268 Address before the Association of American G'eologists. 
hints, therefore, may afford some feeble aid in the great work of 
tracing out the systems of elevation that exist on this continent. 
- Lhave alluded to some peculiarities in the Green Mountain sys- 
tem of strata; and if I may venture a little longer upon your pa- 
tience, I will ask a few moments’ attention to what I must regard 
as one of the most remarkable features in American geology. 
Sull, [have so imperfect a knowledge of the subject, as to be 
conscious of venturing forward with few landmarks to guide me, 
into an almost unknown region. I am aware, also, that there 
are gentlemen before me, who have given the subject more atten- 
tion than I asatie and gee are ~/ abiegas prepared for its full — 
opement. 
We havé all teed vis 7 enormous dislocations and inversions 
of the:strata of the Alps; and similar phenomena are said to exist 
in the Andes. Will it be believed, that we have an example in 
the United States on a-still more magnificent scale than any yet 
described? Ihave mentioned in another connection, a series 0 
strata, consisting of gneiss, mica, talcose, and argillaceous slates, 
with limestones and Silurian rocks, extending from Canada, along 
the western side of New England and the eastern side of New 
York, to the Highlands on Hudson river, and thence southwes- 
terly through the Appalachian mountains as far as Alabama; a 
distance of at least twelve hundred miles. Along a large part of 
this distance, a remarkable apparent inversion of the: dip exhibits 
itself ; so. that the newer rocks appear to pass beneath the older 
ones ; and that too over a great width of surface. Certainly this 
is the case from Canada to New Jersey, and thence through 
Pennsylvania and Virginia, I infer from the reports of the Profes- 
sors Rogers, that similar phenomena occur, which thése gentle- 
men have been studying with great care and success; and the 
results, I learn, will soon be given to the public. ‘The effects of 
the extraordinary agency under consideration, has not been sim- 
ply to toss over the strata, so-as to give them an inverted dip, but 
in general to. produce a succession of folded axes, with a gentle 
_ Slope and dip-onstheiz eastern sida and a. a dip, or more fre- 
quently an inverted one, on their western 
Such a disturbance as this would be far Teite: scenadiaini' were 
_ Wnt so extensive. I cannot describe the width of the belt that 
Gane mene, except in that portion of it which has 
_ fallenvunder my notice. It appears to me, that in the latitude of 
