Tubul Formation
Stratigraphic range: Early Pleistocene
Type	Geological formation
Underlies	Quaternary sediments
Overlies	Ranquil Formation
Thickness	>100 m (330 ft)
Lithology
Primary	Clay-rich sandstone and silt
Location
Coordinates	37°48′S 73°18′W / 37.8°S 73.3°W / -37.8; -73.3
Approximate paleocoordinates	37°54′S 72°48′W / 37.9°S 72.8°W / -37.9; -72.8
Region	Bío Bío Region
Country	Chile
Type section
Named for	Caleta Tubul
Named by	Egidio Feruglio
Year defined	1949
Tubul Formation (Chile)

Tubul Formation (Spanish: Formación Tubul) is an Early Pleistocene (formerly described as Middle Pliocene in 1968 and Late Pliocene in 1976)^[1] sedimentary formation located in Arauco Province in south–central Chile. Its sediments were deposited in marine conditions. It overlies unconformably the folded sedimentary formations of Ranquil (Miocene–Pliocene), Quiriquina (Late Cretaceous) and the Lebu Group (Paleocene-Eocene).^[2]

Mollusc fossils found in the formation derives from soft-bed environments (contrary to rocky coasts). Evidence from the fossil mollusc fauna of the Tubul Formation seem to indicate that local water temperatures were lower in the Pliocene than today. Waters and mollusc faunas of Magallanes Region are modern-day equivalents of Tubul Formation.^[3]

The formation was first defined by Egidio Feruglio in 1949.^[3]

• Arauco Peninsula
• Arauco Basin
• Cerro Ballena

• S. N. Nielson and C. Valdovinos. 2008. Early Pleistocene mollusks of the Tubul Formation, south-central Chile. The Nautilus 122(4):201-216

v t e Geology of Chile
Terranes	Arequipa-Antofalla Chaitenia Chilenia Chiloé Cuyania Fitz Roy Madre de Dios Mejillonia Patagonia
Sedimentary formations and groups	Cenozoic Neogene Abanico Fm. Angostura Fm. Ayacara Fm. Bahía Inglesa Fm. Caldera Beds Caleta Godoy Fm. Caleta Herradura Fm. Campanario Fm. Chaicayán Gp. Cheuquemó Fm. Cholchol Fm. Chucal Fm. Cola de Zorro Fm. Coquimbo Fm. Cura-Mallín Gp. Farellones Fm. La Cascada Fm. Lacui Fm. La Montaña Fm. La Portada Fm. Lauca Fm. Malleco Fm. Mininco Fm. Navidad Fm. Oxaya Fm. Parga Fm. Puduhuapi Fm. Pupunahue Beds Quebrada Macusa Fm. Ranquil Fm. Río Frías Fm. San Pedro Beds Santo Domingo Fm. Temuco Fm. Traiguén Fm. Trapa-Trapa Fm. Tubul Fm. Vargas Fm. Paleogene Abanico Fm. Azapa Fm. Caleta Chonos Fm. Cheuquemó Fm. Cura-Mallín Gp. La Cascada Fm. Lebu Gp. Loreto Fm. Lupica Fm. Oxaya Fm. Parga Fm. Purilactis Gp. Pupunahue Beds Temuco Fm. Vargas Fm. Mesozoic 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. Paleozoic Llano de Chocolate Beds
Batholiths	Coastal central Chile Elqui-Limarí Futrono-Riñihue North Patagonian Panguipulli South Patagonian Vicuña Mackenna
Metamorphic complexes	Bahía Mansa Belén Chañaral Choapa Chonos Cordillera Darwin Eastern Andes Mejillones Puerto Edén Punta de Choros Quebrada del Carrizo Trafún Tierra del Fuego
Faults	Atacama Fault Biobío-Aluminé Fault Cachet Fault Domeyko Fault El Arrayán Fault Futrono Fault Gastre Fault Lanalhue Fault Liquiñe-Ofqui Fault Magallanes-Fagnano Fault Mocha-Villarrica Fault Pichilemu Fault Reigolil-Pirihueico Fault San Ramón Fault Valeriano Fault
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