The origin of slope deposits in the southern Drakensberg, eastern Lesotho
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 m...
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ftunivwitwaters:oai:wiredspace.wits.ac.za:10539/4726 2023-06-11T04:15:57+02:00 The origin of slope deposits in the southern Drakensberg, eastern Lesotho Mills, Stephanie Christiane 2008-03-31T09:46:04Z 109977 bytes 4194502 bytes 7186772 bytes 7409638 bytes 4333761 bytes application/pdf http://hdl.handle.net/10539/4726 en eng http://hdl.handle.net/10539/4726 slope deposits sedimentology periglaciation glaciation Lesotho Thesis 2008 ftunivwitwaters 2023-05-15T10:23:51Z 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. Thesis permafrost University of the Witwatersrand, Johannesburg: WITS Institutional Repository on DSpace (WIReDSpace) |
institution |
Open Polar |
collection |
University of the Witwatersrand, Johannesburg: WITS Institutional Repository on DSpace (WIReDSpace) |
op_collection_id |
ftunivwitwaters |
language |
English |
topic |
slope deposits sedimentology periglaciation glaciation Lesotho |
spellingShingle |
slope deposits sedimentology periglaciation glaciation Lesotho Mills, Stephanie Christiane The origin of slope deposits in the southern Drakensberg, eastern Lesotho |
topic_facet |
slope deposits sedimentology periglaciation glaciation Lesotho |
description |
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. |
format |
Thesis |
author |
Mills, Stephanie Christiane |
author_facet |
Mills, Stephanie Christiane |
author_sort |
Mills, Stephanie Christiane |
title |
The origin of slope deposits in the southern Drakensberg, eastern Lesotho |
title_short |
The origin of slope deposits in the southern Drakensberg, eastern Lesotho |
title_full |
The origin of slope deposits in the southern Drakensberg, eastern Lesotho |
title_fullStr |
The origin of slope deposits in the southern Drakensberg, eastern Lesotho |
title_full_unstemmed |
The origin of slope deposits in the southern Drakensberg, eastern Lesotho |
title_sort |
origin of slope deposits in the southern drakensberg, eastern lesotho |
publishDate |
2008 |
url |
http://hdl.handle.net/10539/4726 |
genre |
permafrost |
genre_facet |
permafrost |
op_relation |
http://hdl.handle.net/10539/4726 |
_version_ |
1768373248067633152 |