IN THE ALLEGHENY REGION OF SOUTH-WESTERN VIRGINIA. 243 



rose.* Thus the inhabitants of the fresh waters on either side could have had no 

 descent from a common fresh-water ancestry, but must have been supplied by inde- 

 pendent creations or migrations, or descent from marine types. There has been no 

 doubt a later submergence of the Allegheny region both before and subsequent to 

 postpliocene times, as indicated by the remains of the Eocene at Brandon, Vermont, 

 and of the same at Monte Alto, Pennsylvania, by the great number of smaller and 

 larger boulders containing fossils from the Silurian and Carboniferous rocks scattered 

 over the Miocene regions of Eastern Maryland and Virginia. The destruction of the 

 greater part of a ridge by denudation, in Wythe Co., Va., near the Kanawha River, 

 left remains of the floor and galleries of a cavern or caverns along a line of eight 

 miles, which contain a limestone breccia of postpliocene age, containing remains of 

 Taplrus, Dkotyles, Ecjuus, Castor, Lepus, and modern Pulmonates. There was, then, 

 one submergence to deposit the early tertiaries, and another to denude postpliocene 

 deposits; no doubt the same that has stratified the drift. The latter occurrence has 

 been also connected with local phenomena, dependent on the condition of the 

 Kanawha (new) River, which, near the ridge in question, has brought d^own from the 

 south huge boulders of chlorite and Silurian conglomerate, to a point below its passage 

 through both the Poplar Camp Mountains above, and the ridges in question. The 

 great streams of immense, somewhat rounded sandstone rocks which occur in many 

 places on the slopes of the mountains of the back-bone in this region, might readily 

 have been gathered into submarine ravines and gorges, as they were undermined by 

 the wave action at the surfiice of the ocean. A species of local drift, however, occurs. 

 On the hills from a quarter to a half mile from the right bank of the Kanawha (new) 

 River, at Eggleston's Springs (which is at the eastern base of the main Allegheny 

 back-bone, but separated from the valley by three mountains), at an elevation of from 

 250 to 400 feet, a bed of coarse and fine gravel, in red clay, forms the crest of a hill 

 of three miles in extent. On the opposite side of the river, four miles lower down, 

 opposite Pearisburg, there is a ridge covered with very coarse gravel; the stones 

 several inches in diameter, and of white semi-transparent quartz, which I did not find 

 in the sandstones of the adjacent mountains. A similar coarse^ local drift is seen on 

 the bank of the Roanoke about 200 feet above the level of the water, near Salem, 

 Roanoke County, where the railroad cuts it. Similar deposits have not been observed 

 away from the neighborhood of these rivers. This distribution of these deposits- 

 would indicate the action of streams flowing at a level of, at the most, 350 feet 

 higher than now, perhaps owing to the opposition of remains of fractured moun- 

 tain barriers which cross both streams shortly below these points. These have so far 

 yielded to the action of the water, as to be indicated now by nothing more than 



"This view is expressed by Rogers, Geology Pennsylvania, ii, p. 92-t. 



62 



