Los Alamitos Formation
| Los Alamitos Formation | |
|---|---|
| Stratigraphic range: Late Campanian-Maastrichtian ~ | |
| Type | Geological formation |
| Sub-units | Coli Toro Member |
| Lithology | |
| Primary | Siltstone |
| Other | Sandstone |
| Location | |
| Coordinates | 42°06′S 66°18′W / 42.1°S 66.3°W |
| Approximate paleocoordinates | 45°00′S 52°18′W / 45.0°S 52.3°W |
| Region | Río Negro Province |
| Country | Argentina |
| Extent | North Patagonian Massif |
The Los Alamitos Formation is a geological formation of the North Patagonian Massif in Rio Negro Province, northwestern Patagonia, Argentina, whose strata date back to the Late Cretaceous (Late Campanian to Maastrichtian). Dinosaur remains are among the fossils that have been recovered from the formation.