24 
bedded roeks of the entire area can not be read off directly 
from any more or less continuous or connected horizontal sec- 
tions. But we find instead numerous isolated vertical sections, 
which can only be correlated, if at all, by a critical ledge-to- 
ledge study and comparison. The best results of such an inves- 
tigation are presented in the subjoined general section of the 
Nantasket strata; from which it appears that above the granite 
floor there are no fewer than six beds of conglomerate, alterna- 
ting with five sheets of mel: aphyr and tuff and one sheet of por- 
phyrite. 
Table of the Nantasket Strata. 
Granite, bordering and underlying the bedded rocks. 
First Conglomerate, basal, resting on granite. . . . . . 295-50 feet. 
Rocky Neck, Granite Plateau, Cliff Plateau, cte. 
First Melaphyr, compact and jaspery . . . . 25-40 feet. 
Rocky Neck, East and West Porphyrite Hills ‘ia clin Баб 
Second Conglomerate, jaspery . . * ^. « 20-00 feet. 
Rocky Neck, East and West Rouri Hills, ( rreat Hill, etc. 
Ро ДУ еу . 50-100 feet. 
East and West Porphyrite Hills, Blac k ‘Rock: es 
Third Conglomerate . . . 1 50-100 feet. 
Conglomerate Hill and Pl. ibid, vicina 8 ШЕН Round Hill 
and Green Hill. 
Second Melaphyr, green and amygdaloidal . . . . 2080 feet, 
Crescent Hill, Melaphyr Plateau, and South Sidra 
Fourth Conglomerate . . ege wow %% „ NOR O 
Crescent Hill, Marsh island, etc. 
Third Melaphyr, green and amygdaioidal . . . . . 85-45 feet. 
Rocky Neck, Melaphyr Peninsula and Plateau, C vesdelit Hill 
and Marsh Island. 
Fifth Conglomerate . . . WO Q bee 
Rocky Neck and Long Bodd h Rod к. 
Fourth Melaphyr and Tuff, green, compact or brecciated . 300-450 feet, 
Atlantic and Centre Hills, Gun Rock, Little Black Rock, etc. 
SUSU Gone sce VU UNI eec oe re ce CL vo O 
Rocky Neck. 
Fifth Melaphyr, green and amygdaloidal. , . . . . . . 185-20 fact, 
Rocky Neck, 
600—960 
