IN THE SOUTH OF xVERAN. 533 



ruins. The soft sandstone rock here appeared about 40 feet above the bui-n, and 

 over its face lay a dark bed of fine clay, in which shells were both abundant and 

 remarkably fresh and unbroken, the bivalves being in pairs, and retaining both 

 their ligament and epidermis. 



Above this is a long, narrow gorge, about 60 feet deep and half a mile long, 

 cut through the soft shales in the line of their strike, which is north-west. The 

 l)0ulder-clay lies down the dip of the strata on the north-east. (Plate XXII., 

 fig. 10.) At about 130 feet above the sea the gorge turns a little more westward 

 than before, and in the angle it expands and forms a small basin, with huge 

 boulder-clay banks 120 feet high on the north-east side. About 60 feet up, the 

 bank is crossed by a dense bed, a few inches thick, of dark brown clay, very hard, 

 with small gravel in it, and very rich in shells, especially Leda in pairs, and 

 Balanus valves. 



Above the gorge is a great stretch of laminated felstone, which occupies 

 both sides of the burn-course. It is this felstone which seems to have protected 

 the shales lower down the burn. 



The phenomena of the clay -beds for half a mile above this point, which is 

 from 250 to 300 feet above the sea, are extremely instructive and interesting, 

 but very difficult to explain. (Plate XXII. fig. 11.) 



Cut through by the burn is a bank, 7 feet high, of intensely hard yellow 

 clayey gravel, resembling that which I have described in Cloinoid Glen, and like 

 it, chiefly made up of felstone porphyry. Like it, too, it has all the appearance 

 of having been travelled over by the glacier, so compressed and yet so dry and in 

 itself incoherent is it. The upper surface of this bed seems to be quite uncon- 

 formable in its slope to any of the other contour lines, either of the rock below, 

 or of the beds above, for it dips to the westward, while the whole land is rising 

 in that direction. It seems, in short, just like a bank that had nestled in be- 

 hind the edge of the rock, and was thus preserved from the abrasion of the glacier. 

 On this back slope of the yellow gravel lies the much redder and somewhat 

 softer common boulder-clay, in which I found a fragment of shell. (Plate 

 XXII. fig. 12.) Horizontally overlying this, and abutting unconformably against 

 the 3'^ellow gravel, is a ten-foot thick bed of coarse sand, on the top of which is a 

 layer, 8 feet thick, of very large stones. Above this is some 6 inches of fine light- 

 coloured sand, and over all is earth. On the east side of the burn, this bed of 

 yellow gravel (Plate XXII. fig. 11) nestles in behind a strangely isolated mass of 

 the felstone, close above which is another rock of rotten felstone, round which the 

 old burn-course lies. The new channel is 3 feet deeper than the old one. Some 

 very large and well-striated boulders of greenstone lie in the yellow gravel bank 

 ' opposite this point, as shown in Plate XXII. fig. 12. 



Just above this, in the burn-course, there appears on the west side, a long 

 face of felstone, which rises 4 or 5 feet above the burn. It seems glacier- worn 



