On the Physical Geology of the United States, fc. 11 
some comparatively local exceptions.* This is not mere hy- 
pothesis. 'The evidences will be adduced in the discussion of 
the causes and periods of elevation of the land and mountains. 
The primary ranges of rocks and mountains of the Atlantic 
states, those of northern New York and north of the great lakes, 
and those of the Rocky Mountains and Cordilleras of Mexico, 
existed in the same relative position as now before the deposition 
of the newer sedimentary rocks of the United States.t Similar 
primary ranges in South America give form also to its coasts. 
We will here withdraw our attention from the great equilibra- 
ting currents of the ocean, and consider only that part of the 
compensating system of circulation that constitutes the equatorial 
current, the Gulf Stream and the Labrador current in the Atlantic 
Ocean. From the operation of dynamical causes already ex- 
plained, the currents here alluded to, or others analogous to them 
in their directions and effects, may be supposed to have flowed 
during long periods, when the largest portion of the American 
continent was beneath the level of the sea. 
_ The equatorial current in its westward flow, may be supposed 
to have been deflected by the primary ranges of the coast of 
South America, (or at least by the Andes,) in part to the south- 
ward over the vast pampas, but mostly to the northward through 
the Caribbean Sea, the Gulf of Mexico, and over the broad val- 
leys of the Mississippi and St. Lawrence, which were then parts 
of the ocean. 
As the direction of the equatorial current before its obstruction 
was to the west, if deflected by the eastern coast of South Amer- 
ica, its course was then as now to the N. W., as above men- 
tioned ; but bending around more and more to the N., N. E. and 
K. as it progressed into higher and higher latitudes, in conse- 
quence of the dynamical law already explained. ‘This current 
flowing to the W., N. W., N. and N. E., would progress by the base 
of the Cordilleras to the N. and N. E. towards Hudson’s Bay ; 
another part deflected still more to the east by the primary range 
in Arkansas and Missouri, and by meeting the polar current from 
the north through the Mississippi valley,t seems to have flowed 
* The Green Mountains, Highlands, the Apalachian chain, &c., large in them- 
selves, but local when we consider the vast expanse of undisturbed rocks. 
t The evidence of this, is their unconformability. 
t The evidence of the transport by such currents in this direction, is found in 
the transported materials of various degrees of coarseness in Mississippi, Alabama, 
and Louisiana, &c. 
