Page:The Journal of geology (IA journalofgeology11893univers).pdf/291
ON THE GEOLOGICAL STRUCTURE OF THE MOUNT WASHINGTON MASS OF THE TACONIC RANGE.
(With Two Plates.)
Published with the permission of the Director of the United States Geological Survey.
CONTENTS.
- Introduction.
- Topography.
- Previous Work within the Area.
- Conditions and Progress of the present Investigation.
- Horizons Represented.
- Their Lithological Character.
- Explanation of Map, Areal Geology.
- Method of constructing Sections.
- Structure of the Mountain.
- Variable Thickness of the Egremont Limestone.
- Metamorphic Character of the Rocks as indicated by Microscopic Studies.
- Summary and Conclusion.
That portion of the Taconic Range which is known as Mount Washington is both topographically and geologically a unit. It covers an elongated elliptical area, about fifteen miles in length and four and one-half miles in average breadth, lying in the states of Massachusetts, Connecticut and New York. It occupies the entire township of Mt. Washington, and portions of Sheffield and Egremont in Massachusetts; about one-third of Salisbury in Connecticut; and portions of Northeast, Ancram, Copake and Hillsdale in New York.
Topography.—The Mt. Washington mass is a double ridge enclosing a summit plain. Mt. Everett, or the "Dome of the
717