Pottsville Formation (lower part)

Light-gray thick-bedded to massive pebbly quartzose sandstone, containing varying amounts of interbedded dark-gray shale, siltstone, and thin discontinuos coal. In both the Cahaba and Coosa synclinoria the members in descending order include: the Pine Sandstone Member and the Shades Sandstone Member. Top of unit is mapped at top of Pine Sandstone Member.
State Alabama
Name Pottsville Formation (lower part)
Geologic age Pennsylvanian
Lithologic constituents
Major
Sedimentary > Clastic > Siltstone (Bed)
Sedimentary > Clastic > Mudstone > Shale (Bed)
Sedimentary > Clastic > Sandstone (Bed)
Incidental
Sedimentary > Coal (Bed)
Comments Note: Printed map uses unit symbol 'Ppv2l'; digital map uses 'Ppv21(one)'.
References

Szabo, M.W., Osborne, E.W., Copeland, C.W. Jr., and Neathery, T.L., 1988, Geologic Map of Alabama, Geological Survey of Alabama Special Map 220, scale 1:250,000.

NGMDB product
Counties Bibb - Calhoun - Jefferson - Saint Clair - Shelby