Comparison of Soils in Midwestern United States and Western Europe with the Interglacial Record

Abstract

Paleosols that formed primarily before the last glaciation cannot be adequately explained by a model of Holocene-like interglacial periods of about 10,000 yr in length which has been inferred from the marine18O16O record. Geological and palynological evidence from terrestrial, midlatitude sites suggests that temperate conditions conducive to soil formation existed for periods greatly in excess of 10,000 yr during the middle and late Pleistocene. Available data on soils formed during this interval from Western Europe and midwestern United States are best explained by relatively long interglaciations or the development of composite soils over a number of temperate periods. Climatic contrasts between the interglaciations appear to have been overemphasized: widespread assumptions regarding greater warmth in interglaciations prior to the present one are generally unproven. In the absence of precise dating, progress in relating paleosols to fragmentary local records of Quaternary climatic changes will be achieved by detailed analytical techniques such as soil micromorphology.