W. W. Dodge—Menevian Argillites at Braintree, Mass. 67 
r at one point near 
the beach at the head of the Cove, calcite has replaced large 
Served, giving a thickness of about 475 feet; on the sout’ the 
dip is occasionally much lower. The southern half of the 
fold is overlaid in Weymouth at its eastern end by a light- 
colored eruptive, chiefly quartzo-feldspathic ; and this is cut 
and capped by diabase, which may also be seen in contact with 
the slate on both sides of Washington street at the corner of 
Commercial, in Braintree. At its western end and to some 
extent on its southern margin, this band of slate passes under 
hills of drift. Westward, in the northern part of Braintree, 
the surface configuration shows it probable that the slates con- 
‘nue beneath the surface in that direction. 
Station, are slates. In the railroad cut (where the strike is 
about east-west} they may be seen 
usual dip, to 15° under the masses of eruptive rock at the 
South side of the railroad. This last named rock, while quite 
unlike the typical form of the Braintree syenite, resembles a 
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