Sökning: "Dating"

Visar resultat 6 - 10 av 248 avhandlingar innehållade ordet Dating.

  1. 6. Improving archaeomagnetic dating through new data acquisition and method development

    Författare :Megan Allington; Kvartärgeologi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Archaeomagnetism; Palaeomagnetism; Geomagnetic field; Archaeomagnetic dating;

    Sammanfattning : The Earth’s magnetic field (or geomagnetic field) has been measured for hundreds of years, starting with maritime observations from logbooks for navigation purposes to present day real-time recording by satellites. From these records, the geomagnetic field variation throughout recent time is well-understood. LÄS MER

  3. 7. Geochronology of impact structures - constraining syn- and post-impact processes using the 40Ar/39Ar and U-Pb techniques

    Författare :Maria Herrmann; Berggrundsgeologi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Impact structure; Dating impact events; 40Ar 39Ar dating; U-Pb dating; Siljan impact structure; Mien impact structure; Hummeln impact structure; Puchezh-Katunki impact structure;

    Sammanfattning : The discovery, at the beginning of the 20th century, that elements can transform into other elements, due to the spontaneous decay of an instable to a stable atomic nuclei, gave rise to a powerful source for age information in many fields of earth science. For impact structures, it is crucial to establish well-defined and precise ages in order to understand how impact events affect the Earth’s geo and biosphere and also with regard to possible future events that can have devastating effects on our civilization. LÄS MER

  4. 8. 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

  5. 9. Evolution of the Biodiversity Hotspot of Madagascar from the Eye of Diving Beetles : Phylogeny, colonization and speciation

    Författare :Rasa Bukontaite; Johannes Bergsten; Ingi Agnarsson; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Dytiscidae; diving beetles; Biogeography; Phylogeny; Dating; phylogenetic informativeness; colonization; speciation; microendemism; Madagascar; systematisk zoologi; Systematic Zoology;

    Sammanfattning : Dytiscidae, contains numerous endemic and non-endemic species on Madagascar. Their evolutionary history is largely unknown on the island. Herein, I use analyses to infer phylogenetic relationship among groups of diving beetles, with a focus on the subfamily Dytiscinae and endemic species in two other groups of Dytiscidae. LÄS MER

  7. 10. The Great Trajanic Frieze. The Study of a Monument and of the Mechanisms of Message Transmission in Roman Art

    Författare :Anne-Marie Leander Touati; Antikens kultur och samhällsliv; []
    Nyckelord :HUMANIORA; HUMANITIES; State art; visual quotation; systematization; hierarchisation; viewer; setting; reuse; fragments; stone work; recarving; dating;

    Sammanfattning : The Great Trajanic Frieze is a Monument firmly entranched in the tradition of Graeco-Roman art.The study of the different components of its imagery, such as composition, iconography and antiquarian details, reveals how it transmits and transforms this tradition. LÄS MER