| Sierra Barrosa Formation | |
|---|---|
| Stratigraphic range: Mid-late Coniacian ~ | |
| Type | Geological formation |
| Unit of | Neuquén Group Río Neuquén Subgroup |
| Underlies | Plottier Formation |
| Overlies | Los Bastos Formation |
| Thickness | Up to 62 m (203 ft) |
| Lithology | |
| Primary | Mudstone |
| Other | Sandstone |
| Location | |
| Coordinates | 38°52′10″S 68°51′20″W / 38.86944°S 68.85556°W |
| Approximate paleocoordinates | 42°48′S 48°24′W / 42.8°S 48.4°W |
| Region | Mendoza & Neuquén Provinces |
| Country |  Argentina |
| Extent | Neuquén Basin |
| Type section | |
| Named for | Sierra Barrosa |
| Named by | 2010 |
| Year defined | Garrido |
  Sierra Barrosa Formation (Argentina) | |
The Sierra Barrosa Formation is a geologic formation of the Neuquén Basin in the northern Patagonian provinces of Mendoza and Neuquén. The formation dates to the Late Cretaceous, middle to late Coniacian, and belongs to the Río Neuquén Subgroup of the Neuquén Group. The formation overlies the Los Bastos Formation and is overlain by the Plottier Formation. As the underlying Los Bastos Formation, the Sierra Barrosa Formation comprises mudstones and sandstones deposited in a fluvial environment.