ABSTRACT Four conodont biozones, including three subzones, are interpreted within a revised lithostratigraphic framework for the upper Boone Group and Mayes Group in northeastern Oklahoma and adjacent parts of Missouri, Kansas, and Arkansas. Although revised lithostratigraphy is principally based on observed lithologic characteristics and stratigraphic relationships, conodont biostratigraphic data played an important role in correlation and final organization of units. Within the upper Boone Group, Biozone 1 (lower Meramecian) includes the Ritchey Formation and the Tahlequah limestone and Biozone 2 (middle Meramecian) includes the Moccasin Bend Formation and Quapaw Limestone. The Mayes Group spans Biozone 3 and Biozone 4. Biozone 3 (upper Meramecian) is represented by the Bayou Manard Member of the Pryor Creek Formation (new name). Biozone 4 marks the appearance of definitive Chesterian conodont fauna. The lower two subzones within Biozone 4 correspond to the Lindsey Bridge (Biozone 4L) and Ordnance Plant (Biozone 4M) members of the Pryor Creek Formation, whereas the upper subzone consists of the Hindsville Formation (Biozone 4U). Documentation of conodont taxa and recognition of the proposed biozones provides relative time constraints for genetically meaningful interpretations of regional geology and subsequent evaluation of the Mayes Group and upper Boone Group within a broader interregional context.

Abstract The geomagnetic polarity pattern for the Carboniferous is incompletely known with the best-resolved parts in the Serpukhovian and Bashkirian. Hence, data from both igneous and sedimentary units are also used in an additional polarity bias evaluation. In the Tournaisian to mid Visean interval polarity is mainly derived from palaeopole-type palaeomagnetic studies, allowing identification of polarity bias chrons. Seven polarity bias chrons exist in the Mississippian (MI1n B to MI4n B ) with an additional 33 conventional magnetochrons and submagnetochrons (MI4r to MI9r). The Moscovian and Gzhelian polarity is best resolved in magnetostratigraphic studies from the Donets Basin and the southern Urals. Dispute about the reliability of these data is ill-founded, since an assessment of supporting data from palaeopole-type studies suggests that these datasets currently provide the best magnetic polarity data through the Pennsylvanian. Polarity bias assessment indicates a normal polarity bias zone in the Kasimovian. In the Pennsylvanian there are 27 conventional magnetochrons and submagnetochrons (PE1n to CI1r) and one normal polarity bias chron (PE8n B ). The Kiaman Superchron begins in the mid Bashkirian, with clear data indicating brief normal polarity submagnetochrons within the Superchron. The magnetochron timescale is calibrated using 31 U–Pb zircon dates and a quantitative Bayesian-based age-scaling procedure.