Sedimentary Studies in Lake Windermere.
Doctoral thesis, University of London.
Late Quaternary sediments, soils,and parent rocks in and around the Windermere North Basin are studied by modern sedimentological techniques. Tho data obtained is examined statistically. Till points, scattered randomly on the Sand/silt/clay triangle, were redistributed into a "still later group", glaciolacustrine clays and main Windermere sediments; and a coarse fluvioglacial group which is better sorted and more rounded than the till. Fine sands, negatively skewed due to finer admixtures, typify certain lake environments. Beach deposits are better sorted and more rounded than the till from which they were partly derived; they are more rounded and coarser on the eastern exposed beaches than on sheltered ones; they are positively skewed due to inefficient fluviatile saltation. Three assumptions: a. Flocculation caused real mechanical bimodality of organic sediments. b. Spasmodic sedimentation was by underflowing "turbidity" currents during storms. c. Deposition occurred when settling (discrete or flocculated) overcame mechanical dispersal. Loss of river water impetus, and organic content and biological activity, controlled Poet Glacial sed1mentation. The relative importance of the two main rivers has alternated. Two basic mineralogical populations formed Late Quaternary material: a)Pink Late Glacial form, non hydrated. Post Glacial form, illite and aluminosilicates, hydrated and flocculated due to organic content and acidic environment (occurs up to 0.020 mm). b) Silt. Chloritic rock fragments (magnesium rich ripidolite, iron rich thuringite); calcite was removed from all but buried varves by Post Glacial acid corrosion. A marked change in lake sedimentation occurred with the spread of plant growth at the end of Late Glacial times 11,000 years ago. Controlled erosion, flocculation, and a high organic content characterised Post Glacial reddish gyttja sedimentation. Human settlement in the last 200 years caused further changes: accelerated erosion due to forest removal, reducing lakewater conditions due to sewage caused stronger flocculation in the blackish surface ooze.
|Title:||Sedimentary Studies in Lake Windermere|
|Open access status:||An open access version is available from UCL Discovery|
|Additional information:||Thesis digitised by British Library EThOS. Some images have been excluded due to third party copyright.|
|UCL classification:||UCL > School of BEAMS > Faculty of Maths and Physical Sciences > Earth Sciences|
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