Excerpt from Topographic and Geological Survey of Pennsylvania, 1906-1908 The results of the geological work are only published by the United States Geological Survey, and the issuing of reports is quite slow. In order that some of the results may be available an outline of geological explorations in the State and a summary of the results of the present co-operative work, including short accounts of the more important unpublished results have been incorporated ia' a short report and the same is submitted herewith as a part of this report (appendix E). In various publications of the United States Geological Survey 17 quadrangles of the State have been reported upon in the folio form of publication, and 4 bulletins have been issued covering the economic geology of 5 quadrangles. 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.