Cheuquemó Formation

Cheuquemó Formation Stratigraphic range: Upper Oligocene–Lower Miocene
Underlies	Santo Domingo Formation
Overlies	Bahía Mansa Metamorphic Complex
Thickness	more than 1,200 m (3,900 ft)
Lithology
Primary	Conglomerate, sandstone, mudstone, tuff
Other	Coal
Location
Region	Los Lagos Region
Country	Chile
Type section
Named by	Floreal García, 1968

Cheuquemó Formation (Spanish: Formación Cheuquemó) is a geological formation of sedimentary rock in south-central Chile. The sediments of the formation were deposited during the Late Oligocene and Early Miocene epochs. The formations lower sections are made up of conglomerate, then successions of sandstone, tuff and mudstone rich in organic material follows. The formation indicates that sedimentation occurred in a estuarine (paralic) and other non-marine (continental) environments. It contains fossils of the following genera: Mytilus, Cardium and Turritella. Stratigraphically it overlies the Bahía Mansa Metamorphic Complex and underlies the Miocene Santo Domingo Formation.

The formation is very similar to the Pupunahue Beds found further north, with the sole difference that the fossil assemblage in both seem to indicate different ages. While Cheuquemó is possibly about 14 million years old (Miocene), the Pupunahue Beds are 35–25 million years old.

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