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

Geologic units in Cleburne county, Alabama

[Additional scientific data in this geographic area]

Ketchepedrakee Amphibolite (Precambrian to Paleozoic) at surface, covers 7 % of this area

Ketchepedrakee Amphibolite - dark-green to black fine to coarse-grained, layered to massive amphibolite mixed with zones of chlorite actinolite schist, includes all amphibolite associated with the Poe Bridge Mountain Group.

Lithology: amphibolite; schist

Poe Bridge Mountain Group; Garnet quartzite (garnetite) and garnitiferous altered mafic rock (Precambrian to Paleozoic) at surface, covers 0.2 % of this area

Poe Bridge Mountain Group; Garnet quartzite (garnetite) and garnitiferous altered mafic rock. Rocks in the area of Turkey Heaven Mountain in Cleburne and Randolph Counties that are here assigned to the Poe Bridge Mountain Group also have been interpreted as part of the Wedowee Group.

Lithology: quartzite; mafic metavolcanic rock

Frog Mountain (Devonian) at surface, covers < 0.1 % of this area

Frog Mountain

Lithology: sandstone

Talladega Group; No name on map (Silurian?-Devonian) at surface, covers 5 % of this area

No name on map - fossiliferous chert facies in vicinity of Jemison, Chilton County, contains marine invertabrate fossils of early to Middle Devonian age.

Lithology: chert

Hillabee Greenstone (Paleozoic) at surface, covers 1 % of this area

Hillabee Greenstone - pale-green to light-olive-brown massive, fine-grained greenstone interbedded locally with well-foliated mafic phyllite.

Lithology: greenstone; phyllite

Shady Dolomite (Cambrian) at surface, covers 2 % of this area

Shady Dolomite - bluish-gray or pale-yellowish-gray thick-bedded siliceous dolomite; characterized by coarsely crystalline porous chert.

Lithology: dolostone (dolomite); chert

Knox Group undifferentiated (Ordovician-Cambrian) at surface, covers 0.2 % of this area

Knox Group undifferentiated - Light-gray to light-brown locally sandy dolomite, dolomitic limestone, and limestone; characterized by abundant light-colored chert.

Lithology: dolostone (dolomite); limestone; chert

Phyllite and Quartzite (Precambrian-Paleozoic) at surface, covers < 0.1 % of this area

Phyllite and Quartzite

Lithology: phyllite; quartzite

Heflin Phyllite (Cambrian?) at surface, covers 22 % of this area

Heflin Phyllite - grayish-green, medium-gray, and medium-bluish-gray calcareous sandy metasiltstone interbedded with minor greenish-gray fine to coarse-grained metasandstone and rare thin lenses of calcite and dolomite marble; an interval of greenish-gray to dark-gray phyllitic quartzite or quartz-pebble metaconglomerate is locally present near the base. The Heflin underlies the Lay Dam Formation and overlies the rocks tentatively identified as the Chilhowee Group undifferentiated.

Lithology: metasedimentary rock; quartzite; marble

Talladega Group; Lay Dam Formation (Silurian?-Devonian) at surface, covers 37 % of this area

Lay Dam Formation (Talladega Group) - interbedded dark-green phyllite, medium-gray to light-brown and black metasiltstone, dark-green feldspathic metagraywacke, and light-gray and dark-gray medium to coarse-grained arkosic quartzite and metaconglomerate; graphitic phyllite common in upper part. In Cleburne and Calhoun Counties, rocks mapped as the Lay Dam include the Abel Gap Formation of Bearce (1973) and consist of interbedded greenish-gray metasiltstone and quartzite, black phyllitic metasiltstone, medium-gray to greenish-gray arkosic quartzite, and dark-gray pyritic quartzite. In Clay Chounty the upper part of the Lay Dam includes black graphitic sericite phyllite and slate reportedly containing plant fossils (Erin Slate Member).

Lithology: phyllite; metasedimentary rock; quartzite; slate; meta-conglomerate

Talladega Group; Cheaha Quartzite Member of Lay Dam Formation (Silurian?-Devonian) at surface, covers 0.3 % of this area

Cheaha Quartzite Member of Lay Dam Formation - white to light-gray medium to coarse-grained arkosic quartzite and metaconglomerate.

Lithology: quartzite; meta-conglomerate

Knox Group undifferentiated (Ordovician-Cambrian) at surface, covers < 0.1 % of this area

Knox Group undifferentiated

Lithology: dolostone (dolomite); limestone

Nichols Formation (Cambrian) at surface, covers 0.5 % of this area

Nichols Formation - massive to laminated greenish-gray and black micaceous mudstone containing minor interbeds of siltstone and very fine-grained sandstone.

Lithology: mudstone; siltstone; sandstone

Phyllite undifferentiated (Precambrian-Paleozoic) at surface, covers < 0.1 % of this area

Phyllite undifferentiated

Lithology: phyllite

Chilhowee Group undifferentiated (Cambrian) at surface, covers 4 % of this area

Chilhowee Group undifferentiated - light to medium-gray arkose, arkosic conglomerate, and discontinous mudstone overlain by greenish-gray mudstone with minor siltstone and sandstone; dominantly light-gray pebbly quartzose sandstone in upper part.

Lithology: conglomerate; mudstone; siltstone; sandstone

Beaverdam Amphibolite (Precambrian to Paleozoic) at surface, covers < 0.1 % of this area

Beaverdam Amphibolite - dark-green to dark-gray hornblende amphibolite, extensively sheared and folded, and locally retrograded to actinolite-tremolite-chlorite schist. Includes all amphibolite associated with the Wedowee Group.

Lithology: amphibolite; schist

Weisner and Wilson Ridge Formations undifferentiated (Cambrian) at surface, covers 5 % of this area

Weisner and Wilson Ridge Formations undifferentiated -- interbedded quartzose to slightly feldspathic sandstone and laterally continous conglomerate in ledge-forming units separated by greenish-gray silty mudstone.

Lithology: sandstone; conglomerate; mudstone

Chickamauga Group; Middle Ordovician rocks; Rockmart Slate (Middle Ordovician) at surface, covers < 0.1 % of this area

Chickamauga Group; Middle Ordovician rocks; Rockmart Slate

Lithology: slate

Wedowee Group; Wedowee Group undifferentiated (Precambrian to Paleozoic) at surface, covers 8 % of this area

Wedowee Group undifferentiated - Wedowee Group undifferentiated includes the Cragford Phyllite and Cutnose Gneiss. Cragford Phyllite -- interbedded fine-grained graphite-chlorite-sericite schist and phyllite, garnet-sericite schist and phyllite, graphite-quartz-sericite phyllite, locally feldspathic biotite gneiss, calc-silicate rock, and quartzite. Cutnose Gneiss -- cyclically interbedded fine-grained quartz-biotite feldspathic gneiss, graphite-chlorite-sericite schist, locally thin interbeds of graphite-quartz-sericite phyllite, and quartzite. Rocks in the area northeast of Clanton in Chilton and Coosa Counties that are here assigned to the Wedowee Group also have been interpreted as part of the Higgins Ferry Group.

Lithology: schist; phyllite; felsic gneiss; quartzite; calc-silicate rock

Poe Bridge Mountain Group (Precambrian to Paleozoic) at surface, covers 6 % of this area

Poe Bridge Mountain Group - coarse to fine-grained feldspathic graphite schist, +/- staurolite +/- kyanite +/- sillimanite-muscovite-biotite schist, and garnet-biotite-muscovite schist, and gneiss; locally common pegmatites. Rocks in the area of Turkey Heaven Mountain in Cleburne and Randolph Counties that are here assigned to the Poe Bridge Mountain Group also have been interpreted as part of the Wedowee Group.

Lithology: mica schist; gneiss; pegmatite

Conasauga Formation (Cambrian) at surface, covers < 0.1 % of this area

Conasauga Formation - Medium-bluish-gray fine-grained, thin-bedded argillaceous limestone and interbedded dark-gray shale in varying proportions.

Lithology: limestone; shale

Newala Limestone (Ordovician) at surface, covers < 0.1 % of this area

Newala Limestone

Lithology: limestone

Mad Indian Group (Precambrian to Paleozoic) at surface, covers 0.2 % of this area

Mad Indian Group - fine-grained feldspathic biotite gneiss; medium to coarse-grained muscovite-biotite-garnet schist; locally kyanite and sillimanite. Many of the schists have been retrograded to chlorite-garnet-quartz-sericite schist. Both mi and migr extensively cut by feldspathic dikes and pegmatites.

Lithology: felsic gneiss; schist; pegmatite

Poe Bridge Mountain Group; Roscoelite-graphite quartz schist and graphitic quartzite (Precambrian to Paleozoic) at surface, covers 3 % of this area

Poe Bridge Mountain Group; Roscoelite-graphite quartz schist and graphitic quartzite. Rocks in the area of Turkey Heaven Mountain in Cleburne and Randolph Counties that are here assigned to the Poe Bridge Mountain Group also have been interpreted as part of the Wedowee Group.

Lithology: schist; quartzite

Cochran Formation (Cambrian) at surface, covers < 0.1 % of this area

Cochran Formation - poorly sorted arkosic sandstone and conglomerate containing interbedded greenish-gray siltstone and mudstone. The Cochran Formation is exposed only in northeastern Calhoun and northwestern Cleburne Counties.

Lithology: arkose; conglomerate; siltstone; mudstone

Rome Formation (Cambrian) at surface, covers < 0.1 % of this area

Rome Formation - variegated thinly interbedded mudstone, shale, siltstone, and sandstone; limestone and dolomite occur locally. Quartzose sandstone commonly present near top of formation.

Lithology: mudstone; shale; siltstone; sandstone; limestone; dolostone (dolomite)