| La Amarga Formation | |
|---|---|
| Stratigraphic range: Barremian-Early Aptian ~ | |
| Type | Geological formation |
| Unit of | Rayoso Group |
| Sub-units | Puesto Antigual, Bañados de Caichigüe & Piedra Parada Members |
| Underlies | Lohan Cura Formation |
| Overlies | Agrio Formation |
| Thickness | 160 m (520 ft) |
| Lithology | |
| Primary | Sandstone |
| Other | Mudstone |
| Location | |
| Coordinates | 39°36′S 70°12′W / 39.6°S 70.2°W |
| Approximate paleocoordinates | 39°36′S 35°12′W / 39.6°S 35.2°W |
| Region | Río Negro, Mendoza & Neuquén Provinces |
| Country | Argentina |
| Extent | Neuquén Basin |
| Type section | |
| Named for | La Amarga Arroyo |
| Named by | Musacchio |
| Year defined | 1970 |
  La Amarga Formation (Argentina) | |
The La Amarga Formation is a geologic formation with outcrops in the Argentine provinces of Río Negro, Neuquén, and Mendoza. It is the oldest Cretaceous terrestrial formation in the Neuquén Basin.
The type locality is La Amarga Arroyo and China Muerta Hill.[1] The La Amarga Formation unconformably overlies the marine Agrio Formation of the Mendoza Group. It is in turn overlain by the Lohan Cura Formation, separated by another unconformity.
- ^ Musacchio, 1970