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THE JOURNAL OF GEOLOGY.

not been measured. The former probably has a thickness of much less than a thousand feet. A locality where the Canaan Dolomite appears below it in the core of a fold, is shown in Plate VII., Fig. 3.

Conclusions.—Some of the results of this study may be summed up in the following statements:

I. The district is geologically closely connected with Mt. Washington, and contains the same horizons, viz: Canaan Dolomite, Riga Schist, Egremont Limestone, and Everett Schist. For the most part the same general lithological features characterize these horizons as on Mt. Washington. Pyroxene is a characteristic mineral in the lower but absent from the upper calcareous member. Garnets and staurolites are abundant in the lower but absent from the upper schist member. Locally important beds of calcareous schist occur in the Egremont Limestone. The Everett Schist differs from much of that of Mt. Washington in being essentially non-chloritic. The Egremont Limestone has a thickness of less than 100 feet in the southern part of the area.

II. The tongue-like outline of the area containing schist exposures is due to a general northerly pitch of the flexures to the west of the Housatonic River, though the local pitch of these flexures varies greatly and is as often south as north. Most of the prominent ridges are anticlinals of the Riga Schist, the few area of Everett Schist being synclinals and largest where basins are formed by a coincidence of longitudinal and transverse synclinals. The schist areas exhibit an arrangement in four[1] east and west belts having each a width of about two miles, as the result of four marked undulations in the crest lines of the flexures. Particularly toward the north these belts are further subdivided by a secondary series of undulations a half mile or more in width, and a tertiary series of yet smaller waves can in some cases be made out at localities. These facts show that the area has been subjected to compression in a north and south direction,

  1. ↑ (1) Bear's Den, Barnard Mt., and Johnny's Mt.; (2) Horse Hill, Peck's Hill, etc.; (3) Northern Chapinville area, Tom's Hill, and Miles Hill; (4) Southern Chapinville area, and area No. 6.
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