GEOLOGY OF NEW HAMPSHIRE 57 
As thus defined the New Hampshire Montalban is like the 
Coutcliching division of Ontario, proposed by Professor A. C. 
Lawson for a system that occupies just this horizon. 
The hydro-mic-aschists and associated diabases, etc., corre- 
sponded well petrographically to the Huronian complex, and 
were so referred. At first it was thought that our White Mountain 
porphyries might be referred to the lower Huronian or Arvonian 
of Dr. Hunt, but the reasons demanding the removal of the gab- 
bro from the stratified systems prevailed equally well as applied 
to the porphyries. 
As to the various mica-schists and related rocks, called 
locally Kearsarge, Merrimack and Rockingham, no satisfactory 
reference could be made; and hence they were called Paleozoic 
in general, their alliance being obviously Huronian or Cambrian. 
The argillites were all referred to the Cambrian, having in mind 
the fact that this seemed to be the place for rocks of this class, 
whether in Vermont (Georgia), Massachusetts (Braintree), or 
Nova Scotia. The Coéds quartzites, schists and slates, also the 
Calciferous mica schists all received an assignment to horizons 
superior to the Cambrian. 
An improved classification.—The question now arises, How can 
our early classification be improved? It is eighteen years since 
the New Hampshire report was published, and there are many 
new workers in the field, all placing great reliance upon petro- 
graphical principles, such as were inaugurated in Dr. Hawes’ 
report. Some are advocates of extreme metamorphism, and 
hence the conclusions are not harmonious. It seems to us that 
our early views may be modified by the following principles: 
(1) The mineral characters of crystalline rocks are not a sure 
guide to geological age. (2) Protogenes, diabases and diorites 
more or less interstratified with hydro-micas are of true igneous 
origin. (3) The Archean gneisses and protogenes may also be 
of igneous origin, and their apparent stratification has no con- 
nection with sedimentary or chemical deposition. (4) The 
Huronian* era may properly represent the beginning of sedi- 
* There seems to be no need of introducing a new term—Al]gonkian — to replace 
