Paper No. 9
Presentation Time: 10:00 AM
THE SOUTHERN EXTENT OF THE KANSAN (PLEISTOCENE) GLACIATION IN KANSAS AND ITS GEOLOGICAL IMPLICATIONS
The Kansan glaciation was more extensive and made the most southerly advance into Kansas of any of the four classical glacial episodes. The older Nebraskan glaciation was buried by the Kansan, whereas the younger episodes (Illinoisan and Wisconsinan) are represented only by alluvial sediments, river terraces, and wind-blown material. The southernmost advance in Douglas County (northeastern Kansas) is marked by a series of discontinuous outcrops of erratic boulder beds in a reworked terminal-like moraine. The Clearfield tongue extended as far south as 38o 50' latitude. Most remnants of the Kansan episode are glacial outwash or reworked till which together with the boulder beds are definitive in marking the southern limit of the glacier. The glacier(s) blocked the Kansas (Kaw) River and Wakarusa River forming large temporary lakes and altered the nearby drainage. Several of the higher topographic features near the glacier's snout apparently were not overridden and give a hint as to the ice thickness. The prominent Oread Limestone cuesta escarpment deflected the ice into adjacent low areas. Although subdued, the Pleistocene deposits modify the local landscape and are important in piecing together the late geologic history of the region.