OLD RED SANDSTONE OF WESTERN EUROPE. 385 
1500 feet higher above the sea than on the shore of the Kyle of Tongue. Yet 
the distance between the two points, in a straight line, is not more than about 
seven miles. 
One further fragment of the Old Red Sandstone in the north of Sutherland- 
shire occurs in the little bay of Kirktomy, where it was observed by CunninG- 
HAM. It consists of dull red and reddish-grey sandstone, sometimes mottled 
and marked with nodular bands and intercalations of soft dull red sandy clay or 
“marl.” These strata rest upon the gnarled quartzose schists which run out 
into the promontory of Kirktomy Point. They dip gently towards the north- 
west, and are probably cut off by a fault on the west side. There can be little 
doubt that these beds occupy a considerably higher zone of the Old Red Sand- 
stone than the Morven conglomerates and sandstones. They lie well to the 
north of what must have been the old shore-line. Possibly they may belong to 
the same horizon as the sandstones and conglomerates of Strathy, to be after- 
wards described. 
Looking at the distribution of the Sutherlandshire outliers of Old Red 
Sandstone towards the north-west, we perceive that they must represent 
merely the last fragments of a once much more extensive deposit. And this 
conclusion is strengthened when we observe on the ground how very gentle is 
the inclination of the strata in these outliers, and how, accordingly, the trun- 
cated edges of the beds cut the sky-line from every point of view. At the 
same time, if, in endeavouring to restore in imagination what has been removed, 
we fill up the whole of the intervening space with conglomerate, and thus 
cover most of the east of Sutherlandshire with a deposit at least as thick as 
what remains in the outliers, that is, avout 1000 or 1500 feet, we may err by 
somewhat exaggerating the quantity of material denuded. Conglomerates 
and coarse conglomeratic sandstones are notoriously local formations, suddenly 
swelling out into great masses, and as rapidly dwindling down again or dis- 
appearing altogether. The conglomerate may indeed have once extended from 
Morven to the Kyle of Tongue in a continuous belt, as it still does for many 
miles down the east side of Sutherlandshire and Ross-shire. On the other 
hand, though continuous along the ancient shingly coast-line of the Old Red 
Sandstone period, it probably varied greatly in thickness, even at the time of 
deposit. Some parts of the shore, owing to the nature of their rocks, to the set 
of the prevalent winds, or to the quantities of shingle brought down by streams 
from the interior, may have received and accumulated enormous piles of con- 
glomerate, while intermediate tracts, from failure of supply, witnessed the for- 
| mation of none at all, or, at most, of trifling beds of sand and gravel. On the 
subsequent consolidation and denudation of the formation it might well happen 
that the local piles of shingle, compacted into conglomerate, should remain 
| still conspicuous masses, notwithstanding the general degradation of the 
VOL, XXVIII. PART II, 5 H 
