Presentation on theme: "The Talladega Slate Belt By Steven Stokes, Daniel Rollins, Matthew Sahawneh, Krystal Russell, and Ashley Stewart."— Presentation transcript:
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 Where We’re Going
Location: North- Eastern Alabama Near 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