﻿1848. RIVER TERRACES. 183 



A tliermal spring, much resembling sea- water in 

 its saline contents, issues from tlie front of the cliff, 

 and the fissure from whence it flows is incrusted 

 with crystallised gypsum.* Shale beds abut against 

 the lower side of the Rock, covering the limestone 

 beds above mentioned; but they are in a great 

 measure concealed by the shelving debris of the 

 bank. Contiguous to the upper or south side of 

 the Rock there are sloping banks of gravel, capped 

 by a vertical wall of friable sandstone. And three 

 miles higher up the stream, there are two river 

 terraces, more complete than any I noticed else- 

 where on the Mackenzie, though in many places 

 a hiQ-h and low bank can be traced. These ter- 

 races are composed of fine sand ; and the slope 

 between them is so steep as to require to be 

 ascended on all fours. Both terraces are very 

 regular in their outlines, and are covered with 

 well grown Pinus hanksiana. The uppermost is 

 about two hundred and fifty feet above the river. 

 From this terrace, the Rock by the River's Side is 

 clearly seen to be part of a chain, which is crossed 

 there by the river, as has been already mentioned. 

 This is not so evident from the channel of the 

 stream. The high sand-banks continue almost with- 



* Dr. Davj, who kindly analysed some water from this 

 spring, ascertained that the chief saline ingredient was sulphate 

 of magnesia. 



N 4 



