CHAP. XXXVII.] GRAVEL TERRACES. 299 



&quot; Travels.&quot; * It is between 60 and 70 feet high, 

 rising from a flat terrace of loam, and a very striking 

 object, reminding one, by its shape, of the pyramidal 

 Teocallis of the ancient Mexicans, of which Hum- 

 boldt has given figures, and which are so well de 

 scribed by Prescott, in his &quot; History of Cortes.&quot; As 

 we approached Wheeling, the valley of the Ohio 

 became narrower, and the hills, composed of strata of 

 the coal formation, sensibly higher. The State of 

 Ohio was on our left hand, or on the northern 

 bank of the river, and that of Virginia on our right. 

 The flat terrace of loam and gravel, extending every 

 where from the base of the hills to the river s bank, 

 forms a picturesque contrast to the steep slope of the 

 boundary hills, clothed partly with ancient timber, 

 and partly with a second growth of trees of less 

 height, which has sprung up where clearings have 

 been made. It is worthy of remark, that the mate 

 rials of the great terrace of loam and gravel become 

 more and more coarse as we approach nearer the 

 mountains between Wheeling and Pittsburg, and at 

 the same time the terrace itself is more and more 

 elevated above the level of the river. It appeared 

 to be about 60 feet high near the mouth of the 

 Great Kanawha, and about 80 feet high at George 

 town, 40 miles below Pittsburg, which I can only 

 explain by reference to the theory before advanced f ; 

 namely, by supposing the amount of subsidence, as well 

 as of the subsequent upward movement, to have been 



* Vol. ii. p. 32. t See ante, p. 259. 



O 6 



