Excerpt from Ancient Water Levels of the Champlain and Hudson Valleys The valley of the Hudson river, from the point of view of the stream bearing that name, is a geographic group of drainage slopes whose axial trough, if we except the Adirondack portion of the river, has a nearly north and south direction, traversing a geologic area of variable structure formed of rocks of widelv different ages in its various parts, and having different degrees of topographic development. The order and structure of the rocks of its valley have long been portrayed on the geologic maps of the State, and the contour of the land forms bordering the river are now faithfully delineated on topographic maps, but the precise history of the origin of this river has not been determined. The reader must, therefore, be content with a statement of the main facts in the form and cross-section of this vallev and it is important that these features should be understood in following any attempt to unravel the Pleistocene history of the vallev. Particularly in relation to its occupation by the last ice sheet and to the retreat of that ice from eastern New York and the subsequent invasion by the sea of at least the neighboring Cham plain valley. 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.