Geology and Mineralogy. 319 
Again: a similar petetieareene occurs one to two miles north 
of the Notch, (pp. 163, 165). Two miles southwest of Crawford’s, 
on Cascade Brook, the Mount Willard gran- 
ite “contains many fragments of the hard 
seem to carry andalusite quite abundantly. ite 
Half a mile farther west up this same brook, 
andalusite slate succeeds to the granite (but 
with an intermediate po orp yritic junction- 
rock, like that observed in Mount Willard), 
and it continues up Mount Tom. 
The writer had the pleasure, in 1875 
examiring this part of the White Mountain 
region with Professor Hitehcock, adds 
here a pir representing a portion, six feet 
wide, of the surface of fo anite, just 
below the Notch. 
e great number and erates size of the granite veins ——- ng 
ei the gorge in a north-and-south direction, and the extensive 
ange of breccia-granite followin ng the same course, seem + 4 su 
‘ain the opinion, which Professor Hitchcock quotes in his incon 
from the writer, that the gorge, like most valleys of the Appa- 
oba 
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of 
lachians, was pr y the course of a lofty anticlinal, the frac- 
tures in which led to degradation and so de - 
ion of the valley. And if this conclusion ght, the Mount 
tch is the central and lowest rock he anticlinal; that the 
Mount Willard (or Conway) granite is the amorphic 
stratum on both the east and west sides, it lying conformably 
against the slate in Mount Willard and elsewhere; and that the 
andalusite slate on the west and the Montalban schists (often anda- 
a and part an ra a — together on the _ consti- 
ute the succeeding stratum. e dissimilarity in the eastern 
se western portions of is last sougeie ma ac is Atha of 
a small variation from east to west in the constitution of the sedi- 
ments and of differences in the degree of metamorphism. The 
dissimilarity is chemically small; for the analysis of the andalu- 
sitic slate from this region by Mr. G. W. Hawes (Report, p. 233) 
found it to consist (No. 1, below) of— 
SiO, AIO, FeO; FeO MnO MgO K,O Na.O hots H,0 
1. 4601 30°56 144 6°85 0°10 Bs 666 1: 3 1-91  4:13=100°22 
2. 4623 83:08 3°48  ... a) 290, 887). i 412= 99°28 
which corresponds very nearly e the bes of common 
mica (muscovite), or rather wie hydrous variety wiih one 
A similar pe pd amg the Franconia Notch, near the Basin, 
zag pis 137 of Professo’ r Hitcheock’s Report) masses “of porphyritic granite, 
iss, hornblendic ona other siliceous rocks, are cemented together by a 
tight Sotorel feldspathic paste.” Other localities also are mention 
