Lu/(177)Hf = 0.0315. Zircons from four out of five rapakivi intrusions (1.53-1.50 Ga) in central Sweden yield negative epsilon(Hf)(t) in the range -9.8 to -4.6, suggesting mixed Archean and juvenile Svecofennian sources. One intrusion farther south ranges between epsilon(Hf)(t) of -4.1 and -1.6, and has a larger contribution from Svecofennian crust. The data suggest that the crust in Bergslagen, southern Sweden, is dominantly Paleoproterozoic, while higher proportions of Archean material are present below central Sweden.

  • 15.
    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.
    CER200-Rare earth elements in minerals; a minisymposium organized Sept. 24th 2004 by the Swedish Mineralogical Society to commemorate the publication of the discovery of cerium by W. Hisinger and J.J. Berzelius in 1804, with an excursion guide to the Bastnäs-type REE-mineralizations in NW Bergslagen, central southern Sweden2004Conference proceedings (editor) (Refereed)
  • 16.
    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.
    Regional overview: Fennoscandian Shield, Bergslagen. I: The Bastnäs-type REE-mineralisations in north-western Bergslagen, Sweden – a summary with geological background and excursion guide2004In: Sveriges geologiska undersökning, Rapporter och meddelanden, 2004, 7-9 p.Chapter in book (Refereed)
  • 17.
    Andersson, U.B
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Regional overview: Fennoscandian Shield, Bergslagen. I: The Bastnäs-type REE-mineralisations in north-western Bergslagen, Sweden – a summary with geological background and excursion guide2004Conference proceedings (editor) (Refereed)
  • 18.
    Andersson, U.B
    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.
    Claeson, D.T
    Högdahl, K
    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.
    Geological features of the Småland-Värmland Belt along the Svecofennian margin. Part II: the Nygården, Karlskoga, and Filipstad areas2004In: The Transscandinavian Igneous Belt (TIB) in Sweden; a review of its character and evolution, 2004, 39-47 p.Chapter in book (Refereed)
  • 19.
    Andersson, U.B
    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.
    Eklund, O
    Claeson, D.T
    Geochemical character of the mafic-hybrid magmatism in the Småland-Värmland belt2004In: The Transscandinavian Igneous Belt (TIB) in Sweden; a review of its character and evolution, 2004, 47-55 p.Chapter in book (Refereed)
  • 20.
    Andersson, U.B
    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.
    Grandin, L
    Petrographical analysis of saddle querns and flakes from Skogsmossen in the province of Västmaland, and Skumparberget and Hjulberga in the province of Närke, Sweden. Geoarchaeological Laboratory, Analytical report 11-2005, The National Heritage Board, Department of Archaeological Excavations, UV GAL2005Report (Other scientific)
  • 21.
    Andersson, U.B
    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.
    Hode Vuorinen, J
    CER200-Rare earth elements in minerals. Minisymposium med Svenska Mineralogiska Sällskapet, abstract-samling. GFF 1272005Conference proceedings (editor) (Refereed)
  • 22.
    Andersson, U.B
    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.
    Högdahl, K
    Eklund, O
    Foreword – A note on nomenclature2004In: The Transscandinavian Igneous Belt (TIB) in Sweden, 2004, 3-4 p.Chapter in book (Refereed)
  • 23.
    Andersson, U.B.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Högdahl, K.
    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.
    Multistage growth and reworking of the  Palaeoproterozoic crust in the Bergslagen area, southern Sweden: evidence from U-Pb  geochronology2006In: Geological Magazine, ISSN 0016-7568, E-ISSN 1469-5081, Vol. 143, no 5, 679-697 p.Article in journal (Refereed)
  • 24.
    Andersson, U.B
    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.
    Nysten, P
    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.
    Lundström, P
    Holtstam, D
    Locality descriptions. I: The Bastnäs-type REE-mineralisations in north-western Bergslagen, Sweden – a summary with geological background and excursion guide2004In: Sveriges geologiska undersökning, Rapporter och meddelanden, 2004, 25-28 p.Chapter in book (Refereed)
  • 25.
    Andersson, U.B.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Rutanen, H.
    Johansson, Å.
    Mansfeld, J.
    Rimsa, A.
    Characterization of the Paleoproterozoic Mantle beneath the Fennoscandian Shield: Geochemistry and Isotope Geology (Nd, Sr) of ~ 1.8 Ga Mafic Plutonic Rocks from the Transscandinavian Igneous Belt in Southeast Sweden2007In: International Geology Review, ISSN 0020-6814, E-ISSN 1938-2839, Vol. 49, no 7, 587-625 p.Article, review/survey (Refereed)
    Abstract [en]

    Geochemistry and Sr-Nd isotope geochemistry of ca. 1.8 Ga, mafic intrusions of the Transscandinavian Igneous Belt (TIB-1) in the Fennoscandian shield were studied in southeastern Sweden. These rocks show LILE-LREE-enriched, HFSE-depleted, calc-alkaline, continental arc signatures in the north, grading to slightly less enriched, oceanic affinities southward.εNd(1.80) values range from +2.0 to +0.7 and 87Sr/86Sr(1.80) from 0.7022 to 0.7029 (with one outlier at 0 and 0.7033), without correlation to fractionation (e.g., Mg#) or crustal contamination, indicating sources that are mildly depleted. The most depleted ratios occur in the south, trending with the geochemistry toward more enriched compositions northward. The sources represent depleted mantle wedge material that was subjected to enrichment not long before (TDM ca. 2.0 Ga), i.e., during the preceding arc subduction (2.1-1.82 Ga), and/or during the TIB-1 magmatism itself, by hydrous fluids with a sediment and/or melt input increasing northward. The TIB-1 magmatism occurred above a south(west)ward-retreating subduction zone along the continental margin of the juvenile Svecofennian continent at 1.81-1.76 Ga.

  • 26.
    Andersson, U.B
    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.
    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.
    Högdahl, K
    Eklund, O
    The Transscandinavian Igneous Belt; evolutionary models2004In: The Transscandinavian Igneous Belt (TIB) in Sweden; a review of its character and evolution, 2004, 104-112 p.Chapter in book (Refereed)
  • 27.
    Andersson, U.B
    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.
    Wikström, A
    The Småland-Värmland belt (SVB). Overview2004In: The Transscandinavian Igneous Belt (TIB) in Sweden; a review of its character and evolution, 2004, 15-20 p.Chapter in book (Refereed)
  • 28.
    Andersson, U.B
    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.
    Öhlander, B
    The late Svecofennian magmatism2004In: The Transscandinavian Igneous Belt (TIB) in Sweden; a review of its character and evolution, 2004, 102-104 p.Chapter in book (Refereed)
  • 29.
    Andersson, Ulf B.
    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.
    Eklund, O.
    Fröjdö, S.
    Konopelko, D.
    1.8 Ga magmatism in the fennoscandian shield; lateral variations in subcontinental mantle enrichment2006In: Lithos, Vol. 86, 110-136 p.Article in journal (Refereed)
  • 30.
    Andersson, Ulf B.
    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.
    Ghebreab, W.
    Teklay, M.
    Crustal evolution and metamorphism in east-central eritrea, south-east Arabian-Nubian shield2006In: J. African Earth Sci., Vol. 44, 45-65 p.Article in journal (Refereed)
  • 31.
    Andersson, Ulf B
    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.
    Högdahl, Karin
    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.
    Bergman, Stefan
    Multistage growth and reworking of the Palaeoproterozoic crust in the Bergslagen area, southern Sweden: evidence from U–Pb geochronology2006In: Geological Magazine, Vol. 143, no 679-697Article in journal (Refereed)
  • 32.
    Anderssson, Ulf B
    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.
    Högdahl, Karin
    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.
    Bergman, Stefan
    Magmatic, detrital and metamorphic ages from metamorphic rocks from south-central Sweden2004In: 26th Nordic Geological Wintermeeting: Abstracts, 2004Conference paper (Other (popular scientific, debate etc.))
  • 33. Andrault, D
    et al.
    Morard, G
    Bolfan-Casanova, N
    Ohtaka, O
    Fukui, H
    Arima, H
    Guignot, N
    Funakoshi, K
    Lazor, P
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Mezouar, M.
    Study of partial melting at high-pressure using in situ X-ray diffraction2006In: High Pressure Research, ISSN 0895-7959, E-ISSN 1477-2299, Vol. 26, no 3, 267-276 p.Article in journal (Refereed)
    Abstract [en]

    The high-pressure melting behavior of different iron alloys was investigated using the classical synchrotron-based in situ X-ray diffraction techniques. As they offer specific advantages and disadvantages, both energy-dispersive (EDX) and angle-dispersive (ADX) X-ray diffraction methods were performed at the BL04B1 beamline of SPring8 (Japan) and at the ID27-30 beamline of the ESRF (France), respectively. High-pressure vessels and pressure ranges investigated include the Paris- Edinburgh press from 2 to 17GPa, the SPEED-1500 multi-anvil press from 10 to 27 GPa, and the laser-heated diamond anvil cell from 15 to 60 GPa. The onset of melting (at the solidus or eutectic temperature) can be easily detected using EDX because the grains start to rotate relative to the X-ray beam, which provokes rapid and drastic changes with time of the peak growth rate. Then, the degree of melting can be determined, using both EDX and ADX, from the intensity of diffuse X-ray scattering characteristic of the liquid phase. This diffuse contribution can be easily differentiated from the Compton diffusion of the pressure medium because they have different shapes in the diffraction patterns. Information about the composition and/or about the structure of the liquid phase can then be extracted from the shape of the diffuse X-ray scattering.

  • 34.
    Annersten, H
    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.
    Affholter, K
    Cation distribution in synthetic allanite- a Mössbauer spectroscopic study: CER 200 Rare Earth Minerals2005In: GFF, Vol. 127, 34- p.Article in journal (Refereed)
  • 35.
    Annersten, Hans
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Jonsson, Erik
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Axel Hamberg som mineralog2012In: Sarek, Arktis och akademinsk vardag: en bok om geografen Axel Hambberg / [ed] Andersson, Lars, Uppsala: Acta Universitatis Upsaliensis, 2012, 93-111 p.Chapter in book (Other academic)
  • 36. Appelquist, K
    et al.
    Brander, L
    Johansson, Å
    Andersson, Ulf Bertil
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Cornell, D.
    Character and origin of variably deformed granitoids in central southern Sweden: implications from geochemistry and Nd isotopes2011In: Geological Journal, ISSN 0072-1050, E-ISSN 1099-1034, Vol. 46, no 6, 597-618 p.Article in journal (Refereed)
    Abstract [en]

    We present major and trace element data for eighteen 1.71–1.66 Ga granitoid samples, and Sm–Nd whole‐rock isotope data for eleven ofthese samples, in a transect across the border between the Transscandinavian Igneous Belt (TIB) and the Eastern Segment in central southernSweden. The geochemistry of the granitoids varies from alkalic to alkali‐calcic and peraluminous in the east to predominantly calc‐alkalineand metaluminous in the west. Rocks in the west also have lower SiO2 contents. Trace element signatures favour formation in an activecontinental margin setting. Nd isotope data are completely overlapping along the transect and initial εNd values are mildly depleted in therange +0.3 to +2.6. The combined data suggest that the magmas were derived mainly from juvenile, pre‐existing crust, increasingly mafic andless alkaline towards the west.

  • 37.
    Aswad, Khalid J. A.
    et al.
    Department of Geology, College of Science, Mosul University, Iraq.
    Aziz, Nabaz R. H.
    Department of Geology, College of Science, Sulaimani University, Kurdistan Region, Iraq.
    Koyi, Hemin
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Cr-spinel compositions in serpentinites, and their implications for the petrotectonic history of the Zagros Suture Zone, Kurdistan Region, Iraq2011In: Geological Magazine, ISSN 0016-7568, E-ISSN 1469-5081, Vol. 148, no 5-6, 802-818 p.Article in journal (Refereed)
    Abstract [en]

    Accessory chrome spinels are scattered throughout the serpentinite masses in two allochthonous thrust sheets belonging to the Penjween–Walash sub-zone of the northwestern Zagros Suture Zone in Kurdistan. Based on field evidence, the serpentinites are divided into two groups: (1) highly sheared serpentinites (110–80 Ma), which occupy the lower contact of the ophiolitic massifs of the Upper Allochthonous sheet (Albian–Cenomanian age), and (2) ophiolitic mélange serpentinites of mixed ages (150 and 200 Ma) occurring along thrust faults on the base of the volcano-sedimentary segment (42–32 Ma) of the Lower Allochthonous sheet. The Cr-spinels of both groups show a wide range of YCr (Cr/(Cr + Al) atomic ratio) from 0.37 to 1.0, while the XMg (Mg/(Mg + Fe2+) atomic ratio) ranges from 0.0 to 0.75. Based on the Cr-spinel compositions of the entire dataset and in conjunction with back-scattered electron imaging, from core to rim, three spinel stages have been recognized: the residual mantle stage, a Cr-rich stage and a third stage showing a very narrow magnetite rim. These three stages are represented by primary Cr-spinel, pre-serpentinization metamorphosed spinel and syn- or post-serpentinization spinel, respectively. The chemical characteristics of primary (first-stage) Cr-spinels of both serpentinite groups indicate a tectonic affinity within a fore-arc setting of peridotite protoliths. The second stage indicates that Cr-spinels have undergone subsolidus re-equilibration as a result of solid–solid reaction during pre-serpentinization cooling of the host rock. Here the primary Cr-spinel compositions have been partly or completely obscured by metamorphism. During the third stage, the Cr-spinels have undergone solid–fluid re-equilibration during syn- or post-serpentinization processes. Both the second and third stages point to diachronous metamorphic paths resulting from continuous tectonic evolution influenced by either slow or fast uplift of mantle protoliths. In the fast metamorphic paths, the primary chrome spinels are flanked by a very narrow magnetite rim. The presence of two groups of distally separated serpentinites with different emplacement ages and fore-arc tectonic affinity could indicate that the closure of the Tethys Ocean culminated in two fortuitous subduction processes.

  • 38. Azdouz, M
    et al.
    Azrour, M
    Manoun, B
    Bih, L
    El Ammari, L
    Benmokhtar, S
    Lazor, Peter
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Crystal structure and Raman Spectroscopy of NaKPbVO4 orthovanadates2009Conference paper (Other academic)
  • 39. Azdouz, M
    et al.
    Manoun, B
    Azrour, M
    Bih, L
    El Ammari, L
    Benmokhtar, S
    Lazor, Peter
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Synthesis, Rietveld refinements and Raman spectroscopy studies of the solid solution Na1-xKxPb4(VO4)(3) (0 <= x <= 1)2010In: Journal of Molecular Structure, ISSN 0022-2860, E-ISSN 1872-8014, Vol. 963, no 2-3, 258-266 p.Article in journal (Refereed)
    Abstract [en]

    In the present study we report the synthesis, crystal structure and Raman spectroscopy studies of Na1-xKxPb4(VO4)(3) orthovanaclates solid solutions (0 <= x <= 1). Rielveld refinements showed that this solid solution is continuous adopting P6(3)/m (no. 176) space group. Some of Pb(II) cations are located in the (6 h) sites. The ninefold coordination sites (4f) are equally occupied by the other lead cations and the K+ and Na+ monovalent ions. The structure can be described as built up from [VO4](3-) tetrahedral and Ph2+ of sixfold coordination cavities (6 h positions), which delimit void hexagonal tunnels running along [0 0 1]. These tunnels are connected by cations of mixed sites (4f) half occupied by Pb(II) and half by Na+/K+ mixed cations. The existence of this type of lacunar apatite seems to be conditioned by the presence of lone pair cations Pb(II). Raman spectra of all the compositions are similar and show some linear shifts in band positions as a function of the composition toward high values due the substitutions of Na+ by K+ with a larger radius. No considerable changes in the temperature dependence of the Raman modes and the corresponding FWHM are observed and thus no temperature induced phase transition is observed in Na0.5K0.5Pb4(VO4)(3) up to 650 K.

  • 40. Azdouz, M
    et al.
    Manoun, B
    Bih, L
    Azrour, M
    Ait Hou, A
    Benmokhtar, S
    Lazor, Peter
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    On the crystal structure and high temperature Raman spectroscopy of Pb2BaP2O8 orthophosphate2009Conference paper (Other academic)
  • 41. Azdouz, M.
    et al.
    Manoun, B.
    Essehli, R.
    Azrour, M.
    Bih, L.
    Benmokhtar, S.
    Ait Hou, A.
    Lazor, P.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Crystal chemistry, Rietveld refinements and Raman spectroscopy studies of the new solid solution series: Ba3−xSrx(VO4)2 (0≤x≤3)2010In: Journal of Alloys and Compounds, ISSN 0925-8388, E-ISSN 1873-4669, Vol. 498, no 1, 42-51 p.Article in journal (Refereed)
    Abstract [en]

    The new solid solution series Ba3-xSrx(VO4)(2) (0 <= x <= 3) has been synthesized and studied by a combination of X-ray powder diffraction and Raman vibrational spectroscopy. This continuous solid solution crystallise in the hexagonal system with R (3) over barm space group. The structure has been determined at room temperature from X-ray diffraction by the Rietveld method analysis. It is formed by a 3D network of (Ba/Sr)((1))(VO4)(2)(4-) layers linked into a crystal network by (Ba/Sr)(2+)((2)) cations. The vibrational spectra of this crystalline orthovanadate solid solution series are interpreted by means of factor group analysis in terms of space group R (3) over barm (D-3d(5)). Assignments of the V-O vibrational stretching and bending modes, as well as some of the external modes, have been made. While all the modes show a monotonous shift as a function of the composition x, a break in the curves of intensities, full width at half maximum and band areas as a function of x is observed and attributed to the statistical distribution of Ba and Sr ions in the same crystallographic sites.

  • 42. Aziz, Nabaz R. H.
    et al.
    Aswad, Khalid J. A.
    Koyi, Hemin
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Contrasting Settings of Serpentinite Bodies in Northwestern Zagros Suture Zone, Kurdistan Region, Iraq2011In: Geological Magazine, ISSN 0016-7568, E-ISSN 1469-5081, Vol. 148, no 5-6, 819-837 p.Article in journal (Refereed)
    Abstract [en]

    Protrusions and lenses of serpentinite–matrix mélanges occur at several places along the thrust faults of the Zagros Suture Zone. They separate the lower allochthonous thrust sheet, the ‘Lower Allochthon’ (i.e. Walash–Naopurdan nappe), of Paleocene–Eocene age from sediments of the Arabian platform and the upper thrust sheet of Mesozoic, ophiolite-bearing terranes termed the ‘Upper Allochthon’ (i.e. Gemo–Qandil nappe). The serpentinite–matrix mélanges occur mostly as stretched bodies (slices) on both sides of the Lower Allochthon (Hero, Halsho and Pushtashan (HHP) and Galalah, Qalander and Rayat (GQR)). Their overall chondrite-normalized rare earth element (REE) patterns form two main groups. Group One exhibits enrichment in the total REEs (> 1 × chondrite) whereas the Group Two pattern shows depletion (i.e. < 1 × chondrite). Bulk-rock MORB-normalized profiles of Group Two are almost flat in the MREE–HREE region with flattening profiles in the Gd–Lu range (> 3 times the MORB composition). In comparison with Group One, Group Two has extremely high REE content and displays variable depletions in the moderately incompatible high-field-strength elements (HFSEs) (Zr, Hf, Y) relative to their adjacent REEs. The REEs in the GQR serpentinite–matrix mélanges have a noticeably high LREE content, and a positive Eu anomaly, and their HREE content never reaches more than 1 × chondrite (i.e. < 0.01 to 1 × chondrite). The latter indicates that the hemipelagic sedimentary, melt-like components (i.e. high LREE, U/La, La/Sm and low Ba/Th) control the geochemical peculiarities of this type of serpentinite. The HHP serpentinite–matrix mélanges, however, are either equally divided between the two REE pattern groups (e.g. Hero, Halsho) or inclined towards Group One (e.g. Pushtashan). Contrary to GQR serpentinites, the variation in HHP serpentinite–matrix mélanges spans a compositional spectrum from U/La-rich to more Ba/Th-rich. Such ratio variations reflect the large variation in these two subducted sedimentary components (i.e. carbonate and hemipelagic sediment mix). The obvious differences in the trace element signatures of the GQR and HHP serpentinite–matrix mélanges might be related to plate tectonic parameters such as convergence rate, subduction age and thickness and type of subducted slab. It is more likely that the influx of subducted components to the mantle wedge relied heavily on the composition of the sedimentary inputs. These vary considerably with time from the relatively deepwater hemipelagic sediments (Qulqula Radiolarite Formation) to platform carbonate sediments (Balambo limestone). The trace element signatures of the GQR and HHP serpentinite–matrix mélanges might suggest multi-staging of the allochthonous sheet emplacement on the Arabian platform sediments.

  • 43.
    Bahroudi, A
    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. Solid Earth.
    Koyi, H.A.
    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. Solid Earth.
    Effect of Hormuz salt deformation style of the Zagros fold-thrust belt.2004In: Bullettino di Geofisica Teorica ed Applicata, Vol. 45, 61-65 p.Article in journal (Refereed)
  • 44.
    Bahroudi, A
    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.
    Koyi, H.A
    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.
    Tectono-Sedimentary framework of the Gachsaran Formation in the Zagros foreland basin2004In: Marine and Petroleum Geology, Vol. 21, 1295-1310 p.Article in journal (Refereed)
  • 45.
    Bahroudi, A
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Koyi, Hemin
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Talbot, Christopher J.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Effect of ductile and frictional decollements on style of extension2003In: Journal of Structural Geology, ISSN 0191-8141, E-ISSN 1873-1201, Vol. 25, no 9, 1401-1423 p.Article in journal (Refereed)
    Abstract [en]

    Scaled analogue models were used to study the effect of frictional and ductile detachments on thin-skinned extension. Models consisted of two halves; one half is the ductile and the other has a frictional detachment. Extension occurred above two different basal configurations: a stretchable rubber sheet and a folded, banded sheet intended to produce homogeneous and heterogeneous extension, respectively. Model parameters varied systematically and included the brittle/ductile thickness ratio, rheologies, and bulk strain. Structures in the two halves are compared in profiles and plan views. A series of graben developed above both halves of models extended above a banded sheet, although there were differences in style, propagation rate and width of the deformation zone between the two halves. Different rates of propagation of structures in the two halves led to the formation of an accommodation or transfer zone parallel to the extension direction. Most relay ramps and inflection of normal faults in this zone indicate differential extension between the two halves.

    In contrast, in models extended above a stretchable rubber sheet, extensional structures such as horst and graben developed only above the ductile detachment. Model results indicate that heterogeneous mechanical stratigraphy and displacement rate have no effect on extensional structure above a rubber sheet. However, above 20% bulk extension, deformation becomes heterogeneous along multiple sets of conjugate faults oblique to the extension direction.

  • 46.
    Bahroudi, A
    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.
    The configuration of the basement beneath the Zagros basin2003In: Journal of Petroleum Geology, Vol. 26, 257-282 p.Article in journal (Other scientific)
  • 47.
    Bahroudi, Abbas
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Koyi, H. A
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Effect of spatial distribution of Hormuz salt on deformation style in the Zagros fold and thrust belt: an analogue modelling approach2003In: Journal of the Geological Society of London, Vol. 160, 719-733 p.Article in journal (Refereed)
    Abstract [en]

    Scaled analogue models of thin-skinned simultaneous shortening above adjacent viscous and frictional décollements simulate the effect of Hormuz salt on the shortening in the Zagros fold and thrust belt. The models consisted of sand layers that partly overlay a viscous layer of silicone and were shortened from one end. Spatial distribution of the viscous décollement varied along strike and dip, as occurs in part of the Zagros fold and thrust belt. In this belt, Phanerozoic sedimentary cover was shortened partly above the Hormuz salt lying on the Precambrian crystalline basement, behaving as a basal viscous décollement. Model results display how the nature of the décollement affects the evolution of an orogenic belt. Using model results, we explain the development of deflection zones, and discuss strain partitioning, formation of different topographic wedges and differential sedimentation along the Zagros fold and thrust belt. Model results suggest the formation of a gentle taper, consisting of both foreward and backward thrusts above a viscous décollement and a relatively steeper taper consisting only of forward-vergent imbricates above a frictional décollement. However, in our models, the steepest wedge with the highest topography formed where the viscous substrate had a limited extent with a transitional boundary (pinch-out) perpendicular to the shortening direction. Shortening of this boundary led to development of frontal ramps associated with significant uplift of the area behind the deformation front.

  • 48.
    Baikpour, S.
    et al.
    Department of Geology and Palaeontology, J. W. Goethe Universität, Frankfurt, Germany .
    Talbot, C. J.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    The Garmsar salt nappe and seasonal inversions of surrounding faults imaged by SAR interferometry, Northern Iran2012In: Geological Society of London, Special Publications, Vol. 363, 563-578 p.Article in journal (Refereed)
    Abstract [en]

    The allochthonous Tertiary salt of the Garmsar salt nappe extruded from where the most southerly point of the Alborz Mountain front is offset by the Zirab–Garmsar strike-slip fault. We used eleven descending Advanced Synthetic Aperture Radar (SAR) images, acquired by the European Space Agency's ENVISAT satellite from 2003 to 2006, to map surface displacement over 23 increments ranging in time from 30 to 2 months. A 30 month SAR interferogram of the area shows that the regional folds and faults are active south of the mountain front, but are dampened by the allochthonous salt that otherwise appears to be merely degrading at rates that vary with the season. Interferograms for shorter epochs display different patterns of fault blocks in the country rocks that rose and fell with the seasons. By relating surface displacements mapped in these interferograms to the contemporaneous seismic record, we find that seismic faults reactivate repeatedly while their kinematics may have inverted on remarkably short timescales. Seismic disturbances propagate very slowly and faults are longer than expected for earthquakes with ML<3.5, indicating that the regional strains are more aseismic than anticipated by earlier studies.

  • 49.
    Barker, Abigail
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Coogan, L. A.
    Gillis, K. M.
    Hayman, N. W.
    Weis, D.
    Direct observation of a fossil high-temperature, fault-hosted, hydrothermal upflow zone in crust formed at the East Pacific Rise2010In: Geology, ISSN 0091-7613, E-ISSN 1943-2682, Vol. 38, no 4, 379-382 p.Article in journal (Refereed)
    Abstract [en]

    Fault zones in the ocean crust are commonly hypothesized to act as high-permeability conduits that focus fluid flow in oceanic hydrothermal systems. However, there has been little direct study of faults in crust formed at fast-spreading ridges. Here we describe the geology and geochemistry of an ∼40-m-wide fault zone within the uppermost sheeted dike complex exposed at Pito Deep (northeastern Easter microplate). Titanium in quartz thermometry gives temperatures of 392 ± 33 °C for quartz precipitation, indicating that this fault zone focused upwelling fluids at temperatures similar to those of black-smoker vent fluids. Correlated enrichment in 87Sr/86Sr and MgO in fault breccias, along with 87Sr/86Sr ratios higher than in average vent fluids, provide evidence for mixing between high-temperature upwelling fluids and a seawater-like fluid within the fault zone. Large high-temperature fluid fluxes are required to maintain high temperatures during mixing. If this fault zone is representative of upflow zones beneath hydrothermal vents on the East Pacific Rise, then it is possible that vent fluids evolve thermally and chemically during their ascent and may not record the precise conditions at the base of the hydrothermal system.

  • 50.
    Barker, Abigail
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Solid Earth Geology.
    Coogan, L.A.
    Gillis, K.M., K.M.
    Insights into the behaviour of sulphur in mid-ocean ridge axial hydrothermal systems from the composition of the sheeted dyke complex at Pito Deep2010In: Chemical Geology, ISSN 0009-2541, E-ISSN 1872-6836, Vol. 275, no 1-2, 105-115 p.Article in journal (Refereed)
    Abstract [en]

    The behaviour of seawater sulphate in hydrothermal systems at intermediate- to fast-spreading ridges is investigated using new analyses of the δ34S, sulphur concentration and Fe2O3/Fe2O3total, combined with existing 87Sr/86Sr, of sheeted dykes from the Pito Deep tectonic window. The Pito Deep sheeted dyke complex has a similar composition to the sheeted dykes drilled at ODP Hole 504B suggesting that the measured compositions are representative of sheeted dyke complexes at intermediate- to fast-spreading ridges. The dykes show only small increases in δ34S which, combined with the rock dominated δ34S of vent fluids, requires the majority of seawater sulphate to be precipitated as anhydrite before the fluid reacts with the sheeted dyke complex. This loss of sulphate from the fluid means that a much higher Fe2O3 in the sheeted dyke complex than in fresh MORB glasses cannot be explained by oxidation due to seawater sulphate reduction during fluid-rock reaction. Instead, oxidation probably occurs due to degassing of reduced species, largely H2, during dyke emplacement and solidification. A mass balance model that accounts for anhydrite precipitation and Sr partitioning into the anhydrite, as well as fitting the concentration and isotopic ratios of S and Sr in the sheeted dykes and vent fluids, suggests water/rock ratios of -1. For a 1km thick sheeted dyke complex this is equivalent to a fluid flux of ~3×106kgm-2, sufficient to remove ~60% of the latent heat of crystallization from the lower crust.

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