OF THE PARALLEL ROADS OP LOCHABER. 
673 
The base of the mound is better seen in sections on the banks of the Turret, which 
expose a mass of imstratified light grey sandy clay, from 50 to 80 feet thick, full of 
angular fragments, including a lew large blocks, of the local rocks. Its general 
appearance, viewed in front and looking towards Glen Turret, at its terminal slopes 
facing Glen Roy, is shown in the following sketch. 
Fig. 3. 
View looking down Glen Roy from its junction with Glen Turret. 
a'. Bed of river gravel. 
b. Detrital mound of the Turret valley. 
The lower “road” No. 4. 
2, 3. The upper two parallel roads. 
The want of continuity in the “mound ” is due at the first break to the passage of a roadway, and at the 
second to the passage of the Turret. 
I do not see therefore how this deposit can be due to delta formation. Not only is 
the accumulation of the main mass at the most remote instead of the nearest point of 
discharge, but there is an absence of the bedding or stratification that would belong to 
a deposit formed in tranquil lake waters. It appears to me to be moraine detritus, 
brought down from Glen Turret and its tributary glens descending from Ben Erin 
and the other hills at the head of the glen, subsequently worn and remodelled on the 
surface by water action (post, p. 688). Its present terminal slopes are clearly due, 
as pointed out by Macculloch, to the River Roy, which has undermined and removed 
that portion of it, and of the other such mounds, which projected into the Roy 
Valley, while the loose debris at top has fallen down and formed slopes, the angle of 
which is almost invariably one of 40°. 
The following is a diagram section, from the foot of the Turret Pass at fig. 1, to the 
Roy at fig. 3. 
4 r 2 
