Photos • Location
| Angostura Formation | |
|---|---|
|
Stratigraphic range:
Late Miocene ( Mayoan- Montehermosan) ~ | |
| Type | Geological formation |
| Unit of | Santiago Group |
| Underlies | Onzole Formation |
| Overlies | Viche Formation |
| Thickness | 150 m (490 ft) |
| Lithology | |
| Primary | Sandstone |
| Other | Conglomerate |
| Location | |
| Coordinates | 1°00′N 79°36′W / 1.0°N 79.6°W |
| Approximate paleocoordinates | 0°36′N 78°00′W / 0.6°N 78.0°W |
| Region | Esmeraldas Province |
| Country | 
Ecuador |
| Extent | Borbón Basin |
  Angostura Formation, Ecuador (Ecuador) | |
The Angostura Formation is a Late Miocene ( Mayoan to Montehermosan in the SALMA classification) geologic formation of the Borbón Basin in northwestern Ecuador. [1]
The coarse sandstones and beds of conglomerates, about 150 metres (490 ft) in thickness. The formation is resistant to erosion and is largely barren, but at a few places there are lenses or interbeds filled with finely preserved fossils. The formation overlies the Viche Formation, and is overlain by the lower Onzole Formation. The Angostura Formation is time-equivalent with the fossiliferous Gatún Formation of Panama. [1]
The formation has provided bivalve and gastropod fossils. [1]
- ^ a b c Angostura Formation at Fossilworks.org
- Beu, A.G (2010), "Neogene Tonnoidean Gastropods of Tropical and South America; contributions to the Dominican Republic and Panama Paleontology Projects and Uplift of the Central American Isthmus", Bulletins of American Paleontology, 377–378: 1–550, retrieved 2019-02-09
- P. Jung. 1989. Revision of the Strombina-group (Gastropoda; Columbellidae), fossil and living. Schweierische Paläontologische Abhandlungen 111:1-298
- A. A. Olsson. 1964. Neogene Mollusks From Northwestern Ecuador
- E. H. Vokes and H. E. Vokes. 2000. Catalogue of Tulane University fossil localities.