Type Geological formation Country Chile Underlies Pliocene | Other Conglomerate Named for Cuesta Santo Domingo | |
Thickness Up to 110 m in surface and more than 1500 m below surface Named by R. Martínez-Pardo and Mario Pino Regions Los Ríos Region, Los Lagos Region Primary Sandstone, Siltstone, Mudstone Overlies Bahía Mansa Metamorphic Complex, Cheuquemó Formation, Estratos de Pupunahue | ||
Santo Domingo Formation (Spanish: Formación Santo Domingo) is a mainly marine Miocene sedimentary formation located in south–central Chile. 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. Sediments of the formation accumulated in Valdivia and Osorno–Llanquihue Basin.
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. The sedimentary facies of Santo Domingo Formation are composed of sandstone, siltstone and mudstone plus smaller amounts of conglomerate. The formation underlies Pliocene and Quaternary sediments.
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.
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. The most common formaineral species of Santo Domingo Formation are Hansenisca altiformis, Rectuvigerina transversa and Sphaeroidina bulloides.