On Evidences of Ice- action, by Mr. Wm, Stevenson. 200 



and broken up for road metal. This is particularly the case 

 along the post road between Reston and Ayton, where 

 fragments of gneiss, mica slate, pure vein-quartz, porphyries, 

 and other rocks of Grampian origin, were a few years ago 

 to be seen in every depot by the road-side. The current 

 which brought the ice upon which these were conveyed, 

 must have come from westward, where these rocks occur in 

 situ. Among the more remarkable of these boulders may 

 be mentioned a rounded block of gneiss (?) on the road at the 

 top of Ecclaw Edge — a large block of mica slate on the slope 

 of the hill east from Burnhouses, — several smaller masses at 

 Windshiel, Kidshielhaugh, and Abbey St. Bathans, and a 

 block of a very peculiar diorite, which formerly was one of 

 the stepping-stones in the Whiteadder at Ellemford. This 

 diorite, which is composed of greyish quartz, red felspar, 

 and a little chlorite, occurs in situ in the neighbourhood of 

 Aberfoyle, and is beautifully exposed at the waterfall de- 

 scribed in " Waverley." Rounded pebbles of the same have 

 been found in the Whiteadder below Preston Bridge, where 

 also mica slate, quartz, sandstone from the Lothians, &c, are 

 to be met with in the river shingle. Some years ago, in the 

 course of a ramble with the late Mr. Blackadder, of Glammis, 

 we picked up, on the bed of the river near Blanerne, a small 

 piece of a very peculiar porphyry, which he at once identified 

 as that of Lintrathen, in Forfarshire. Small pieces of coal 

 have also been found in a sand-pit near Ayton Castle, and 

 in boulder clay at Woodheads, near Marchmont, 700 feet 

 above sea-level. These must have come from the Lothians, 

 and it is not at all probable that water alone was the 

 carrying power. From the nature of the rocks in Berwick- 

 shire and the amount of detritus with which they are 

 generally covered, traces of glaciation are rare and dubious ; 

 the only well marked case being, so far as I am aware, that 

 at St. Abb's Head. Ancient sea-margins are very numerous 

 and well defined throughout the county, notably so in the 

 valleys of the Eye and the Whiteadder. They are very 

 conspicious upon the southern slope of the hills above 

 Preston. 



But the most remarkable and striking exhibition of ice- 

 action is shewn in the breaking up of rocks by grounded 

 bergs, or heavy floes. An instance of this may be seen in 

 the freestone quarry at Langton, about a mile from Dunse. 

 There a section of about 35 or 40 feet is exposed, the lower 



