Tufs et calcaires de Rosan

The Tufs et calcaires de Rosan is a geologic formation in France. It preserves fossils dating back to the Katian to Hirnantian (Kralodvorian to Kosovian in the regional stratigraphy) stages of the Late Ordovician period.

Tufs et calcaires de Rosan
Stratigraphic range: Katian-Hirnantian (Kralodvorian-Kosovian) ~
Geologic map of the Armorican Massif
Type	Formation
Lithology
Primary	Tuff, limestone
Other	Pillow lava, claystone, sandstone
Location
Coordinates	48.3°N 4.2°W / 48.3; -4.2
Approximate paleocoordinates	70.3°S 53.9°E / -70.3; 53.9
Region	Finistère
Country	France
Extent	Armorican Massif
Type section
Named for	Rosan
Tufs et calcaires de Rosan (France) Tufs et calcaires de Rosan (Brittany)

Fossil content

The formation has provided fossils of:

Strophomenata

• Hedstroemina sp.
• Iberomena sp.
• Leptaena sp.
• Leptestiina sp.

Rhynchonellata

• Porambonites sp.
• Eoanastrophia sp.
• Rostricellula sp.
• ?Dalmanella sp.
• Bancroftina sp.
• Nicolella sp.
• Retrorsirostra sp.
• Ptychopleurella sp.
• Dolerorthis sp.
• Mcewanella sp.
• Aberia sp.
• ?Rhactorthis sp.

See also

• List of fossiliferous stratigraphic units in France

References

Bibliography

• M. Melou. 1990. Brachiopodes articules de la coupe de l'ile de Rosan (Crozon, Finistere); formation des tufs et calcaires de Rosan (Caradoc-Ashgill). Géobios 23(5):539-579