Cryptic disc structures resembling ediacaran discoidal fossils from the lower Silurian Hellefjord Schist, Arctic Norway
The Hellefjord Schist, a volcaniclastic psammite-pelite formation in the Caledonides of Arctic Norway contains discoidal impressions and apparent tube casts that share morphological and taphonomic similarities to Neoproterozoic stem-holdfast forms. U-Pb zircon geochronology on the host metasediment...
| Main Authors: | , , , |
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| Format: | Journal Article |
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Public Library of Science
2016
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| Online Access: | http://hdl.handle.net/20.500.11937/19994 |
| _version_ | 1848750186035150848 |
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| author | Kirkland, Chris Macgabhann, B. Kirkland, B. Daly, J. |
| author_facet | Kirkland, Chris Macgabhann, B. Kirkland, B. Daly, J. |
| author_sort | Kirkland, Chris |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | The Hellefjord Schist, a volcaniclastic psammite-pelite formation in the Caledonides of Arctic Norway contains discoidal impressions and apparent tube casts that share morphological and taphonomic similarities to Neoproterozoic stem-holdfast forms. U-Pb zircon geochronology on the host metasediment indicates it was deposited between 437 ± 2 and 439 ± 3 Ma, but also indicates that an inferred basal conglomerate to this formation must be part of an older stratigraphic element, as it is cross-cut by a 546 ± 4 Ma pegmatite. These results confirm that the Hellefjord Schist is separated from underlying older Proterozoic rocks by a thrust. It has previously been argued that the Cambrian Substrate Revolution destroyed the ecological niches that the Neoproterozoic frond-holdfasts organisms occupied. However, the discovery of these fossils in Silurian rocks demonstrates that the environment and substrate must have been similar enough to Neoproterozoic settings that frond-holdfast bodyplans were still ecologically viable some hundred million years later. © 2016 Kirkland et al. |
| first_indexed | 2025-11-14T07:32:49Z |
| format | Journal Article |
| id | curtin-20.500.11937-19994 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T07:32:49Z |
| publishDate | 2016 |
| publisher | Public Library of Science |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-199942017-09-13T13:48:13Z Cryptic disc structures resembling ediacaran discoidal fossils from the lower Silurian Hellefjord Schist, Arctic Norway Kirkland, Chris Macgabhann, B. Kirkland, B. Daly, J. The Hellefjord Schist, a volcaniclastic psammite-pelite formation in the Caledonides of Arctic Norway contains discoidal impressions and apparent tube casts that share morphological and taphonomic similarities to Neoproterozoic stem-holdfast forms. U-Pb zircon geochronology on the host metasediment indicates it was deposited between 437 ± 2 and 439 ± 3 Ma, but also indicates that an inferred basal conglomerate to this formation must be part of an older stratigraphic element, as it is cross-cut by a 546 ± 4 Ma pegmatite. These results confirm that the Hellefjord Schist is separated from underlying older Proterozoic rocks by a thrust. It has previously been argued that the Cambrian Substrate Revolution destroyed the ecological niches that the Neoproterozoic frond-holdfasts organisms occupied. However, the discovery of these fossils in Silurian rocks demonstrates that the environment and substrate must have been similar enough to Neoproterozoic settings that frond-holdfast bodyplans were still ecologically viable some hundred million years later. © 2016 Kirkland et al. 2016 Journal Article http://hdl.handle.net/20.500.11937/19994 10.1371/journal.pone.0164071 http://creativecommons.org/licenses/by/4.0/ Public Library of Science fulltext |
| spellingShingle | Kirkland, Chris Macgabhann, B. Kirkland, B. Daly, J. Cryptic disc structures resembling ediacaran discoidal fossils from the lower Silurian Hellefjord Schist, Arctic Norway |
| title | Cryptic disc structures resembling ediacaran discoidal fossils from the lower Silurian Hellefjord Schist, Arctic Norway |
| title_full | Cryptic disc structures resembling ediacaran discoidal fossils from the lower Silurian Hellefjord Schist, Arctic Norway |
| title_fullStr | Cryptic disc structures resembling ediacaran discoidal fossils from the lower Silurian Hellefjord Schist, Arctic Norway |
| title_full_unstemmed | Cryptic disc structures resembling ediacaran discoidal fossils from the lower Silurian Hellefjord Schist, Arctic Norway |
| title_short | Cryptic disc structures resembling ediacaran discoidal fossils from the lower Silurian Hellefjord Schist, Arctic Norway |
| title_sort | cryptic disc structures resembling ediacaran discoidal fossils from the lower silurian hellefjord schist, arctic norway |
| url | http://hdl.handle.net/20.500.11937/19994 |