Santo Domingo Formation

This article is about the Miocene formation in southern Chile. For the Eocene formation in northwestern Argentina see Laguna Brava Formation.
Santo Domingo Formation
Stratigraphic range: Miocene
Type Geological formation
Underlies Pliocene and Quaternary sediments
Overlies Bahía Mansa Metamorphic Complex, Cretaceous granitoids, Estratos de Pupunahue
Thickness Up to 110 m in surface[1] and more than 1500 m below surface[2]
Lithology
Primary Sandstone, siltstone, mudstone
Other Conglomerate
Location
Region Los Ríos Region
Los Lagos Region
Country Chile
Type section
Named for Cuesta Santo Domingo
Named by R. Martínez-Pardo and Mario Pino

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 km south-east of Valdivia.[1][2] Sediments of the formation accumulated in Valdivia and Osorno–Llanquihue Basin.[3]

The formations overlies the basement of metamorphic and igneous rocks, that is Bahía Mansa Metamorphic Complex and Cretaceous granitoids respectively. In parts it further overlies the coal–bearing Pupunahue–Catamutún Formation.[1] The sedimentary facies of Santo Domingo Formation are composed of sandstone, siltstone and mudstone plus smaller amounts of conglomerate.[2] The formation underlies Pliocene and Quaternary sediments.[2]

Fossils

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

See also

References

  1. 1 2 3 4 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
  2. 1 2 3 4 Elgueta et al. p. 16
  3. 1 2 Elgueta et al. p. 10
  4. ↑ 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
  5. ↑ Finger p. 374
  6. ↑ Finger p. 367

Bibliography

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