| Anacleto Formation | |
|---|---|
| Stratigraphic range: early-middle Campanian ~ | |
 Outcrop of the formation at Auca Mahuida | |
| Type | Geological formation |
| Unit of | Neuquén Group Río Colorado Subgroup |
| Underlies | Malargüe Group Allen Formation |
| Overlies | Bajo de la Carpa Formation |
| Thickness | 60–90 m (200–300 ft) |
| Lithology | |
| Primary | Mudstone |
| Other | Sandstone, limestone |
| Location | |
| Location | Patagonia |
| Coordinates | 37°54′S 68°30′W / 37.9°S 68.5°W |
| Approximate paleocoordinates | 40°48′S 53°00′W / 40.8°S 53.0°W |
| Region | Neuquén, Mendoza & Río Negro Provinces |
| Country |  Argentina |
| Extent | Neuquén Basin |
| Type section | |
| Named for | Aguada de Anacleto |
  Anacleto Formation (Argentina) | |
The Anacleto Formation is a geologic formation with outcrops in the Argentine Patagonian provinces of Mendoza, Río Negro, and Neuquén. It is the youngest formation within the Neuquén Group and belongs to the Río Colorado Subgroup. Formerly that subgroup was treated as a formation, and the Anacleto Formation was known as the Anacleto Member.[1]
The type locality of this formation lies 40 kilometres (25 mi) west of the city of Neuquén. At its base, the Anacleto Formation conformably overlies the Bajo de la Carpa Formation, also of the Río Colorado Subgroup, and it is in turn unconformably overlain by the Allen Formation of the younger Malargüe Group.[2]
The Anacleto Formation varies between 60 and 90 metres (200 and 300 ft) thick, and consists mainly of claystones and mudstones, purple and dark red in color, deposited in fluvial, lacustrine and floodplain environments. Geodes are often found scattered throughout this formation.[3]