208 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 
Granite Rocks (diorite, granite, felsite). 
1. conglomerate (basal) — thickness uncertain 
2 melaphyr Be . 120-240 feet 
3. fine conglomerate and dandslone alterneting . 120-200 “ 
4. gray inte a . 40-60 “ 
5. conglomerate, sandstone and slate alter nating 100-170 * 
D Olay and wedisiate, o so danre e aa 
L O E e a a ea a aa a a 2, 
8. red slate ee 20 A 
Ye Conglomertte ess il A ee Alle 
10. red slate sey eh A UE BU as 
del console 0 a a a a ae 
12. redslate . . La id US uD ae 
13. sandstone and conglomer ate alternating $2 200300. 8 
905-1445 feet 
ld A A o 
Melaphyr occurs in only one horizon at Hingham, near the base. 
The distribution of the scoriae and amygdules of the melaphyr are 
such as to suggest a composite flow (ibid., p. 212). 
:—Nantasket. An isolated area of sediments with inter- 
bedded lavas and tuffs occurs at Nantasket. The whole has been 
greatly broken by faults and cut by dikes. Crosby’s account of this 
region, published in 1894, is the most complete and detailed study at 
present available, and the following brief summary is taken largely from 
his work. According to his interpretations the entire peninsula of Hull, 
with the exception of a narrow belt passing under Strawberry Hill 
is underlaid by slate, but the entire peninsula is composed of drumlins 
and connecting beaches of sand and shingle, and there is only one out- 
crop of slate —a single ledge on the south side of Thornbush Hill 
(Crosby, k, p. 1) — so that the interpretation is based on scanty 
evidence. Beneath Strawberry Hill he thinks the underlying rock 
is conglomerate, though no outcrops appear, for at Harding’s Ledge, 
off shore in the line of strike of Bumpkin Island and Strawberry Hill, 
indications of conglomerate have been found, and it is supposed that 
the conglomerate of Hough’s Neck may be continued in that direc- 
tion (ibid., p. 104). 
The mainland immediately adjoining the southern end of the penin- 
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