216 MAN AND THE GLACIAL PERIOD. 



" At Clarksburg, where the river unites with Elk Creek, 

 there is a wide stretch of terrace deposits, and the upper 

 limit is there about 1,050 feet above tide, or only 130 feet 

 above low water (920 feet) ; while at Weston, forty miles 

 above (by the river), these deposits cease at seventy feet 

 above low water, which is there 985 feet above tide. It 

 will thus be observed that the upper limit of the deposits 

 retains a practical horizontality from Morgantown to Wes- 

 ton, a distance of one hundred miles, since the upper limit 

 has the same elevation above tide (1,045 to 1,065 feet) at 

 every locality. 



" These deposits consist of rounded boulders of sand- 

 stone, with a large amount of clay, quicksand, and other 

 detrital matter. The country rock in this region consists 

 of the soft shales and limestones of the upper coal-meas- 

 ures, and hence there are many ' low gaps ' from the head 

 of one little stream to that of another, especially along the 

 immediate region of the river ; and in every case the sum- 

 mits of these divides, where they do not exceed an eleva- 

 tion of 1,050 feet above tide, are covered with transported 

 or terrace material ; but where the summits go more than 

 a few feet above that level we find no transported ma- 

 terial upon them, but simply the decomposed country 

 rock." 



Other noteworthy terraces naturally attributable to the 

 Cincinnati ice-dam are to be found in the valley of the Ka- 

 nawha, in West Virginia, and one of special significance 

 on the pass between the valleys of the Ohio and Mononga- 

 hela, west of Clarksburg, West Virginia. According to 

 Professor White, there is at this latter place "a broad, 

 level summit, having an elevation of 1,100 feet, in a gap 

 about 300 feet below the enclosing hills. This gap, or 

 valley, is covered by a deposit of fine clay. The cut 

 through it is about thirty feet, and one can observe the 

 succession of clays of all kinds and of different colours, 

 from yellow on the surface down to the finest white pot- 



