30 G On the Upheaval and Sinking of land [No. 4. 



Near Crail the rock dips under the sea, and exposes a surface 



well suited to withstand the surge, and there accordingly we have ex- 

 tensive raised beaches with the old sea cliffs a considerable way inland. 

 Near St. Andrew's, again, it is the reverse of this. The rock dips away 

 from the sea, 



and the upheaved beach has been worn away, the waves now attacking 

 and abrading the old sea cliff. In this, again, ten or twenty feet up 

 the cliff, we have caverns— Lady Buchan's at St. Andrew's, and that of 

 Kinketh to the south, which doubtless opened out on the former beach, 

 and were excavated by the surges of the ancient ocean. 



I have rarely met with shell or gravel beaches off the mouths of our 

 great rivers ; the deltas or mud deposits have in these cases taken 

 the place of the original beach, or covered or concealed it — or the 

 whole has been eaten away again up to the verge of the purely fresh 

 water deposits by the advance of the ocean. The alluvium of the del- 

 tas of our great rivers can only be accounted for on the hypothesis of 

 upheaval. Streams, which run sluggishly, or are partially stagnant, may 

 give us sandbank ; — silt, such as that of the Ganges, the Taptee, the In- 

 dus, the Nile, &c, is only precipitated when the water in which it is 

 suspended, is permitted for some time to remain in a state of absolute 

 repose. Even were it otherwise, the deposit of silt must be restricted 

 to the limits of the inundation, and yet in fact the inundation rarely 

 extends over more than a mere fraction of the true alluvial delta. The 

 same is the case with our carse lands in Scotland — clearly consisting of 

 river-silt, yet of silt which could only have become accumulated and 

 consolidated under water in a state of repose. The level of our delta, 



