| Cancañiri Formation | |
| Type: | Geological formation |
| Period: | Hirnantian |
| Age: | Katian-Hirnantian ~ |
| Prilithology: | Sandstone, shale |
| Otherlithology: | Siltstone |
| Namedfor: | Cancañiri |
| Region: | Cochabamba & Potosí Departments |
| Coordinates: | -17.7°N -66.3°W |
| Paleocoordinates: | -44.2°N -127.4°W |
| Underlies: | Uncía Formation |
| Overlies: | Amutara & San Benito Formations |
| Thickness: | Up to 1500m (4,900feet) |
| Extent: | Cordillera Oriental |
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 1500m (4,900feet) thick formation,[1] were deposited in a glacial foreshore to deep water turbiditic environment.[2] [3] [4] [5] The formation is named after Cancañiri, a mining town close to Llallagua, where a local legend of a possessed woman is believed.[6] 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.[7]
The formation has provided the following fossils: