Excerpt from Mineral Zonation of Woodfordian Loesses of Illinois Three-fourths of the surface of Illinois is underlain by loess that commonly ranges from a few feet to more than 50 feet in thickness. It rests on both glacially derived deposits and on bedrock, and because of its position just below the surface, it is important in construction projects, as fill material, as the parent material for much of the state' s soil, and locally for such uses as ceramic raw material. The Illinois State Geological Survey has studied the stratigraphy and mineral comp051 tion of the surficial loesses (frye, Glass, and Willman, 1962; Frye and Willman, 1963; Glass, Frye, and Willman, and this report gives the results of stud ies of the mineralogical zonation of the younge st, or uppermost, loess units. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.