Stevenson., £.)\r [Aug. 15, 



The Alleghanies of Virginia are reached in Maryland. They are not 

 the same with those of Pennsylvania, but belong to the series of anticlinals 

 next east. In this region, the Potomac river, rising near the Alleghanies 

 of Pennsylvania, breaks through the Alleghanies of Virginia and flows 

 past Cumberland on its way to the Atlantic Ocean. 



Within the whole area examined, no traces of glacial drift occur, except 

 along the banks of the Ohio river, where such material appears on the ter- 

 races, having been brought down by the Beaver and Alleghany rivers 

 from the northern counties. 



Some notes respecting the river terraces of the Ohio and Monongahela 

 rivers were given in my report on the Greene and Washington district of 

 Pennsylvania (1875). The observations begun in 1875 were continued 

 during 1876 and 1877, and the surface geology was studied as closely as 

 was possible without interfering with the economic, investigations, which 

 were the main object of the survey. Some of the observations are recorded 

 in my report on the Ligonier Valley of Fayette and Westmoreland coun- 

 ties (1877). Barometric measurements were made wdierever a terrace or 

 bench could be recognized, but, in very many cases, these observations 

 proved to be worthless as no spirit-leveled line was within reach to be used 

 as a base. The measurements given in this paper were verified by direct 

 reference to leveled lines and by repetitions. 



I. 

 Benches' along Cheat River and its Vicinity. 

 Cheat and Monongahela rivers unite in Pennsylvania at about two miles 

 north from the line of West Virginia. Their channel-ways diverge rapidly, 

 so that the former stream issues from Chestnut ridge at little more than 

 three or four miles south from the State line, while the latter breaks 

 through the same ridge at fully thirty miles further south. The course of 

 Cheat is rudely north-west, and that of the Monongahela rudely north and 

 south. 



StewarMown Benches. In the peninsula betw T een these rivers and west 

 from Chestnut Ridge, a line of high knobs begins at about a mile west of 

 south from the mouth of Cheat and continues in an irregularly south direc- 

 tion to Dorsey's knob beyond Morgantown in West Virginia. These hills 

 are nearly alike in height and reach to about 600 feet above the rivers at 

 their junction. They are rudely conical and their sides are terraced. On 

 one of these hills is the village of Stewartstown, at nearly three miles from 

 Cheat river. In descending from this place to either river, the following 

 series of benches was seen : 



Tenth Bench 525 ft. above river, 1295 ft. above tide. 



Ninth " 465 " " 1235 " 



Eighth " 425 " " 1195 " 



Seventh " 360 " " 1130 " 



Sixth " 330 " " 1100 " 



Fifth " 280 " " 1050 " 



Fourth " 210 " " 980 " 



Third " 180 " " 950 " 



Second " 80 " " 850 " 



First " 20 " " 790 " " 



