Formation
body of rock identified by lithic characteristics and stratigraphic position; it is usually but not necessarily tabular and is mappable at the Earth's surface or traceable in the subsurface. Smaller than a subgroup
Great Scar Limestone
Great Scar Limestone Group
Brandon Bridge Formation
Amole Arkose
Brawley Formation
Brazer Dolomite
Brazil Formation
Crescent Formation
Mill Formation
Greta Grit
Crockett Formation
Brian Head Formation
Crooked Creek Formation
Cross Lake Dolomite
Bridwell Formation
Briggs Formation
Briones Sandstone
Angola Formation
Crystal River Limestone
Mont Formation
Anguilla Formation
Cub Mountain Formation
Cumberland Formation
Anse Maranda Formation
Antelope Shale
Antelope Valley Limestone
Bronson Group
Monteils Formation
Antler Peak Formation
Haida Formation
Cutties Hillock Sandstone
Brownstone Marl
Hambleton Oolite
Han Formation
Cuyahoga Formation
Bryant Knob Formation
Mural Formation
Aran Volcanic Group
Arcadia Park Shale
Archer City Formation
Myrtle Group
Arcturus Formation
Hartz Fjeld Formation
Nanaimo Group
Buffalo Canyon Formation
Narwhal Sound Formation
Haslam Formation
Bull Fork Formation
Bullion Creek Formation
Haverford Mudstone