The “Ricker Hills Tillite” (Victoria Land, Antarctica): new contribution for reconstructing the Cenozoic history of the East Antarctc Ice Sheet.)
A semi-lithified to lithified diamicton, the "Ricker Hills Tillite", outcrops in places under a discontinuous Late Pleistocene glacial drift on the homonymous nunatak in the Prince Albert Mts, to the South of David Glacier. The geomorphologic evolution of the area, the sedimentary facies,...
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ftunivpisairis:oai:arpi.unipi.it:11568/88299 2024-02-11T09:56:50+01:00 The “Ricker Hills Tillite” (Victoria Land, Antarctica): new contribution for reconstructing the Cenozoic history of the East Antarctc Ice Sheet.) BARONI, CARLO SALVATORE, MARIA CRISTINA FASANO F. GIORGETTI G. - Baroni, Carlo Fasano, F. Giorgetti, G. Salvatore, MARIA CRISTINA 2004 http://hdl.handle.net/11568/88299 eng eng SGI country:ITA ispartofbook:Abstract Volumes 32nd International Geological Congress firstpage:5 lastpage:5 numberofpages:1 http://hdl.handle.net/11568/88299 glacial deposit micromorphology temperate ice sheet Climate change Antarctica Cenozoic info:eu-repo/semantics/conferenceObject 2004 ftunivpisairis 2024-01-17T17:43:08Z A semi-lithified to lithified diamicton, the "Ricker Hills Tillite", outcrops in places under a discontinuous Late Pleistocene glacial drift on the homonymous nunatak in the Prince Albert Mts, to the South of David Glacier. The geomorphologic evolution of the area, the sedimentary facies, and the fabric of glacial deposits have been reconstructed through detailed geomorphologic and glacial-geologic surveys. The tillite has been described and sampled to investigate the dynamic of the glacier responsible of its deposition. Micromorphological description and petrographic analyses have been carried out on thin sections of impregnated samples. X-ray diffractometry and X-ray fluorescence spectrometry have been performed to determine the clay fraction mineralogical composition and the chemical composition of bulk rocks. The diamictite is generally massive, with a porphiric-related distribution, low sorting, low rounding and medium to high angularity. Chemical analyses indicate that samples derive from mixing of the Ferrar Group dolerites and the Beacon Supergroup sandstones. High smectite and kaolinite contents (from 47% to 78% and from 16% to 34%, respectively) characterize the clay minerals composition; illite and chlorite occur in minor amount. Deformation structures induced by glacial stress are visible in glacial deposits and in bedrock samples collected at the base of the tillite. Phyllosilicate reorientation patterns (plasmic fabrics) due to glacial stress are clearly visible. The morphological and compositional characteristics of this deposit indicate that an ice mass advanced on the Ricker Hills and deposited a glacial drift in climatic conditions warmer than present, with a diffused availability of water during deposition. Finally, the tillite experienced a continental weathering in wet condition with percolating water, as testified by illuviation features, by calcite infillings, and by the formation of clay minerals typical of temperate climates. Conference Object Antarc* Antarctica David Glacier Ice Sheet Victoria Land ARPI - Archivio della Ricerca dell'Università di Pisa David Glacier ENVELOPE(160.000,160.000,-75.333,-75.333) Ricker Hills ENVELOPE(159.167,159.167,-75.683,-75.683) Victoria Land |
institution |
Open Polar |
collection |
ARPI - Archivio della Ricerca dell'Università di Pisa |
op_collection_id |
ftunivpisairis |
language |
English |
topic |
glacial deposit micromorphology temperate ice sheet Climate change Antarctica Cenozoic |
spellingShingle |
glacial deposit micromorphology temperate ice sheet Climate change Antarctica Cenozoic BARONI, CARLO SALVATORE, MARIA CRISTINA FASANO F. GIORGETTI G. The “Ricker Hills Tillite” (Victoria Land, Antarctica): new contribution for reconstructing the Cenozoic history of the East Antarctc Ice Sheet.) |
topic_facet |
glacial deposit micromorphology temperate ice sheet Climate change Antarctica Cenozoic |
description |
A semi-lithified to lithified diamicton, the "Ricker Hills Tillite", outcrops in places under a discontinuous Late Pleistocene glacial drift on the homonymous nunatak in the Prince Albert Mts, to the South of David Glacier. The geomorphologic evolution of the area, the sedimentary facies, and the fabric of glacial deposits have been reconstructed through detailed geomorphologic and glacial-geologic surveys. The tillite has been described and sampled to investigate the dynamic of the glacier responsible of its deposition. Micromorphological description and petrographic analyses have been carried out on thin sections of impregnated samples. X-ray diffractometry and X-ray fluorescence spectrometry have been performed to determine the clay fraction mineralogical composition and the chemical composition of bulk rocks. The diamictite is generally massive, with a porphiric-related distribution, low sorting, low rounding and medium to high angularity. Chemical analyses indicate that samples derive from mixing of the Ferrar Group dolerites and the Beacon Supergroup sandstones. High smectite and kaolinite contents (from 47% to 78% and from 16% to 34%, respectively) characterize the clay minerals composition; illite and chlorite occur in minor amount. Deformation structures induced by glacial stress are visible in glacial deposits and in bedrock samples collected at the base of the tillite. Phyllosilicate reorientation patterns (plasmic fabrics) due to glacial stress are clearly visible. The morphological and compositional characteristics of this deposit indicate that an ice mass advanced on the Ricker Hills and deposited a glacial drift in climatic conditions warmer than present, with a diffused availability of water during deposition. Finally, the tillite experienced a continental weathering in wet condition with percolating water, as testified by illuviation features, by calcite infillings, and by the formation of clay minerals typical of temperate climates. |
author2 |
- Baroni, Carlo Fasano, F. Giorgetti, G. Salvatore, MARIA CRISTINA |
format |
Conference Object |
author |
BARONI, CARLO SALVATORE, MARIA CRISTINA FASANO F. GIORGETTI G. |
author_facet |
BARONI, CARLO SALVATORE, MARIA CRISTINA FASANO F. GIORGETTI G. |
author_sort |
BARONI, CARLO |
title |
The “Ricker Hills Tillite” (Victoria Land, Antarctica): new contribution for reconstructing the Cenozoic history of the East Antarctc Ice Sheet.) |
title_short |
The “Ricker Hills Tillite” (Victoria Land, Antarctica): new contribution for reconstructing the Cenozoic history of the East Antarctc Ice Sheet.) |
title_full |
The “Ricker Hills Tillite” (Victoria Land, Antarctica): new contribution for reconstructing the Cenozoic history of the East Antarctc Ice Sheet.) |
title_fullStr |
The “Ricker Hills Tillite” (Victoria Land, Antarctica): new contribution for reconstructing the Cenozoic history of the East Antarctc Ice Sheet.) |
title_full_unstemmed |
The “Ricker Hills Tillite” (Victoria Land, Antarctica): new contribution for reconstructing the Cenozoic history of the East Antarctc Ice Sheet.) |
title_sort |
“ricker hills tillite” (victoria land, antarctica): new contribution for reconstructing the cenozoic history of the east antarctc ice sheet.) |
publisher |
SGI |
publishDate |
2004 |
url |
http://hdl.handle.net/11568/88299 |
long_lat |
ENVELOPE(160.000,160.000,-75.333,-75.333) ENVELOPE(159.167,159.167,-75.683,-75.683) |
geographic |
David Glacier Ricker Hills Victoria Land |
geographic_facet |
David Glacier Ricker Hills Victoria Land |
genre |
Antarc* Antarctica David Glacier Ice Sheet Victoria Land |
genre_facet |
Antarc* Antarctica David Glacier Ice Sheet Victoria Land |
op_relation |
ispartofbook:Abstract Volumes 32nd International Geological Congress firstpage:5 lastpage:5 numberofpages:1 http://hdl.handle.net/11568/88299 |
_version_ |
1790606306957066240 |