Search for dissertations about: "Paleoproterozoic"

Showing result 11 - 15 of 19 swedish dissertations containing the word Paleoproterozoic.

2. 11. 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. 12. Tectonic evolution of NW Svalbard

   Author : Carl Pettersson; Stockholms universitet; []
   Keywords : Svalbard; Migmatization; Zircon; Provenance;

   Abstract : The Neoproterozoic is a remarkable era in Earth’s history with dramatic variations in climate and biota, possibly resulting in global glaciations events (eg. “snowball earth”, Kirschvink, 1992) and the first appearance of metazoans (Conway Morris, 1993). READ MORE

5. 13. Understanding Zircon Geochronology - Constraints from Imaging and Trace Elements

   Author : Andrius Rimsa; Berggrundsgeologi; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; hydrothermal; Petrology; mineralogy; hydraulic fracturing; Sveconorwegian; incipient charnockite; EBSD; cathodoluminescence; REE; Zircon; U-Pb geochronology; geochemistry; Petrologi; mineralogi; geokemi; Kerala Khondalite Belt;

   Abstract : Formation of incipient charnockite in Söndrum, SW Sweden and the Kerala Khondalite Belt (KKB), S. India is accompanied by zircon growth. The age of the dehydration event is constrained by dating newly formed zircon to 1397±4 Ma (2?, MSWD=1.7) in Söndrum and ca. READ MORE

6. 14. 3D Geophysical and Geological Modeling in the Skellefte District: Implications for Targeting Ore Deposits

   Author : Alireza Malehmir; Ari Tryggvason; Christopher Juhlin; Bernd Milkereit; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Geophysics; Seismic reflection; Hardrock; VHMS deposits; Potential field; 3D geologic model; Skellefte District; Geofysik;

   Abstract : With the advancements in acquisition and processing of seismic reflection data recorded over crystalline rocks, building three-dimensional geologic models becomes increasingly favorable. Because of little available petrophysical data, interpretations of seismic reflection data in hardrock terrains are often speculative. READ MORE

7. 15. Tectonic setting and metallogeny of the Kiruna greenstones

   Author : Olof Martinsson; Luleå tekniska universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Malmgeologi; Ore Geology;

   Abstract : The Paleoproterozoic Kiruna Greenstones belong to a large c. 2.1 Ga tholeiitic province in the north-eastern part of the Baltic Shield. The mainly basaltic volcanism was related to an event of continental rifting, which ended up with continental rupture. READ MORE