Excerpt from Short Papers on Geologic Subjects: Major Aquifers in Glacial Drift Near Mattoon, Illinois; Notes on the Illinois "Lafayette" Gravel; Cambrian and Lower Ordovician Exposures in Northern Illinois; An Occurrence of Barite in the Lasalle Limestone of Illinois Subsurface Pleistocene studies near Mattoon recently conducted by the Illinois State Geological Survey have revealed the probable origin and nature of occurrence of two gravel aquifers of major importance. 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.