The Marnes d’Auzas Formation (Auzas Marls Formation) is a geological Formation in southwestern France (departments of Ariège and Haute-Garonne) whose strata date back to the Late Maastrichtian.
[1] It is about 100 metres thick and consists primarily of marls with some interbeds of sandstones.
[1] It corresponds to sediments whose depositional environment evolved from the paralic domain (coastal lagoons, tidal marsh, tidal muddy channel) at the base of the formation, towards a more continental domain (alluvial plain, fluvial channels) in its upper part.
[1] The Marnes d’Auzas Formation was deposited in the west coast of the former Ibero-Armorican Island, which included much of France and Spain.
[2]