Parga Formation

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.

Geological formation in Chile

Parga Formation
Stratigraphic range: Late Oligocene–Middle Miocene
Underlies	Pliocene and/or Quaternary sediments
Overlies	Bahía Mansa Metamorphic Complex
Thickness	750 m (2,460 ft)
Lithology
Primary	Conglomerate, sandstone, mudstone
Other	Tuff, coal
Location
Coordinates	41°30′S 73°42′W / 41.5°S 73.7°W / -41.5; -73.7
Region	Los Lagos Region
Country	Chile
Type section
Named for	Caleta Parga
Named by	Flores
Year defined	1976
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]

See also

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• Coal mining in Chile

References

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1. ^ 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.