La Portada Formation

La Portada Formation
Stratigraphic range: Miocene–Pliocene
View of La Portada, the namesake arch made of La Portada Formation rocks resting on darker rocks of Jurassic La Negra Formation
Type	Geological formation
Sub-units	Cerro Bandurrias & Cuesta del Burro Members
Underlies	Mejillones Formation
Overlies	Caleta Herradura Formation
Lithology
Primary	Sandstone
Location
Coordinates	23°24′S 70°30′W / 23.4°S 70.5°W / -23.4; -70.5
Approximate paleocoordinates	23°36′S 69°30′W / 23.6°S 69.5°W / -23.6; -69.5
Region	Antofagasta Region
Country	Chile
Type section
Named for	La Portada de Antofagasta
La Portada Formation (Chile)

La Portada Formation (Spanish: Formación La Portada) is a geologic formation of Miocene and Pliocene age located near the Coast Range of northern Chile. The coarse-grained sandstones of the formation contain penguin fossils.^[1][2]

• Cerro Ballena
• Coquimbo Formation
• Navidad Formation

• L. Ragaini, C. di Celma, and G. Cantalamessa. 2008. Warm-water mollusc assemblages from northern Chile (Mejillones Peninsula): new evidence for permanent El Nino-like conditions during Pliocene warmth?. Journal of the Geological Society 165:1075-1084