14 
Rocks — is all granite, coarse and pinkish. Та the large ledgy 
tract nearly half a square mile in extent between the Gulf and 
the Scituate shore, diorite appears to be the prevailing rock 3 
but the granite is always close at hand and forms some large 
— — 
masses. The ledges along the Scituate shore, east of Cohasset 
Harbor and the Glades, and advaneing from the south, are, 
except for an occasional inclusion of diorite, wholly composed 
АЕ 
of a beautiful, coarsely but uniformly erystalline and massive 
pinkish granite, which also forms the adjacent islands, from 
Darr's Rocks to the Osher Rocks. On reaching the prominent 
point a short distance north of the Osher Rocks, however, we 
pass abruptly from the granite to diorite with only oceasional 
irregular dikes of granite breaking through it. The diorite forms 
the north shore of this point; but, crossing a short shingle 
beach, we find that the east shore of Strawberry Point is chiefly 
coarse granite ; while across the north side there is much diorite 
alternating with the granite. It is partly in solid, unbroken 
masses, more commonly veined with granite, and to a consid- 
erable extent completely morcellated, yielding a very coarse 
breccia in which the diorite forms the fragments and the granite 
the cement. Gull Island presents at low tide a broad flat sur- 
face of diorite irregularly veined with granite; but Sheppard’s 
Ledge and the ledges southwest of Gull Island are granite 
with little or no diorite. These characteristic relations of 
the two rocks are frequently repeated on the many other ledges l. 
and islets between Cohasset Harbor and Minot’s Light, although 
the granite usually predominates. Along the north side of Co- 
hasset Harbor, between the railroad and White Head, the ledges, 
so far as observed, are nearly all granite ; and following the 
shore northward from White Head, around Sandy Cove, to the ‘ 
mouth of Little Harbor, the rock is all the most typical, coarsely 
erystalline, light gray granite, weathering pink or reddish, very 
massive in structure and with only very rarely a small inclusion 
of diorite. North of the narrow mouth of Little Harbor, on 
Beach Island, the granite continues, unchanged, to a point be- 
ween 200 and 300 feet south of the artificial harbor on the 
