Abstract A regional-scale, digital geologic model was created for carbon sequestration planning in the Michigan and north-central Appalachian sedimentary basins. This regional model and database include well data (picks) from more than 85,000 locations, structure and isopach maps for target and confining rock layers, and oil- and gas-field boundaries with production and petrophysical data. This model confirms the wide range of sequestration options available in the seven-state region. Target sequestration layers include coal and shales rich in organic matter (for CO 2 -enhanced methane recovery) and sandstones and carbonates with sufficient porosity to support enhanced oil recovery and disposal in saline formations. Maps created for this study are compared to those from previous compilations to illustrate advances in geologic understanding and to identify topics for future research. In addition, the utility of the Geographic Information System database in planning and decision support is presented through maps used to select study sites and through the use of the new structure and isopach models in sequestration capacity estimates. These derived products demonstrate that the study region has many promising sequestration targets with the combined capacity to contain hundreds of years of CO 2 production emitted from coal-burning power plants and other point industrial sources.

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.

Abstract The Trenton Limestone of northwestern Ohio consists of three primary facies: open shelf, platform margin, and platform. The platform margin and platform facies appear to be equivalent to the Point Pleasant Formation. Secondary dolomitization of the Trenton Limestone has resulted in a number of zones and types of dolomite within the unit. A combination of dolomitization models involving shale dewatering and fluid migration along fracture trends are presented to explain the dolomite occurrence. A thorough understanding of Trenton lithologies, depositional and tectonic settings, and diagenesis should aid future exploration efforts within this once prolific producer of northwestern Ohio.