Miles and 
Kilometres. 
90° 
144: 
94° 
150: 
100: 
160: 
103 
165 
Om. 
5 km. 
-O m. 
-O km. 
87 
of a granite which shows no evidence of having 
undergone pressure, isseen. At first the rounded 
glaciated surfaces are abundant, but toward and 
beyond Plaisance they are less numerous, being 
covered by Leda clay and Saxicava sand. The 
sea-cliff, which has been noted in the introduc- 
tory statement, is frequently visible. 
Thurso.—Alt. 186 ft. (56-7 m.). The 
. same conditions continue west of Plaisance, the 
Pre-Cambrian margin now approaching the 
railway, now receding for half a mile. Between 
Thurso and Lochaber the sea-cliff is well- 
marked. 
Lochaber.—At Lochaber there are a few 
. small exposures of well-banded gneiss immedi- 
ately north of the railway, but from here to 
Buckingham Junction the Pre-Cambrian margin 
is again covered. 
Buckingham Junction—Alt. 183 ft. (55-8 
m.). The journey from Buckingham Junction 
to Buckingham affords little of interest to the 
geologist. The road runs over Leda clay to 
the sea-cliff, which it climbs. Along the upper 
level, also the index of a former sea-level, the 
view is interrupted by thick bush. Occasionally 
the capping of Saxicava sand is visible. Pre- 
Cambrian exposures occur in Lievre river to the 
west, but are nowhere visible from the road. 
On the right-hand side of the road, immedi- 
ately north of the Alexandra hotel at Bucking- 
ham, crystalline Grenville limestone is cut by 
a gabbro dyke. These two are the most im- 
portant rock types exposed in and around 
Buckingham. The limestone is part of a band, 
having a general north-east trend, and the 
gabbro is important, both as dykes and as 
larger intrusions. West of the road, at the 
slight rise where it leaves the town, is a mass of 
this gabbro. The most important exposures 
for two miles (3-2 km.) north of Buckingham 
are of this same type of gabbro. At the bank 
of the river is a much altered limestone, and 
limestone is again seen east of the road and 
the railway. 
