530 REV. R. B. WATSON ON THE GREAT DRIFT-BEDS WITH SHELLS 



bottom is exposed a small face of soft friable sandstone, above which is a dense 

 sandy clay apparently about a foot thick, but very little of it can be seen from 

 the debris. It is best seen at the south end of the rock, and its laminae corre- 

 spond to the slope of the rock. About 20 feet above this the face of the boulder- 

 clay is crossed by a band 2 feet thick of big stones, some of which are 2 

 feet long and broad. This bed runs downwards across the bank till it sinks to 

 8 or 10 feet above the burn. Ten feet above this is a less marked bed of stones, 

 which, on the whole, keeps its relative position to the other, till, at their point of 

 lowest depression, they seem to run into one another. As the centre of this 

 section is obscured for 100 yards by a grassy bank, of course there is no certainty 

 that these stone beds are the same throughout ; they seem however to be so. 

 If they are their dip is probably due to the fact that they were deposited on the 

 slope of the hill side, and that the section which the burn has made is not in the 

 line of their strike but transverse to it, — as indeed is obviously the case from the 

 exposure of the rock where they are highest, and its concealment where they 

 sink lower. The irregularity of the two beds relatively to each other is no more 

 than might be expected. A close examination of these beds is impossible from 

 the steepness of the bank, and the view of them from below, or from the other 

 side, is unsatisfactory, owing to the debris, the irregularity of the surface, and 

 the similarity of the colour throughout. Above this bed of stones is a layer of 

 clay a few inches thick. Little bands of clay and sand traverse the boulder-clay, 

 and about half-way up the bank is at one point (Plate XXL, fig. 4), a bed of 

 stratified sand, overlaid by a stratum of boulder-clay, which last is separated 

 from the mass of the boulder-clay above by a parting of sand. The sand-bed 

 contained a few fragments of shells. The layers of sand curve sharply over 

 upon themselves, as if they had been thrust forwards under a heavy weight 

 from behind, and forced to over-ride one another. The boulder-clay resting on 

 this sand seems to have shared in the thrust, but being less easily bent has 

 merely swelled out into a club-shaped mass. 



BetAveen this and the next good section a considerable mass of felstone porphyry 

 appears in the burn. Above this is by far the finest section of all (Plate XXL, 

 fig. 5.) It is from 200 to 300 yards long, and the bank is 140 feet high. It pre- 

 sents two or three broad perpendicular faces, intersected by deep hollows 

 channelled out by the running of water. The lower 20 feet or so is a debris 

 talus. Just above this the rock crops out through the bank at one place. It is 

 a soft, crumbly shale. It is covered by a bed much more sandy, and with fewer 

 stones, than the rest of the deposits. It was in this bed that I found Naticas 

 quite unbroken, but so fragile that they could not be got out uninjured. In it 

 I also found a fragment of Litorina. The boulder-clay above the sand shows 

 a tendency to bedding. A very marked line, apparently of large stones, crosses 

 the whole face of the bank from 25 to 50 feet up, rising as it goes down the 



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