198 J. S. Hunt on the Crystalline Limestones of N. America. 
Some of the fine dark-colored mica-slates exhibit crystals of chi- 
astolite, and others near Canaan, abound with black hornblende 
and small garnets. (For the details of this section see Mr. Lo- 
gan’s Report for 1847—48. )* 
‘These Upper Silurian strata constitute the micaceo-calcareous 
rocks of Vermont, which Prof. Adams traced through the state, to 
Halifax on the border of Massachusetts, and they are continued 
in what Hitchcock has called the micaceous limestones of this 
state, which according to him pass by insensible degrees into 
mica slate. The limestones of Coleraine, Ashfield, Deerfield and 
Whately, Mass., belong to this formation, and perhaps also the 
three miles N. E. and S. W. Dr. Hitchcock, to whose report 02 
the Geology of Massachusetts we are indebted for the present 
details, says of this serpentine, “I am satisfied that it is embraced 
in the great gneiss formation, whose strata run from N, E. to S. W: 
across the state.” p.159. He further remarks of the syenite of 
Newbury ard Stoneham, which includes the erystalline wie 
it 5 {10E 
ture 
Stones of Massachusetts are of sedimentary origin; p. 550. 
ratified 
pe gage’ Sie om the Geology of Canada, this Journal [2] vol ix p. 12, and 2, 
