Date of this Version
Northeastern Kansas is characterized by dissected till plains. Glacial sediments overlie the older Paleozoic sedimentary rocks. Outcropping rocks of Paleozoic age include the Pennsylvanian and Permian rocks extensively studied in other reports. This report includes the twelve northeastern Kansas Counties (Atchison, Brown, Doniphan, Douglas, Jackson, Jefferson, Johnson, Leavenworth, Nemaha, Shawnee, Wabaunsee, and Wyandotte) that were glaciated during Pleistocene time. The study area was entirely glaciated during pre-Illinoian (classical Kansas and Nebraskan) time, except for its southern fringe. The deposits exposed in the area include glacial drift (till, outwash, lake deposits), loess, and alluvium. Pregacial drainage ways became buried valleys after glaciation, filled by deposits ranging from clayey sediments to sand and gravel.
The discussion of recent changes in the pre-Illinoian glacial stratigraphy recognizes that several tills indicate that more than the traditional two glacial advances occurred in Kansas and Nebraska. Age dating shows that the well-known Pearlette Ash marker bed for the top of the Kansan represents deposits of three distinct ages, making it useless as a marker bed. Other convincing evidence indicates that the classical terms "Nebraskan, Kansas" should be dropped from glacial stratigraphy.