Parga Formation

Geological formation in Chile

Parga Formation (Chile)

Parga Formation (Spanish: Formación Parga) is a geological formation of sedimentary rock in south-central Chile. The sediments of the formation were deposited during the Late Oligocene and Middle Miocene epochs. The formation's lower sections are made up of conglomerate, sandstone and mudstone some of which is rich in organic material. Additionally there are thin beds of tuff and coal. The formation's composition indicates that sedimentation occurred in an estuarine (paralic) and marine environments. Stratigraphically it overlies the Bahía Mansa Metamorphic Complex and is similar in age and type to Lacui Formation to the south and Cheuquemó and Santo Domingo Formation to the north. It is overlain across an angular unconformity by Pliocene or Quaternary sediments. The formation is intruded by porphyritic trachyte of Oligocene to Miocene age (Ancud Volcanic Complex). The outcrops of the formation are restricted to a NW-SE strip near Caleta Parga north of the estuary of Maullín River.^[1]

References

^ Elgueta, Sara; Le Roux, Jacobus; Duhart, Paul; McDonough, Michael; Urqueta, Esteban. Estratigrafía y sedimentología de la cuencas terciarias de la Región de Los Lagos (39-41°30’S) (in Spanish). Santiago, Chile: Servicio Nacional de Geología y Minería. p. 16. ISSN 0020-3939.

Geology of Chile

Terranes

Sedimentary
formations
and groups

Cretaceous	Baños del Flaco Fm. Cerro Colorado Fm. Chacarilla Fm. Chañarcillo Gp. Coihaique Gp. Divisadero Gp. Dorotea Fm. Hornitos Fm. La Liga Fm. Ñirehuao Fm. Punta del Cobre Fm. Purilactis Gp. Quiriquina Fm. Viñita Fm. Way Gp. Zapata Fm.
Jurassic	Chacarilla Fm. Coihaique Gp. Ibáñez Fm. La Liga Fm. La Negra Fm. Nacientes del Biobío Fm. Nacientes del Teno Fm. Pan de Azúcar Fm. Tobífera Fm.
Triassic	Canto del Agua Fm. Choiyoi Gp. Panguipulli Fm. Santa Juana Fm. Tralcán Fm.