Graptolite faunas of the Llandovery “phtanites” at Les Fresnaies (Chalonnes-sur-Loire, southeastern Armorican Massif): Palaeontology and biostratigraphy

 

Authors: Piçarra JM, Robardet M, Oliveira JT, Paris F, Lardeux H

Published in: Bulletin of Geosciences, volume 84, issue 1; pages: 41 - 50; Received 20 July 2008; Accepted in revised form 19 November 2008; Online 6 January 2009

Keywords: Silurian, Armorican Massif, France, graptolites, biostratigraphy,

full text (PDF, 1.55 MB)

Export to RIS

 

Abstract

In the SE of the Armorican Massif (France), the Ordovician-Silurian transition and the lower part of the Silurian are exposed at the locality Les Fresnaies at Chalonnes-sur-Loire. The Silurian graptolitic “phtanites” (black cherts) are richly fossiliferous. Detailed sampling allows a description of the graptolite faunas and a precise stratigraphical analysis of the succession that comprises the whole of the Rhuddanian and Aeronian stages. Both the Llandovery graptolite assemblages and the lithologies of Les Fresnaies are similar to those of other lower Silurian successions throughout peri-Gondwanan Europe, like Portugal, Spain, Sardinia, Bohemia, Germany and Carnic Alps, and in the Middle East (Jordan and Saudi Arabia).

References

Barrois, C. 1892. Mémoire sur la distribution des Graptolites en France. Annales de la Société Géologique du Nord 20, 75-191.

Bourahrouh, A. 2002. Chitinozoaires et palynomorphes de l’Ordovicien Supérieur nord-gondwanien: impact de la glaciation ashgillienne. 300 pp. These de Doctorat, Université Rennes I (No. d’ordre 2602), Rennes.

Chen, X., Zhang, Y.D., Yu, G.H. & Liu, X. 2007. Latest Ordovician and earliest Silurian graptolites from northwestern Zhejiang, China. Acta Palaeontologica Sinica 46 (Supplement), 77-82.

Cogné, J. 1974. Le Massif Armoricain, 105-161. In Debelmas, J. (ed.) Géologie de la France I . Doin, Paris.

Davy, L.P. 1895. Contribution a l’étude géologique des environs de Chalonnes-sur-Loire (Maine-et-Loire). Terrain Silurien supérieur. Bulletin de la Société des Sciences Naturelles de l’Ouest de la France 5, 199-204.

Davy, L.P. 1906. Ce que l’on croit savoir aujourd’hui sur la constitution géologique des environs de Chalonnes-sur-Loire. Bulletin de la Société d’Etudes Scientifiquesd’Angers 35(1905), 91-125.

Dubreuil,M. 1980. Hypothese sur la mise en place, au Dinantien, du complexe du Tombeau Leclerc (Bassin d’Ancenis, sud-est du Massif armoricain) sous forme d’un olistostrome. Conséquences géodynamiques. Comptes Rendus de l’Académie des Sciences, Paris, Série D 290, 1455-1458.

Dubreuil, M. 1986. Evolution géodynamique du Paléozoique ligérien (Massif Armoricain). 258 pp. These de Doctorat d’Etat, Université de Nantes, Nantes.

Dubreuil, M., Cavet, P., Blaise, J., Estéoule-Choux, J., Gruet, M. & Lardeux, H. 1989. Notice explicative de la feuille Saint-Mars-la-Jaille a 1/50.000 No. 421. 73 pp. Bureau de Recherches Géologiques et Minieres, Orléans.

Gutiérrez-Marco, J.C. & Štorch, P. 1998. Graptolite biostratigraphy of the Lower Silurian (Llandovery) shelf deposits of the Western Iberian Cordillera, Spain. Geological Magazine 135, 71-92.View article

Jaeger, H. 1976. Das Silur und Unterdevon vom thüringischen Typ in Sardinien und seine regionalgeologische Beteudung. Nova Acta Leopoldina, neue Folge 45(224), 263-299.

Jaeger, H. 1988. The Ordovician-Silurian boundary in the Saxothuringian Zone of the Variscan Orogen, 101-106. In Cocks, L.R.M. & Rickards, R.B. (eds) A Global Analysis of the Ordovician-Silurian boundary. Bulletin of the British Museum (Natural History), Geology 43.

Jaeger, H. & Robardet, M. 1979. Le Silurien et le Dévonien basal dans le Nord de la Province de Séville (Espagne). Géobios 12(5), 687-714.View article

Koren’, T.N. & Bjerreskov, M. 1997. Early Llandovery monograptids from Bornholm and the southern Urals: taxonomy and evolution. Bulletin of the Geological Society of Denmark 44, 1-43.

Koren’, T. & Sobolevskaya, R.F. 1983. Graptolity, 97-160. In Sokolov, B.S., Koren’, T. & Nikitin, I.F. (eds) The Ordovician and Silurian boundary in the Northeast of the USSR. Nauka, Leningrad. [in Russian with English summary]

Lardeux, H. & Cavet, P. 1994. Paleozoic of the Ligerian Domain, 152-156. In Keppie, J.D. (ed.) Pre-Mesozoic Geology in France and related Areas. Springer-Verlag, Berlin & Heidelberg.View article

Lardeux, H., Chauvel, J.J., Henry, J.L.,Morzadec, P., Paris, F., Racheboeuf, P.&Robardet,M. 1977. Evolution géologique du Massif Armoricain au cours des temps ordoviciens, siluriens et dévoniens. Colloques internationaux du C.N.R.S. 243, 181-192.

Loydell, D.K. 1991. The biostratigraphy and formational relationships of the upper Aeronian and lower Telychian (Llandovery, Silurian) formations of western mid-Wales. Geological Journal 26, 209-244.View article

Loydell, D.K. 2007. Graptolites from the Upper Ordovician and Lower Silurian of Jordan. Special Papers in Palaeontology 78, 1-66.

Masiak, M., Podhalanska, T. & Stempien-Salek, M. 2003. Ordovician-Silurian boundary in the Bardo Syncline, Holy Cross Moutains, Poland - new data and fossil assemblages and sedimentary sucession. Geological Quarterly 47(4), 311-330.

Melchin, M.J. 1989. Llandovery graptolite biostratigraphy and paleobiogeography, Cape Phillips Formation, Canadian Arctic Islands. Canadian Journal of Earth Sciences 26, 1726-1746.View article

Melchin, M.J. 2004. Restudying a global stratotype for the base of the Silurian: a report the members of the Subcommission on Silurian Stratigraphy. Silurian Times 12, 12-13.

Mu, E. 1988. The Ordovician-Silurian boundary in China, 117-131. In Cocks, L.R.M. & Rickards, R.B. (eds) A Global Analysis of the Ordovician-Silurian boundary. Bulletin of the British Museum (Natural History), Geology 43.

Paris, F. & Robardet, M. 1977. Paléogéographie et relations ibéro-armoricaines au Paléozoique anté-Carbonifere. Bulletin de la Société géologique de France 19(7),1121-1126.View article

Paris, F. & Robardet, M. 1994. The Variscan Orogeny in the Armorican Massif. Introduction, 133-135. In Keppie, J.D. (ed.) Pre-Mesozoic Geology in France and Related Areas. Springer-Verlag, Berlin & Heidelberg.

Philippot, A. 1950. Les Graptolites du Massif Armoricain. Etude stratigraphique et paléontologique. Mémoires de la Société géologique et minéralogique de Bretagne 11, 1-295.

Piçarra, J.M., Gutiérrez-Marco, J.C., Sá, A.A.,Meireles, C. & González-Clavijo, E. 2006. Silurian graptolite biostratigraphy of the Galicia - Trás-os-Montes Zone (Spain and Portugal). G.F.F. 128(2), 185-188.View article

Piçarra, J.M., Robardet, M., Bourahrouh, A., Paris, F., Pereira, Z., LeMenn, J., Gourvennec, R., Oliveira, J.T. & Lardeux, H. 2002. Le passage Ordovicien-Silurien et la partie inférieure du Silurien (Sud-Est du Massif armoricain, France). Comptes Rendus Géoscience 334, 1177-1183.View article

Piçarra, J.M., Štorch, P., Gutiérrez-Marco, J.C. & Oliveira, J.T. 1995. Characterization of the Parakidograptus acuminatus graptolite Biozone in the Silurian of the Barrancos region (Ossa Morena Zone, south Portugal). Comunicaçôes do Instituto Geológico e Mineiro 81, 3-8.

Rickards, R.B. 1976. The sequence of Silurian graptolite zones in the British Isles. Geological Journal 11, 153-188.View article

Riviere, L.M. 1977. Le Culm frano-dinantien du synclinal d’Ancenis (SE du Massif armoricain) au N de la Loire. Bulletin de la Société géologique etminéralogique de Bretagne, C 9(1), 19-57.

Robardet, M., Verniers, J., Feist, R. & Paris, F. 1994. Le Paléozoique anté-varisque de France, contexte paléogéographique et géodynamique. Géologie de la France 1994(3), 3-31.

Robardet, M. & Gutiérrez-Marco, J.C. 2002. Silurian, 51-66. In Gibbons, W. & Moreno, T. (eds) The Geology of Spain. Geological Society of London.

Robardet, M., Piçarra, J.M., Štorch, P., Gutiérrez-Marco, J.C. & Sarmiento, G.N. 1998. Ordovician and Silurian stratigraphy and faunas (graptolites and conodonts) in the Ossa Morena Zone of the SW Iberian Peninsula (Portugal and Spain). Temas Geológico-Mineros ITGE 23, 289-318.

Štorch, P. 1986. Ordovician-Silurian boundary in the Prague Basin (Barrandian area, Bohemia). Sborník geologických věd, Geologie 41, 69-103.

Štorch, P. 1994. Graptolite biostratigraphy of the Lower Silurian (Llandovery and Wenlock) of Bohemia. Geological Journal 29, 137-165.View article

Štorch, P. 1996. The basal Silurian Akidograptus ascensus-Parakidograptus acuminatus Biozone in peri-Gondwanan Europe: graptolite assemblages, stratigraphical ranges and palaeobiogeography. Věstník Českého geologického ústavu 71, 177-188.

Štorch, P. 1998. Graptolites of the Pribylograptus leptotheca and Lituigraptus convolutus biozones of Tmaň (Silurian, Czech Republic). Journal of the Czech Geological Society 43(4), 209-272.

Štorch, P. 2001. Graptolites, stratigraphy and depositional setting of the middle Llandovery (Silurian) volcanic-carbonate facies at Hýskov (Barrandian area, Czech Republic). Bulletin of the Czech Geological Survey 76(1), 55-76.

Štorch, P. 2006. Facies development, depositional settings and sequence stratigraphy across the Ordovician-Silurian boundary: a new perspective from the Barrandian area of the Czech Republic. Geological Journal 41, 163-192.View article

Štorch, P. & Serpagli, E. 1993. Lower Silurian graptolites from southwestern Sardinia. Bollettino della Societa Paleontologica Italiana 32(1), 3-57.

Zalasiewicz, J., Williams, M., Miller, M., Page, A. & Blackett, E. 2007. Early Silurian (Llandovery) graptolites from Central Saudi Arabia: first documented record of Telychian faunas from the Arabian Peninsula. GeoArabia 12(4), 15-36.View article