“…The stratigraphic record for this region is well-constrained due to conodont and fusulinid biostratigraphic studies (e.g., Ross, 1963;Ross, 1995;, which allows for accurate correlations with the U.S. Midcontinent (e.g., . An erosional unconformity marks the boundary between Pennsylvanian and Permian strata in the Permian Basin (Candelaria et al, 1992;Fitchen et al, 1995;Mazzullo, 1995;Hill, 1996;Harrell and Lambert, 2007; Figure 2). In places, the boundary is expressed as an angular unconformity, which has been attributed to tectonic activity related to the final phase of thrusting within the Marathon orogenic belt (Ross, 1986;Hill, 1996).…”