Hitcheock.] 306 {March 5, 
The evidence of its inferior position to the Labrador group is very 
decided. lt appears in four or five places in deep valleys, beneath 
the granite in the area of the overflow. The south-westerly course 
of the strata in the main range of mountains is interrupted by the 
granite, but reappears in Tamworth, Sandwich, etc., showing that 
the gneiss is covered by the granite. In the valley of Dry or Mt. 
Washington River, about five miles from Mt. Washington, there is a 
limited synclinal of ossipyte resting upon the upturned edges of the ~ 
andalusite gneiss. The granites usually lying between the two rocks 
are wanting in this valley. The upper rock is nearly horizontal, 
while the gneiss dips 60° N. W. 
The Franconia breccia contains fragments of the porphyritic and 
andalusite series, and, as it lies on both sides of the common granite 
in the shape of mountains, it is surmised that it underlies the latter. 
Some gneiss is connected with it in Eagle Cliff. The third series 
has been known as the metamorphic part of the Quebec group of 
Canada; but it is better to call it Huronian, as suggested by Mac- 
farlane, Credner and Hunt. 
Careful sections across this formation in Lyman show green cupri- 
ferous schists at the base, with conglomerates composed of fragments 
of the same. The series is capped by a light colored schist, weather- 
ing white, having the following composition : Silica 75.20, Ferric 
oxide 3.28, Alumina 6.07, Magnesia 2.80, Potash 3.04, Soda 9.86. In 
the valley of the Upper Ammonoosuc there is a siliceous rock some- 
what resembling this schist. It adjoins genuine Huronian schist on 
the one hand and Labrador felsite upon the other, and is probably of 
1 Prof. H. D. Rogers seems to have understood that this system of rocks must 
be distinguished both from the Laurentian and the Paleozoic. My recollections of 
a conversation with him in 1858 are expressed in Proc. Amer. Assn. Adv. Sci.. 
1859, p. 822, where the disagreement between the Pennsylvania and Canada Surveys 
in respect to the age of the talcose rocks is spoken of. In Proc. of this Soc., Vol. Vr., 
p. 148, Geol. Pa., Vol. 11., p. 745 et. seq., the difference between the Huronian rocks and 
the metamorphosed Paleozoic is clearly expressed. The former are stated to con- 
stitute a system overlying the Gneissic and beneath the “ Primal.’’ The talcoid 
and chloritic schists of the southern strata are also compared with the Huronian 
rocks of Michigan. But the name of Huronian is not employed in the descrip- 
tions, so far as I can ascertain. The system, however, is clearly recognized in the 
Southern States, and the credit of the recognition should be given to Prof. Rog- 
ers. I remember distinctly that in the conversation alluded to, these formations 
in the Southern States were spoken of as probably identical with those in Michi- 
gan, then recently denominated Huronian by Logan. Prof. Rogers seems to have 
regarded the New England talcose rocks as altered Paleozoic, and the credit of 
their identification with the Huronian certainly cannot be given to him. 
