The Talladega Slate Belt

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

2. Where We’re Going • Cheaha State Park • Located in northern Clay and southwestern Cleburne counties • May 20-25

3. Location:North-EasternAlabamaNear the town of Sylacauga, Alabama

5. 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.

6. 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.

7. Sequences • Composed of 4 lithologic groups • Hillabee Greenstone • Sylacauga Marble • Talladega • Kahatchee Mountain

8. 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

9. Sylacauga Marble • Jumbo Dolomite at base • Dolomite and Calcite marbles • Nature of Dolomite • Nature and use of marble

10. 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

11. Talladega Group • Clastic • Divided into several formations • Lay Dam Formation • Cheaha Quartzite Member • Erin Slate Member • Butting Ram Sandstone • Jemison Chert

12. 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.

13. 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

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

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

16. 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

17. 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)

18. Formations within the Kahatchee Mountain Group • Waxahatchee Slate • Brewer Phyllite • Wash Creek Slate • Sawyer Limestone • *Chilton Fault

19. 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

20. 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

21. 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

22. Questions?