Fluvial sedimentology and revised stratigraphy of the Triassic Flagstone Bench Formation, northern Prince Charles Mountains, East Antarctica
The Flagstone Bench Formation ranges in age from earliest Triassic to Norian (Late Triassic) and is exposed in the Beaver Lake area of the northern Prince Charles Mountains. This sandstone-dominated formation rests conformably on the Bainmedart Coal Measures and represents the upper part of the Perm...
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Online Access: | http://dx.doi.org/10.1017/s0016756897007528 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0016756897007528 |
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crcambridgeupr:10.1017/s0016756897007528 2024-05-12T07:55:47+00:00 Fluvial sedimentology and revised stratigraphy of the Triassic Flagstone Bench Formation, northern Prince Charles Mountains, East Antarctica MCLOUGHLIN, STEPHEN DRINNAN, ANDREW N. 1997 http://dx.doi.org/10.1017/s0016756897007528 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0016756897007528 en eng Cambridge University Press (CUP) https://www.cambridge.org/core/terms Geological Magazine volume 134, issue 6, page 781-806 ISSN 0016-7568 1469-5081 Geology journal-article 1997 crcambridgeupr https://doi.org/10.1017/s0016756897007528 2024-04-18T06:54:35Z The Flagstone Bench Formation ranges in age from earliest Triassic to Norian (Late Triassic) and is exposed in the Beaver Lake area of the northern Prince Charles Mountains. This sandstone-dominated formation rests conformably on the Bainmedart Coal Measures and represents the upper part of the Permian–Triassic Amery Group. It is divisible into three members: the Ritchie, Jetty and McKelvey members (in ascending order). Nine sedimentary facies assignable to three facies associations (major channel, crevasse/fan and flood-basin deposits) are recognized within the formation. Ritchie Member sedimentation took place during a transition from consistently hygric to seasonally dry conditions and the unit comprises sandstone-dominated, sheet-like channel deposits interspersed with few, thin, mottled, haematite-rich flood-basin siltstones. Deposition took place under fluctuating discharge conditions chiefly within the channel tracts of axially (northwesterly/northeasterly) flowing, low-sinuosity braided rivers. The Jetty Member shows a gross upward-fining profile dominated in the lower part by poorly sorted pebbly sandstones and in the upper part by ferruginous mudcracked siltstones, mottled palaeosols, calcrete and thin massive sandstone sheets. This unit reflects deposition of easterly directed alluvial fans and extensive flood-basin silt under a semi-arid climatic regime. The Upper Triassic sandstone-dominated McKelvey Member shows a return to axial drainage along the Lambert Graben with sedimentation occurring primarily within low-sinuosity braided channel tracts under wetter climatic conditions. Article in Journal/Newspaper Antarc* Antarctica East Antarctica Prince Charles Mountains Cambridge University Press East Antarctica Amery ENVELOPE(-94.063,-94.063,56.565,56.565) Prince Charles Mountains ENVELOPE(67.246,67.246,-71.427,-71.427) Beaver Lake ENVELOPE(68.295,68.295,-70.793,-70.793) McKelvey ENVELOPE(-87.300,-87.300,-85.350,-85.350) Flagstone Bench ENVELOPE(68.178,68.178,-70.844,-70.844) Ritchie ENVELOPE(158.417,158.417,-78.533,-78.533) Geological Magazine 134 6 781 806 |
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Cambridge University Press |
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crcambridgeupr |
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English |
topic |
Geology |
spellingShingle |
Geology MCLOUGHLIN, STEPHEN DRINNAN, ANDREW N. Fluvial sedimentology and revised stratigraphy of the Triassic Flagstone Bench Formation, northern Prince Charles Mountains, East Antarctica |
topic_facet |
Geology |
description |
The Flagstone Bench Formation ranges in age from earliest Triassic to Norian (Late Triassic) and is exposed in the Beaver Lake area of the northern Prince Charles Mountains. This sandstone-dominated formation rests conformably on the Bainmedart Coal Measures and represents the upper part of the Permian–Triassic Amery Group. It is divisible into three members: the Ritchie, Jetty and McKelvey members (in ascending order). Nine sedimentary facies assignable to three facies associations (major channel, crevasse/fan and flood-basin deposits) are recognized within the formation. Ritchie Member sedimentation took place during a transition from consistently hygric to seasonally dry conditions and the unit comprises sandstone-dominated, sheet-like channel deposits interspersed with few, thin, mottled, haematite-rich flood-basin siltstones. Deposition took place under fluctuating discharge conditions chiefly within the channel tracts of axially (northwesterly/northeasterly) flowing, low-sinuosity braided rivers. The Jetty Member shows a gross upward-fining profile dominated in the lower part by poorly sorted pebbly sandstones and in the upper part by ferruginous mudcracked siltstones, mottled palaeosols, calcrete and thin massive sandstone sheets. This unit reflects deposition of easterly directed alluvial fans and extensive flood-basin silt under a semi-arid climatic regime. The Upper Triassic sandstone-dominated McKelvey Member shows a return to axial drainage along the Lambert Graben with sedimentation occurring primarily within low-sinuosity braided channel tracts under wetter climatic conditions. |
format |
Article in Journal/Newspaper |
author |
MCLOUGHLIN, STEPHEN DRINNAN, ANDREW N. |
author_facet |
MCLOUGHLIN, STEPHEN DRINNAN, ANDREW N. |
author_sort |
MCLOUGHLIN, STEPHEN |
title |
Fluvial sedimentology and revised stratigraphy of the Triassic Flagstone Bench Formation, northern Prince Charles Mountains, East Antarctica |
title_short |
Fluvial sedimentology and revised stratigraphy of the Triassic Flagstone Bench Formation, northern Prince Charles Mountains, East Antarctica |
title_full |
Fluvial sedimentology and revised stratigraphy of the Triassic Flagstone Bench Formation, northern Prince Charles Mountains, East Antarctica |
title_fullStr |
Fluvial sedimentology and revised stratigraphy of the Triassic Flagstone Bench Formation, northern Prince Charles Mountains, East Antarctica |
title_full_unstemmed |
Fluvial sedimentology and revised stratigraphy of the Triassic Flagstone Bench Formation, northern Prince Charles Mountains, East Antarctica |
title_sort |
fluvial sedimentology and revised stratigraphy of the triassic flagstone bench formation, northern prince charles mountains, east antarctica |
publisher |
Cambridge University Press (CUP) |
publishDate |
1997 |
url |
http://dx.doi.org/10.1017/s0016756897007528 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0016756897007528 |
long_lat |
ENVELOPE(-94.063,-94.063,56.565,56.565) ENVELOPE(67.246,67.246,-71.427,-71.427) ENVELOPE(68.295,68.295,-70.793,-70.793) ENVELOPE(-87.300,-87.300,-85.350,-85.350) ENVELOPE(68.178,68.178,-70.844,-70.844) ENVELOPE(158.417,158.417,-78.533,-78.533) |
geographic |
East Antarctica Amery Prince Charles Mountains Beaver Lake McKelvey Flagstone Bench Ritchie |
geographic_facet |
East Antarctica Amery Prince Charles Mountains Beaver Lake McKelvey Flagstone Bench Ritchie |
genre |
Antarc* Antarctica East Antarctica Prince Charles Mountains |
genre_facet |
Antarc* Antarctica East Antarctica Prince Charles Mountains |
op_source |
Geological Magazine volume 134, issue 6, page 781-806 ISSN 0016-7568 1469-5081 |
op_rights |
https://www.cambridge.org/core/terms |
op_doi |
https://doi.org/10.1017/s0016756897007528 |
container_title |
Geological Magazine |
container_volume |
134 |
container_issue |
6 |
container_start_page |
781 |
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806 |
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1798835644143763456 |