Abstract
The high Drakensberg of southern Africa has received considerable
geomorphological interest during recent decades. In particular, there has been an
ongoing debate concerning the accuracy of landform interpretations which
propagate past glaciation and permafrost. This research examines the macro and
micro-sedimentology of various deposits found in eastern Lesotho and compares
them with possible geomorphological process origins such as debris flows, debris
avalanches, mudflows, mudslides, landslides, solifluction deposits, rock glaciers,
pronival ramparts, glacial moraines and fluvial deposits. The results support the
contention that four of the deposits are moraines, formed by small glaciers, and
one is a debris flow which was initiated by a small glacier. However, two further
deposits indicate that localities in close proximity to the linear deposits
experienced mass wasting, associated with past periglacial conditions. With the
assistance of applying glacier reconstruction methods, modelling hillshade, the
provision of new palaeoclimatic extrapolations, and correlation of deposits with
contemporary snow patch distribution, it is demonstrated that the valley slope
deposits are determined by a past climate that was within the glacial/periglacial
equilibrium zone, and was influenced by specific topographic and associated
micro-climatic thresholds. It is shown that macro-topographic factors (e.g. slope
gradient, aspect etc) and summit altitude are critical factors determining whether
slopes were influenced by periglacial (mass wasting) or glacial processes (small
niche/cirque glaciers) in adjacent valleys.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:wits/oai:wiredspace.wits.ac.za:10539/4726 |
| Date | 31 March 2008 |
| Creators | Mills, Stephanie Christiane |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | English |
| Type | Thesis |
| Format | 109977 bytes, 4194502 bytes, 7186772 bytes, 7409638 bytes, 4333761 bytes, application/pdf, application/pdf, application/pdf, application/pdf, application/pdf, application/pdf, application/pdf, application/pdf, application/pdf, application/pdf |
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