Rocks above this contact, everywhere, are Middle Ordovician in age. When this is generally recognized, Ohio will be back to the basics. Other research material will contend, along with evidence to follow, that the Preknox clastics are deltaic and have influenced the overlying Knox Group. The standard Cambrian nomenclature showing clear formation distinctions does not adequately describe the basins in central and western Ohio. Structured areas only lightly felt the influence of the delta, while in the basins, the clear distinctions of formation changes become blurred.
Correlations are more in line with color changes rather than changes in lithology.
In general, the entire Preknox clastics, found in the basins and influenced by rivers, are dominated by shales and coarse grained, mud supported sand. Shales without sand suggest natural levees while the mud supported medium to coarse grained sands suggest distributer flood plain sediments. Unlike the structured formations, saturated with water, the depositional environment of the basins provide excellent lateral as well as overlying closure to distributaries. Samples and logs show that distributaries do indeed exist and contain gas and oil. There is no doubt that the Ohio professional has problems with his perceptions of what he sees on structure and his ability or inability to understand the basinal depositional environment.