The characterisation of an openwork block deposit, northern buttress, Vesleskarvet, Dronning Maud Land, Antarctica.
Investigating openwork block accumulation has the potential to further our understanding of rock weathering, the control of geological structure on landforms, the production of substrates for biological colonisation and the impacts of climate change on landform development and dynamics. Various mode...
Main Author: | |
---|---|
Format: | Master Thesis |
Language: | English |
Published: |
Rhodes University
2014
|
Subjects: | |
Online Access: | http://vital.seals.ac.za:8080/vital/access/manager/Repository/vital:4878 http://hdl.handle.net/10962/d1013138 |
id |
ftsealsdc:vital:4878 |
---|---|
record_format |
openpolar |
spelling |
ftsealsdc:vital:4878 2024-09-15T17:46:06+00:00 The characterisation of an openwork block deposit, northern buttress, Vesleskarvet, Dronning Maud Land, Antarctica. Hansen, Christel Dorothee 2014 220 p. pdf http://vital.seals.ac.za:8080/vital/access/manager/Repository/vital:4878 http://hdl.handle.net/10962/d1013138 English eng Rhodes University Faculty of Science, Geography vital:4878 http://vital.seals.ac.za:8080/vital/access/manager/Repository/vital:4878 http://hdl.handle.net/10962/d1013138 Hansen, Christel Dorothee Formations (Geology) -- Antarctica -- Queen Maud Land Geology Structural -- Antarctica -- Queen Maud Land Weathering -- Antarctica -- Queen Maud Land Climatic changes -- Antarctica -- Queen Maud Land Physical geography -- Antarctica -- Queen Maud Land Paleoclimatology -- Antarctica Thesis Masters MSc 2014 ftsealsdc 2024-07-29T23:41:47Z Investigating openwork block accumulation has the potential to further our understanding of rock weathering, the control of geological structure on landforms, the production of substrates for biological colonisation and the impacts of climate change on landform development and dynamics. Various models for the development of these landforms have been proposed. This includes in situ weathering, frost heave and wedging. Furthermore, it has been suggested that cold-based ice has the potential to preserve these features rather than to obliterate them. Blocky deposits are also frequently used as proxy evidence for interpreting palaeoclimates. The morphology and processes acting on a blockfield located on the Northern Buttress of the Vesleskarvet Nunataks, Dronning Maud Land, Antarctica (2°W, 71°S) were investigated and characterised. Given block dimensions and orientations that closely resembled the parent material and only small differences in aspect related characteristics observed, the blockfield was found to be autochthonous with in situ block production and of a young (Holocene) age. Small differences in rock hardness measurements suggest some form of aspect control on rock weathering. South-facing sides of clasts were found to be the least weathered. In comparison, consistently low rock hardness rebound values for the north-facing aspects suggest that these are the most weathered sides. Additional indicators of weathering, such as flaking and pitting, support analyses conducted for rock hardness rebound values. Solar radiation received, slope gradients and snow cover were found to influence weathering of clasts across the study site. Furthermore, ambient temperatures and wind speed significantly influenced near-surface ground temperatures dynamics. However, the lack of a matrix and paucity of fine material in textural analyses suggest a limited weathering environment. It is suggested that the retreat of the Antarctic ice sheet during the last LGM led to unloading of the surface, causing dilatation and subsequent ... Master Thesis Antarc* Antarctic Antarctica Dronning Maud Land Ice Sheet Queen Maud Land Low Rock SEALS Digital Commons (South East Academic Libraries System, South Africa) |
institution |
Open Polar |
collection |
SEALS Digital Commons (South East Academic Libraries System, South Africa) |
op_collection_id |
ftsealsdc |
language |
English |
topic |
Formations (Geology) -- Antarctica -- Queen Maud Land Geology Structural -- Antarctica -- Queen Maud Land Weathering -- Antarctica -- Queen Maud Land Climatic changes -- Antarctica -- Queen Maud Land Physical geography -- Antarctica -- Queen Maud Land Paleoclimatology -- Antarctica |
spellingShingle |
Formations (Geology) -- Antarctica -- Queen Maud Land Geology Structural -- Antarctica -- Queen Maud Land Weathering -- Antarctica -- Queen Maud Land Climatic changes -- Antarctica -- Queen Maud Land Physical geography -- Antarctica -- Queen Maud Land Paleoclimatology -- Antarctica Hansen, Christel Dorothee The characterisation of an openwork block deposit, northern buttress, Vesleskarvet, Dronning Maud Land, Antarctica. |
topic_facet |
Formations (Geology) -- Antarctica -- Queen Maud Land Geology Structural -- Antarctica -- Queen Maud Land Weathering -- Antarctica -- Queen Maud Land Climatic changes -- Antarctica -- Queen Maud Land Physical geography -- Antarctica -- Queen Maud Land Paleoclimatology -- Antarctica |
description |
Investigating openwork block accumulation has the potential to further our understanding of rock weathering, the control of geological structure on landforms, the production of substrates for biological colonisation and the impacts of climate change on landform development and dynamics. Various models for the development of these landforms have been proposed. This includes in situ weathering, frost heave and wedging. Furthermore, it has been suggested that cold-based ice has the potential to preserve these features rather than to obliterate them. Blocky deposits are also frequently used as proxy evidence for interpreting palaeoclimates. The morphology and processes acting on a blockfield located on the Northern Buttress of the Vesleskarvet Nunataks, Dronning Maud Land, Antarctica (2°W, 71°S) were investigated and characterised. Given block dimensions and orientations that closely resembled the parent material and only small differences in aspect related characteristics observed, the blockfield was found to be autochthonous with in situ block production and of a young (Holocene) age. Small differences in rock hardness measurements suggest some form of aspect control on rock weathering. South-facing sides of clasts were found to be the least weathered. In comparison, consistently low rock hardness rebound values for the north-facing aspects suggest that these are the most weathered sides. Additional indicators of weathering, such as flaking and pitting, support analyses conducted for rock hardness rebound values. Solar radiation received, slope gradients and snow cover were found to influence weathering of clasts across the study site. Furthermore, ambient temperatures and wind speed significantly influenced near-surface ground temperatures dynamics. However, the lack of a matrix and paucity of fine material in textural analyses suggest a limited weathering environment. It is suggested that the retreat of the Antarctic ice sheet during the last LGM led to unloading of the surface, causing dilatation and subsequent ... |
format |
Master Thesis |
author |
Hansen, Christel Dorothee |
author_facet |
Hansen, Christel Dorothee |
author_sort |
Hansen, Christel Dorothee |
title |
The characterisation of an openwork block deposit, northern buttress, Vesleskarvet, Dronning Maud Land, Antarctica. |
title_short |
The characterisation of an openwork block deposit, northern buttress, Vesleskarvet, Dronning Maud Land, Antarctica. |
title_full |
The characterisation of an openwork block deposit, northern buttress, Vesleskarvet, Dronning Maud Land, Antarctica. |
title_fullStr |
The characterisation of an openwork block deposit, northern buttress, Vesleskarvet, Dronning Maud Land, Antarctica. |
title_full_unstemmed |
The characterisation of an openwork block deposit, northern buttress, Vesleskarvet, Dronning Maud Land, Antarctica. |
title_sort |
characterisation of an openwork block deposit, northern buttress, vesleskarvet, dronning maud land, antarctica. |
publisher |
Rhodes University |
publishDate |
2014 |
url |
http://vital.seals.ac.za:8080/vital/access/manager/Repository/vital:4878 http://hdl.handle.net/10962/d1013138 |
genre |
Antarc* Antarctic Antarctica Dronning Maud Land Ice Sheet Queen Maud Land Low Rock |
genre_facet |
Antarc* Antarctic Antarctica Dronning Maud Land Ice Sheet Queen Maud Land Low Rock |
op_relation |
vital:4878 http://vital.seals.ac.za:8080/vital/access/manager/Repository/vital:4878 http://hdl.handle.net/10962/d1013138 |
op_rights |
Hansen, Christel Dorothee |
_version_ |
1810494078480023552 |