Alsea Formation

The Alsea Formation is a geologic formation in Oregon. It preserves fossils dating back to the Rupelian stage of the Oligocene period.^[1]

Alsea Formation
Stratigraphic range: Rupelian (Whitneyan) ~33.7–30.6 Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓
Type	Formation
Underlies	Yaquina Formation
Lithology
Primary	Siltstone
Other	Mudstone
Location
Coordinates	44.6°N 124.0°W / 44.6; -124.0
Approximate paleocoordinates	44.3°N 113.1°W / 44.3; -113.1
Region	Lincoln County, Oregon
Country	United States
Alsea Formation (the United States) Show map of the United States Alsea Formation (Oregon) Show map of Oregon

Fossil content

The following fossils have been reported from the formation:^[1]

Mammals

• Aetiocetus cotylalveus^[2]
• Maiabalaena nesbittae^[3]
• Simocetus rayi^[4]

Fish

• Orthechinorhinus davidae^[5]

See also

• List of fossiliferous stratigraphic units in Oregon
• Paleontology in Oregon