Search for dissertations about: "Mesoproterozoic"

Showing result 1 - 5 of 10 swedish dissertations containing the word Mesoproterozoic.

  1. 1. Palaeobiology and diversification of Proterozoic-Cambrian photosynthetic eukaryotes

    Author : Heda Agić; Małgorzata Moczydłowska; Shuhai Xiao; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; microfossils; eukaryotes; Mesoproterozoic; Neoproterozoic; Cambrian; Ordovician; palaeobiology; biostratigraphy; phylogeny; China; Estonia; Siberian Platform; prasinophytes; microstructure; Raman spectroscopy; Earth Science with specialization in Historical Geology and Palaeontology; Geovetenskap med inriktning mot historisk geologi och paleontologi;

    Abstract : One of the most important events in the history of life is the evolution of the complex, eukaryotic cell. The eukaryotes are complex organisms with membrane-bound intracellular structures, and they include a variety of both single-celled and multicellular organisms: plants, animals, fungi and various protists. READ MORE

  2. 2. Tectonic implications of ca. 1.45 Ga granitoid magmatism at the southwestern margin of the East European Craton

    Author : Audrius Cecys; Berggrundsgeologi; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Geologi; southern Sweden; fysisk geografi; physical geography; Mesoproterozoic; geochemistry; syntectonic; petrology; structural geology; anisotropy of magnetic susceptibility; Danopolonian orogeny; Geology; granite;

    Abstract : Between ca 1.53 and 1.40 Ga, the southwestern margin of the East European Craton was subjected to extensive magmatism and deformation. While various suites of anorthositic, mangeritic and charnockitic-granitic rocks were emplaced between ca. READ MORE

  3. 3. Mesoproterozoic crustal evolution in Southern Africa

    Author : Åsa Pettersson; Göteborgs universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Namaqua-Natal province; Mezoproterozoic; geochronology; U-Pb zirkon dating; Sm-Nd model ages; Ar-Ar dating; Southern Africa;

    Abstract : The objects of this thesis were to use geochronology to investigate crustal evolution of part of Southern Africa that formed during a global event, resulting in the ~1 Ga supercontinent Rodinia. The timing of assembly by continent-continent collisions and the position of the individual continental blocks of this ancient landmass is still largely unknown. READ MORE

  4. 4. The Mesoproterozoic Hallandian event - a region-scale orogenic event in the Fennoscandian Shield

    Author : Linus Brander; Göteborgs universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Fennoscandian Shield; Hallandian orogeny; Eastern Segment; Protogine Zone; U-Pb geochronology; zircon; baddeleyite; Nd-isotopes; Hf-isotopes; tectonic model;

    Abstract : The Sveconorwegian Province occupies the southwestern part of the Fennoscandian Shield. The easternmost tectonic unit of the Province is the 1710-1660 Ma parautochthonous Eastern Segment, which bears the imprint of at least two metamorphic events; the 1460-1380 Ma Hallandian and the 1150-970 Ma Sveconorwegian. READ MORE

  5. 5. 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