Excerpt from Limestones of Southwestern Pennsylvania The greater part of western Pennsylvania is underlain by coal bearing rocks, in which the number of limestones is very great, though only a few Of them attain workable thickness. Following is a list of the principal limestone beds, together with their maximum thick nesses and approximate stratigraphic positions10 limestones or southwestern pennsylvania. (saunas. List of principal limestones. 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.