Search for dissertations about: "Gondwana"

Showing result 6 - 10 of 13 swedish dissertations containing the word Gondwana.

  2. 6. New Zircon geochronological and Nd isotopic evidence for Neoproterozoic crust reworking events in the Abas terrane, Yemen

    Author : Fitsum Girum Yeshanew; Victoria Pease; Martin Whitehouse; Hugh Rollinson; Kjell Billström; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Precambrian; Arabian Shield; magmatism; U-Pb; zircon; post-collisional magmatism; Nd isotopes; Geology; geologi;

    Abstract : The Arabian-Nubian Shield is an excellent natural laboratory to study crust formation processes during the Neoproterozoic. It is one of the largest juvenile tracts of continental crust formed during this time. It diachronously evolved between the breakup of Rodinia (c.780 Ma) and amalgamation of Gondwana (c. READ MORE

  4. 7. Biostratigraphy and Systematics of Cambrian Small Shelly Fossils from East Antarctica and South Australia

    Author : Thomas M. Claybourn; Lars E. Holmer; Glenn A. Brock; Christian B. Skovsted; Graham Budd; David Harper; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Cambrian; Biostratigraphy; Systematics; East Antarctica; Small Shelly Fossils;

    Abstract : The remote lower Cambrian Byrd group of sedimentary rocks from East Antarctica has been studied intermittently since its discovery over a century ago. Previous insights into the trilobites and archaeocyaths indicated a close correlation to the sedimentary sequences of South Australia. READ MORE

  5. 8. Pan-African and Red Sea tectonics of eastern Eritrea

    Author : Woldai Ghebreab; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Earth sciences; Pan-African tectonic grain; Geovetenskap; Earth sciences; Geovetenskap; mineralogi; petrologi och tektonik; Mineral Chemistry; Petrology and Tectonics;

    Abstract : This thesis proposes that the Pan-African tectonic grain in eastem Eritrea influenced theCenozoic opening of the Red Sea. Evidence is based on studies of the structures and fabrics of various phases associated with both the Pan-African orogeny and subsequent Red Sea extension. READ MORE

  6. 9. Ice Sheet, Climate, and Landscape Interactions in Dronning Maud Land, Antarctica

    Author : Jens-Ove Näslund; Sugden David; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Antarctica; Basal temperature; Dronning Maud Land; Erosion; Escarpments; Glacial landforms; Ice Sheets; Ice sheet modelling; Landscape development; Palaeosurfaces; Radar; Other earth sciences; Övrig geovetenskap; naturgeografi; Physical Geography;

    Abstract : The impact of glaciers and ice sheets on the subglacial landscape are of fundamental importance for studies of glacial history and landscape development, both in previously glaciated areas and in areas that are glaciated today. The thesis concerns the present and past erosive capacity of the ice sheet in Dronning Maud Land, East Antarctica. READ MORE

  7. 10. Evolution of the Biodiversity Hotspot of Madagascar from the Eye of Diving Beetles : Phylogeny, colonization and speciation

    Author : Rasa Bukontaite; Johannes Bergsten; Ingi Agnarsson; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Dytiscidae; diving beetles; Biogeography; Phylogeny; Dating; phylogenetic informativeness; colonization; speciation; microendemism; Madagascar; systematisk zoologi; Systematic Zoology;

    Abstract : Dytiscidae, contains numerous endemic and non-endemic species on Madagascar. Their evolutionary history is largely unknown on the island. Herein, I use analyses to infer phylogenetic relationship among groups of diving beetles, with a focus on the subfamily Dytiscinae and endemic species in two other groups of Dytiscidae. READ MORE