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Title: The depositional landforms and sediments produced by two surging glaciers
Author: Croot, David Graham
Awarding Body: University of Aberdeen
Current Institution: University of Aberdeen
Date of Award: 1978
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Abstract:
This thesis considers the interface between three related fields of scientific research, all of which are concerned with glaciers and glacial deposits. The three main research areas which acted as stimuli! for the work are glacial geomorphology, glaciology and sedimentary geology. Glacial depositional geomorphology lags behind other areas of geomorphological research, particularly those of slope and fluvial geomorphology. During the last century the main focus of Western European glacial geomorphology (both erosional and depositional) has been the study of Pleistocene landforms and chronologies. According to Price (1973), the former (the study of landforms) has developed as "an inexact science", which Sugden and John (1976) attribute to the lack of studies of process-form relationships, the lack of application of polar evidence to glacial problems, and the paucity of research links between glaciology and glacial geomorphology (Sugden and John 1976, p.3). Such criticisms prompted the study of process-form relationships within a currently glacierized zone of the polar regions. The recent glaciological literature contains numerous articles on "surging glaciers". These glaciers appear to differ markedly from other glaciers in their mechanism of movement (Paterson 1969) and dynamics of self-regulation (Miller 1973)" perhaps to such an extent that the depositional landforms and landfox-m associations produced by their activity may differ from those created by non-surging glaciers (liller 1973). One way of testing this suggestion is to collect field data relating to landforms from the snout areas of surging glaciers, and subsequently compare the results with existing knowledge relating to landforms and landform associations produced by non-surging glaciers. A major criticism of much work on the Pleistocene landforms and deposits in Britain is that workers too often rely on intuitive guesswork to ascertain process-form relationships, basing their interpretation on form alone. Whilst this approach may be successful to a large degree, the amount of controversy arising from contrasting interpretations leads to scepticism about the method (litchell et al. 1973). An increasing number of workers turn to particle size analysis of deposits to add objectivity and scientific support to their interpretation. (British Geomorphological Research Group Current Research in Geomorphology Series 1973-5). Their argument is that different types of material, attributable to different depositional processes, can be separated by particle size analysis. This approach is a well tried and tested method in sedimentary geology, where workers are dealing with deposits for which modern process-form relationships are well established. This is not the case in glacial sedimentology, where there is a need for basic data on the textural characteristics of glacial material from areas where the depositional processes and environments can be clearly linked to a particular deposit (siatt 1971) This thesis sets out to examine the depositional landforms, landform associations and particle size characteristics of sedimentary deposits associated with surging glaciers. The first part of the work critically examines the current state of knowledge with regard to surging glaciers, in the light of current glacier movement theories (Chapters 1 ,2 and 3) the subsequent sections deal with process-landform links by, firstly, examining the glacier debris cascade system of non-surging glaciers, and secondly, by applying the fundamentals of this modelling approach to the known features of surging glaciers. The first part terminates with a discussion of the context within which the particle size analysis of glacial deposits is set. The second part is concerned with data collection and presentation. Data were collected from two surging glacier snout areas: Battyebreen in the High Arctic area of Svalbard, and tr Eyjabakkajokull in the maritime area of Iceland. The morphology and proglacial features of Battyebreen strongly suggest that it is a surging glacier (see below: Chapter 1), although there are ii no records of a surge event. The surges of Byjabakkajokull in Iceland are better documented (Thorarinsson 1938, 1964, 1969) and this glacier is known to have surged twice during the last century. The most recent surge occurred between October 1972 and October 1973. Two types of data were collected in accordance with the aims of the thesis: depositional landforms and landforming processes in the stagnant zone of Battyebreen and the proglacial n area of Eyjabakkajokull were mapped, and samples of sediment from these landforms collected and subsequently analysed. The results of each data collection are presented in Chapters 5, 6 and 7. In the third part of the thesis the results of the field and laboratory work are reviewed in the light of publications by authors in related fields. A general model of the development of depositional landforms resulting from glacier surges and the effect of surges on the texture of glacial and fluvioglacial sediments are presented. In the final chapter (Chapter 11) the work as a whole is reviewed, and several conclusions drawn.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.452626  DOI: Not available
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