62 CHANNELS AND GLENS OF AYRSHIRE. 



River Doon. — Ness Glen on the Doon, as has already been 

 remarked, is cut through the rocky barrier of Loch Doon, there 

 not being in this instance any drift-filled glen draining at one 

 time the hollow in which the loch lies. In getting out of Ness 

 Glen, at its upper end, there is a complete absence of high scaurs 

 of drift, such as characterise districts where there are recent rocky 

 glens and old drift-filled ones. Boreland Glen on the Doon is 

 excavated in rock of calciferous age, the river having left the 

 old valley. Some distance above the head of the glen, opposite 

 Shankston Loch, there is a 70-feet drift-scaur on the left bank. 

 The old glen or valley may be on this side, but on this point I 

 cannot speak with certainty. 



Garepool Burn. — At about 1000 feet of altitude the Garepool, 

 New Cumnock parish, turns suddenly to the left, leaves the old 

 valley, and has cut a new channel through rock, with almost 

 perpendicular walls, at first to a depth of about 40 feet. In this 

 rocky gorge it descends for about 400 feet (vertical) till it comes 

 to the plain of the Nith. This burn has perhaps the greatest 

 declivity of any Ayrshire stream, falling 1000 feet in a distance of 

 12 furlongs. The drift-filled valley is to the south of the new 

 rocky cut. 



River Girvan. — The Girvan about the neighbourhood of the 

 Straiton to Newton-Stewart road bridge, in the lower reaches of 

 the Blairquhan Policies, and further down, has made a few rock- 

 cuttings, but they are of no great magnitude, and some of them 

 may be in the bottom of the old glen. 



Penwhapple Burn. — The Penwhapple below the furthest up 

 bridge over it, cuts deeply into the fossiliferous Silurians, the old 

 glen being probably to the south of the rocky cutting. 



River Stinchar. — The Stinchar above Black Row cuts a rock- 

 glen in the greywackes, and, as the drift immediately below this 

 glen on its (the Stinchar's) left side is about 100 feet thick, the old 

 glen may be on that side. 



Dunnach Burn. — The Dunnach (a tributary of the Tig) does 

 not leave the old valley very much, but for a considerable distance 

 on its left it has bared the old, glaciated, steep rock-bank of 

 deposits, the right bank showing great high scaurs of drift (See 

 Figure 5). 



