AIS On the Geological Age of the White Mountains. 
tain, until we are certain of the latest age in which any of the 
fossiliferous rocks of the White Mountains were produced. ‘That 
the elevation was before the Carboniferous period, which witness- 
ed the final draining of the Apalachian sea, seems manifest enough 
from two considerations. 
It is almost certain, in the first place, that none of the Apalach- 
ian strata of the middle or latter ages were deposited within this 
region ; for no traces of the coal rocks nor of the fossiliferous Post- 
medial shales, (Marcellus shales, &c.,) nor any of the red shales 
referable either to the later Levant or the Ponent (Catskill group) 
periods have yet been met with: and since these newer palaozoic 
formations abound both to the S. W. and N. E. we must infer that 
their absence in this locality is due to a lifting out from the bed 
of the sea previous to their deposition. Had they been depos- 
ited within this area, some remnants of these strata would almost 
certainly have been preserved from denudation in the close folds 
or synelinal bends of:this contorted district. In the second place, 
there is abundant evidence in the region of the Hudson valley, ° 
where the Levant rocks rest almost horizontally on the upturned 
edges of the Matinal, that the bed of the Apalachian waters un- 
derwent a local disturbance at the close of the Matinal period, 
and it is equally obvious that the direction of this disturbance, as 
seen in the course of the axes of elevation and depression, was 
different from that of the subsequent movement by which all the 
deposits at the end of the Apalachian ages were contorted and 
upraised. So in like manner we may perceive, in the structure 
of the White Mountains, the proofs of two distinct intersecting 
systems of dip, the components of two separate sets of axes or 
contortions of the crust, indicating two different epochs of eleva- 
tion. One of these, and apparently the latest, is a N. N. E. and 
S. S. W. set of anticlinal and synclinal folds; and is therefore 
probably a part of the general movement which lifted the whole 
Apalachian or Alleghany chain, and drained away the palzeozoic 
waters; but whether the other accords as nearly in direction and 
date with the earlier system of the Hudson valley, the epoch of 
which was either at the close of the Matinal or early in the Le- 
vant times, is an important and interesting question which only 
future research can answer. The most natural inference from 
all the facts would seem to be, that in the somewhat disturbed 
period last referred to, when, as geologists are already aware, all 
