Group5_2012 - University of South Alabama

The Talladega Slate Belt
By Steven Stokes, Daniel Rollins,
Matthew Sahawneh, Krystal Russell,
and Ashley Stewart
Where We’re Going
• Cheaha State Park
• Located in northern Clay and southwestern
Cleburne counties
• May 20-25
Near the
town of
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.
• 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
– Lay Dam Formation
– Cheaha Quartzite Member
– Erin Slate Member
– Butting Ram Sandstone
– Jemison Chert
Lay Dam Formation
Overlies Sylacauga
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
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
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
• White to pale light gray, very dense, very fined
• Complexly folded
• Intense deformation
• Lower Devonian
Kahatchee Mountain Group
• Named Mountain Group because it can be
found in the mountains northwest of
• 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
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
• A major faulting event

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