Print this pageCorrelation of Upper Carboniferous and Lower Permian (Desmoinesian-Wolfcampian) 4th Order (Milankovitch band) Depositional Sequences from the Midcontinent to the Eastern Shelf of the Midland Basin: A New Approach to High Resolution Stratigraphy
BOARDMAN, DARWIN R
Upper Carboniferous and Lower Permian (Desmoinesian, Missourian, Virgilian, and Wolfcampian) strata from the Northern Shelf of the Anadarko Basin and Eastern Shelf of the Midland Basin as well as coeval strata throughout the world consist of numerous alternations of marine and non-marine strata that constitute fourth-order cyclothemic-scale depositional sequences. These fourth-order depositional sequences can be grouped into composite third-order depositional sequences based on the observed stacking patterns of the depositional sequences. Sea-level fluctuation curves derived from analysis of these depositional sequences and composite depositional sequences are presented from both of these geographically isolated basins in order to test whether the pattern of successive sea-level events can be utilized for high resolution interbasinal and interprovincial correlation. Multitaxial (conodonts, ammonoids, and fusulinaceans) biostratigraphic tie points are utilized in order to calibrate the sea-level curves developed, from each basin. The results presented herein demonstrate that the pattern of sea-level fluctuations in the two basins is virtually identical with 100 percent of the major and intermediate scale eustatic events being recognized in each basin. The same pattern is discernible regardless of whether the depositional sequences are carbonate-dominated or primarily siliciclastic influenced. The composite depositional sequences that constitute the third order depositional sequences are also present in each basin.
These results demonstrate that high resolution correlation of depositional sequences on an interbasinal and perhaps even interprovincial basis is plausible using biostratigraphically- calibrated patterns of successive sea-level eustatic events. This method has distinct advantages over traditional biostratigraphy due to provincialism as well as ecologic restriction of biostratigraphically useful taxa in many of the individual depositional sequences.