| 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 (360 ft) at surface[1] 1,500 m (4,900 ft) in subsurface[2] |
| Lithology | |
| Primary | Sandstone, siltstone, mudstone |
| Other | Conglomerate |
| Location | |
| Coordinates | 40°00′S 73°00′W / 40.0°S 73.0°W |
| Region | Los Ríos & Los Lagos Regions |
| Country |  Chile |
| Extent | Osorno–Llanquihue & Valdivia Basins |
| Type section | |
| Named for | Cuesta Santo Domingo |
| Named by | Martínez Pardo & Pino |
| Year defined | 1979 |
  Santo Domingo Formation (Chile) Location of type section in Chile | |
Santo Domingo Formation (Spanish: Formación Santo Domingo) is a mainly marine Miocene sedimentary formation located in south–central Chile.[1][3] The formation was defined by R. Martínez Pardo and Mario Pino in 1979 and named after the roadcut locality they studied about 19 kilometres (12 mi) southeast of Valdivia.[1][2] Sediments of the formation accumulated in Valdivia and Osorno–Llanquihue Basin.[3]
The formations overlie a basement consisting of metamorphic and igneous rocks, the Bahía Mansa Metamorphic Complex and Cretaceous granitoids, respectively. In parts, it further overlies the coal–bearing Pupunahue–Catamutún Formation.[1] The sedimentary facies of the Santo Domingo Formation are composed of sandstone, siltstone, and mudstone with smaller amounts of conglomerate.[2] The formation underlies Pliocene and Quaternary sediments.[2]