Correlation of scientifically-drilled cores in the Cherokee Group, type Desmoniesian stage (upper Middle Pennsylvanian series), south-central Iowa
This study improves previous research from core logs drilled in south-central Iowa through the Cherokee Group (Middle Pennsylvanian) of the Forest City Basin. Abundant coal members are the best reference for correlation. However, coal-based palynomorph correlation has been inconsistent. This study introduced conodont data to modify the previous work, and improved the correlations from before. Cross-sections built from the new data suggests that the strike and dip directions of the Forest City Basin in south-central Iowa are different than interpreted in previous work. The relationship of facies through the section shows that the Cherokee Group has many characteristics of cyclothems. These characteristics developed over time as the marine influence increased while the Cherokee Group filled in the unconformable Mississippian surface.