Sökning: "Ar-Ar dating"

Hittade 3 avhandlingar innehållade orden Ar-Ar dating.

  1. 1. Mesoproterozoic crustal evolution in Southern Africa

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

    Sammanfattning : 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. LÄS MER

  3. 2. Proterozoic to Quaternary Events of Fracture Mineralisation and Oxidation in SE Sweden

    Författare :Henrik Drake; Göteborgs universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; fracture minerals; low-temperature evolution; paleohydrogeology; redox front; wall rock alteration; stable isotopes; geochemistry; Ar-Ar dating; fluid inclusions; Mössbauer spectroscopy; U-series disequilibrium; Simpevarp; Laxemar; SE Sweden; nuclear waste repository.;

    Sammanfattning : Fracture minerals and altered wall rock have been analysed to reveal the low-temperature evolution, especially regarding redox conditions, of the Simpevarp area, SE Sweden. This area is one of the two areas in Sweden investigated by the Swedish Nuclear fuel and Waste Management Co. LÄS MER

  4. 3. Pressure, temperature and time constraints on tectonic models for southwestern Sweden

    Författare :Eric Austin Hegardt; Göteborgs universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Sveconorwegian; Gothian; Hallandian; U‐Pb zircon ion probe dating; Sm-Nd garnet dating; thermobarometry; continental subduction; Eastern Segment; Median Segment; Western Segment;

    Sammanfattning : In this work, a number of key localities have been investigated in detail in order to provide precise constraints on models for the tectonic evolution of southern Sweden. The new data presented in this thesis show that there are large differences in terms of pre-Sveconorwegian tectonic evolution between the Eastern and Median-Western Segments situated on either side of the Mylonite Zone, a major shear zone as well as a structural and lithological boundary. LÄS MER