Stevenson.] -L • 4 [Maj' 20, 



1914 feet. This bench extends eastward from New river for more than 

 eight miles between Little Walker and Price mountains, and it is probably 

 the same with the fine terrace shown above the railroad bridge over New 

 river. It is distinct on the west side at four miles from the river on the 

 railroad ; and it appears to be the same with the plain seen nearly six 

 miles further west on the road leading across Pulaski county from Dublin 

 to Pearisburg ; but the barometric readings on that road are not wholly 

 satisfactory. 



The deposit on these benches is of clay and sand, containing pebbles of 

 varying size, most of them, as before, of local origin, but not a few 

 of them have come from the Blue Ridge. The upper bench is deeply 

 trenched here and there by narrow valleys in which rock exposures 

 occur ; elsewhere such exposures are rare, as the detrital cover is from 

 five to thirty feet thick. River terraces, apparently unbroken and almost 

 as perfect as those shown in theoretical diagrams were seen in the 

 "Horseshoe bend" bottom, but they could not be reached for measure- 

 ment. 



Erosion planes are equally well marked along New river within Wythe 

 county for some distance above and below the Wythe lead and zinc mines. 

 The lead company has sunk a shaft at about half a mile south from New 

 river, beginning at the topmost part of the bench, which, according to the 

 barometer, is 310 feet above the river at Thorn's ferry opposite the com- 

 pany's offices, or 2260 feet above tide. The surface is covered with loose 

 boulders, mostly three inches or less, though some are fully eight inches. 

 The deposit, as found in the shaft, is nearly fifty feet thick, and the bench 

 is of great extent on this southerly side of the river. Crossing to the 

 other side and taking the road over Lick mountain to Wytheville, one 

 soon comes to a bench, 120 feet by barometer above the river or 2070 feet 

 above tide. This was not recognized at the lead mines on the southerly 

 side of the river, but on this side it is distinct almost from Jackson's ferry 

 to the Wytheville road, on which it is reached at three miles from New 

 river. The higher bench is reached by the Wytheville I'oad at six miles 

 from the river, and, according to the barometer, is 320 feet above low 

 water at Thorn's ferry or 2270 feet above tide. It carries a thick coat of 

 debris loaded with pebbles. 



The tributary streams of New river are terraced. A fine bench was 

 seen on Wolf creek in Giles county at a mile or so from the river. It is 

 sixty -five feet above the stream and carries a thick deposit, which is rich 

 in rolled stones. The upper terrace of Reed creek below Wytheville was 

 not measured, but it is fully 150 feet above the stream. It shows huge 

 boulders of Potsdam sandstone resting on the Knox limestone, though a 

 broad and deep ravine separates their resting place from Lick mountain, 

 whence they came. An erosion plane, similar to that seen in Pulaski 

 county, was observed north from Wytheville within the New river area. 

 Its superficial deposit of sand, often carrying many pebbles, is so thick as 

 to conceal the bedded rocks for long distances. 



