Excerpt from Geology of Sangamon County Beginning at the top and proceeding downward, the following layers are encountered: First - There is a layer of soil which is worked over by man and penetrated by plant roots, and which is about one foot thick. Below it are two or three feet of buff clay, which is penetrated in digging cellars for houses and which, when spread out over back yards, causes would be gardeners much annoyance, since it is sticky when wet and very hard when dry. It is followed by several feet of a mixture of clay, lime and fine sand, in places rich in organic materials. This earth is called loess. It had been borne by wind and water from some distant place and spread out over the country, and later was buried by the overlying deposits. The particles which compose it are quite uniform in size, as would be expected of wind borne material, or earth that had been deposited in quiet lakes. Even in recent years the people of this and neighboring states have seen dust carried by high winds, darkening the sun and drifting like black snow on lawns and porches. Loess was formed in some such manner and consequently exhibits slight. Stratification, but parts vertically, so that ravines cut through it retain for a long time vertical walls. As can well be seen in the Zoo Park, four miles north of Springfield. 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.