THE MOUNTAIN. 77 



slightly deviating lines; some geologists having numbered 

 and described specifically the alterations of the line of trend. 

 They are from a few miles to several hundred long, and as a 

 general fact show steeper dips on their western sides, while 

 they decrease in abruptness of inclination on both sides of 

 lines of fracture, from east to west, or in a line transverse to 

 the line of fracture, thus demonstrating that the violence of 

 the forces which have ruptured the strata diminishes most ob- 

 viously proceeding westward toward the central line of the 

 continent. This will be seen by contrasting the gentle arches 

 of the bituminous coal-measures with the abrupt and, in some 

 places, vertical and collapsed, even overturned and crushed 

 axes of the lower part of the series, as exhibited in the eastern 

 range of mountains approaching the great foci of volcanic 

 or earthquake action. 



One region reveals violent crimping, wrinkling, or foldings, 

 with steep dips, and great crushing of the strata from flexures 

 and fractures, showing evidence of vast oscillations, followed 

 by fissures and chasms, splitting and rending of rocks, with 

 injections of trap and crystalline metamorphosis of sand layers 

 and mud masses : the other showing increased respect for the 

 law of gravitation, with preponderance of inertia, allowing 

 the rocks to repose with gentle dips, or in horizontal position, 

 comparative immobility or sleep of the elements predomi- 

 nating over extensive ranges of quiet and undisturbed basins, 

 the waves gradually subsiding from violent tossings to gen- 

 tlest undulations, and dying away into absolute repose. 



It is a natural inquiry, Where do these rocks belong? 

 what are they ? and, is the geological structure of this Con- 

 tinent the same as that of the Old World ? Have we the 

 same order of position of mineral masses, the same lithological 

 characters, and organic remains ? 



Many American observers, struck with the beauty and 

 perfection of the classification of the English geologists, 

 have been explaining the geology of this country by reference 

 to that classification. 



They seem to be successful in identifying species of organic 

 7* 



