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.

[2][3] 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.

[1][3] Small nests with eggs inside, found in this formation, probably belonged to the bird Neuquenornis.