Pottsville Formation (lower part) (ALPApv21;4)

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
Original map label	Ppv21
Comments	Note: Printed map uses unit symbol 'Ppv2l'; digital map uses 'Ppv21(one)'; used Ppv21(one) here.
Primary rock type	sandstone
Secondary rock type	shale
Other rock types	siltstone; coal
Lithologic constituents	Major Sedimentary > Clastic > Sandstone (Bed) Incidental Sedimentary > Coal (Bed)
Map references	Szabo, M. W., Osborne, E. W., Copeland, C. W. Jr., Neathery; T. L., 1988, Geologic Map of Alabama, Geological Survey of Alabama Special Map 220, scale 1:250,000. [http://www.ogb.state.al.us/ogb/ogb_gisdata/algeomap.zip]
Unit references	Szabo, M. W., Osborne, E. W., Copeland, C. W. Jr., Neathery; T. L., 1988, Geologic Map of Alabama, Geological Survey of Alabama Special Map 220, scale 1:250,000. [http://www.ogb.state.al.us/ogb/ogb_gisdata/algeomap.zip]
Geographic coverage	Bibb - Calhoun - Jefferson - Saint Clair - Shelby