ON THE GEOLOGY OF THE UNITED STATES. 
63 
moiintains in North America,, on the western side of that conti- 
nent, between the sources of the Missouri and Cokunbia rivers^ 
two very hot-springs were found by Capt. Lewis, and the same 
mountains hkewise contain rocks of the newest floetz-trap for- 
mation. 
Since the date when Mr. Maclure submitted the interesting 
account alhided to, and from which we have borrowed largely, 
but little has been done to enable the geologist to lay down an 
accurate chart of the distribution of the various formations ; the 
investigations which have been conducted, are generally too cur- 
sory, and treat too largely upon the posterior disturbances and 
intrnsion of igneous rocks (a very favourite subject now-a-days) ; 
and perhaps this may be excused, upon the ground that the area 
of geological research in the American continent is so large and 
extended that it were vain to grapple with the whole subject ere 
the minutise affecting the general continuity were determined. It 
is on the ground then, that it is as yet impossible for us to give 
any other than a chart exhibiting the distribution of the general 
classes of rocks. 
To the east of Hudson^s river, the primitive class prevails, 
bounded on the side of the ocean by vast tracts of alluvial for- 
mation which skirt the granite ridge. To the westward of the 
State of New York, the stratification runs nearly north and south, 
and generally dips to the east, looking up to the white hills, the 
most elevated ground. In New York State, and to the west- 
ward, the stratification runs nearly north-east and south-west, 
and still dips to the east. All the rivers east of the Delaware 
run nearly north and south, following the stratification, while 
southern rivers incline to the south-east and north-west direc- 
tion. 
Throughout the greatest portions of the eastern and northern 
states, the sea washes the foot of the primitive rock ; the depo- 
sition of an extensive alluvial formation commences at Long 
Island, increasing in breadth to the south, forming a great part 
