Sökning: "Quaternary geology"

Visar resultat 26 - 30 av 85 avhandlingar innehållade orden Quaternary geology.

  1. 26. A multimethod approach to dating Quaternary sediments from the Arctic Ocean

    Författare :Gabriel West; Matthew O'Regan; Darrell Kaufman; Helena Alexanderson; Guillaume St-Onge; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Arctic Ocean; Amino Acid Geochronology; Optically Stimulated Luminescence Dating; Palaeomagnetism; maringeologi; Marine Geology;

    Sammanfattning : The marine sedimentary environment in the polar regions is different from the rest of the world’s oceans, as it is greatly influenced by the cryosphere. In the Arctic, sea ice and icebergs can transport vast amounts of sediments, delivered by extensive fluvial systems from the surrounding continents, which have been shaped by the waxing and waning of large terrestrial ice sheets during the Quaternary period. LÄS MER

  3. 27. Cellulose in Quaternary Ammonium-based Solvents: Dissolution, Modification and Coagulation

    Författare :Shirin Naserifar; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; gelation; etherification; quaternary ammonium hydroxides; cellulose; dissolution;

    Sammanfattning : Processing cellulose through dissolution and regeneration is essential for many applications, yet challenges are posed because it does not readily melt or dissolve in commonly used aqueous and organic solvents. Consequently, extensive efforts have been devoted to developing novel and efficient solvents for cellulose, as well as exploring new functionalization routes. LÄS MER

  4. 28. Benthic environmental responses to climatic changes during the late Quaternary: a micropalaeontological and geochemical approach

    Författare :Claire McKay; Kvartärgeologi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; late Quaternary; rapid climate change; Benguela; Mauritania; productivity; upwelling; benthic foraminifera;

    Sammanfattning : There is a limited understanding of how the benthic environment within upwelling regions responded to past rapid climatic changes. Within this thesis, a multiproxy approach is applied to two marine sediment cores from two coastal upwelling sites in the low latitude subtropical Atlantic. LÄS MER

  5. 29. Provenance of the pre-Quaternary aeolian dust deposits of East Asia

    Författare :Katja Bohm; Thomas Stevens; Anu Kaakinen; Alex Pullen; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Chinese Loess Plateau; Red Clay; mineral dust; sediment provenance; detrital zircon; detrital rutile; Neogene; Paleogene; Earth Science with specialization in Physical Geography; Geovetenskap med inriktning mot naturgeografi;

    Sammanfattning : Atmospheric mineral dust is a key component in the climate system, but its effect on and response to climate changes are poorly understood, especially over long timescales. This thesis investigates the sources of late Paleogene and Neogene dust deposits that formed under warmer-than-present global climates in the northern Chinese Loess Plateau (CLP) region in mid-latitude East Asia. LÄS MER

  7. 30. Late Quaternary palaeoecological event stratigraphy in the Horton Plains, central Sri Lanka : with contributions to the recent pollen flora

    Författare :Rathnasiri Premathilake; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Kvartärtiden; Sri Lanka;

    Sammanfattning : .... LÄS MER