The Niobrara formation is an upper cretaceous formation that runs throughout Wyoming and Colorado. The Niobrara contains many different layers of chalk, shale and marl.
The Niobrara Shale has similar characteristics to other unconventional basins, including a high total organic content, thermal maturity, boundary seals to trap the hydrocarbons and sufficient thickness in many areas to allow commercial development.
The official name that some use to describe this formation is the “Upper Cretaceous Niobrara Fractured Calcareous Shale Oil Play.”
The Niobrara Shale is also able to be stimulated with hydraulic fracturing or already has natural fractures.
The Niobrara formation is present in many different basins including the Park Basins in Colorado. The Niobrara Shale is 800 feet thick in the North Park Basin, and 500 feet thick in the South Park Basin.
Source: Park Basins Province