ABSTRACT

Continuous core and geophysical data from the Serpent Mound disturbance indicate structural and stratigraphic anomalies, which may serve as hydrocarbon traps in the Cambrian-Lower Ordovician Sauk Sequence. The Sauk Sequence in the region of the Serpent Mound disturbance of southern Ohio (Adams, Highland, and Pike Counties) consists of clastic and carbonate rocks beneath the Knox unconformity and above the Precambrian. Reprocessed seismic reflection data show a highly faulted and structurally complex depression. New gravity data indicate a local negative anomaly, associated with the central uplift of the structure. The nearest significant hydrocarbon production is from the Cambrian Rose Run sandstone approximately 40 miles (65 kilometers) to the northeast in Pickaway County, Ohio. Minor hydrocarbon production and shows have been reported from the Cambrian Knox Dolomite and Conasauga, Eau Claire, and Rome Formations of southern Ohio and northern Kentucky. These intervals contain the least explored sequence of potential reservoirs in this region. The number of scattered shows reported from below the Knox unconformity in deep wells in Ohio and Kentucky shows promise in a largely untested region. We speculate that accumulations of hydrocarbons have occurred in both stratigraphic and structural traps. Recurrent movement on basement faults has resulted in stratigraphic variations in the Rose Run sandstone, Eau Claire and Rome Formations, and Mount Simon Sandstone. Movement along basement faults also resulted in local and regional structures. As deep drilling continues on favorable seismic prospects, the additional geologic information gathered will allow the refinement of current depositional and structural models representative of the deeper intervals.