Bajo de la Carpa Formation
The Bajo de la Carpa Formation is a geologic formation of the Neuquén Basin that crops out in northern Patagonia, in the provinces of Río Negro and Neuquén, Argentina. It is the oldest of two formations belonging to the Río Colorado Subgroup within the Neuquén Group. Formerly, that subgroup was treated as a formation, and the Bajo de la Carpa Formation was known as the Bajo de la Carpa Member.
| Bajo de la Carpa Formation | |
|---|---|
| Stratigraphic range: Mid-Late Santonian ~ | |
| Type | Geological formation |
| Unit of | Neuquén Group Río Colorado Subgroup |
| Underlies | Anacleto Formation |
| Overlies | Río Neuquén Subgroup Plottier Formation |
| Thickness | Up to 150 m (490 ft) |
| Lithology | |
| Primary | Sandstone |
| Other | Mudstone, siltstone, paleosol |
| Location | |
| Coordinates | 38.8°S 68.8°W |
| Approximate paleocoordinates | 43.4°S 49.8°W |
| Region | Neuquén & Río Negro Provinces |
| Country | Argentina |
| Extent | Neuquén Basin |
Bajo de la Carpa Formation (Argentina) | |
At its base, this formation conformably overlies the Plottier Formation of the older Río Neuquén Subgroup, and it is in turn overlain by the Anacleto Formation, the youngest and uppermost formation of the Neuquén Group.
The Bajo de la Carpa Formation can reach 150 metres (490 ft) in thickness in some locations, and consists mainly of sandstones of various colors, all of fluvial origin, with thin layers of mudstone and siltstone in between. Geological features such as geodes, chemical nodules, impressions of raindrops, and paleosols (fossil soils) are commonly found in this formation as well.