| Cancañiri Formation | |
|---|---|
| Stratigraphic range: Katian-Hirnantian ~460–439 Ma PreꞒ Ꞓ O S D C P T J K Pg N | |
| Type | Geological formation |
| Underlies | Uncía Formation |
| Overlies | Amutara & San Benito Formations |
| Thickness | Up to 1,500 m (4,900 ft) |
| Lithology | |
| Primary | Sandstone, shale |
| Other | Siltstone |
| Location | |
| Coordinates | 17°42′S 66°18′W / 17.7°S 66.3°W / -17.7; -66.3 |
| Approximate paleocoordinates | 44°12′S 127°24′W / 44.2°S 127.4°W / -44.2; -127.4 |
| Region | Cochabamba & Potosí Departments |
| Country |  Bolivia |
| Extent | Cordillera Oriental |
| Type section | |
| Named for | Cancañiri |
  Cancañiri Formation (Bolivia) | |
The Cancañiri Formation, also named as Cancañiri Tillite, is a Katian to Hirnantian geologic formation of central Bolivia. The pebbly, argillaceous sandstones, shales and siltstones of the up to 1,500 metres (4,900 ft) thick formation, were deposited in a glacial foreshore to deep water turbiditic environment. The formation is named after Cancañiri, a mining town close to Llallagua, where a local legend of a possessed woman is believed. The formation overlies the San Benito Formation in Cochabamba and the Amutara Formation in other parts. The Cancañiri Formation is overlain by the Uncía Formation.
Fossil content
The formation has provided the following fossils:
- Destombesium pacochicoensis
- Dinorthis flabellulum
- Drabovinella curiosa
- Tunariorthis cardocanalis
- Oanduporella sp.
- Rostricellula sp.
See also
References
- Díaz Martínez, 2005, p.237
- Díaz Martínez, 1997, p.55
- Along "Coboce" Road near Irpa Irpa Railway Station at Fossilworks.org
- Changolla, railway on the Cochabamba - Oruro Railway at Fossilworks.org
- Paco Chico, ~40 km west of Potosí at Fossilworks.org
- La Llorona de Cancañiri
- Díaz Martínez, 1997, p.56
Bibliography
- Díaz Martínez, E (2005), "Procedencia y edad de las diamictitas del Paleozoico inferior de la cuenca de Perú-Bolivia (Gondwana occidental) - Provenance and age of diamictites in the lower Palaeozoic of the Peru-Bolivia basin (western Gondwana)" (PDF), Geogaceta, 38: 235–238, retrieved 2019-03-03
- Díaz Martínez, E (1997), "Facies y ambientes sedimentarias de la Formación Cancañiri (Silúrico inferior) en La Cumbre de La Paz, norte de la Cordillera Oriental de Bolivia" (PDF), Geogaceta, 22: 55–57, retrieved 2019-03-03
Further reading
- V. Havlicek and L. Branisa. 1980. Ordovician brachiopods of Bolivia: Succession of assemblages, climate control, affinity to Anglo-French and Bohemian provinces. Rozpravy Ceskoslovenske Akademie Ved. Rada Matematickych a Prirodnich Ved. Academia Praha, Prague, Czechoslovakia 90(1):1-54
- Geologic formations of Bolivia
- Ordovician System of South America
- Silurian System of South America
- Ordovician Bolivia
- Silurian Bolivia
- Katian
- Hirnantian
- Sandstone formations
- Shale formations
- Siltstone formations
- Glacial deposits
- Deep marine deposits
- Turbidite deposits
- Ordovician southern paleotemperate deposits
- Silurian southern paleotemperate deposits
- Paleontology in Bolivia
- Geology of Cochabamba Department
- Geology of Potosí Department