New insights into the early evolution of horizontal spiral trace fossils and the age of the Brioverian series (Ediacaran–Cambrian) in Brittany, NW France
| العنوان: | New insights into the early evolution of horizontal spiral trace fossils and the age of the Brioverian series (Ediacaran–Cambrian) in Brittany, NW France |
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| المؤلفون: | Romain Gougeon, Marc Poujol, Didier Néraudeau, Alfredo Loi |
| المساهمون: | Géosciences Rennes (GR), Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR), Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Centre National de la Recherche Scientifique (CNRS), University of Saskatchewan [Saskatoon] (U of S), Università degli Studi di Cagliari = University of Cagliari (UniCa), Fondazione Banco di SarDEGNA, Regione Autonoma della Sardegna’ (grant numbers F74I19000960007, J81G17000110002), VIBRIO project of the INSU InterrVie program, Observatoire des Sciences de l’Univers de Rennes (OSUR)., Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR)-Centre National de la Recherche Scientifique (CNRS), Universita degli Studi di Cagliari [Cagliari] |
| المصدر: | Geological Magazine Geological Magazine, 2021, 159 (7), pp.1284-1294. ⟨10.1017/S0016756820001430⟩ Geological Magazine, Cambridge University Press (CUP), In press, pp.1-11. ⟨10.1017/S0016756820001430⟩ |
| بيانات النشر: | HAL CCSD, 2021. |
| سنة النشر: | 2021 |
| مصطلحات موضوعية: | 010506 paleontology, Series (stratigraphy), Geology, Trace fossil, 010502 geochemistry & geophysics, 01 natural sciences, Paleontology, [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry, planispira, Ediacaran–Fortunian, 14. Life underwater, Spiral (railway), [SDU.STU.PG]Sciences of the Universe [physics]/Earth Sciences/Paleontology, l Spirodesmos, ichnology, U–Pb dating, 0105 earth and related environmental sciences |
| الوصف: | In northwestern France, the Brioverian series is a thick siliciclastic succession deposited during the Cadomian cycle (c. 750–540 Ma). In the uppermost Brioverian beds, previous studies unravelled an assemblage dominated by simple horizontal trace fossils associated with microbially stabilized surfaces. Here, we report Spirodesmos trace fossils – one-way, irregular and regular horizontal spirals – from Crozon (Finistère, Brittany), Montfort-sur-Meu and St-Gonlay (Ille-et-Vilaine, Brittany). After reviewing the literature on horizontal spiral trace fossils, an Ediacaran–Fortunian Spirodesmos pool is identified from marginal-marine to shelf settings, while an Ordovician–Recent trend formed in the deep-marine realm. These results suggest that an onshore–offshore migration in Spirodesmos took place during Ediacaran–Fortunian to Ordovician time, similar to what happened in graphoglyptids. In addition, the age of the uppermost Brioverian beds (Ediacaran or early Cambrian) is still a pending question. Here, we report two new U–Pb detrital zircon datings from sandstone samples in St-Gonlay, giving maximum deposition ages of 551 ± 7 Ma and 540 ± 5 Ma. Although these results do not discard an Ediacaran age for the uppermost Brioverian beds, a Fortunian age is envisioned because the new dating corroborates previous dating from Brittany, Mayenne and Normandy. However, the intervals of error of the radiometric dating, and the dominance of non-penetrative trace fossils associated with matgrounds (an ecology more typical of the Ediacaran Period), do not allow definitive conclusions on the age of the uppermost Brioverian beds. |
| اللغة: | English |
| تدمد: | 0016-7568 1469-5081 |
| URL الوصول: | https://explore.openaire.eu/search/publication?articleId=doi_dedup___::24fcb14208a2987b0d281d434fab75b2 https://insu.hal.science/insu-03124898/file/gougeon-2022.pdf |
| حقوق: | CLOSED |
| رقم الأكسشن: | edsair.doi.dedup.....24fcb14208a2987b0d281d434fab75b2 |
| قاعدة البيانات: | OpenAIRE |
| تدمد: | 00167568 14695081 |
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