Permo-Carboniferous conglomerates in the Trinity Peninsula Group at View Point, Antarctic Peninsula: sedimentology, geochronology and isotope evidence for provenance and tectonic setting in Gondwana
Abstract Field observations from the Trinity Peninsula Group at View Point on the Antarctic Peninsula indicate that thick, southward-younging and overturned clastic sedimentary rocks, comprising unusually coarse conglomeratic lenses within a succession of fine-grained sandstone–mudstone couplets, ar...
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crcambridgeupr:10.1017/s001675681100080x 2024-05-19T07:32:14+00:00 Permo-Carboniferous conglomerates in the Trinity Peninsula Group at View Point, Antarctic Peninsula: sedimentology, geochronology and isotope evidence for provenance and tectonic setting in Gondwana BRADSHAW, JOHN D. VAUGHAN, ALAN P. M. MILLAR, IAN L. FLOWERDEW, MICHAEL J. TROUW, RUDOLPH A. J. FANNING, C. MARK WHITEHOUSE, MARTIN J. 2011 http://dx.doi.org/10.1017/s001675681100080x https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S001675681100080X en eng Cambridge University Press (CUP) https://www.cambridge.org/core/terms Geological Magazine volume 149, issue 4, page 626-644 ISSN 0016-7568 1469-5081 journal-article 2011 crcambridgeupr https://doi.org/10.1017/s001675681100080x 2024-04-25T06:51:42Z Abstract Field observations from the Trinity Peninsula Group at View Point on the Antarctic Peninsula indicate that thick, southward-younging and overturned clastic sedimentary rocks, comprising unusually coarse conglomeratic lenses within a succession of fine-grained sandstone–mudstone couplets, are the deposits of debris and turbidity flows on or at the foot of a submarine slope. Three detrital zircons from the sandstone–mudstone couplets date deposition at 302 ± 3 Ma, at or shortly after the Carboniferous–Permian boundary. Conglomerates predominantly consist of quartzite and granite and contain boulders exceeding 500 mm in diameter. Zircons from granitoid clasts and a silicic volcanic clast yield U–Pb ages of 466 ± 3 Ma, 373 ± 5 Ma and 487 ± 4 Ma, respectively and have corresponding average εHf t values between +0.3 and +7.6. A quartzite clast, conglomerate matrix and sandstone interbedded with the conglomerate units have broadly similar detrital zircon age distributions and Hf isotope compositions. The clast and detrital zircon ages match well with sources within Patagonia; however, the age of one granite clast and the εHf characteristics of some detrital zircons point to a lesser South Africa or Ellsworth Mountain-like contribution, and the quartzite and granite-dominated composition of the conglomerates is similar to upper Palaeozoic diamictites in the Ellsworth Mountains. Unlike detrital zircons, large conglomerate clasts limit possible transport distance, and suggest sedimentation took place on or near the edge of continental crust. Comparison with other upper Palaeozoic to Mesozoic sediments in the Antarctic Peninsula and Patagonia, including detrital zircon composition and the style of deformation, suggests deposition of the Trinity Peninsula Group in an upper plate basin on an active margin, rather than a subduction-related accretionary setting, with slow extension and rifting punctuated by short periods of compression. Article in Journal/Newspaper Antarc* Antarctic Antarctic Peninsula Cambridge University Press Geological Magazine 149 4 626 644 |
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English |
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Abstract Field observations from the Trinity Peninsula Group at View Point on the Antarctic Peninsula indicate that thick, southward-younging and overturned clastic sedimentary rocks, comprising unusually coarse conglomeratic lenses within a succession of fine-grained sandstone–mudstone couplets, are the deposits of debris and turbidity flows on or at the foot of a submarine slope. Three detrital zircons from the sandstone–mudstone couplets date deposition at 302 ± 3 Ma, at or shortly after the Carboniferous–Permian boundary. Conglomerates predominantly consist of quartzite and granite and contain boulders exceeding 500 mm in diameter. Zircons from granitoid clasts and a silicic volcanic clast yield U–Pb ages of 466 ± 3 Ma, 373 ± 5 Ma and 487 ± 4 Ma, respectively and have corresponding average εHf t values between +0.3 and +7.6. A quartzite clast, conglomerate matrix and sandstone interbedded with the conglomerate units have broadly similar detrital zircon age distributions and Hf isotope compositions. The clast and detrital zircon ages match well with sources within Patagonia; however, the age of one granite clast and the εHf characteristics of some detrital zircons point to a lesser South Africa or Ellsworth Mountain-like contribution, and the quartzite and granite-dominated composition of the conglomerates is similar to upper Palaeozoic diamictites in the Ellsworth Mountains. Unlike detrital zircons, large conglomerate clasts limit possible transport distance, and suggest sedimentation took place on or near the edge of continental crust. Comparison with other upper Palaeozoic to Mesozoic sediments in the Antarctic Peninsula and Patagonia, including detrital zircon composition and the style of deformation, suggests deposition of the Trinity Peninsula Group in an upper plate basin on an active margin, rather than a subduction-related accretionary setting, with slow extension and rifting punctuated by short periods of compression. |
format |
Article in Journal/Newspaper |
author |
BRADSHAW, JOHN D. VAUGHAN, ALAN P. M. MILLAR, IAN L. FLOWERDEW, MICHAEL J. TROUW, RUDOLPH A. J. FANNING, C. MARK WHITEHOUSE, MARTIN J. |
spellingShingle |
BRADSHAW, JOHN D. VAUGHAN, ALAN P. M. MILLAR, IAN L. FLOWERDEW, MICHAEL J. TROUW, RUDOLPH A. J. FANNING, C. MARK WHITEHOUSE, MARTIN J. Permo-Carboniferous conglomerates in the Trinity Peninsula Group at View Point, Antarctic Peninsula: sedimentology, geochronology and isotope evidence for provenance and tectonic setting in Gondwana |
author_facet |
BRADSHAW, JOHN D. VAUGHAN, ALAN P. M. MILLAR, IAN L. FLOWERDEW, MICHAEL J. TROUW, RUDOLPH A. J. FANNING, C. MARK WHITEHOUSE, MARTIN J. |
author_sort |
BRADSHAW, JOHN D. |
title |
Permo-Carboniferous conglomerates in the Trinity Peninsula Group at View Point, Antarctic Peninsula: sedimentology, geochronology and isotope evidence for provenance and tectonic setting in Gondwana |
title_short |
Permo-Carboniferous conglomerates in the Trinity Peninsula Group at View Point, Antarctic Peninsula: sedimentology, geochronology and isotope evidence for provenance and tectonic setting in Gondwana |
title_full |
Permo-Carboniferous conglomerates in the Trinity Peninsula Group at View Point, Antarctic Peninsula: sedimentology, geochronology and isotope evidence for provenance and tectonic setting in Gondwana |
title_fullStr |
Permo-Carboniferous conglomerates in the Trinity Peninsula Group at View Point, Antarctic Peninsula: sedimentology, geochronology and isotope evidence for provenance and tectonic setting in Gondwana |
title_full_unstemmed |
Permo-Carboniferous conglomerates in the Trinity Peninsula Group at View Point, Antarctic Peninsula: sedimentology, geochronology and isotope evidence for provenance and tectonic setting in Gondwana |
title_sort |
permo-carboniferous conglomerates in the trinity peninsula group at view point, antarctic peninsula: sedimentology, geochronology and isotope evidence for provenance and tectonic setting in gondwana |
publisher |
Cambridge University Press (CUP) |
publishDate |
2011 |
url |
http://dx.doi.org/10.1017/s001675681100080x https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S001675681100080X |
genre |
Antarc* Antarctic Antarctic Peninsula |
genre_facet |
Antarc* Antarctic Antarctic Peninsula |
op_source |
Geological Magazine volume 149, issue 4, page 626-644 ISSN 0016-7568 1469-5081 |
op_rights |
https://www.cambridge.org/core/terms |
op_doi |
https://doi.org/10.1017/s001675681100080x |
container_title |
Geological Magazine |
container_volume |
149 |
container_issue |
4 |
container_start_page |
626 |
op_container_end_page |
644 |
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1799470229772828672 |