San Benito Formation, Bolivia

San Benito Formation Stratigraphic range: Katian ~460–446 Ma PreЄ Є O S D C P T J K Pg N
Type	Geological formation
Unit of	Cochabamba Group
Underlies	Cancañiri Formation
Overlies	Anzaldo Formation
Thickness	500 m (1,600 ft)
Lithology
Primary	Sandstone, siltstone
Other	Shale
Location
Coordinates	[ ⚑ ] : 17°00′S 66°00′W / 17.0°S 66.0°W / -17.0; -66.0
Paleocoordinates	[ ⚑ ] 45°36′S 126°36′W / 45.6°S 126.6°W / -45.6; -126.6
Region	Cochabamba Department
Country	Bolivia
Extent	Cordillera Oriental
Type section
Named for	Cerro San Benito
San Benito Formation, Bolivia (Bolivia)

The San Benito Formation is a Katian geologic formation of central Bolivia. The formation belongs to the Cochabamba Group, overlies the Anzaldo Formation and is overlain by the Cancañiri Formation. The 500 metres (1,600 ft) thick formation comprises a succession of shallow water quartzitic sandstones with minor interbeds of dark grey micaceous siltstones. Shelly fossils have been found at few horizons and consist mainly of linguliformean brachiopods, bivalves, and a few homalonotid trilobite remains. Poorly preserved graptolites occur occasionally in the shaly beds.^[1]

Fossil content

The formation has provided the following fossils:

• Desmochitina minor
• Rafinesquina pseudoloricata
• Tunariorthis cardocanalis
• Villosacapsula setosapellicula
• Ancyrochitina cf. ancyrea
• Hirnantia cf. transgrediens
• Rhabdochitina cf. magna
• Bistramia sp.
• Ctenodonta sp.
• Lingula sp.

See also

• List of fossiliferous stratigraphic units in Bolivia

References

Further reading

• J. L. Benedetto. 2013. Upper Ordovician Brachiopods from the San Benito Formation, Cordillera del Tunari, Bolivia. Ameghiniana 50(4):418-428
• R. Suárez Soruco. 1976. El sistema ordovícico en Bolivia. Revista Tecnica YPF Bolivia 5(2):111-123

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