Lourinhã Formation
The Lourinhã Formation (Portuguese pronunciation: [loɾiˈɲɐ̃] ⓘ) is a fossil rich geological formation in western Portugal, named for the municipality of Lourinhã. The formation is mostly Late Jurassic in age (Kimmeridgian/Tithonian), with the top of the formation extending into the earliest Cretaceous (Berriasian). It is notable for containing a fauna especially similar to that of the Morrison Formation in the United States and a lesser extent to the Tendaguru Formation in Tanzania. There are also similarities to the nearby Villar del Arzobispo Formation and Alcobaça Formation. The stratigraphy of the formation and the basin in general is complex and controversial, with the constituent member beds belonging to the formation varying between different authors.
| Lourinhã Formation | |
|---|---|
| Stratigraphic range: late Kimmeridgian-earliest Berriasian ~ | |
| Type | Geological formation |
| Sub-units |
|
| Underlies | Porto da Calada Formation |
| Overlies | Consolação & Alcobaça Formations |
| Thickness | 200–1,100 metres (660–3,610 ft) |
| Lithology | |
| Primary | Sandstone, mudstone, marl |
| Other | Conglomerate, limestone |
| Location | |
| Region | Lisbon Region |
| Country | Portugal |
| Extent | Lusitanian Basin |
| Type section | |
| Named for | Lourinhã |
| Named by | Hill |
| Year defined | 1988 |
Besides the fossil bones, Lourinhã Formation is well known for the fossil tracks and fossilized dinosaur eggs.
The Lourinhã Formation includes several lithostratigraphic units, such as Praia da Amoreira-Porto Novo Members, Praia Azul Member, the Santa Rita Member, and the Assenta Member.