the underground of kansas is made of dipping sedimentary rocks, and they are slightly slanted west. a series of mississippian, pennsylvanian, and permian rocks are found in the eastern and southern parts of the state. in the western part of kansas, cretaceous can be found sticking up from the ground. this happened because of the erosion from the geologically uplifted rocky mountains west of kansas. northeastern kansas was affected by glaciation during the pleistocene.