MINERALOGY OF THE REDHEAD. S4f3 



and is at present making very rapid encroachments 

 upon the land. 



The Lunan Burn, which empties itself into the 

 German Ocean at the head of Lunan Bay, runs in 

 a valley in every respect similar to the Brothick. 

 The alluvial hills which occur towards its mouth, 

 have been greatly altered in form by the opera- 

 tions of agriculture, but they evidently present 

 the same abrupt terminations towards the sea, 

 which we have noticed above. They are de- 

 fended from any farther encroachments of that 

 element, by a number of low ridges of drifted sea- 

 sand, closely held together by the roots of the 

 Elymus arenarius, A r undo armaria^ Car ex are- 

 naria, and Triticum junceum. 



The structure of these hills of gravel, deserves 

 very particular consideration. Far from being a 

 mere heap of rubbish, the beds of sand are often 

 continuous and of considerable extent, and the 

 rolled masses of gravel are deposited in beds with 

 considerable regularity. These beds do not al- 

 ways possess a horizontal position, but present in. 

 their stratification a few of those appearances 

 which are usually considered as peculiar to the 

 more ancient strata. Thus, on the banks of the 

 Lunan, about a mile east from Kennell, I observed 

 beds of sand and fine gravel, inclining to the hori- 

 zon, at an angle of 20'' ; and on the extremities 

 of these beds, were deposited strata of gravel, dip- 

 ping in an opposite direction at an angle of 15**. 



z2 



