LAKES IN RELATION TO GEOLOGICAL FEATURES 507 
MucKLE LuNGA. — Rock-basin in granite. 
MucKLE Water. — Ponded by drift at head of valley excavated in Middle 
Old Red flagstones. 
MuiCK. — Simple rock-basin at edge of Lochnagar granite massif. Many 
Scottish lakes occm- in a similar position, probably due to the zone 
of hornfels which usually surrounds the later granite masses being 
less tractable than the granite. 
MuLLARDocH. — Valley rock-basin in granulitic schists in Glen Cannich. 
Nant. — Rock-basin in Lower Old Red volcanic rocks of the Lorne 
plateau. 
Naver, — Valley rock-basin along the strike of Moine schists, and partly 
ponded by drift. The hollow in which Loch Naver is situated was 
one of the outlets for the ice from the Mid-Sutherland area. 
Nell. — Lies in hollow partly in the Lorne volcanic plateau, partly in 
the underlying Lower Old Red sediments, and probably in the floor 
of schistose rocks on which they rest. The barrier consists of 
. gravels of the 100-ft. raised beach and morainic material, while 
moraines form islands in the loch. It is therefore highly probable 
that a lobe of the great confluent glacier which emanated from the 
Highland glens and crossed part of the Lorne plateau occupied the 
site of Loch Nell when this beach was being laid down by the sea. 
Evidences of the retreat of the glacier are abundant in Glen Lonan. 
The loch has been reduced in size by the deltas of the River Lonan 
and the Cabrachan Burn. 
Ness.^ — Long U-shaped flat-bottomed rock-basin along the Great Glen 
fault. The lower end of the loch is ponded by glacial, fluvio- 
glacial, and raised beach deposits. 
North-house. — Rock-basin in altered Old Red Sandstone and intrusive 
igneous rocks. 
Nostarie, an. — Small shallow loch partly in granulitic schists and partly 
drift-dammed. It is situated on the watershed. 
Oban a' Chlachain. — Small tidal loch, partly a rock-basin, in Lewisian 
Gneiss. 
Oban nam Fiadh. — Ponded by drift overlying Lewisian Gneiss and 
partly tidal. 
Obisary. — Complex rock-basin in Lewisian Gneiss, full of strike basins 
and islands, one of which encloses a small lochan. There are fifteen 
basins below the 25-ft. contour line, ten below the 50-ft. line, 
and one below the 75-ft. line. The loch is partly tidal. 
Ochiltree. — Ponded by drift resting on Silurian greywackes. 
OiCH. — Rock-basin along the shatter-belt of the Great Glen, reduced in 
size by the delta of the Garry. It may be part of the same rock- 
basin as Loch Lochy, and is separated from it only by drift and 
alluvium. 
Oidhche, na H-. — Valley rock-basin in Torridon Sandstone. 
Olavat. — Shallow rock-basin in Lewisian Gneiss. 
