Table Nunatak: a key outcrop of Upper Cretaceous shallow-marine strata in the southern Larsen Basin, Antarctic Peninsula
The northern, James Ross Island region of the Larsen Basin, on the eastern, back-arc margin of the Antarctic Peninsula magmatic arc, includes one of the thickest and most complete Upper Cretaceous sedimentary successions exposed in the Southern Hemisphere. However, the southern part of the basin rem...
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Cambridge University Press
1998
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Online Access: | http://nora.nerc.ac.uk/id/eprint/504052/ http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=4427 |
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ftnerc:oai:nora.nerc.ac.uk:504052 2023-05-15T13:48:08+02:00 Table Nunatak: a key outcrop of Upper Cretaceous shallow-marine strata in the southern Larsen Basin, Antarctic Peninsula Hathway, B. Macdonald, D.I.M. Riding, J.B. Cantrill, D.J. 1998 http://nora.nerc.ac.uk/id/eprint/504052/ http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=4427 unknown Cambridge University Press Hathway, B.; Macdonald, D.I.M.; Riding, J.B. orcid:0000-0002-5529-8989 Cantrill, D.J. 1998 Table Nunatak: a key outcrop of Upper Cretaceous shallow-marine strata in the southern Larsen Basin, Antarctic Peninsula. Geological Magazine, 135 (4). 519-535. Publication - Article PeerReviewed 1998 ftnerc 2023-02-04T19:38:10Z The northern, James Ross Island region of the Larsen Basin, on the eastern, back-arc margin of the Antarctic Peninsula magmatic arc, includes one of the thickest and most complete Upper Cretaceous sedimentary successions exposed in the Southern Hemisphere. However, the southern part of the basin remains poorly known, mainly owing to inaccessibility and lack of exposure. Table Nunatak, an isolated, 1-km-long, 400-m-wide outcrop at the tip of Kenyon Peninsula, is the only known exposure of Upper Cretaceous or younger strata in this region. The 62-m-thick succession exposed there is assigned to the newly defined Table Nunatak Formation. It consists mainly of sharp-based, amalgamated beds of fine-grained sandstone up to 2.8 m thick, with subordinate intervals of intensely bioturbated mudstone. Wave ripples are present at some levels, and locally developed swaley cross-stratification provides evidence for storm-generated combined-flow deposition. However, most sandstone beds appear to be internally structureless apart from normal grading, and are interpreted as the direct suspension deposits of highly sediment-charged storm- and/or flood-related flows. The succession represents relatively nearshore deposition, probably at the mouth of a river or deltaic distributary channel. Charcoalified plant debris, abundant at the tops of some sandstone beds, suggests a periodically wildfire-swept hinterland forested largely by coniferous trees. Dinoflagellate cyst assemblages indicate a late Santonian age, and suggest correlation with the basal part of the Lachman Crags Member of the Santa Marta Formation (Marambio Group) on James Ross Island. Palaeocurrents, sandstone petrography and the high sediment supply rate proposed for the Table Nunatak Formation, suggest a relatively high-relief source area to the west, with large-scale erosion of granitoid plutons and metamorphic rocks, possibly related to arc uplift during a mid-Cretaceous compressional episode. The formation is evidence of a major southward extension of the Upper ... Article in Journal/Newspaper Antarc* Antarctic Antarctic Peninsula James Ross Island Ross Island Natural Environment Research Council: NERC Open Research Archive Antarctic The Antarctic Antarctic Peninsula Ross Island Marambio ENVELOPE(-56.750,-56.750,-64.283,-64.283) Kenyon ENVELOPE(-174.867,-174.867,-85.167,-85.167) Larsen Basin ENVELOPE(-60.000,-60.000,-68.000,-68.000) Lachman ENVELOPE(-57.781,-57.781,-63.780,-63.780) Lachman Crags ENVELOPE(-57.832,-57.832,-63.874,-63.874) Kenyon peninsula ENVELOPE(-63.550,-63.550,-68.450,-68.450) Table Nunatak ENVELOPE(-62.950,-62.950,-68.517,-68.517) |
institution |
Open Polar |
collection |
Natural Environment Research Council: NERC Open Research Archive |
op_collection_id |
ftnerc |
language |
unknown |
description |
The northern, James Ross Island region of the Larsen Basin, on the eastern, back-arc margin of the Antarctic Peninsula magmatic arc, includes one of the thickest and most complete Upper Cretaceous sedimentary successions exposed in the Southern Hemisphere. However, the southern part of the basin remains poorly known, mainly owing to inaccessibility and lack of exposure. Table Nunatak, an isolated, 1-km-long, 400-m-wide outcrop at the tip of Kenyon Peninsula, is the only known exposure of Upper Cretaceous or younger strata in this region. The 62-m-thick succession exposed there is assigned to the newly defined Table Nunatak Formation. It consists mainly of sharp-based, amalgamated beds of fine-grained sandstone up to 2.8 m thick, with subordinate intervals of intensely bioturbated mudstone. Wave ripples are present at some levels, and locally developed swaley cross-stratification provides evidence for storm-generated combined-flow deposition. However, most sandstone beds appear to be internally structureless apart from normal grading, and are interpreted as the direct suspension deposits of highly sediment-charged storm- and/or flood-related flows. The succession represents relatively nearshore deposition, probably at the mouth of a river or deltaic distributary channel. Charcoalified plant debris, abundant at the tops of some sandstone beds, suggests a periodically wildfire-swept hinterland forested largely by coniferous trees. Dinoflagellate cyst assemblages indicate a late Santonian age, and suggest correlation with the basal part of the Lachman Crags Member of the Santa Marta Formation (Marambio Group) on James Ross Island. Palaeocurrents, sandstone petrography and the high sediment supply rate proposed for the Table Nunatak Formation, suggest a relatively high-relief source area to the west, with large-scale erosion of granitoid plutons and metamorphic rocks, possibly related to arc uplift during a mid-Cretaceous compressional episode. The formation is evidence of a major southward extension of the Upper ... |
format |
Article in Journal/Newspaper |
author |
Hathway, B. Macdonald, D.I.M. Riding, J.B. Cantrill, D.J. |
spellingShingle |
Hathway, B. Macdonald, D.I.M. Riding, J.B. Cantrill, D.J. Table Nunatak: a key outcrop of Upper Cretaceous shallow-marine strata in the southern Larsen Basin, Antarctic Peninsula |
author_facet |
Hathway, B. Macdonald, D.I.M. Riding, J.B. Cantrill, D.J. |
author_sort |
Hathway, B. |
title |
Table Nunatak: a key outcrop of Upper Cretaceous shallow-marine strata in the southern Larsen Basin, Antarctic Peninsula |
title_short |
Table Nunatak: a key outcrop of Upper Cretaceous shallow-marine strata in the southern Larsen Basin, Antarctic Peninsula |
title_full |
Table Nunatak: a key outcrop of Upper Cretaceous shallow-marine strata in the southern Larsen Basin, Antarctic Peninsula |
title_fullStr |
Table Nunatak: a key outcrop of Upper Cretaceous shallow-marine strata in the southern Larsen Basin, Antarctic Peninsula |
title_full_unstemmed |
Table Nunatak: a key outcrop of Upper Cretaceous shallow-marine strata in the southern Larsen Basin, Antarctic Peninsula |
title_sort |
table nunatak: a key outcrop of upper cretaceous shallow-marine strata in the southern larsen basin, antarctic peninsula |
publisher |
Cambridge University Press |
publishDate |
1998 |
url |
http://nora.nerc.ac.uk/id/eprint/504052/ http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=4427 |
long_lat |
ENVELOPE(-56.750,-56.750,-64.283,-64.283) ENVELOPE(-174.867,-174.867,-85.167,-85.167) ENVELOPE(-60.000,-60.000,-68.000,-68.000) ENVELOPE(-57.781,-57.781,-63.780,-63.780) ENVELOPE(-57.832,-57.832,-63.874,-63.874) ENVELOPE(-63.550,-63.550,-68.450,-68.450) ENVELOPE(-62.950,-62.950,-68.517,-68.517) |
geographic |
Antarctic The Antarctic Antarctic Peninsula Ross Island Marambio Kenyon Larsen Basin Lachman Lachman Crags Kenyon peninsula Table Nunatak |
geographic_facet |
Antarctic The Antarctic Antarctic Peninsula Ross Island Marambio Kenyon Larsen Basin Lachman Lachman Crags Kenyon peninsula Table Nunatak |
genre |
Antarc* Antarctic Antarctic Peninsula James Ross Island Ross Island |
genre_facet |
Antarc* Antarctic Antarctic Peninsula James Ross Island Ross Island |
op_relation |
Hathway, B.; Macdonald, D.I.M.; Riding, J.B. orcid:0000-0002-5529-8989 Cantrill, D.J. 1998 Table Nunatak: a key outcrop of Upper Cretaceous shallow-marine strata in the southern Larsen Basin, Antarctic Peninsula. Geological Magazine, 135 (4). 519-535. |
_version_ |
1766248718660534272 |