Jama Formation
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| Jama Formation | |
|---|---|
| Stratigraphic range: Pliocene-Early Pleistocene (Montehermosan-Ensenadan) ~ | |
| Type | Geological formation |
| Lithology | |
| Primary | Claystone, sandstone |
| Location | |
| Coordinates | 0°12′S 80°18′W / 0.2°S 80.3°W |
| Approximate paleocoordinates | 0°18′S 79°54′W / 0.3°S 79.9°W |
| Region | Manabí Province |
| Country | Ecuador |
| Type section | |
| Named for | Jama |
  Jama Formation (Ecuador) | |
The Jama Formation is a Pliocene to Early Pleistocene (Montehermosan to Ensenadan in the SALMA classification) geological formation in Ecuador. The claystones and sandstones were deposited in a coastal environment. The age of the Jama Formation is constrained by 40Ar/39Ar dating of tephra beds.[1] The formation is correlated to the Charco Azul Formation of western Panama and southeastern Costa Rica.[2]
The formation is subdivided in, from top to base:
- El Matal Member (60 metres (200 ft), fluvial)
- Punta Ballena Member (lower shoreface)
- Punta Pasa Borracho Member (20 metres (66 ft), marine)
