OF THE APPALACHIAN CHAIN. 



523 



basins, in which the upper carboniferous rocks have been preserv- 

 ed, all traces of that newer gi'oup, if deposited, should have been 

 so entirely swept away, as not to have left its fragments ^even in 

 any part of the wide tracts over which the coal-rocks are spread. 

 An additional reason for believing that the elevation and flexure 

 of the strata did not take place as late as the era of the new red 

 sandstone, is to be found in the remarkably undisturbed manner 

 in which a set of rocks of the age, approximately at least, of the 

 European new red group, rest unconformably on the axes which 

 ti-averse the Appalachian formations. All the geological relations 

 of these overlying rocks, occupying a very prolonged belt to the 

 southeast of all the carboniferous sti'ata, but especially those of 

 their organic remains, would seem to ally them closely to the 

 New red sandstone group of Europe, and probably to its newest 

 division. Extending almost continuously in a narrow belt from 

 the valley of the Connecticut, to beyond the southern boundary 

 of Virginia, these strata neither contain any axes of elevation, nor 

 do they exhibit even a conformity of strike with the neighboring 

 Appalachian and metamorphic rocks ; and, although they repose, 

 throughout a great part of the belt, immediately on the folded and 

 inverted older sti'ata, they furnish not the slightest indication of 

 having been disturbed by the movements which produced the 

 numerous axes beneath. We may hence confidently infer, that 

 the gi-eat undulations which elevated those older formations, from 

 the metamorphic to the carboniferous rocks inclusively, were an- 

 tecedent to the deposition of these newer beds, and therefore that 

 the age of the axes has been correctly determined to be antece- 

 dent to the commencement of the new red sandstone period. 



That few or none of the principal Appalachian axes originated 

 before the last of the coal strata were deposited, is demonstrably 

 proved by the almost universal conformity or parallelism of all 

 the strata. It is only necessary to consult the several sections 

 appended to this paper, to recognize the important fact, that from 

 the earliest to the latest of these Palseozoic rocks, extending prob- 

 ably somewhat further back than the Silurian formations of 

 Europe,* and terminating with the last layers of the coal, no per- 



* See a paper by Conrad, in Journal Academy of Natural Science, vol. S, part 21. 



