1873.] 305 [Hitehcock. 
show marks of stratification. Ossipyte is a compound of labradorite 
and chrysolite. This, and the succeeding layers of compact feldspar, 
appear to be stratified, and in many cases to overlie the granites with 
scarcely any dip. ‘The series is cut by the syenites upon Tripyramid 
mountain in Waterville. The hichest mountains between Saco and 
Pemigewassett rivers are capped by either the labradorite or com- 
pact orthoclase. Examples are the Lafayette range, Mts. Flume, 
Liberty, Twin and Carrigain, some of them over 5000 feet above the 
level of the ocean. 
It follows from the general horizontal disposition of these masses, 
that the valleys of this mountain region are to be compared with the 
ravines of West Virginia and other countries where the strata consti- 
tute an elevated plateau. Several of the mountains mentioned above 
show four divisions of the group. The lowest is generally outermost 
as seen upon the map, and the highest band is most central and least 
abundant of all. 
Of the Lowest series, the porphyritic gneiss is the most marked. 
Two or three bands of this formation pass southerly from the White 
Mountains, one of these probably across Massachusetts into Connecti- 
cut. Its greater age than that of the other series is inferred from 
the occurrence of several bands of andalusite and granitic gneisses, 
very similar to each other, upon both flanks. The central rock is 
along the water-shed of the State, though the ridge does not carry 
hicher mountains than some of the adjacent schists. T'wo bands of 
this porphyritic eneiss terminate at the edge of the mountain region, 
being covered up by the Labrador group. 
The Bethlehem eneiss in its typical areas has an east and west 
strike, and seems to rest upon the group just mentioned, as seen in a 
section from Dalton to Mt. Lafayette. The strata are monoclinal, 
and it is therefore difficult to know whether the axis is anticlinal or 
synclinal. If the formation is the same with the gneiss at Berlin, 
the structure may be anticlinal. The prevailing rock is character- 
ized by the presence of a talcose appearing mineral in connection 
with the mica. 
The relations of the andalusite gneiss to the other members of the 
first group are not clear. It occurs on both sides of the porphyritic 
eneiss anticlinal in the south part of the State, and seems therefore 
to be the newer of these two series. It also flanks the anticlinal of 
supposed Bethlehem gneiss in Berlin. . These considerations make it 
probable that the andalusite gneiss is newer than both the others. 
