CORRELATIONS OF PALEOZOIC SEQUENCES IN THE SOUTHERN APPALACHIAN BLUE RIDGE: INSIGHTS INTO TECTONIC EVOLUTION

Comparison of key stratigraphic sequences from different structural/geographic positions in the southern Appalachian western Blue Ridge/Talladega belt offers important insights into tectonic development, palinspathic reconstructions, and timing of orogenic activity. For example, three separate belts of the cosmopolitan, early drift facies, L. Cambrian clastic sequence are thought to occur here: A) along the west flank of the Blue Ridge (Chilhowee Gp,) and Talladega belt (Kahatchee Mtn. Gp.), and somewhat more outboard equivalents of these groups to the southeast occurring: B) (lower Whilhite Fm.) stratigraphically above Ocoee Supergroup rift-facies units on the overturned west limb of the Copper Hill (Ducktown) anticline, and C) on both flanks of the Murphy syncline (Nantahala/Brasstown Fms.) to the southeast. The L. Cambrian-L. Ordovician trailing margin carbonate bank facies is well preserved within part of the Talladega belt (Sylacauga Marble Gp.) above Chilhowee Gp. rocks, but only a thin discontinuous basal part of this sequence is believed to occur on the flanks of the Murphy syncline (Murphy Marble), and this entire sequence is apparently missing along the west limb of the Copper Hill anticline in the Foothills. Post-drift facies sequences are also known to occur in three different structural/geographic positions: A) upper (SE) part of the Talladega belt (Talladega Gp.), B) core of the Murphy syncline (Mineral Bluff Gp.), and C) fossiliferous parts of the Walden Creek Gp. in the Foothills belt. Fossil discoveries document that the Talladega Gp. and part of the Walden Creek Gp. (Upper? Wilhite Fm.) are middle Paleozoic in age, and that the Mineral Bluff Gp. is post-Cambrian, but the degree of correlation among these three geographically (palinspastically) separated groups is in debate and awaits further study. Importantly, possibly correlative low-angle regional unconformities are believed to exist at the base of the Talladega and Mineral Bluff Gps., and it is highly likely that a similar, but previously unrecognized unconformity exists within the Walden Creek Gp. between the Cambrian and middle Paleozoic sequences there.