Knox Group undifferentiated
Chickamauga Group; Middle Ordovician rocks; Rockmart Slate
Phyllite and Quartzite
Fort Payne Chert (Mfp) with Lavender Shale Member (Mls)
Includes limestone unit (Ccls), possible equivalent of Rutledge Limestone of Tennessee and shale unit (Cc), possible equivalent of Rogersville Shale of Tennessee
Includes limestone and shale unit (Ccsl). Possible equivalent of the Maryville Limestone and Nolichucky Shale of Tennessee with a dolostone member (Ccd).
Includes the Hartselle Sandstone Member (Mh) in Floyd County and an unnamed limestone member (Ml in Floyd County) at the base
Chickamauga Group; Middle Ordovician rocks; Lenoir Limestone
Includes shale and sandstone unit (Ccs) with lower dolostone unit (Ccdl). Possible equivalent of Pumpkin Valley Shale of Tennessee
Light to dark-gray finely to coarsely crystalline, medium to thick-bedded dolomite containing minor greenish-gray shale and light-bluish-gray chert. In the Columbiana area of Shelby County, the Conasauga is dominated by thin to medium-bedded, dark-gray dolomitic limestone and minor dark-gray shale. In Bibb County and southwestern Shelby County, the Conasauga consists of medium-bluish-gray fine-grained, thin-bedded argillaceous limestone and interbedded dark-gray shale. In the eastern Valley and Ridge the lower part includes dark-green to pale-olive fossiliferous shale with a few dark-gray limestone interbeds.
Light-gray to light-brown locally sandy dolomite, dolomitic limestone, and limestone; characterized by abundant light-colored chert.