Sökning: "precambrian rocks"

Visar resultat 1 - 5 av 18 avhandlingar innehållade orden precambrian rocks.

  1. 1. P-T evolotion and High-temperature deformation of Precambrian eclogite, Sveconorwegian orogen

    Författare :Lorraine Tual; Berggrundsgeologi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Eclogite; Precambrian; P–T path; Basal shear zone; Sveconorwegian orogen; Deformation; thermometry;

    Sammanfattning : The 1.1-0.9 Ga Sveconorwegian orogen is one of several Grenvillian-aged orogenic belts that mark the amalgamation of supercontinent Rodinia. The highest-pressure rocks in the Sveconorwegian orogen are eclogites in the Eastern Segment (SW Sweden). LÄS MER

  3. 2. New Zircon geochronological and Nd isotopic evidence for Neoproterozoic crust reworking events in the Abas terrane, Yemen

    Författare :Fitsum Girum Yeshanew; Victoria Pease; Martin Whitehouse; Hugh Rollinson; Kjell Billström; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Precambrian; Arabian Shield; magmatism; U-Pb; zircon; post-collisional magmatism; Nd isotopes; Geology; geologi;

    Sammanfattning : The Arabian-Nubian Shield is an excellent natural laboratory to study crust formation processes during the Neoproterozoic. It is one of the largest juvenile tracts of continental crust formed during this time. It diachronously evolved between the breakup of Rodinia (c.780 Ma) and amalgamation of Gondwana (c. LÄS MER

  4. 3. Magnetic anisotropy and paleomagnetism of precambrian rocks in the Fennoscandian shield

    Författare :Håkan Johannes Mattsson; Luleå tekniska universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Tillämpad geofysik; Applied Geophysics;

    Sammanfattning : This thesis presents three applications of the anisotropy of magnetic susceptibility (AMS) technique, dealing with tectonic and magmatic flow fabrics of Proterozoic igneous rocks in the central and northern parts of the Fennoscandian Shield. Paleomagnetic measurements were performed in attempts to put the different rock units into a geological and plate tectonic context. LÄS MER

  5. 4. Constraining the timing of veins, faults and fractures in crystalline rocks by in situ Rb-Sr geochronology

    Författare :Mikael Tillberg; Henrik Drake; Mats E. Åström; Thomas Zack; Johan Hogmalm; Bjarne Almqvist; Linnéuniversitetet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; geochronology; brittle deformation; crustal fluids; mineral precipitation; ancient microbial activity; Precambrian craton; Scandinavia; Natural Science; Naturvetenskap;

    Sammanfattning : Precambrian cratons are continent cores archiving the oldest crustal histories on Earth. The crystalline basement of cratons is typically characterized by complex arrays of multiple fracture and fault generations hosting minerals formed by fluids flowing through fracture networks. LÄS MER

  7. 5. Research in rock magnetism and palaeomagnetism with reference to Caledonian and Precambrian rocks in Sweden

    Författare :Sten-åke Elming; Luleå tekniska universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Tillämpad geofysik; Applied Geophysics;

    Sammanfattning : .... LÄS MER