274 



of the lc(l<j;es in the vicinity of Martin's Lane or Planter's Hill. 

 Another large bowlder of granite, almost concealed by young 

 trees and vines, is partly buried in the swamp, close to the 

 north side of Pleasant Street and immediately west of Beech- 

 wood River. 



Two bowlders of conglomerate are large enough to merit 

 special mention. One of these lies on the shore at the north 

 end of Crow Point Hill and is partly submerged at high tide. 

 It was originally from 12 to 15 feet in diameter, but has been 

 ruthlessly broken by blasting into three unequal masses. It is 

 a very firm, distinct, and coarse conglomerate, with many 

 pebbles of reddish granite one foot or more in diameter ; quite 

 distinct from any conglomerate observed in Hingham, but 

 resembling the coarse conglomerate of the Green Hill ledge at 

 Nantaskct. The other conglomerate bowlder is in the northwest 

 part of Planter's Fields, northeast of Huit's Cove and about 

 midway between the nearest water of the cove and the north 

 shore. It rests on a ledge of melaphyr sloping northward, 

 within a few feet of the northwestern extremity of the belt of 

 conglomerate shown on the map, and measures 15 feet in 

 length, 8 feet in width, and 9 feet in height. It is also a firm 

 and rather coarse rock, the pebbles ranging mostly from 2 to (5 

 inches in diameter. 



MODIFIED DRIFT AXD TEREACES. 



The modified drift, in its various forms, is a very prominent 

 feature of Hingham geology ; and it is here that we find tlie 

 stron(>-est contrast between the o^eoloiry of Hingham and that of 

 Cohasset and Nantaskct. The sandplains, except the low 

 j)lains immediately bordering the streams, are, to a large 

 extent at least, indicative of standing water; and, except 

 possibly for the very lowest plain, we must, as explained in 

 Part I, i)ostulate fresh rather than salt water. It appears 

 pr()bal)le, therefore, that the slight development of sandplains 



