Three transects were conducted across the main channel of the abandoned Teays River valley in Pike, Jackson, and Scioto Counties, Ohio, to evaluate the lithology and general stratigraphy of valley-fill deposits. Field observations obtained from both deep borings and surface excavations indicate that much of the Pleistocene lacustrine fill has been removed and that the modern landscape reflects primarily a sequence of erosional and secondary fill surfaces. Thus, the current valley fill includes lacustrine clays and channel sands, as well as younger sediments of varied origin. A general sequence of three sedimentary stratigraphic units was commonly encountered in the transects. A silty surface unit overlay an intermediate deposit, which in turn, rested on channel sands or on highly laminated lacustrine materials that were equated with the Minford Clay Member of the Teays Formation. The silty surface unit occurred at almost all sites to a depth of 50 to 60 cm. The mineralogy was mixed, and clay-free particle-size profiles indicated the material was loessial in origin. The intermediate deposit was also encountered in most borings and could be classified as colluvial, alluvial or lacustrine depending on the location. The lithology of this deposit was highly variable and frequently reflected the properties of local bedrock units. Minford Clay was distinguished from younger lacustrine sediments of the intermediate unit on the basis of higher clay content, more micaceous mineralogy, and an elemental Zr content that was two to four times less. Discriminant statistical analyses of data from a total of 180 samples indicated that the Minford Clay could also be easily distinguished from all other Quaternary sediments in the Teays Valley on the basis of selected chemical attributes. By using the same parameters, however, lacustrine deposits in overlying stratigraphic units could not be clearly separated from associated colluvium, alluvium, and loess.

Abstract The Silurian rocks of the Cincinnati Arch in Ohio, Kentucky, and Indiana have been studied for nearly two centuries. Compilation of data from these studies, combined with detailed analysis of nearly 20 continuous drill cores and remeasuring and resampling of more than 60 major outcrops, is the basis for a high-resolution sequence stratigraphic framework. Seven depositional sequences are assigned on the basis of through-going unconformities, which mirror those already recognized in the early Llandovery to early Ludlow of the northern Appalachian Basin. Revision of the conodont biostratigraphy for the Cincinnati Arch has produced results that both agree and disagree with the other lines of data implemented in the sequence stratigraphic depositional model. Biostratigraphic correlations between southern Ohio and the Niagara Falls area are largely in agreement with correlations based on other lines of data, as are correlations between west-central and western Ohio, southeastern Indiana, and northern Kentucky. However, correlations between southern and west-central Ohio show major areas of disagreement. Preliminary whole rock carbonate carbon isotope analyses in western-central Ohio show patterns roughly comparable to those documented in the Niagara region, Gotland, and elsewhere. Chemostratigraphic data that might resolve inconsistencies in the correlations between southern and west-central Ohio were not yet available at the time of publication.

Studies of the physical stratigraphy and analyses of the Middle Pennsylvanian flora and fauna of some coal beds and marine units of the Breathitt Formation in Kentucky, the Pottsville and Allegheny Formations in Ohio, and the Kanawha Formation and Charleston Sandstone in West Virginia show a need for the revision of stratigraphic nomenclature of the Pottsville Formation and the lower part of the Allegheny Formation and equivalent strata. Attempts to project single stratigraphic elements from one region to another have resulted historically in multiple miscorrelations. A major marine unit (previously misidentifled as the Vanport limestone of the Breathitt and Allegheny Formations) is here named the Obryan Member of the Breathitt Formation in northeastern Kentucky and of the Allegheny Formation in southern Ohio. The Obryan is characterized by the fusulinid Beedeina ashlandensis Douglass and is correlated with the Columbiana Member of the Allegheny Formation in central Ohio, which also contains that fusulinid. This correlation and the correlation of the Boggs Limestone Member of the Pottsville Formation in Ohio with the Stoney Fork Member of the Breathitt Formation in Kentucky are supported by analyses of Middle Pennsylvanian conodonts. A preliminary zonation of conodonts for strata of the Pottsville and Allegheny Formations shows that the major marine units of these formations in Ohio are biostratigraphically distinct. The Obryan Member is locally absent, but its position is marked by overlying clay beds in many parts of Kentucky, Ohio, and West Virginia. The Vanport Limestone Member of the Allegheny Formation (as identified in Pennsylvania and central Ohio) is here correlated with the Zaleski Flint Member (Allegheny Formation) in southern Ohio. The Kilgore Flint Member (new name, Breathitt Formation), the informal Limekiln limestone and informal Flint Ridge flint (Breathitt Formation) in Kentucky, and the informal Kanawha black flint (Kanawha Formation) in West Virginia are correlated with the Putnam Hill Limestone Member (Allegheny Formation) in Ohio. These latter chert deposits are shoreward (southward and southeastward) facies of a marine unit deposited mostly in restricted estuaries and bays. The chert deposits appear to result from a widespread episode of silicification of fossiliferous marine siltstones and limestones that locally affected underlying peats and silts. The Kilgore and Obryan Members and their equivalents are used as the two principal stratigraphic marker beds for analyses of Middle Pennsylvanian sections extending across northeastern Kentucky from central Ohio to central West Virginia. Clay units and coal beds that overlie the Obryan Member contain flint clay beds (tonsteins) that are, in part, the product of volcanic ash falls. The range zones of selected palynomorphs from northeastern Kentucky and southeastern Ohio corroborate some of the correlations proposed herein.

Abstract The top surface of the Trenton Limestone and equivalent carbonate units has be variously described as a subaerial exposure surface (paleokarst), a submarine erosion surface, and a submarine hardground. Detailed study of the contact between the carbonates and overlying shale in outcrop and core and regional stratigraphic analysis indicate that the surface represents a drowning unconformity on the Galena and Lexington carbonate platforms in Ohio and Indiana. This unconformity also appears within the Sebree Trough in Indiana between the platforms, but it is within the overlying shale section rather than at its base. The unconformity has not been recognized in the Point Pleasant Basin in central and southern Ohio. Paleokarst may locally exist on this surface in southern Ontario.