A NEW INTERPRETATION OF THE NORTHERN TALLADEGA BELT INTERNAL STRUCTURE: A MEGASCOPIC OVERTURNED ISOCLINAL ANTICLINE

The Talladega Belt (TB) in Alabama represents the eastern-most Laurentian continental margin terrane within the region and is composed of predominately metaclastic and metacarbonate units capped by metavolcanics. The lowermost stratigraphy within the TB is the Kahatchee Mountain Group (KMG) that represents early Paleozoic drift facies deposited during opening of Iapetus. The Talladega Group (TG) overlies the KMG along the regional Pre-Lay Dam Unconformity (PLDU), and represents a successor basin sequence related to mid-Paleozoic back-arc extension. Recent mapping funded by the USGS EDMAP program has discovered units of the KMG and repetition of TG units in the Oak Level and Borden Springs AL 7.5' quadrangles near the Alabama-Georgia state boundary. The megascopic structure controlling the distribution of these units consists of an overturned, northwest verging, closed to isoclinal anticline cored by the Waxahatchee formation, the basal unit in the KMG. Southeast of the axial trace of the anticline the overlying Brewer and Wash Creek formations are exposed and overlain unconformably by units of the TG. Northwest of the axial trace units of the KMG and TG are overturned based on bedding/cleavage relations, and primary features. The overturned limb of the megascopic anticline composes the immediate hanging wall of the Talladega thrust in this portion of the Talladega Belt, and is truncated by the fault along strike to the northeast and southwest, however, a similar structure, the Salem Church anticline, occupies an equivalent structural position north of Cartersville GA.