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Mineral Resources > Online Spatial Data > Geology > by state > Georgia Geology

Geologic units in Walker county, Georgia

[Additional scientific data in this geographic area]

Devonian-Missisippian undivided (Devonian-Mississippian) at surface, covers < 0.1 % of this area

Devonian-Missisippian undivided (DMu): Includes Fort Payne Chert, Chattanooga Shale in Dade Co.; Fort Payne Chert at top, Chattanooga Shale in middle and Armuchee Shale at bottom in all areas except Polk Co. and Dade Co.; Fort Payne Chert, and Armuchee Chert in Polk Co. CHATTANOOGA Shale (Dc)

Lithology: shale ; chert

Knox Group undifferentiated (Ordovician-Cambrian) at surface, covers 26 % of this area

Knox Group undifferentiated

Lithology: dolostone (dolomite); limestone

St. Louis Limestone and Warsaw Limestone (Mississippian) at surface, covers < 0.1 % of this area

St. Louis Limestone - Residuum of nodules and blocks of chert in sandy clay. (Originally grayish-brown, medium-bedded limestone.) Maximum preserved thickness about 50 feet. Warsaw Limestone - Residuum of porous chert blocks in sandy clay. (Originally gray, medium- to coarse-grained, thick- bedded limestone.) Thickness about 60 feet.

Lithology: clay or mud; chert

Chickamauga Group; Upper and Middle Ordovician rocks (Oum) includes Sequatchie Limestone, Murfreesboro Limestone, Ridley Limestone, Moccasin Limestone and Bays Formation. (Ordovician) at surface, covers 2 % of this area

Chickamauga Group; Upper and Middle Ordovician rocks (Oum) includes Sequatchie Limestone, Murfreesboro Limestone, Ridley Limestone, Moccasin Limestone and Bays Formation.

Lithology: limestone

Conasauga Group; Middle unit; Shale unit (Cambrian) at surface, covers 0.3 % of this area

Conasauga Group; Middle unit; Shale unit: Includes limestone unit (Ccls), possible equivalent of Rutledge Limestone of Tennessee and shale unit (Cc), possible equivalent of Rogersville Shale of Tennessee

Lithology: shale; limestone

Pennington Formation (Mississippian) at surface, covers < 0.1 % of this area

Pennington Formation - Highly variegated clay shale, distinctive; contains siltstone and locally gray, fine-grained sandstone. Thickness 400 to 700 feet.

Lithology: shale; siltstone; sandstone

Rockwood Formation (Silurian) at surface, covers < 0.1 % of this area

Rockwood Formation - Brown to maroon shale, thin gray siltstone and sandstone, and thin lenticular layers of oolitic and fossiliferous red hematite. Thickness 200 to 800 feet.

Lithology: shale; siltstone; sandstone

Monteagle Limestone (Mississippian) at surface, covers < 0.1 % of this area

Monteagle Limestone - Fragmental and oolitic limestone, light-gray; and fine-grained, brownish-gray limestone. Thickness 180 to 350 feet.

Lithology: limestone

Fort Payne Formation (Mississippian) at surface, covers < 0.1 % of this area

Fort Payne Formation - Bedded chert, calcareous and dolomitic, somewhat crinoidal; and minor shale. Thin green shale (Maury) at base. Average thickness about 200 feet.

Lithology: chert; shale

Pennsylvanian undifferentiated (Pennsylvanian) at surface, covers 16 % of this area

Pennsylvanian undifferentiated

Lithology: sandstone; shale; conglomerate

Red Mountain Formation (Silurian) at surface, covers 9 % of this area

Red Mountain Formation

Lithology: sandstone; shale

Fort Payne Chert (Mississippian) at surface, covers 5 % of this area

Fort Payne Chert (Mfp) with Lavender Shale Member (Mls)

Lithology: chert

Floyd Shale (Mississippian) at surface, covers 2 % of this area

Floyd Shale (Mfs): includes the Hartselle Sandstone Member (Mh) in Floyd County and an unnamed limestone member (Ml in Floyd County) at the base

Lithology: shale

Mississippian undifferentiated (Mississippian) at surface, covers 8 % of this area

Mississippian undifferentiated: Includes Pennington Shale, Bangor Limestone (except in Floyd County), Hartselle Sandstone, Golconda Formation, Gasper Limestone, Ste. Genevieve Limestone and St. Louis Limestone

Lithology: limestone; shale; sandstone

Conasauga Group; Maynardville Limestone (Cambrian) at surface, covers 0.4 % of this area

Conasauga Group; Maynardville Limestone

Lithology: limestone

Unnamed (upper part of Knox Group), including Newala Formation, Mascot Dolomite, Kingsport Formation, Longview Dolomite, and Chepultepec Dolomite (Ordovician) at surface, covers < 0.1 % of this area

(Onc) Unnamed (upper part of the Knox Group), including the (On) Newala Formation; (Oma) Mascot Dolomite - Light-gray, fine-grained, well-bedded cherty dolomite; mottled (red and green) dolomite characteristic; interbeds of bluish-gray limestone in upper part; chert-matrix quartz sandstone at base. Erosional unconformity at top. Thickness 350 to 800 feet; (Ok) Kingsport Formation - Gray, fine-grained, sparingly cherty dolomite with basal dense, gray limestone sequence. Thickness about 250 feet. and (Olc) Unnamed (middle part of the Knox Group), including (Olv) Longview Dolomite - Siliceous, gray, fine-grained, medium-bedded dolomite; interbeds of gray limestone in upper part. Thickness about 300 feet; (Oc) Chepultepec Dolomite - Light-gray, fine-grained, well-bedded dolomite, moderately cherty; fine-grained limestone locally in upper part; quartz sandstone beds at base. Average thickness about 800 feet.

Lithology: dolostone (dolomite); limestone; sandstone

Chickamauga Group; Upper and Middle Ordovician Rocks (Omb) includes Moccasin Limestone and Bays Formation (Ordovician) at surface, covers 3 % of this area

Chickamauga Group; Upper and Middle Ordovician Rocks (Omb) includes Moccasin Limestone and Bays Formation.

Lithology: limestone; sandstone

Newala Limestone (Ordovician) at surface, covers 7 % of this area

Newala Limestone

Lithology: limestone

Chickamauga Group, includes Upper part of Chickamauga Group (Reedsville Shale, and Unnamed limestone unit) and Middle and Lower part of Chickamauga Group (Moccasin Formation, Bays Formation, Ottosee Shale, Holston Formation, Lenoir Limestone, Athens Shale, and Sevier Shale) (Ordovician) at surface, covers < 0.1 % of this area

Chickamauga Group - In the northwest part of the Valley and Ridge a predominantly limestone sequence about 2,000 feet thick. Becomes progressively more clastic and thicker to the southeast, including Upper part of Chickamauga Group (Reedsville Shale- Greenish-gray calcareous shale. Thickness 0 to 400 feet, and Unnamed Limestone Unit - Medium-grained, fossiliferous, gray limestone, shaly in part. Thickness as much as 600 feet ) and.Middle and lower parts of Chickamauga Group (Omlc)

Lithology: limestone; shale; siltstone; sandstone

Lookout Sandstone; Sewanee Sandstone (Pennsylvanian) at surface, covers < 0.1 % of this area

Lookout Sandstone; Sewanee Sandstone

Lithology: conglomerate; sandstone

Chickamauga Group undivided (Ordovician) at surface, covers 12 % of this area

Chickamauga Group undivided

Lithology: limestone

Conasauga Group; Upper unit; limestone and shale unit (Cambrian) at surface, covers 0.8 % of this area

Conasauga Group; Upper unit; limestone and shale unit: Includes limestone and shale unit (Ccsl). Possible equivalent of the Maryville Limestone and Nolichucky Shale of Tennessee with a dolostone member (Ccd).

Lithology: shale; limestone

Crab Orchard Mountains Group (Pennsylvanian) at surface, covers < 0.1 % of this area

Crab Orchard Mountains Group - Only the lowest formation of the group, the Sewanee Conglomerate, is preserved in the area of this sheet. Sewanee is gray to brown, medium- to coarse-grained conglomeratic sandstone, with a thin zone of ferruginous quartz- and shale-pebble conglomerate at base. Maximum preserved thickness 35 feet.

Lithology: conglomerate; sandstone

Rome Formation (Cambrian) at surface, covers 8 % of this area

Rome Formation

Lithology: sandstone; shale

Gizzard Group including Warren Point Sandstone and Raccoon Mountain Formation (Pennsylvanian) at surface, covers < 0.1 % of this area

Gizzard Group - Sandstone, conglomeratic sandstone, siltstone, shale, and minor coal. Thickness 100 to 200 feet. Includes Warren Point Sandstone - Gray to brown sandstone and minor conglomeratic sandstone. Thickness 60 to 160 feet; Raccoon Mountain Formation - Siltstone, sandstone, shale, and minor coal. Thickness 0 to 65 feet.

Lithology: sandstone; shale; siltstone; coal