Remarks on a " Raised Beach" at Ar dross. 



73 



winter (1862-3) having exposed a new section of it, I have 

 thought it worth while to set down the results of a fresh 

 examination. 



The beach begins a little way east of the railway bridge, 

 at the cottages of the farm of Ardross. There the land rises 

 gradually from the high-water mark ; and the bed of shells 

 of which we speak is scarcely at all elevated above high- 

 water, and, by the percolation of water impregnated with 

 iron, has been formed into a kind of rock. 



Passing eastward, the same bed may be noticed at various 

 elevations, according to the character and configuration of 

 the shore. Before travelling many steps in that direction, 

 the shore presents a perpendicular escarpment, rising about 

 eight feet above high-water mark. There the bed of shells 

 appears at about the height of six feet. It is not level, but 

 undulating ; and it is noticeable that the shells occur most 

 abundantly- in the higher portions of the bed, while the 

 lower portions are chiefly occupied with rolled pebbles. 



The shells themselves are generally fragments of the 

 cardium, mactra, trochus, patella, and Utorina, with an occa- 

 sional land-snail shell, and are disposed in no kind of order, 

 and mixed with rolled pebbles. 



The cliff on the shore gradually becomes higher, and the 

 shell-bed rises along with it from six feet to nine, and ulti- 

 mately, on the summit of the rock on which the ruins of 

 Ardross Castle stand, to twelve feet above high-water mark. 



It is worthy of remark, that, as the bed rises higher, the 

 number of rolled pebbles diminishes, and their place is sup- 

 plied by angular and unworn fragments ; and at the highest 

 point the latter so far preponderate that scarcely a rolled 

 pebble can be found. 



On the whole, the conclusion to be drawn from all these 

 appearances is, that this is no proper example of a raised 

 beach- — 



1. Because the different heights at which within a few 

 yards it makes its appearance cannot well be accounted for 

 by any supposed elevation of the land. 



2. Because the entire absence of rolled pebbles from the 

 higher portions of the bed indicates that these were never, 



VOL. III. K 



