THE HOUSATONIC VALLEY. 78 1 



usually either chloritic or sericitic, but always free from garnets 

 and staurolite — the Everett Schist. 



The area studied. — To the eastward of Mt. Washington, 

 at a distance of five or six miles, flows the Housatonic river, its 

 general course being like the crest-line of the mountain, nearly 

 south. To the northeastward of the mountain the intervening 

 area is a nearly level plain in which are extensive outcrops of the 

 Egremont Limestone, sometimes with thin intercalated mica- 

 ceous or quartzitic layers. This limestone belt extends almost to 

 the river at Great Barrington and Sheffield Plain. South of the 

 village of Sheffield, however, the level expanse of the plain is 

 broken by the occurrence along its eastern margin of low, sharp 

 ridges trending northeasterly to northwesterly, and increasing in 

 number as well as in height and breadth in going south. The 

 area covered by these ridges begins at Sheffield where two nar-« 

 row ridges are separated by only a few hundred feet, and broad- 

 ens steadily in going southward, thus narrowing the belt of lime- 

 stone on its western border, and finally cutting it off near the 

 village of Salisbury by making connection with the southeastern 

 base of Mt. Washington. (Cf. Plate III. of Mt. Washington 

 paper). Corresponding with the increase in breadth which 

 characterizes the area in its southern portion, there is a marked 

 increase both in the height and the width of the individual 

 ridges. East of the Twin Lakes in Salisbury is Tom's Hill, 

 which rises to a height of over 1,200 feet, while further south, to 

 the east of the village of Salisbury, is Barack M'Teth (1,300 

 feet), and Watawanchu Mountain (1,300 feet), and farther east 

 in about the latitude of Watawanchu Mountain is Mt. Pros- 

 pect 1 (1,460). This tongue of alternating schist ridges so 

 sharply outlined, presents so much of unity in topographical and 

 geological features as to be eminently suited to separate treat- 

 ment. As the ridges are composed of the Riga and Everett 

 Schists, the area is closely connected geologically with Mt. 

 Washington. This paper is devoted to the consideration of 



1 To be distinguished from one of the northwest peaks of Mt. Washington which 

 bears the same name. 



