GEOLOGY OF NEW HAMPSHIRE 53 
starting point where the succession seemed obvious. The hori- 
zon selected was the superposition of hornblende-schist upon 
gneiss. My first work of a stratigraphical nature had been the 
study of a low anticline of this nature at Shelburne Falls, Mass." 
At the base was a well defined gneiss, capped in succession by 
hornblende-schist, mica-schist and the same with interbedded 
limestones.* The first two rocks occupied quite a small area, and 
were exposed only through denudation. On proceeding nor- 
therly similar relations of gneiss and hornblende-schist were seen 
upon several of our sections. Hence the generalization, horn- 
blende-schist overlies gneiss. The next point was to follow out 
the distribution of these two rocks. The gneiss of the Halifax- 
Hartland range proved to bea well-defined geanticlinal sixty 
miles long, dipping westerly to reappear in the Green Mountain 
gneissic area, and dipping easterly to reappear in the gneisses of 
Cheshire, Sullivan and Grafton counties, traceable for over one 
hundred miles with a westerly dip. On traversing the country to 
the east still other gneisses appear. Hence the second generaliza- 
tion, there exist several parallel anticlines of gneiss, connecting 
the Green Mountain and Lake areas. But twoof these ranges cover 
an area of porphyritic gneiss, between Jaffrey and Groton, sixty 
miles in length, thirteen miles in its greatest breadth, following 
the height of land between the Connecticut and Merrimack rivers. 
Its stratification is obscure, while the representation of the dips 
upon the six revised sections crossing it, conform to the notion 
of its inferior position. Nothing has been found underlying this 
rock, so that it must be considered as the base of the crystalline 
succession for New England. More than twenty patches of this 
basal gneiss occur in the state, a few carrying fibrolite schist and 
one contains fragments of a dark gneiss—possibly an older 
layer. 
The place of the chloritic (Bethlehem) gneiss is not so readily 
determined. It occurs only on the east slope of the Connecticut 
*Proc. Boston Soc. Nat. Hist., Vol. VI., p. 330. 
? Upon the Hawley sheet Professor Emerson describes the same succession, using 
the local names, Becket gneiss, Hawley amphibolite, Goshen schist and Conway 
schist. 
