Santo Domingo Formation

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]

Fossil content

Some of the trace fossils that can be found in the Santo Domingo Formation are Zoophycos isp., Chondrites isp., Phycoshiphon isp., Ophiomorpha isp. Thalassinoides isp., Asterosoma isp., and Terebellina isp.^[4]

The benthic foraminifera found in the Santo Domingo Formation are broadly similar to those found in other Chilean sedimentary formations of the Neogene, like the Navidad Formation of Central Chile, Ranquil Formation of Arauco Province, and Lacui Formation of Chiloé Island. ^[5] The most common formaineral species of the Santo Domingo Formation are Hansenisca altiformis, Rectuvigerina transversa, and Sphaeroidina bulloides.^[6]

References

^ ^a ^b ^c ^d Encinas et al., 2008
^ ^a ^b ^c ^d Elgueta et al.., 2000, p.16
^ ^a ^b Elgueta et al.., 2000, p.10
^ Encinas et al., 2012
^ Finger, 2013, p.374
^ Finger, 2013, p.367

Bibliography

Elgueta, Sara; McDonough, Michael; Le Roux, Jacobus; Urqueta, Esteban & Duhart, Paul (2000), Estratigrafía y sedimentología de las cuencas Terciarias de la Región de Los Lagos (39-41°30'S) (in Spanish), Santiago, Chile: Servicio Nacional de Geología y Minería, ISSN 0020-3939
Encinas, Alfonso; Finger, Kenneth L.; Buatois, Luis A.; Peterson, Dawn E. (2012), "Major forearc subsidence and deep-marine Miocene sedimentation in the present Coastal Cordillera and Longitudinal Depression of south-central Chile (38°30'–41°45'S)", Geological Society of America Bulletin, 124 (7–8): 1262–1277, doi:10.1130/b30567.1, hdl:10533/135235
Encinas, Alfonso; Buatois, Luis A.; Finger, Kenneth L. (2008), "Paleoecological and paleoenvironmental implications of a high-density Chondrites association in slope deposits of the Neogene Santo Domingo Formation, Valdivia, south-central Chile", Ameghiniana, 45 (1): 225–231
Finger, Kenneth L. (2013), "Miocene foraminifera from the south-central coast of Chile", Micropaleontology, 59 (4–5): 341–492, Bibcode:2013MiPal..59..341F, doi:10.47894/mpal.59.4.01, retrieved 2019-02-21

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.