Santo Domingo Formation

Santo Domingo Formation Stratigraphic range: Miocene
Type	Geological formation
Underlies	Pliocene and Quaternary sediments including Caleta Godoy Formation
Overlies	Bahía Mansa Metamorphic Complex, Cretaceous granitoids, Cheuquemó Formation, Estratos de Pupunahue
Thickness	Up to 110 m in surface and more than 1500 m below surface
Lithology
Primary	Sandstone, siltstone, mudstone
Other	Conglomerate
Location
Region	Los Ríos Region Los Lagos Region
Country	Chile
Type section
Named for	Cuesta Santo Domingo
Named by	R. Martínez-Pardo and Mario Pino

Santo Domingo Formation (Spanish: Formación Santo Domingo) is a mainly marine Miocene sedimentary formation located in south–central Chile. The formation was defined by R. Martínez-Pardo and Mario Pino in 1979 and named after the roadcut locality they studied about 19 km south-east of Valdivia. Sediments of the formation accumulated in Valdivia and Osorno–Llanquihue Basin.

The formations overlies the basement of metamorphic and igneous rocks, that is Bahía Mansa Metamorphic Complex and Cretaceous granitoids respectively. In parts it further overlies the coal–bearing Pupunahue–Catamutún Formation. The sedimentary facies of Santo Domingo Formation are composed of sandstone, siltstone and mudstone plus smaller amounts of conglomerate. The formation underlies Pliocene and Quaternary sediments.

Some of the trace fossils that can be found in Santo Domingo formation are Zoophycos isp., Chondrites isp., Phycoshiphon isp., Ophiomorpha isp. Thalassinoides isp., Asterosoma isp. and Terebellina isp.