Alcântara Formation
| Alcântara Formation | |
|---|---|
| Stratigraphic range: Cenomanian | |
| Type | Geological formation | 
| Unit of | Itapecuru Group | 
| Underlies | Cujupe Formation | 
| Overlies | Undifferentiated unit | 
| Thickness | 30–35 m (98–115 ft) | 
| Lithology | |
| Primary | Sandstone | 
| Other | Claystone, conglomerate | 
| Location | |
| Coordinates | 2°30′S 44°30′W / 2.5°S 44.5°W | 
| Approximate paleocoordinates | 9°24′S 19°18′W / 9.4°S 19.3°W | 
| Region | Maranhão | 
| Country | Brazil | 
| Extent | São Luís-Grajaú Basin | 
| Type section | |
| Named for | Alcântara (city) | 
| Named by | Rossetti & Truckenbrodt | 
| Year defined | 1997 | 
The Alcântara Formation is a geological formation in northeastern Brazil whose strata date back to the Cenomanian of the Late Cretaceous.