Narrower Terms (21)

• Aux Vases Formation
• Bakken Formation
• Banff Formation (Alta. and B.C.)
• Blue River Group (Ind.)
• Buffalo Wallow Group (Ind.)
• Chattanooga Shale
• Cypress Formation
• Hartselle Sandstone
• Heath Formation (Mont. and N.D.)
• Jackfork Formation (Ark. and Okla.)
• Madison Group
• Pennington Formation
• Peratrovich Formation (Alaska)
• Price Formation (Va. and W. Va.)
• Pride Mountain Formation (Ala. and Miss.)
• Stephensport Group
• Three Forks Formation
• Ullin Limestone (Ill. and Ind.)
• Wahoo Limestone (Alaska)
• Windsor Group (N.B. and N.S.)
• Woodford Shale (Okla. and Texas)