30 



granite in the western part of Wrentham is mainly of the typi- 

 cal variety ; and the same may be said of the granite in West 

 Roxbury, and of that in the immediate vicinity of Dedham 

 Village, and southward to the New York and New England 

 Railroad. The large granitic area in Dover, Medfield, Natick, 

 and Sherborn is mainly composed of the variety under considera- 

 tion, which is here largely characterized by a greenish feldspar. 

 In the northern part of Needliam, also, it asserts itself, nearly 

 to the exclusion of all other varieties ; but ceases to be the pre- 

 vailing rock as we pass into the southern part of Weston. The 

 granites of these western towns ■ — Dedham, Norwood, Dover, 

 Sherborn, Natick, Needham, etc. — are almost universally of 

 a reddish or pink color, sometimes greenish, but very rarely 

 dark gray or bluish, as in Quincy, Rockport, Peabody, and 

 other towns to the east and north-east. The granite about the 

 southern end of Spot Pond, in Medford and Stoneham, is, so 

 far as I know, all of the coarse typical variety ; and the same is 

 true, with unimportant exceptions, of the areas in the northern 

 part of Stoneham, and in Wakefield and Reading.^ Well- 

 marked typical granite occurs in Saugus, south of North Saugus, 

 and in all parts of the large granitic area in Peabody, Lynn- 

 field, and Lynn, north of Wyoma Lake in the latter town. The 

 so-called ' ' Peabody granite " cannot be distinguished from that 

 quarried in Quincy. The granite in eastern Lynn, on the 

 Swampscott shore, and on Marblehead Neck and the adjacent 

 islands, though subject to considerable variations, may be nearly 

 all referred to the typical variety. The granite composing the 

 small area of this rock in the southern part of Marblehead con- 

 tains little or no hornblende, is coarsely crystalline, and would 

 belong to the typical variety but for the fact that it is nearly 

 destitute of quartz. A somewhat similar rock, in which there 

 is an entire absence of quartz, forms a large hill immediately 

 north of the eastern arm of Wenuchus Lake, in Lynn. It does 



1 I am indebted to Mr. J. S. Diller for knowledge of a small area of granite, 

 not marked on the map, which exists in Maiden, north of Salem Street and between 

 Prospect Hill and Maplewood. 



