Sökning: "Sm-Nd dating"

Hittade 3 avhandlingar innehållade orden Sm-Nd 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. 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

4. 3. 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