288 
BATHYMETRICAL SURVEY OF 
by the Conon valley towards the Black Isle. The strise, trending about 
east-south-east, found on the tops of Meall na Speirag and Beinn Liath 
Beag at elevations of about 2000 feet, on the watershed between the 
Blackwater and the streams flowing into Loch Luichart, clearly show 
the development of the ice during this period. 
Important evidence regarding the transport of materials during the 
time of the confluent glaciers is furnished by the distribution of boulders 
of foliated granite and Old Bed Sandstone on the slopes of Ben Wyvis. 
These have been carried from the west or west-north-west, and have 
been traced up to a height of 2400 feet on Cam Gorm and Little Wyvis, 
while their upper limit on Ben Wyvis itself is 2300 feet. It is further 
apparent that the ice moved through the pass between Little Wyvis and 
An Cabar, and streamed down the valley of Loch Glass north of Ben 
Wyvis. Still further north in Kildermorie forest and Strath Busdale, 
the direction of the ice-flow was south of east, as proved by the striae, 
and the transport of boulders of foliated granite or augen gneiss. From 
the period of confluent glaciers to the time of their disappearance in 
the upland glens, the various stages of retrocession are represented by 
the moraines. 
Loch Fannich . — The soundings clearly show that this lake gradually 
deepens towards the eastern portion, the deepest sounding, 282 feet, 
being situated about a mile above the outlet. The hill-slopes on both 
sides of the loch for considerable distances are covered with morainic 
drift, save near the outlet, where there is a prominent barrier of rock. 
At the latter point the southern spur of An Coileachan approaches the 
northern margin of the lake, and is prolonged on the south side in An 
Cabhar and Cam na Beiste. Along the eastern side of this ridge, the 
quartzose granulites and muscovite biotite schists are isoclinally folded 
on vertical axes striking north and south — that is, at right angles to 
the course of the lower part of the loch. At the outlet, and for a mile 
below that point, the Gmdie river flows on alluvial deposits, these 
materials having been largely contributed by side streams, and especially 
by Allt a’ Choin Idir, draining from the north. Beyond the alluvium, 
at the 800-feet level, the Moine schists are exposed in the bed of the 
river and on the hill-slopes, and there is here no indication of a pre- 
glacial river channel filled with drift. The surface of Loch Fannich is 
822 feet above Ordnance datum, so that the depth of the rock basin 
below the rocky barrier, visible about a mile beyond the outlet, is 
260 feet. 
Loch Luichart . — This lake is a true rock basin lying among the 
crystalline schists, with a barrier formed of these materials at its outlet. 
Where the stream issues from the loch, it runs through a narrow gorge 
of rock and over successive waterfalls. In this sheet of water there are 
three basins, of which the most westerly is the most important, its 
greatest depth being 164 feet. The surface of the lake is 250 feet above 
