﻿1848. THE RAPID. 207 



G5° 32' X., longitude 127 W., we were opposite to a 

 magnificent cliff in this ridge, only two or three 

 miles inland, apparently about four hundred feet 

 high, and some miles in length. The escarpment 

 faces directly southwards, is remarkably white, and 

 the layers composing it are nearly horizontal, but 

 with some undulation. The heights of the peaks 

 appeared to me to be about eight hundred feet 

 above the water. The beach is composed of frag- 

 ments of bituminous shale with pieces of lignite ; 

 and five or six miles further down, there is a fjood 

 section of the shale beds interstratified with dark- 

 coloured sandstone. 



At the " Eapid " the Mackenzie crosses another 

 spur, making three elbows in its passage through it. 

 The channel of the river there is formed of limestone, 

 and is shallow, producing, when the water is low, 

 a considerable fall on the east side, and a shelving 

 rapid on the west. At the elbow of the river, above 

 the rapid, one of the hills, which rises steej)ly from 

 the water's edge on the east bank, is composed of 

 limestone beds, wrapping over one another like the 

 coats of an onion, and curving, at the place where 

 this structure was most distinctly seen, at a spherical 

 ano;le of 65°, or thereabouts. These inclined beds 

 are capped and covered on the flanks by strata 

 of sandstone, which breaks down readily and forms 

 a steep talus of pale-red sand. A cliff of the upper 



