Cupressacean origin of the Cretaceous Vendean amber (northwestern France): evidence from fossil woods and chemical signatures - INSU - Institut national des sciences de l'Univers Accéder directement au contenu
Communication Dans Un Congrès Année : 2014

Cupressacean origin of the Cretaceous Vendean amber (northwestern France): evidence from fossil woods and chemical signatures

Vincent Perrichot
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Anais A Boura
Laurent Jeanneau
Didier Néraudeau
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Romain Thomas
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Dany Azar
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Résumé

Ambers, the fossilized tree resins, occur widely in France, with highly fossiliferous deposits ofmiddle to Upper Cretaceous and Eocene age. Previous studies on the mid-Cretaceous (Albian-Cenomanian) amber from southwestern France have revealed the conifer families Araucariaceae and the extinct Cheirolepidiaceae as the two possible plant sources for the fossil resins. Here we investigate the botanical origin of a new amber that was recently discovered from the Upper Cretaceous series (Turonian to Santonian) of the department of Vendée in northwestern France. Analyses were carried out on abundant fossil wood which was found associated with the amber. Anatomical characteristics of the fossil wood allowed the recognition of two distinct coniferous taxa with normal or traumatic resin canals, and assignable to the Pinaceae and the Taxodiaceae (Cupressaceae s.l.). Then we complemented our analyses by the chemical characterization of the amber with established techniques: the Fourier Transform Infra-Red (FTIR) spectrôscopy in transmission mode and the Thermally assisted Hydrolysis and Methylation-Gas Chromatography coupled to Mass Spectrometry (THM-GC-MS). The FTIR spectra showed that Vendean amber has affinities with the resin of both the Araucariaceae and the Cupressaceae s.l., while then THM-GC-MS revealed sorne molecules that are considered biomarkers of the Cupressaceae. Therefore, the coupling of anatomical and chemical analyses strongly support Taxodiaceae (or Cupressaceae s.I.) as the plant source of this resin. This study shows different botanical origins for Cretaceous French ambers, from Araucariaceae/Cheirolepidiaceae during the mid-Cretaceous to Cupressaceae during the Late 189 Cretaceous. Whether this is a global trend in the Cretaceous resin production, that has yet to be confirmed by further investigations, but this is remarkably similar to what was *observed in other major amber deposits throughout the world, e.g., Cheirolepidiaceae for the Lower and mid-Cretaceous ambers of Spain and Lebanon, and Cupressaceae for the Late Cretaceous ambers of North America (Canada and New Jersey).
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Dates et versions

insu-01068204 , version 1 (25-09-2014)

Identifiants

  • HAL Id : insu-01068204 , version 1

Citer

Youssef Nohra, Vincent Perrichot, Anais A Boura, Laurent Jeanneau, Didier Néraudeau, et al.. Cupressacean origin of the Cretaceous Vendean amber (northwestern France): evidence from fossil woods and chemical signatures. 9th European Palaeobotany - Palynology Conference, Aug 2014, Padoue, Italy. pp.189. ⟨insu-01068204⟩
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