Advanced search

Showing result 1 - 5 of 13 swedish dissertations matching the above criteria.

  2. 1. U-Pb geochronology of tectonothermal events related to the Rodinia and Gondwana supercontinents -observations from Antarctica and Baltica

    Author : Oskar Paulsson; Berggrundsgeologi; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; klimatologi; pedology; climatology; Fysisk geografi; geomorfologi; marklära; kartografi; geomorphology; Physical geography; Gondwana; Rodinia; Antarctica; Baltica; Dronning Maud Land; cartography;

    Abstract : This thesis presents data from two areas, Dronning Maud Land, Antarctica, and the Scandinavian Caledonides, Baltica. In addition, a comparative geochronological study is presented. The bedrock of Dronning Maud Land (DML) is dominated by migmatitic gneisses and post-tectonic intrusions. READ MORE

  4. 2. Crustal evolution of the Arabian–Nubian Shield : Insights from zircon geochronology and Nd–Hf–O isotopes

    Author : Fitsum Girum Yeshanew; Victoria Pease; Martin J. Whitehouse; Robert J. Stern; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Gondwana; Arabian–Nubian Shield; Azania; zircon U–Pb–O–Hf isotopes; Nd isotopes; Cambrian Sandstones; juvenile; pre–Neoproterozoic; reworking; Geology; geologi;

    Abstract : The Arabian–Nubian Shield (ANS) represents a major site of juvenile Neoproterozoic crustal addition on Earth and documents Neoproterozoic tectonics bracketed by two supercontinent cycles, namely the fragmentation of Rodinia and the amalgamation of Gondwana. There is general consensus that the ANS formed by juvenile magmatic arc accretion and subsequent shield–wide post–tectonic magmatism. READ MORE

  5. 3. Morphology, Taxonomy and Interrelationships of Tristichopterid Fishes (Sarcopterygii, Tetrapodomorpha)

    Author : Daniel Snitting; Per Erik Ahlberg; Graham Budd; Henning Blom; Zerina Johanson; Uppsala universitet; []
    Keywords : Organismic biology; Sarcopterygii; Tetrapodomorpha; Tristichopteridae; biogeography; phylogeny; Computed Tomography; Devonian; Organismbiologi;

    Abstract : Tristichopterids (Sarcopterygii, Tetrapodomorpha) form a monophyletic group of exclusively Devonian fishes. This thesis consists of descriptions of new material of tristichopterids and closely related taxa, as well as new interpretations and descriptions of previously figured material. READ MORE

  6. 4. Diversification on an ancient Darwinian island : Evolutionary history of caddisflies (Trichoptera) and other organisms on New Caledonia

    Author : Marianne Espeland; Kjell Arne Johanson; Niklas Wahlberg; Michael Balke; Stockholms universitet; []
    Keywords : New Caledonia; Trichoptera; island; biogeography; phylogenetics; DNA; dispersal; vicariance; adaptation; ultramafic; diversification; new species; environmental factors; Systematic Zoology; zoologisk systematik och evolutionsforskning;

    Abstract : Islands are either of continental or oceanic origin, and the biota of such islands are a result of vicariance and dispersal, respectively. New Caledonia, in the South Pacific, is a part of former Gondwana, but the origin of its biota is heavily debated. READ MORE

  7. 5. Seismic Studies of Paleozoic Orogens in SW Iberia and the Middle Urals

    Author : Artem Kashubin; Christopher Juhlin; Lars Nielsen; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Reflection seismics; Traveltime tomography; Uralian orogeny; Variscan orogeny; Crustal structure; Geophysics; Geofysik;

    Abstract : Controlled source seismic methods were employed in this study to investigate the reflectivity and velocity structure of two Hercynian orogens – the Uralides and Variscides. Conventional common depth point (CDP) sections from five reflection seismic campaigns and a velocity model obtained from tomographic inversion of wide-angle observations were the main datasets studied from the Middle Urals. READ MORE