Sökning: "Eastern Segment"

Visar resultat 1 - 5 av 12 avhandlingar innehållade orden Eastern Segment.

1. 1. 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

3. 2. Geochronology of Tectonothermal Events in the Parautochthonous Eastern Segment of the Sveconorwegian (Grenvillian) Orogen, Southwestern Sweden

   Författare :Ulf Söderlund; Berggrundsgeologi; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Sveconorwegian; SW Sweden; Eastern Segment; geochronology; U-Pb; zircon; titanite; polymetamorphic; high-grade; Geology; exhumation; physical geography; Geologi; fysisk geografi;

   Sammanfattning : Timing of deformation and metamorphism yield important information for understanding the development of orogenic processes and correlation of mobile belts and continents. This thesis adds new geochronological data constraining the age of protoliths and events of reworking in the frontal region of the c. 1.2-0. LÄS MER

4. 3. Geochemical Development of Proterozoic Granites in the SW Baltic Shield

   Författare :Kirsten Holme; Berggrundsgeologi; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; principal component analysis; granite classification; magma evolution; magma genesis; granite; Eastern Segment; Western Segment; Southwestern Swedish Gneiss Complex; Sweden; Sveconorwegian Orogen; Petrology; mineralogy; geochemistry; Petrologi; mineralogi; geokemi; Geology; physical geography; Geologi; fysisk geografi;

   Sammanfattning : The plutonic rocks in the Western Segment of the Southwestern Swedish Gneiss Complex show a distinct geochemical evolution. The 1.6 Ga Åmål granitoids and Slottsbron migmatites are a quartz dioritic to granodioritic, calc-alkaline rock suite with smooth, but somewhat fractionated, REE and other trace-element patterns. LÄS MER

5. 4. Sveconorwegian orogenesis in the southwestern Baltic Shield - Zircon geochronology and tectonothermal setting of orthogneisses in SW Sweden

   Författare :Jenny Andersson; Berggrundsgeologi; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Petrology; Geologi; fysisk geografi; physical geography; Geology; structural markers; augen gneiss; orthogneiss; migmatite; ion microprobe; Pb-Pb evaporation; U-Pb; geochronology; zircon; Sweden; Mylonite Zone; Western Segment; Sveconorwegian orogen; Eastern Segment; mineralogy; geochemistry; Petrologi; mineralogi; geokemi;

   Sammanfattning : The Mylonite zone (MZ) is a prominent late-Sveconorwegian lithological terrane boundary in the SW Baltic Shield along which large-scale crustal block movements took place during the Sveconorwegian orogeny. The southern section of the MZ also defines a conspicuous metamorphic break separating upper amphibolite and high-pressure granulite facies rocks in the parautochthonous Eastern Segment (ES), from middle amphibolite facies rocks in the overlying Western Segment (WS). LÄS MER

7. 5. Proterozoic crustal evolution in southcentral Fennoscandia

   Författare :Karin Appelquist; Göteborgs universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Transscandinavian Igneous Belt; TIB; Eastern Segment; Habo Volcanic Suite; Malmbäck Formation; U-Pb zircon ion probe dating; Nd isotopes; geochemistry; Hallandian; Danopolonian;

   Sammanfattning : The Transscandinavian Igneous Belt (TIB) and the Eastern Segment of the Southwest Scandinavian Domain reflect advanced stages of continental growth within the Fennoscandian Shield. The relationship between the two units is not clear, mainly because N-S trending shear zones of the Protogine Zone transect the border zone. LÄS MER