U-Pb geochronology and global context of the Charnian Supergroup, UK: constraints on the age of key Ediacaran fossil assemblages
U-Pb (zircon) ages for key stratigraphic volcanic horizons within the ∼3200-m-thick Ediacaran-age Charnian Supergroup provide an improved age model for the included Avalonian assemblage macrofossils and, hence, temporal constraints essential for intercomparisons of the Charnian fossils with other Ed...
Published in: | Geological Society of America Bulletin |
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Geological Society of America
2015
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Online Access: | http://nora.nerc.ac.uk/id/eprint/509394/ https://nora.nerc.ac.uk/id/eprint/509394/1/Noble%20et%20al%202015%20BGSA%20SOM%20%28Nora%29.pdf https://nora.nerc.ac.uk/id/eprint/509394/2/Noble%20et%20al%202015%20BGSA%20%28Nora%29.pdf https://doi.org/10.1130/B31013.1 |
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ftnerc:oai:nora.nerc.ac.uk:509394 2023-05-15T17:22:39+02:00 U-Pb geochronology and global context of the Charnian Supergroup, UK: constraints on the age of key Ediacaran fossil assemblages Noble, Stephen R. Condon, Daniel J. Carney, John N. Wilby, Philip R. Pharaoh, Timothy C. Ford, Trevor D. 2015 text http://nora.nerc.ac.uk/id/eprint/509394/ https://nora.nerc.ac.uk/id/eprint/509394/1/Noble%20et%20al%202015%20BGSA%20SOM%20%28Nora%29.pdf https://nora.nerc.ac.uk/id/eprint/509394/2/Noble%20et%20al%202015%20BGSA%20%28Nora%29.pdf https://doi.org/10.1130/B31013.1 en eng Geological Society of America https://nora.nerc.ac.uk/id/eprint/509394/1/Noble%20et%20al%202015%20BGSA%20SOM%20%28Nora%29.pdf https://nora.nerc.ac.uk/id/eprint/509394/2/Noble%20et%20al%202015%20BGSA%20%28Nora%29.pdf Noble, Stephen R.; Condon, Daniel J.; Carney, John N.; Wilby, Philip R.; Pharaoh, Timothy C.; Ford, Trevor D. 2015 U-Pb geochronology and global context of the Charnian Supergroup, UK: constraints on the age of key Ediacaran fossil assemblages. Geological Society of America Bulletin, 127 (1-2). 250-265. https://doi.org/10.1130/B31013.1 <https://doi.org/10.1130/B31013.1> Publication - Article PeerReviewed 2015 ftnerc https://doi.org/10.1130/B31013.1 2023-02-04T19:40:49Z U-Pb (zircon) ages for key stratigraphic volcanic horizons within the ∼3200-m-thick Ediacaran-age Charnian Supergroup provide an improved age model for the included Avalonian assemblage macrofossils and, hence, temporal constraints essential for intercomparisons of the Charnian fossils with other Ediacaran fossil assemblages globally. The Ives Head Formation (Blackbrook Group), the oldest exposed part of the volcaniclastic Charnian Supergroup of the late Neoproterozoic Avalonian volcanic arc system of southern Britain, contains a bedding plane with an impoverished assemblage of ivesheadiomorphs that is constrained to between ca. 611 Ma and 569.1 ± 0.9 Ma (total uncertainty). Higher-diversity biotas, including the holotypes of Charnia, Charniodiscus, and Bradgatia, occupy the upper part of the volcaniclastic succession (Maplewell Group) and are dated at 561.9 ± 0.9 Ma (total uncertainty) and younger by zircons interpreted as coeval with eruption and deposition of the Park Breccia, Bradgate Formation. An ashy volcanic-pebble conglomerate in the Hanging Rocks Formation at the very top of the supergroup yielded two U-Pb zircon populations: an older detrital one at ca. 604 Ma, and a younger population at ca. 557 Ma, which is interpreted as the approximate depositional age. The temporal association of the fossiliferous Charnian Supergroup with comparable fossiliferous deep-water successions in Newfoundland, and the probable temporal overlap of the youngest Charnwood macrofossils with those from different paleoenvironmental settings, such as the Ediacaran White Sea macrofossils, indicate a primary role for ecological sensitivity in determining the composition of these late Neoproterozoic communities. Article in Journal/Newspaper Newfoundland White Sea Natural Environment Research Council: NERC Open Research Archive White Sea Geological Society of America Bulletin 127 1-2 250 265 |
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Open Polar |
collection |
Natural Environment Research Council: NERC Open Research Archive |
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ftnerc |
language |
English |
description |
U-Pb (zircon) ages for key stratigraphic volcanic horizons within the ∼3200-m-thick Ediacaran-age Charnian Supergroup provide an improved age model for the included Avalonian assemblage macrofossils and, hence, temporal constraints essential for intercomparisons of the Charnian fossils with other Ediacaran fossil assemblages globally. The Ives Head Formation (Blackbrook Group), the oldest exposed part of the volcaniclastic Charnian Supergroup of the late Neoproterozoic Avalonian volcanic arc system of southern Britain, contains a bedding plane with an impoverished assemblage of ivesheadiomorphs that is constrained to between ca. 611 Ma and 569.1 ± 0.9 Ma (total uncertainty). Higher-diversity biotas, including the holotypes of Charnia, Charniodiscus, and Bradgatia, occupy the upper part of the volcaniclastic succession (Maplewell Group) and are dated at 561.9 ± 0.9 Ma (total uncertainty) and younger by zircons interpreted as coeval with eruption and deposition of the Park Breccia, Bradgate Formation. An ashy volcanic-pebble conglomerate in the Hanging Rocks Formation at the very top of the supergroup yielded two U-Pb zircon populations: an older detrital one at ca. 604 Ma, and a younger population at ca. 557 Ma, which is interpreted as the approximate depositional age. The temporal association of the fossiliferous Charnian Supergroup with comparable fossiliferous deep-water successions in Newfoundland, and the probable temporal overlap of the youngest Charnwood macrofossils with those from different paleoenvironmental settings, such as the Ediacaran White Sea macrofossils, indicate a primary role for ecological sensitivity in determining the composition of these late Neoproterozoic communities. |
format |
Article in Journal/Newspaper |
author |
Noble, Stephen R. Condon, Daniel J. Carney, John N. Wilby, Philip R. Pharaoh, Timothy C. Ford, Trevor D. |
spellingShingle |
Noble, Stephen R. Condon, Daniel J. Carney, John N. Wilby, Philip R. Pharaoh, Timothy C. Ford, Trevor D. U-Pb geochronology and global context of the Charnian Supergroup, UK: constraints on the age of key Ediacaran fossil assemblages |
author_facet |
Noble, Stephen R. Condon, Daniel J. Carney, John N. Wilby, Philip R. Pharaoh, Timothy C. Ford, Trevor D. |
author_sort |
Noble, Stephen R. |
title |
U-Pb geochronology and global context of the Charnian Supergroup, UK: constraints on the age of key Ediacaran fossil assemblages |
title_short |
U-Pb geochronology and global context of the Charnian Supergroup, UK: constraints on the age of key Ediacaran fossil assemblages |
title_full |
U-Pb geochronology and global context of the Charnian Supergroup, UK: constraints on the age of key Ediacaran fossil assemblages |
title_fullStr |
U-Pb geochronology and global context of the Charnian Supergroup, UK: constraints on the age of key Ediacaran fossil assemblages |
title_full_unstemmed |
U-Pb geochronology and global context of the Charnian Supergroup, UK: constraints on the age of key Ediacaran fossil assemblages |
title_sort |
u-pb geochronology and global context of the charnian supergroup, uk: constraints on the age of key ediacaran fossil assemblages |
publisher |
Geological Society of America |
publishDate |
2015 |
url |
http://nora.nerc.ac.uk/id/eprint/509394/ https://nora.nerc.ac.uk/id/eprint/509394/1/Noble%20et%20al%202015%20BGSA%20SOM%20%28Nora%29.pdf https://nora.nerc.ac.uk/id/eprint/509394/2/Noble%20et%20al%202015%20BGSA%20%28Nora%29.pdf https://doi.org/10.1130/B31013.1 |
geographic |
White Sea |
geographic_facet |
White Sea |
genre |
Newfoundland White Sea |
genre_facet |
Newfoundland White Sea |
op_relation |
https://nora.nerc.ac.uk/id/eprint/509394/1/Noble%20et%20al%202015%20BGSA%20SOM%20%28Nora%29.pdf https://nora.nerc.ac.uk/id/eprint/509394/2/Noble%20et%20al%202015%20BGSA%20%28Nora%29.pdf Noble, Stephen R.; Condon, Daniel J.; Carney, John N.; Wilby, Philip R.; Pharaoh, Timothy C.; Ford, Trevor D. 2015 U-Pb geochronology and global context of the Charnian Supergroup, UK: constraints on the age of key Ediacaran fossil assemblages. Geological Society of America Bulletin, 127 (1-2). 250-265. https://doi.org/10.1130/B31013.1 <https://doi.org/10.1130/B31013.1> |
op_doi |
https://doi.org/10.1130/B31013.1 |
container_title |
Geological Society of America Bulletin |
container_volume |
127 |
container_issue |
1-2 |
container_start_page |
250 |
op_container_end_page |
265 |
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1766109451363811328 |