558 C. H. Hitchcock—Helderberg Rocks in New Hampshire. 
schist perhaps, dipping 80°, S. 15° E. On top of the hill there 
is a siliceous rock, which from different observers has received 
the names of sandstone and buhrstone; it dips sometimes north- 
west, but perhaps oftener to the southeast. On the north slope 
of the hill, the sandstone varies in position from about 80°, S. 
8° E. to 8. 8° W. This rock can be followed a mile north- 
easterly across the road going eastward to Mann’s Hill, and then 
is supposed to turn and follow up the hill to the southeast of 
rnham’s house, and to continue southwest to Parker River. 
It has its maximum development on the east side of the basin, 
constituting what would be called a mountain range in many 
wi of the country. It probably connects with the buhrstone 
of fig. 3. 
Overlying the sandstone, as I suppose, is the fossiliferous 
limestone. It has been excavated at several places quite ex- 
tensively, and burnt in a contiguous kiln. It is usually of a 
light drab color, somewhat brecciated, and the fossils are not 
conspicuous, but upon search they prove to be considerably 
abundant; the thickness varies from ten to fifty feet. On the 
north side, the limestone forms a precipice of twenty feet, 1n 
consequence of excavations. In contact with it on the section 
be satisfied with any interpretation of them. Professor Dana 
fea this locality, as well as the region along Parker Brook, 
in 1871. 
I do not suppose that all the facts are indicated by so even a 
synclinal as appears in the figure. re may be hummocks of 
underlying rocks to disturb the continuity, and the strata are 
certainly contorted. The limestone was not observed to the 
east of Mr. Burnham’s house, but, as the sandstone beyond has 
a small reverse dip, we may presume that the limestone changes 
with it. Still farther to the southeast gneiss occurs. The country 
is wooded and slopes rapidly, and would not be likely to afford 
good ledge exposures. : 
A mile to the southwest a more satisfactory section 18 ob- 
tained, so far as the position of the strata is concerned, but the 
limestone has not obs The west end lies in @ 
______ valley, one of the tributaries of Parker Brook, and the rock 1s 
y the ehloritic rock of the Lisbon group, dipping few 
