28 
AMERICAN GEOLOGY. 
and fossiliferous characters, would be regarded as formations of 
different eras. Taking it then as a type of the past, we may 
well doubt the correctness of many of the geological data 
which have formed the foundation of our reasoning. Tidal 
waves, normal oceanic currents, and river currents, with their 
burdens of detritus, have .ever exerted their powerful agency in 
distributing the waste materials of continents, and in construct¬ 
ing the fossiliferous mountains of the globe. Conglomerates, 
coarse and fine sandstones, if we regard the foregoing facts, 
may always be considered as shore deposits, and argillaceous 
and calcareous rocks as pelagic formations; especially may we 
recognize in most of the calcareous rocks formations similar to 
the recent beds in the Pacific and West Indian islands. 
§ 25. The systems of relief of the North American continent 
are not as yet well determined. The mountain ranges, how¬ 
ever, pursue a northerly and north-easterly directions, by which 
it appears that the force which raised the continent acted in 
those directions, or that this force preponderated over all the 
forces acting in other directions. On the Atlantic coast it is 
north-easterly, or parallel with the coast line; on the Pacific 
coast it is northerly, and parallel with the Pacific coast line. 
Considered as water sheds, the ranges of the United States 
may be reduced to five: 1. The Appalachian, which is parallel 
to the Atlantic coast; 2. The Green mountain range, which 
runs north, or six or seven degrees east of north; 3. The Rocky 
Mountain range, which, according to the best maps, is also 
directed to the north; 4. The Pacific coast ranges, which are 
north; 5. The Lawrentine range, which pursues an easterly and 
westerly course. These chains of mountains are often flanked 
by parallel ones, which attain at many points greater heights; 
yet they are evidently subordinate to them, since they are bro¬ 
ken through by the water courses, and are not coextensive with 
them in length. Thus the Taconic range flanks the Green 
mountain on the west in western Massachusetts and Vermont; 
yet Graylock of the former rises nearly 3600 feet above tide, 
and the latter only 2500. Black mountain flanks the Blue 
