Tectonostratigraphic evolution of the Ouachita trough through the study of the deepwater Atoka sandstone and mudrock from central Ouachita, SE Oklahoma: Implication for Rheic Ocean closure
The tectonostratigraphic evolution of the Ouachita trough is studied through physical sedimentology and provenance of the deepwater Atoka sandstone and mudrocks from Boktukola syncline, SE Oklahoma. Physical sedimentology identifies seven deepwater lithofacies, which are categorized into five lithofacies assemblages of four depositional facies. Six retrogradational sequences are identified with each sequence formed by channel fill deposits grading upward to interchannel deposits with/without proximal lower fan channel deposits.
Derivation of sediments from a collisional uplift of the southern Laurentia continental margin and peri-Gondwana accretionary prism is identified from sandstone framework composition and mudrock geochemistry. Sandstone framework composition suggests the recycled orogeny as the dominant source of sediments, and mudrock trace-element geochemistry suggests a complex nature of the provenance including felsic, intermediate, and mafic rocks. Major influence from upper continental curst and continental arc is suggested by enrichment of LREE over HREE. Highly weathered nature of source rock is identified by high chemical index of alteration. Comparable Atokan mudrock geochemistry with Stanley shale suggests the lack of major change in provenance during the Carboniferous sedimentation in the trough.
AAPG Datapages/Search and Discovery Article #90221 © 2015 Mid-Continent Section, Tulsa, Oklahoma, October 4-6, 2015