IN GLEN TILT. 365 



the soil is formed of the decomposed ingredients. On that 

 part of the ridge wliich lies towards Glen Merk, the loose 

 stones are partly mica-slate, and partly grey porphyry. — On 

 Cairn y Chlannan and Cairn Vardenoch, there occurred also a 

 very few loose fragments of gneiss. 



145. Glen Merk merits more attention, as it exhibits a junc- 

 tion between the strata and the granite. 1 he name of Glen 

 Merk is confined to a part of the valley along that stream, ex- 

 tending about two miles above its opening into Glen Tilt. At 

 some distance from the opening, the Merk receives the Deery 

 from the west ; and, above this, the Glen has the direction of 

 due north, being formed on the east by the declivity of Cairn 

 Vardenoch, and on the west by that of Ben y Venny. The 

 head of the Glen is closed in by a rocky steep, about three 

 hundred feet high, connecting the two mountains, but deeply 

 cut by the stream, which falls through the dark chasms of a 

 narrow channel. 



146. At the falls of the Merk, where the Glen opens into 

 Glen Tilt, there are strata of mica-slate, stretching N. 48" E., 

 and dipping to the south at an angle of 27°. They agree there- 

 fore with the general position of the strata through the adjoin- 

 ing part of Glen Tilt. In following up the side of the Merk, 

 to where it receives the Deery, the channel affords a transverse 

 section of the strata. They seem to be either mica-slate, or 

 gneiss ; and, as far as could be judged from a distance, they 

 conform in stretch and dip with those at the falls. 



147. Before I proceed up the channel of the river, I shall 

 mention what we noticed respecting the mountains on each 

 side. Along the declivity of Cairn Vardenoch, at the distance 

 of more than a mile from the head of Glen Merk, the loose 

 fragments shew the higher part of the mountain to consist ei- 

 ther of gneiss, or of a granite, nearly the same in character 



Vol. VII. P. II. 3 A with 



