Argiles d'lignite du Soissonnais


The Argiles d'lignite du Soissonnais is a geologic formation in the Oise department of northern France. The formation has provided fossil mammals, reptiles and fish as well as arthropods in the amber of the formation. The Argiles d'lignite du Soissonnais dates back to the Ypresian stage of the Eocene period.

Description

The formation comprises a succession of lenticular bodies showing two main facies; clayey sands rich in frequently pyritised lignite, together with amber and grey clayey sands with less lignite, with continental vertebrate fauna. These facies, the rarity of mollusk shells and charophytes, probably due to decarbonatation and the presence of pyrrhotite, reflect a hypoxic environment.
The strata were deposited at the bottom of two channels cutting into underlying Thanetian marine green sands. The channels prograde toward the northeast and were discovered under Oise River Quaternary deposits.

Fossil content

The formation has provided among others the following fossils:

Mammals

;PrimatesTeilhardina aff. belgicaCantius sp.Platychoerops sp.
;ArtiodactylsDiacodexis sp.
;CimolestaEsthonyx sp.
;EutheriaPalaeosinopa sp.cf. Landenodon sp.
;FeraeDormaalocyon latouriGracilocyon soleiOxyaena woutersiPalaeonictis giganteaPalaeanodon sp.Vassacyon taxidiotis
;HyaenodontaArfia gingerichiPrototomus girardotiP. minimus
;Macroscelideacf. Macrocranion sp.
;Multituberculata
;PerissodactylsChowliia europeacf. Pachynolophus sp.
;PlacentaliaHyopsodus sp.
;RodentsPliolophus quesnoyensis
  • Ischyromyidae indet.
;SoricomorphaLeptacodon sp.Wyonycteris sp.
;TheriiformesPeratherium sp.

Reptiles

;TurtlesMerovemys ploegiPaleotrionyx cf. vittatus
;CrocodilesAllognathosuchus sp.Asiatosuchus sp.Diplocynodon sp.
;LizardsEolacerta sp.Placosaurus sp.Plesiolacerta sp.
;SnakesDunnophis matronensisSaniwa cf. orsmaelensis

Amphibians

Fish

Anomotodon novusIsurolamna inflataLepisosteus fimbriatusOtodus obliquusPachygaleus lefevreiPalaeogaleus vincentiPalaeohypotodus rutotiSqualus orpiensisStriatolamia striataCyclurus sp.Heterodontus sp.Myliobatis sp.Notorynchus sp.Squatina sp.

Arthropods

;DipteraEurodoliopteryx inexpectatus

Pancrustacea

Flora

Nitellopsis sp.