Sökning: "regional timing"

Visar resultat 21 - 25 av 53 avhandlingar innehållade orden regional timing.

  1. 21. Paleoglaciology of Shaluli Shan, southeastern Tibetan Plateau

    Författare :Ping Fu; Arjen Stroeven; Lewis Owen; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Paleoglaciology; Tibetan Plateau; geomorphological mapping; cosmogenic nuclide; Last Glacial Maximum; glacial erosion; basal thermal regime; paleoglaciologi; Tibetanska platån; geomorfologisk kartering; kosmogena isotoper; senaste glaciala maximat; glacial erosion; subglacial temperatur; Physical Geography; naturgeografi;

    Sammanfattning : Reconstructing the paleoglaciation of the Tibetan Plateau is critical to understanding linkages between regional climate changes and global climate changes. This work focuses on the paleoglaciology of the Shaluli Shan Mountain area in the southeastern Tibetan Plateau. LÄS MER

  3. 22. 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

  4. 23. The origin of the Ryllshyttan stratabound Zn-Pb-Ag-(Cu) + magnetite deposit, Garpenberg, Bergslagen, Sweden

    Författare :Nils Jansson; Luleå tekniska universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Malmgeologi; Ore Geology;

    Sammanfattning : Ryllshyttan is a Palaeoproterozoic lower amphibolite-facies poly-metamorphosed stratabound Zn-Pb-Ag-(Cu) + magnetite deposit. It is located in the Garpenberg inlier of the Bergslagen mining district of southern Sweden and produced ~ 1 Mt sulphide ore and ~ 0.4 Mt magnetite ore from the early 16th century until 1944. LÄS MER

  5. 24. Ashes to ashes : Applications of tephrochronology in Scandinavia

    Författare :Simon A. Larsson; Stefan Wastegård; Britta Sannel; Christine Lane; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; tephrochronology; tephrostratigraphy; tephra; palaeoclimate; Last Glacial–Interglacial Transition; Scandinavia; naturgeografi; Physical Geography;

    Sammanfattning : The project presented in this thesis provides two examples of applications of tephrochronology in Scandinavia. The usage of tephra deposits preserved in sediments—i.e. LÄS MER

  7. 25. The Arctic Ocean Palaeomagnetic Record : A Stratigraphic Approach

    Författare :Steffen Wiers; Ian Snowball; Bjarne Almqvist; Matt O'Regan; Conall Mac Niocaill; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Arctic Ocean; Stratigraphy; Diagenesis; Palaeomagnetism;

    Sammanfattning : The Arctic Ocean is an essential component of the global climate system, yet understanding of its geological archives is hampered by difficulties in age modelling. In addition to the scarcity of dateable microfossils, the palaeomagnetic record of Arctic sediments is unusual. LÄS MER