The Lower Mississippian (Kinderhookian-Osagean) St. Joe and succeeding Boone Formations are well exposed in northwestern Arkansas, southern Missouri, and northeastern Oklahoma, forming the Springfield Plateau of the southern Ozark region. This interval represents a single, third order, transgressive-regressive eustatic cycle deposited broadly across the North American craton. The initial transgression during the Kinderhookian covered the regional erosional surface developed on either the Devonian-Lower Mississippian Chattanooga Shale, or older units with crinoidal packstones deposited as platform successions or transported as down-ramp slurries. The Boone Formation is divided informally into lower and upper divisions that reflect differences in eustatic sea level. The lower Boone (early Osagean) is composed primarily of calcisiltites with interbedded dark, nodular, penecontemporaneous chert deposited below effective wave base during the maximum flooding interval of the third-order eustatic cycle. The upper Boone (late Osagean-early Meramecian?) represents the third-order highstand, and regressive sequences comprising crinoidal grainstones and packstones, mostly deposited within effective wave base. In contrast to the lower Boone, the upper Boone carbonates are interbedded with white to light gray, later diagenetic chert, the product of groundwater replacement. The formally named Short Creek Oolite Member of the upper Boone Formation is only sporadically developed, probably transported as down-ramp slurries across the region during regression. Across the Springfield Plateau, the Boone Formation is separated by a type I sequence unconformably from succeeding strata of Meramecian or younger age.

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