Figure 10. On the left is a partial stratigraphic column of what I have sometimes encountered in the Mississippian in Kansas a few feet of carbonate below the top of the Mississippian, underlain by sandstones (which are not laterally correlative for any distance), in turn underlain by more carbonate. On the right is a possible interpretation of such a stratigraphy that the wells in question encountered sand-filled caverns below the top of the Mississippian.