Sables du Castrais Formation explained

Sables du Castrais Formation
Type:Geological formation
Period:Bartonian
Age:Eocene,
Prilithology:Sandstone, molasse and conglomerate
Namedby:M. Richard (1946)
Country:France
Coordinates:43.3681°N 1.9906°W
Subunits:
  • Lophiodon lautricense and Paleotherium zone
  • Issel Member
  • Villeneuve-la-Comptal Member
  • Grès de Carcassonne Member
  • Argiles rutilants d'Issel et de Saint-Papoul
  • Grès d'Issel
  • Molasses de Castelnaudary
  • Issel Sandstones
Overlies:Danian rocks
Thickness:NaNm (-2,147,483,648feet) at the base and at Castelnaudary. NaNm (-2,147,483,648feet) at Issel.
Extent:Carcassonne, Castelnaudary, Issel, Réalmont and Saint-Papoul

The Sables du Castrais Formation, also known as the Molasses du Castrais, is a geologic formation of Eocene (Ypresian to Bartonian) age,[1] outcropping in the Montagne-Noire region of France.[2]

History

"Petrified fossil remains" were known from the Sables du Castrais Formation since at least the 18th century,[3] and several of these fossils were described by Cuvier (1804) and Cuvier (1822) as belonging to Palaeotherium and Lophiodon.[4] [5]

In 1845, a jaw assigned to Lophiodon lautricensis was discovered in the formation and was described by Noulet (1851);[6] Noulet also mentioned that he had himself collected fossils from the formation alongside pharmacist J. Parayre as early as .[7]

Léonce Roux du Carla discovered several more fossils from the Grès d'Issel Mermber of the Sables du Castrais formation from February 1855 until his death in 1859, and this helped Noulet (1858) to confirm the Eocene age of the deposit. Despite this, all that remains today of du Carla's collection is a single jaw of Palaeotherium castrense from the Sables du Castrais Formation.

Between 1850 and 1868, during the construction of the Castres - Albi railroad, several more fossils were recovered from the Sables du Castrais Formation, including M. Zebrowsky's 1868 discovery of fossils within the area.[8]

The Grès d'Issel Member was identified by Henri de Sévérac in 1873,[9] and the Sables du Castrais Formation was first described by M. Richard in 1946.[10]

The Grès d'Issel Member is located in a quarry which closed around 1966 and is now inaccessible due to it currently being located underneath a private garden.

Age of the formation

The age of the Sables du Castrais Formation was listed as Eocene by Noulet (1858) and in 1867, Gervais noted that the Issel Member likely dated to the Early Eocene, while the Villeneuve-la-Comptal Member likely dated to the Middle Eocene.[11]

Caraven-Cachin (1898) was the first to assign the Sables du Castrais Formation to the Bartonian.[12] Stehlin (1910) and Escarguel (1999) dated the formation to the Lutetian-Bartonian and found it to overlie the Molasses de Saix et de Lautrec Formation.[13] [14] Fauré (2011) agreed with the more recent dating of the formation to the Ypresian-Bartonian.

Geology

The base of the Sables du Castrais Formation, which overlies Danian rocks, is made up of Ypresian gravel clays and the Issel Sandstones, which range from NaNm (-2,147,483,648feet), and the Argiles rutilants d'Issel et de Saint-Papoul Member is deposited within the gravel clays, and is between NaNm (-2,147,483,648feet) thick.

The Argiles rutilants d'Issel et de Saint-Papoul Member is overlain by the Lutetian Grès d'Issel Member, which is between NaNm (-2,147,483,648feet) thick, and is overlain by the Bartonian Molasses du Castelnaudary Member.[15] [16] The whole formation underlies the Molasses de Saix et de Lautrec Formation.

The Grès de Carcassonne Member also appears to be slightly younger than the Grès d'Issel Member, likely dating to the late Lutetian or early Bartonian.[17]

The Sables du Castrais Formation was described by Capera and Baillet (2014) as a typical fluviatile formation, with lenticular channels, formed by conglomerates and sandstones, with calcareous cement and large trough cross-strata.[18]

Paleofauna

Mammals

Artiodactyl
Taxa Species Locality Stratigraphic position Material Notes Images
CatadontheriumC ? paquieri
CebochoerusC.(Gervachoerus) campichii
C.(Cebochoerus) helveticus
ChoeropotamusC. lautricensis
DacrytheriumD. elegans
PseudoamphimeryxP. sp.
RobiacinaR. minuta
TapirulusTapirulus cf. schlosseri
XiphodonX. castrense
Lipotyphia
Marsupial
Pan-Carnivora
Taxa Species Locality Stratigraphic position Material Notes Images
HyaenodonH. nouleti
H. sp
QuercygaleQ. angustidens
Perissodactyl
Taxa Species Locality Stratigraphic position Material Notes Images
AnchylophusA. cf. desmaresti
A. cf. gaudini
EurohippusE. parvulus
LophiodonL. isselense.
L. lautricense.
L. sp.
PlagiolophusP. cartailhaci
P. cf. minor
LeptolophusL. nouleti
LophiaspisL. occitanicus
Paralophiodon[19] P. isselense[20]
PalaeotheriumP. castrense
P. (Frantzenitherium) lautricense
P. isselanum
P. rhinocerodes
P. siderolithicum
P. pomeli
Propalaeotherium P. sp.
Primates
Taxa Species Locality Stratigraphic position Material Notes Images
AdapisA. aff. parisiensis
A. rouxii
NecrolemurN. sp.
Rodent
Taxa Species Locality Stratigraphic position Material Notes Images
GliravusG. sp.
SuevoscuriusS. sp.
PseudoltinomysP. sp.

Reptiles

Crocodilians
Taxa Species Locality Stratigraphic position Material Notes Images
AsiatosuchusA. depressifrons
AtacisaurusA. glareae
A. cf. sp.
CrocodylusC. rouxii
DentaneosuchusD. crassiproratus[21] [22] A mandibular symphysis.A giant sebecid crocodile.
IberosuchusI. cf. macrodon
KentisuchusK. astrei
PristichampsusP. rollinati
Turtles
Taxa Species Locality Stratigraphic position Material Notes Images
AllaeochelysA. pareyrei
A. nouleti
A. castrensis
HadrianusH. castrensis
NeochelysN. mengauti
N. sp.[23]
TrionyxT. filholi
T. sp.[24]

Notes and References

  1. Marandat, B. (1987) La biostratigraphie mammalienne de l'Éocène continental du versant sud de la Montagne noire. Reconsidération d'après les nouvelles données. Muench. Geowiss. Abh. (A), 10 (1987), pp. 149-158
  2. Noulet, J.-B. (1858) – Du terrain éocène supérieur considéré comme l’un des étages constitutifs des Pyrénées. Bulletin de la Société géologique de France, 1858, p. 277-284
  3. Fauré, Philippe. (2011). UN PATRIMOINE GEOLOGIQUE PEU CONNU : LES GISEMENTS DE VERTEBRES FOSSILES DE L’EOCENE MOYEN DU CASTRAIS (TARN, LUTETIEN SUPERIEUR A BARTONIEN SUPERIEUR).
  4. Cuvier, G. (1804). Sur les espèces d’animaux dont proviennent les os fossiles répandus dans la pierre à plâtre des environs de Paris. Ann. Mus. Nat. Hist. Nat. (1804), pp. 275-303 (Pl. 23-29)
  5. Cuvier, G. (1822) – Recherche sur les ossements fossiles où l’on rétablit les caractères de plusieurs animaux dont les révolutions du globe ont détruit les espèces. Nouvelle édition.. Tome second, 1er partie.
  6. Noulet, J.B. (1851) – Sur une nouvelle espèce de Pachyderme fossile du genre Lophiodon (Lophiodon lautricensis). Mémoires de l’Académie des Sciences Inscription et Belles Lettre de Toulouse, 4 ser., t. I, p. 245-250.
  7. Noulet, J.-B. (1863) – Etude sur les fossiles du terrain éocène supérieur de l’Agout (Tarn). Mémoires de l’Académie des Sciences Inscription et Belles Lettre de Toulouse, 6e sér., t. I, p. 181-206.
  8. Noulet, J.B. (1870) – Du Chéropotame de Lautrec, espèce nouvelle des grès à Palaeotherium du bassin de l’Agout (Tarn). Mémoires de l’Académie des Sciences Inscription et Belles Lettre de Toulouse, 7e sér., t.. II, p. 331-335.
  9. Ortega . F. . Buscaloni, A.D . Gasaparini, Z. . 1996 . Reinterpretation and new denomination of Atacisaurus crassiproratus (Middle Eocene; Issel, France) as cf. Iberosuchus (Crocodylomorpha, Metasuchia) . Geobios . 29 . 3 . 353–364 . 10.1016/S0016-6995(96)80037-4.
  10. M. Richard. (1946). Contribution a l'étude du basin d'Aquitaine, Les Gisements de Mammiferes Tertiares. Memoires de la Societe Geologique de France, Nouvelle Serie 24(52):1-380
  11. Gervais P. (1867-69) – Zoologie et Paléontologie générales. Nouvelles recherches sur les Vertébrés vivants et fossiles. Paris, Arthus Bertrand, Editeur. 50 pl.
  12. Caraven-Cascin, A., (1898) – Description géographique, géologique, minéralogique, paléontologique, paléthnologique et agronomique des départements du Tarn et Tarn et Garonne. Privat, Toulouse & Masson, Paris, 1898, 684 p.
  13. Stehlin, H.G. (1910) – Die Säugetiere des schweitzerischen Eocaens. 6ème part. Mémoire de la Société Paléontologique suisse, t. XXXVI, p. 838-1164-258
  14. ESCARGUEL G. (1999) – Les rongeurs de l’Eocène inférieur et moyen d’Europe occidentale. Systématique, Phylogénie, biochronologie et paléobiogéographie des niveaux repères MP 7 à MP 14. Paleovertebrata, 28, n° 2-4, p. 89-351.
  15. Cavaillé, A., Debat, P., Calas, G. (1975). Castelnaudary, notice explicative. Carte géologique de la France à 1/50 000. 1036, Orléans: BRGM, 17 pp.
  16. Adnet, S., Crochet, J-Y., Baillet, L. (2014). Gisement à vertébrés lutétiens d'Issel. Inventaire du patrimoine géologique du Languedoc-Roussilon, LRO-1104, DREAL Languedoc-Roussillon, 4 pp.
  17. Depéret, C. (1921). Sur Un Petit Lophiodontidae (Lophiaspis Occitanicus Mutation Cesserasicus) Des Grès éocènes de Laure (Aude). Bulletin de La Société d'Etudes Scientifiques de l'Aude 27: 44–54.
  18. Capera, J-C., Baillet, L. (2014). Carrière de grès éocènes de Carcassonne. Inventaire du patrimoine géologique du Languedoc-Roussilon, LRO-1052, DREAL Languedoc-Roussillon, 4 pp.
  19. Jouve . Stéphane . 2016-04-17 . A new basal tomistomine (Crocodylia, Crocodyloidea) from Issel (Middle Eocene; France): palaeobiogeography of basal tomistomines and palaeogeographic consequences . Zoological Journal of the Linnean Society . 177 . 1 . 165–182 . 10.1111/zoj.12357 . 0024-4082. free .
  20. Jouve . Stéphane . 2016-04-17 . A new basal tomistomine (Crocodylia, Crocodyloidea) from Issel (Middle Eocene; France): palaeobiogeography of basal tomistomines and palaeogeographic consequences . Zoological Journal of the Linnean Society . 177 . 1 . 165–182 . 10.1111/zoj.12357 . 0024-4082. free .
  21. Astre . G. . 1931 . Les crocodiliens fossiles des terrains tertiaires sous pyrénéens . Bulletin de la Société d'Histoire naturelle de Toulouse . 61 . 25–71.
  22. Martin . J. E. . Pochat-Cottilloux . Y. . Laurent . Y. . Perrier . V. . Robert . E. . Antoine . P.-O. . 2023 . Anatomy and phylogeny of an exceptionally large sebecid (Crocodylomorpha) from the middle Eocene of southern France . Journal of Vertebrate Paleontology . e2193828 . 10.1080/02724634.2023.2193828 . 258361595.
  23. F. Lapparent de Broin. (2003). Neochelys sp. (Chelonii, Erymnochelyinae), from Silveirinha, early Eocene, Portugal. Ciencias da Terra (UNL) 15:117-132
  24. F. Broin. (1977). Contribution a l'etude des Cheloniens. Cheloniens continentaux due Cretace et du Tertiare de France. Memoires du Museum National d'Histoire Naturelle, Nouvelle Serie, Serie C, Sciences de la terre 38:1-366.