C. Hl. Hitchcock— Helderberg Rocks in New Hampshire. 565 
oss is the slate of the quarry. One pebble is a foot long. 
iliceous fragments of a dark color predominate, which seem 
wae show resemblances to the compact feldspars of the 
brador group. There are small bits of black slate like that 
occurring near the east end of fig. 6. 
The next section in fig. 8 is three and three-eighths miles 
long, and passes over more strata. It commences high up the 
early course of Mulliken’s Brook, crosses Blueberry Hill, and 
terminates a short distance north of North Lisbon, reaching the 
gneiss. At the beginning is the Lyman instead of the Lisbon 
group, though the latter would appear if the section had been 
elongated half a mile. Near G. D. Shute’s house and “ Indian 
Rock,” these schists dip 85°, N. 20° W. e east border of 
this group dips 80°, N. 80° W. It weathers whitish, presenting 
a chalky aspect at a little distance. Along the carriage road 
succeeding is an extensive range of Helderberg slates and lime- 
stones containing Favosites. The strata stand perpendicular, 
running northeast. On a tributary stream, near C. Hastings’s 
use, is a fine exposure of grit, slates and calcareous beds, 
greatly resembling fossiliferous strata in Maine and New York, 
but they yielded no relics of life in a half-hour’s search. This 
series of strata forms a steep cliff seventy or eighty feet high, 
which can be followed a mile and a half to the slate quarry. 
The country at the base of the cliff is everywhere a swamp 
forest not intersected by roads, so that its exploration is not 
inviting. 
Passing up the hill, there are so many boulders of con- 
glomerate that we must believe this to be the rock in place. 
Its character does not vary from that seen on section 7. This 
view will make the fossiliferous slates correspond with the 
slates at the quarry. Near the top of Blueberry Hill are slates 
with the course N. 65° E., and irregularities which may be ex- 
plained by supposing cleavage planes to be present having a 
different strike from the strata. On the crest of the hill the 
slates dip 70°, N. 25° W. ‘This continues about half a mile on 
the line of section, or as far as I was able to travel upon it. 
There is room enough for the double thickness of slate seen in 
fig. 7 
The eastern slope has not been examined throughout. 
About half way down I have twice examined ledges apparently 
-of the Lisbon group dipping toward the hill. Mr, Huntington 
travelled over the remainder of the section, and his specimens 
seem to indicate, first, the mica schists of the Cods group, (6) 
followed by considerable hornblende rock, (7) and lastly by a 
conglomerate (8) with whitish cement and pebbles of the size of 
