Illinoian and Wisconsin (Farmdale) Drifts Recently Exposed at Rockford, Illinois

Science  18 Jan 1963:
Vol. 139, Issue 3551, pp. 218-221
DOI: 10.1126/science.139.3551.218


New exposures in Rockford, Illinois, show fresh till overlying ferruginous gravel of marginal glacial origin. These, together with older sections, now slumped or no longer exposed, offer convincing evidence of two glaciations of the Rockford area, the first of Illinoian age and the second of early Wisconsin (Farmdale) age. The sections further suggest that the greater part of the drift fill in Ancient Rock River Valley is Illinoian, and that this is overlain by a relatively thin mantle of Farmdale drift.