Sökning: "glacial sediments"

Visar resultat 21 - 25 av 43 avhandlingar innehållade orden glacial sediments.

1. 21. Past dynamics of a marine-terminating glacier in lower Borgarfjörður, west Iceland - Analyses of glaciotectonic sediments and landforms

   Författare :Thorbjorg Sigfusdottir; Kvartärgeologi; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; glacier dynamics; marine-terminating glacier; glaciomarine processes; thrust-block moraines; glaciotectonics; micromorphology; Early Holocene; Late Weichselian; Iceland;

   Sammanfattning : Large and complete sections through glacial landforms formed in subaqueous environments are rare, impeding our knowledge of their internal composition and the processes responsible for their formation. Following the last deglaciation of the Icelandic Ice Sheet (IIS), a marine-terminating outlet glacier advanced out of the fjord of Borgarfjörður resulting in large-scale glaciotectonic deformation of glaciomarine sediments. LÄS MER

3. 22. Comparison of dating methods for paleoglacial reconstruction in Central Asia

   Författare :Natacha Gribenski; Krister N. Jansson; Arjen P. Stroeven; Frank Preusser; Jonathan M. Harbor; Marc Bateman; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Paleoglaciation; Optically stimulated luminescence dating; Cosmogenic nuclide exposure dating; EMCCD camera; Physical Geography; naturgeografi;

   Sammanfattning : Reconstruction of former Central Asian glaciers extents can provide valuable information about past atmospheric circulation variations. These extents, often marked by terminal moraines, need to be chronologically constrained. Cosmogenic nuclide exposure (CNE) dating is widely used to directly date moraines. LÄS MER

4. 23. Alpine lake sediment archives and catchment geomorphology : causal relationships and implications for paleoenvironmental reconstructions

   Författare :Lena Rubensdotter; Gunhild Rosqvist; Ingmar Borgström; Eve Arnold; Jens-Ove Näslund; Catherine Souch; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; alpine lakes; geomorphology; lacustrine sedimentation; slope processes; glaciofluvial; Holocene; Swedish Lapland; Physical geography; Naturgeografi;

   Sammanfattning : Lake sediments are frequently used as archives of climate and environmental change. Minerogenic sediment variability in alpine lakes is often used to reconstruct past glacier and slope process activity. Alpine lake sediments can however have many different origins, which may induce errors in paleoenvironmental reconstructions. LÄS MER

5. 24. High Arctic submarine glaciogenic landscapes : their formation and significance

   Författare :Francis Fletcher Freire; Richard Gyllencreutz; Martin Jakobsson; Haflidi Haflidason; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; High Arctic; GrIS; marine geophysics; glaciogenic landscapes; ice streams; submarine slides; Marine Geology; maringeologi;

   Sammanfattning : This thesis is focused on studies of glacial and slope morphology in the high Arctic of western Greenland shelf and the Molloy Hole seafloor spreading area, based on high-resolution acoustic methods and other geophysical data. The main purpose is to improve our understanding of glacial dynamics and associated processes in the marginal region of a large marine-terminating ice sheet. LÄS MER

7. 25. Glaciodynamics, Deglacial Landforms and Isostatic Uplift during the last Deglaciation of Norrbotten, Sweden

   Författare :Mattias Lindén; Kvartärgeologi; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Sedimentologi; Sedimentology; Geologi; physical geography; Geology; glaciotectonic; thrust stacking; deforming bed; ribbed moraine; Niemisel moraine; De Geer moraine; isostatic uplift; glaciodynamics; deglaciation; klimatologi; kartografi; marklära; Fysisk geografi; geomorfologi; geomorphology; cartography; climatology; pedology;

   Sammanfattning : The aim of this thesis was to reconstruct the glaciodynamics, deglacial landforms, isostatic uplift and to date the deglaciation. Glaciodynamics and deglacial landforms were focused on to provide a process and depositional model for De Geer moraine and Niemisel moraine and to reveal their internal and spatial relationship, based on detailed sedimentological and structural investigations. LÄS MER