190 M. R. CAMPBELL — PALEOZOIC OVERLAPS IN VIRGINIA. 



described. So far as the evidence of these basins is concerned, this fold- 

 ing must have occurred previous to the deposition of the Walker black 

 shale, but which in a general way will be regarded as occurring at the 

 beginning of the Devonian period. This is doubtless the same disturb- 

 ance recognized by N. H. Darton in the vicinity of Staunton, Virginia,* 

 which produced the unconformity between the Oriskany sandstone and 

 Lower Helderberg limestone. 



The uplifting and probable folding, marked D, which closed the sedi- 

 mentation in Price mountain basin, has not heretofore been recognized ; 

 this must have occurred near the middle of the Lower Carboniferous 

 period. There is considerable evidence in the northwestern portions 

 of the valley, in the vicinity of New river, of the continuation of this 

 period of disturbance throughout the deposition of the Mauch Chunk 

 sediments, but the evidence is not in shape for presentation at this time. 



Lastly, the post-Carboniferous period of folding, E, has long been 

 considered as the only one and accountable for all of the folding of the 

 Appalachian type that exists in this portion of the continent. It now 

 seems as though this was no more important than many which preceded 

 it and that, in fact, the deformation has been practically continuous since 

 early Paleozoic time. 



♦Notes on the Stratigraphy of a portion of Central Appalachian Virginia : Am. Geologist, vol. x, 

 pp. 10-18. 



