734 



THE JOURNAL OF GEOLOGY. 



western part of the great belt which Professor Dana has mapped 

 in this section of Berkshire county. While it has not been found 

 possible to accurately measure its thickness, it may be safely 

 stated that the thickness never exceeds 600 to 800 feet, and that 

 the beds thin out toward the south end of the mountain. They 



Fig. 4. Series of curves showing the probable form of the flexures in the rocks 

 of Mt. Washington. 



also thin out toward the center of the mass from either side. 

 The minimum thickness in the southern portion of the area is 

 probably something less than 100 feet. The general truth of 

 this statement is borne out by an examination of the map and 

 sections (Sage's Ravine, Bear Rock Falls, etc.) As the lime- 

 stones do not again appear on the southeast flank of the Corn- 

 wall-Sharon core of older rocks, it is probable this horizon never 



