Sökning: "U-Th He"

Hittade 4 avhandlingar innehållade orden U-Th He.

  1. 1. 40Ar/39Ar, AFT and (U-Th)/He thermochronologic implications for the low-temperature geological evolution in SE Sweden

    Författare :Pia Söderlund; Berggrundsgeologi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; 40Ar-39Ar; Fennoscandian Shield; U-Th He; AFT; geochronology; thermochronology; cooling; uplift;

    Sammanfattning : The Oskarshamn and Forsmark areas in the Fennoscandian Shield, SE Sweden, have been chosen as potential sites for hosting highly radioactive nuclear waste. To evaluate their respective suitability, the geological history of the bedrock in these two areas has been investigated. This study has focused on the thermal evolution, from c. 500 °C to c. LÄS MER

  3. 2. Cryptic Orogeny : uplift of the Al Hajar Mountains at an alleged passive margin

    Författare :Reuben Johannes Hansman; Ring Uwe; Joachim Jacobs; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; uplift; mountains; structural; low-temperature; thermochronology; dating; fission-track; U-Th He; U-Pb; calcite; structure-from-motion; photogrammetry; UAV; trishear; fault-propagation; Hafit; Al Hajar Mountains; United Arab Emirates; Oman; Geology; geologi;

    Sammanfattning : Mountains evolve and grow because of the large forces that occur from the collision of tectonic plates. Plate boundaries change and move through time, and regions that were once stable, shallow-marine environments can be dragged into subduction zones and get transformed into vast mountain ranges. LÄS MER

  4. 3. Constraining the Uplift History of the Al Hajar Mountains, Oman

    Författare :Reuben Hansman; Uwe Ring; Victoria Pease; Hemin Koyi; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; oman; Al Hajar; mountain; uplift; orogeny; tectonics; structural; geology; Geology; geologi;

    Sammanfattning : Mountain building is the result of large compressional forces in the Earth’s crust where two tectonic plates collide. This is why mountains only form at plate boundaries, of which the Al Hajar Mountains in Oman and the United Arab Emirates is thought to be an example of. 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