106 
The American Geologist. 
February, 1896 
tion of the New Hampshire survey in 1878, the author has further inves¬ 
tigated the geology of portions of the upper Connecticut valley, and 
desires to put on record a few important conclusions. 
1. Re-arrangement of argillites. One series seems to underlie and the 
other to overlie the Calciferous mica schist. Granting that the hydro¬ 
mica schists join the corresponding developments on the east flank of 
the Green mountains, we have the following synclinal succession: (a) 
underlying gneiss: (b) hydro-mica series; (c) lower argillite; (cl) Calcif¬ 
erous mica schist. This lower argillite has not been noticed south of 
Barnard and Hartland, Vt. One band has been extensively quarried for 
roofing slate at Northfield, and it passes into Canada along lake Mem- 
phremagog. The other argillite combines a part of the Cambrian clay 
slate of the New Hampshire report with the Cobs slates, which contain 
delicate staurolites and garnets. Thus combined, this argillite may be 
traced almost continuously from Massachusetts to Dalton. N. H. 
2. The hornblende schists near Hanover, N. H., are disposed in 
masses allied to laccolites. The principal area is ten miles long, with 
very distinct planes of foliation uniformly tilted northwesterly at an 
angle of fifty degrees. On the west side, this band comes successively 
in contact with mica schist, hydro-mica schist, a band of argillite, and 
chlorite schist; and in every case it has altered the adjacent rock 
through its heat. On the east side it universally adjoins mica schist 
where the alterations are less apparent but still visible. Thus this horn¬ 
blende schist behaves exactly like a true igneous ejection. The pres¬ 
ence of abundant foliated jjlanes must therefore have been due to pres¬ 
sure and flow occasioned by the tendency of the paste to work upwards 
against the cap which has now been denuded. 
3. The protogene gneiss areas of Hanover and Lebanon, N. H., and at 
the southwest end of the Bethlehem area, are known to be eruptive, be¬ 
cause both of them contain inclusions of the adjacent mica schists. 
This gneiss was called Laurentian in the report, with the approval of 
both Prof. J. D. Dana and Dr. T. Sterry Hunt. 
L The removal to the igneous category of the foliated hornblende 
schists, diorites, diabases, and two sorts of protogene, all of which had 
been classed as Huronian, will afford the opportunity to revise the ar¬ 
rangement of numerous schists in Littleton and Lisbon, N. H., where 
characteristic Niagara fossils may serve as our guide to identification of 
age. The slates of Blueberry mountain seem to maintain a synclinal 
attitude, overlying the Niagara. A rather nondescript assemblage of 
schists, hesitatingly called the Swiftwater series in the report, may play 
an important part in the re-arrangement. * 
5. It is worthy of note that the Canadian geologists call the Calcifer¬ 
ous mica schist group after it passes the international boundary 
Cambro-Silurian, because of the presence in the terrane of Trenton 
graptolites, after Lapworth. Some Upper Silurian fossils, more or less 
connected with these limestones, are conceived to be remnants, of a 
superior band, now almost entirely removed by denudation, and not 
characterizing the age of the calcareous floor. They also regard as 
