ON THE GEOLOGY OF THE UNITED STATES. 5 ^ 
primitive, from Lay Island to the Gulf of Mexico, consisting of 
sand, gravel, &c., witli silt, both of marine and lacustrine or 
river origin, containing both vegetable and animal remains, found 
from thirty to forty feet below the surface. 
Along the north-west edge of the primitive commences the 
transition formation, occupying, after the primitive, some of the 
highest mountains in the range, and appears to be both higher 
and wider to the west in the states of Pennsylvania, Maryland, 
and part of Virginia, where the primitive is least extended and 
lowest in height. It contains all the varieties of rocks found in 
the same formation in Europe, as the mountains in the Crimea 
&c. and resembles in this the chain of the Carpathian, Bohemian 
and Saxon mountains, which have all a very considerable transi- 
tion formation, succeeding the secondary limestone on their nor 
thern sides. Anthracite has been found in different places within 
the range of this formation, and has not yet been discovered in 
any of the other formations in North America, a fact alluded to 
by Mr. Maclure, but which still holds good in the present ad- 
vanced state of the science. On the north-west side of the tran- 
sition formations, along the whole range of mountains, lays the 
great secondary formation, which, for the extent of surface it co- 
vers, and theuniformity of its deposition, is equal in magnitude and 
importance, if not superior to, any yet known ; there is no doubt 
of its extending to the borders of the great lakes to the north, 
and some hundred miles beyond the Mississippi to the west. 
From the investigations already made it seems clear, indeed, that 
the western limits of this great formation cannot be far from the 
Stony mountains, and to the north, that it reaches beyond Lake 
Superior, giving an area extending from east to west from Fort 
Ann, near Lake Champlain, to near the foot of the Stony moun- 
tains, of about fifteen hundred miles, and from north to south 
from the Natchez to the upper side of the great lakes, about 
twelve hundred miles. The continuity of this formation is no- 
where interrupted, on the east side of the Mississippi, by the 
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