The Talladega Slate Belt By Steven Stokes, Daniel Rollins, Matthew Sahawneh, Krystal Russell, and Ashley Stewart.

The Talladega Slate Belt

By Steven Stokes, Daniel Rollins, Matthew Sahawneh, Krystal Russell,

and Ashley Stewart

• Cheaha State Park • Located in northern Clay and southwestern

Cleburne counties• May 20-25

Where We’re Going

Location:North-Eastern

AlabamaNear the town of

Sylacauga, Alabama

Talladega Slate Belt

• Composed primarily of low-grade metamorphic rocks

• Bounded to the Northwest by a foreland fold and thrust fault system known as the Talladega fault or the Columbiana fault

• To the southeast is marked by high grade metamorphism caused by both the Hollins Line fault and the Goodwater-Enitachopco fault system.

Talladega Slate Belt

• Alleghanian thrust sheet• Metamorphosed to lower green schist facies

during the Acadian orogeny and thrust above the foreland fold and thrust belt.

• Believed to be associated with main pulse of Early to Middle Devonian Acadian orogeny.

Sequences

• Composed of 4 lithologic groups – Hillabee Greenstone– Sylacauga Marble– Talladega– Kahatchee Mountain

Hillabee Greenstone

• 2.6 kilometers thick • Ordovician Age 457m.y.• Greenstones and Greenschists – What is a greenstone?– Bulk of sequence

• Albite, Actinolite, Epidote, Zoisite, Clinozoisite, and Chlorite

• Tabular and extrusive

Sylacauga Marble

• Jumbo Dolomite at base• Dolomite and Calcite marbles • Nature of Dolomite • Nature and use of marble

Sylacauga Marble

• Below Lay Dam Formation of Talladega Group– Unconformity between the two– Diamictites – What is diamictite?

• Lack of fossils make age correlation difficult • Cambrian to Ordovician

Talladega Group

• Clastic • Divided into several

formations– Lay Dam Formation– Cheaha Quartzite Member – Erin Slate Member – Butting Ram Sandstone – Jemison Chert

Lay Dam Formation

• Overlies Sylacauga • Oldest • Silurian to Lower Devonian. • Greenish-gray, slightly calcareous sericite

phyllites and slates• Sandstone bodies small, grade into phyllites• Rapid deposition.

Cheaha Quartzite Member

• Metasandstone in Lay Dam Formation • Sandy phyllites and coarse grained quartzites • Fines upward • Devonian • Primary Structures– Horizontally bedded, graded intervals– Low angle pebbles structures– Channel fill deposits– Tabular and trough bedding

Erin Slate Member

• Also member of Lay Dam Formation • Thick highly carbonaceous phyllites or slate• Less mature than Cheaha Quartzite member • Lagoon depositional environment

Butting Ram Sandstone

• Thin green chloritic, arkosic metasandstone • Subrounded to rounded quartz sand • Feldspathic• Tidal channel deposits • Very discontinuous • Points of elevated crests

Jemison Chert Interval

• Above Butting Ram Sandstone • Interbedded white, paper thin quartzites • Intercalated with black graphitic phyllites of Erin

Slate • White to pale light gray, very dense, very fined

quartzite• Complexly folded• Intense deformation• Lower Devonian

Kahatchee Mountain Group

• Named Mountain Group because it can be found in the mountains northwest of Syllacuaga.

• Width is highly variable.• Carboniferous in age. (Spores found that

indicate carboniferous in metamorphic frontblock of sequence)

Formations within the Kahatchee Mountain Group

• Waxahatchee Slate• Brewer Phyllite• Wash Creek Slate• Sawyer Limestone• *Chilton Fault

Deformational Phase 1 – D1

• F1 folds are invariably tight to isoclinal• Interlimb angle is 20 to 0 degrees• They are assymetric with stort limbs are 20%

shorter than long limbs• It has S1 foliations

Deformational Phase 2 and 3

• F2 folds can be only seen in thin section• F3 folds are small folds 1mm to 1cm• F3 they distort both the compositional layers• F3 crenulation fold axial plane with S1-S2

surface

Deformational Phase 4 – D4

• F4 folds can be seen on regional map• F4 folds cut through the F1 folds• F4 axial plane strikes northwest to

southeast• A major faulting event

Questions?