single interglacial period, and (3,) as originally defined by Leverett in 1898 consist of interglacial sediments, by which the Yarmouthian (Yarmouth) Interglacial (Stage) was defined and recognized have all been found to be false. References External links Aber, J.S., 2006, Regional Glaciation of Kansas and Nebraska. Emporia State University, Emporia, Kansas. anonymous, 1997, Glacial Map of North-Central United States. Work Group on Geospatial Analysis of Glaciated Environments (GAGE), INQUA Commission on Glaciation, Emporia State University, Emporia, Kansas. anonymous, 2000, Pre-Wisconsin Glaciation of Central North America. Work Group on Geospatial Analysis of Glaciated Environments (GAGE), INQUA Commission on Glaciation, Emporia State University, Emporia, Kansas. anonymous, 2007, Global correlation tables for the Quaternary. Subcommission on Quaternary Stratigraphy, Department of Geography, University of Cambridge, Cambridge, England Gibbard, P.L., S. Boreham, K.M. Cohen and A. Moscariello, 2007, Global chronostratigraphical correlation table for the last 2.7 million years v. 2007b., jpg version 844 KB. Subcommission on Quaternary Stratigraphy, Department of Geography, University of Cambridge, Cambridge, England Hallberg, G.R., ed., 1980a, Pleistocene stratigraphy in east-central Iowa., PDF version 15.6 MB. Technical information Series. no. 10. Iowa Geological Survey Bureau, Ames, IA. Hallberg, G. R., T. E. Fenton, T. J. Kemmis, and G. A. Miller, 1980, Yarmouth Revisited: Midwest Friends of the Pleistocene 27th Field Conference., PDF version 4.6 MB. Guidebook no. 3. Iowa Geological Survey Bureau, Ames, IA. Roy, M., P.U. Clark, R.W. Barendregt, J.R., Glasmann, and R.J. Enkin, 2004, Glacial stratigraphy and paleomagnetism of late Cenozoic deposits of the north-central United States, PDF version, 1.2 MB. Geological Society of America Bulletin, vol. 116, no. 1-2; pp. 30–41; See also Ice age Glacial period Last glacial period Timeline of glaciation Pleistocene Interglacials