Kirusillas Formation

The Kirusillas Formation is a Homerian geologic formation of central Bolivia. The formation comprises black shales, overlies the Llallagua Formation and is overlain by the Pampa and Guayabillas Formations. The Kirusillas Formation is laterally equivalent to the Lipeón Formation.^[1][2][3] The formation is a potential source rock for shale oil and shale gas.^[4]

Kirusillas Formation
Stratigraphic range: Homerian ~426–423 Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓
Type	Geological formation
Underlies	Pampa & Guayabillas Formations
Overlies	Llallagua Formation
Lithology
Primary	Black shale
Location
Coordinates	17.8°S 64.8°W / -17.8; -64.8
Approximate paleocoordinates	52.8°S 121.7°W / -52.8; -121.7
Region	Cochabamba & Potosí Departments
Country	Bolivia
Extent	Cordillera Central & Oriental
Type section
Named for	Kirusillas
Kirusillas Formation (Bolivia)

Fossil content

The formation has provided the following fossils:

• Ornatosinuitina reyesi
• Slimonia boliviana^[5]
• Styliolina sp.
• Lingulata indet.

See also

• List of fossiliferous stratigraphic units in Bolivia
  • Lipeón Formation