Date of Graduation


Document Type


Degree Name

Master of Science in Geology (MS)

Degree Level





Walter Manger

Committee Member

Adriana Potra

Second Committee Member

Thomas McGilvery


Arkansas, Boone, Lower Mississippian, St. Joe, Stratigraphy


The Lower Mississippian interval comprises a single, third-order, eustatic cycle subdivided lithostratigraphically into the St. Joe Limestone (Hopkins 1893) and overlying Boone Formation (Branner 1891, Simonds 1891) with type areas in northern Arkansas. Coeval, homotaxial limestones occur in adjacent southwestern Missouri and northeastern Oklahoma. Missouri formation names for the St. Joe interval are recognized in Arkansas as members (ascending order): Bachelor, Compton, Northview, Pierson. The Boone interval in Missouri is represented by the (ascending order): Reeds Spring, Elsey, Burlington-Keokuk undifferentiated, but utilization of those names in Arkansas is problematic. in northern Arkansas, the Boone Formation is subdivided into informal lower and upper members based on chert development: lower with black to gray, penecontemporaneous chert; upper with white to light gray, later diagenetic chert. In adjacent northeastern Oklahoma, the nomenclature is a mixture of the Arkansas and Missouri names, but chert development is not used lithostratigraphically. The St. Joe Limestone rests unconformably on the Chattanooga Shale (Upper Devonian-Lower Mississippian) or older units marking the initial transgression of the Kaskaskian II Cycle (Vail et al. 1977). Thin-bedded, St. Joe crinozoan packstones represent bioclastic sediment and carbonate mud transported from its origin on the Burlington Platform (now Missouri), and down the adjacent northern Arkansas ramp in a lobate manner. Distal limestones are condensed and replaced by shale beyond the ramp. A brief drop in sea level represented by the terrigenous Northview Member, was followed by continued transgression through Pierson deposition, reaching maximum flooding without a break in the lower Boone (=Reeds Spring) represented by calcisiltites and penecontemporaneous chert. Highstand and regression are recorded in the upper Boone as rapidly deposited crinoidal packstones and grainstones with later diagenetic chert replacement. Previous studies of the boundary between the St. Joe and Boone Intervals suggest that an angular unconformity is present. This study will conduct extensive research in the form of measured sections, petrographic analysis, insoluble residue analysis, and SEM/EDX analysis to determine the true nature of this contact.