GONDWANAN AFFINITY OF THE WIGGINS UPLIFT? EVIDENCE FOR LATE- TO POST-ALLEGHANIAN TRUNCATION OF THE SOUTHERN APPALACHIANS

Recent studies suggest that the crust of southeastern North America, now buried beneath Mesozoic and Cenozoic Coastal Plain strata, is of Gondwanan affinity, and that the southern Appalachians were truncated in Late-Alleghanian (Permian) time by a supercontinent-scale transcurrent fault. Primary evidence for this conclusion derives from the subsurface presence of early- to mid-Paleozoic Suwannee basin strata, discovered in petroleum exploration wells in northern Florida, southern Georgia, and southeastern Alabama. The Wiggins uplift in the subsurface of southwestern Alabama and southern Mississippi is penetrated by a number of deep exploration wells, and is marked by metasedimentary rocks which appear to correlate with known lithologies of the Suwannee sequence. Confirmation of this correlation through examination and analysis of core, cuttings, and well log data, would serve to (1) prolong the known extent of Suwannee basin rocks (and Gondwana) by >150 km west of their currently known extent, (2) demonstrate juxtaposition of Gondwanan and Laurentian basement rocks across a very narrow structural boundary (Carolina-Mississippi fault) in the subsurface, and (3) provide the basis for future thermochronology studies to constrain the lastest age of movement on the inferred supercontinent transcurrent fault.