CHAPTER VI. 
SKETCH OF A GEOLOGICAL CLASSIFICATION OF THE MOCNTAINS 
OF A PART OF NORTH AMERICA. 
(Extract from the Annales des Mines, serie, tome VII, page 329 etc. ; Paris, 1855.) 
An attempt to classify geolog-ically , that is, according to their chronological order, the differ- 
ent chains of mountains in the United States and the British Provinces, is an undertaking which 
in reality can be only preliminary, if w e consider the small number of observations which have been 
made, and the vast extent of country embraced in this portion of North America. 
In Western Europe M. Elie de Beaumont has recognized and classified twenty one systems 
of chains of mountains, and, in addition, he has extended many of these systems to other parts 
of the World. Two of these extensions coincide perfectly with tw'O systems of mountains in the 
part of North America included in this sketch. One designated as the System of the Ballons des Vosges 
and the Hills of the Boeage, and which has dislocated the beds of the Carboniferous rocks in Brittany, 
Westmoreland, the Vosges, and the Hartz mountains, coincides exactly with the Alleghany and Ozark 
Mountains system, xvhich has upheaved in the United States the Carboniferous strata of the States 
of Pennsylvania, Maryland, Virginia, Kentucky, Tennessee, Arkansas, etc. The other; known 
under the name of the System of the Thiiringerwald and of the Morvan, extended to North America, 
is found to coincide entirely wdth the Keewenaw Point and Cape Blomfdon system. 
By following the method introduced and explained with so much talent by Elie de Beaumont 
in his late and remarkable work, entitled: «I\'otice sur les Systdmes de Montagnes« , and by the aid of 
some excellent observations made by Dr. Charles T. Jackson and Edward Hitchcock upon the di- 
rections of the ruptured rocks of New England, Nova Scotia, and Lake Superior, I am led to re- 
cognize thirteen chains of mountains in a part of North America. After deducting from this number 
the two systems that Elie de Beaumont has recognized previously by the extension of two of his 
systems of Western Europe, there remain eleven systems of mountains, wdiich I add to those known 
in this department of Geology. 
Nevertheless, I repeat, that this classification is only preliminary, and 1 present it with all re- 
serve, considering the small number, the difficulty, and the insuffiency of the observations. 
N. B. — Very little is known as to the relative age of the chains of mountains of the globe, 
and the methods pursued for this object are still very uncertain. Elie de Beaumont is, certainly, 
the geologist who has contributed the most to advance this part of the science; and in his: Notice 
sur les Systdmes des Montagues, three volumes, 12"'°; Paris; 1852, he has published his principles. 
Without being equally sanguine with M. de Beaumont as to the generality of his theory of the 
