Beds represented within the Area.—In southwestern Berkshire county, Massachusetts, and in northwestern Litchfield county, Connecticut, is an area in which non-calcareous schistose rocks alternate with limestones which are in part micaceous, dolomitic, graphitic, pyroxenic, tremolitic or quartzitic.† Though the schists are the “mountain rock,” they are found in the valleys as well and are frequently inclosed as islands in the limestone. The rocks here described occur in portions of the townships of Egremont, Sheffield and Mount Washington, in Massachusetts, and of Canaan and Salisbury, in Connecticut. They have been studied areally and structurally in the field and petrographically in the laboratory. The full report of the investigation will appear elsewhere.*
The area includes three beds of schist separated by beds of limestone, besides the thin layers of the former which are sometimes found within the limestones near the contact. The lowest of these schist beds is associated with . . .