Geology of the Pinckneyville and Jamestown Areas, Perry County, Illinois (Classic Reprint)

Excerpt from Geology of the Pinckneyville and Jamestown Areas, Perry County, Illinois

The details of the structures, so far as known, are shown in figures 4 and 5 by contours that give the elevation of the top of Herrin (n o. 6) coal. This coal was selected as the key horizon because it is present throughout the area and because many data concerning it are available. Well, coal test, and mine records have been supplemented by studies of rock outcrops and by descriptions of old mines as related by residents of Pinckneyville. At a few places the elevation of the horizon was calculated by adding to or substracting from the elevation of some other stratum the known interval between that stratum and the key horizon. The locations and elevations of datum points used in preparing the structure maps were determined largely by p-lanetable survey. The accuracy and detail of the structure is obviously a function of the number of and intervals between datum points.

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.