In this report, the Indiana Geological and Water Survey (IGWS) evaluates the seal capacity of the Maquoketa Shale Group, a thick and heterogeneous sequence of carbonates, silts, and clay-rich rock units of Upper Ordovician age. This unit has been identified as a regional caprock that can effectively isolate the CO<
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stored in underlying reservoirs for secure sequestration. To accomplish this objective, the Maquoketa Group was assessed using two approaches: (1) development of a lithofacies/qualitative permeability model based on the combined wireline responses, and (2) analysis to characterize the pore size distribution and capillary entry pressures of the various lithologies in the unit using the mercury injection capillary pressure method.