SEDIMENTOLOGY AND DEPOSITIONAL ENVIRONMENTS OF THE TRIASSIC WADESBORO BASIN, NORTH CAROLINA

Breakup of Pangea in Triassic and Jurassic times produced a series of rift basins along the eastern margin of North America extending from New Brunswick to Georgia. The Deep River Basin of North Carolina is the southernmost major rift basin with surface exposures. The southernmost portion of the Deep River Basin is known as the Wadesboro sub-basin. This study examines the sedimentology and depositional environments of strata exposed in a brick quarry in Anson County, NC. 86 meters of section have been sedimentologically logged, sampled, photographed, and petrographically analyzed, and 6 distinctive lithofacies have been identified. Those lithofacies include: 1) a gray, organic rich shale facies at the base of the exposure, 2) an interbedded red and grey mudstone and siltstone facies, 3) an interbedded mudstone, siltstone, and sandstone facies that contains ribbon bedding, vertebrate fossils, burrows, and current ripple cross lamination, 4) a burrowed massive mudstone facies, 5) a coarse grained channelized sandstone facies, 6) and a cyclic fining upward facies composed of 7 medium grained sandstones which grade into mudstone units. The architecture of those lithofacies indicates that they accumulated in a range of environments including: lacustrine (facies 1); deltaic (2, 3); floodplain (4, 6); and fluvial channel (5). The lacustrine deposits appear to be rich in organics indicating that they may be potential sources of natural gas. This study also extends the stratigraphy established at the brick quarry to the surrounding region.