292 
THE TERTIARY VOLCANOES 
BOOK VIII 
During the progress of the Geological Survey through the district of 
Applecross, in the western part of the mainland of Ross-shire, and far away 
from the basalt-plateau of Skye, Mr. John Horne 1 has found two small 
necks rising on each side of a line of fracture, through gently inclined 
Torridon Sandstones. They are conspicuous from a distance by the verdure 
of their slopes, in contrast with the brown tints of the surrounding moor- 
land. The larger of the two necks measures about ISO by 150 feet, and 
abruptly truncates the beds of Torridon Sandstone, which as they approach 
it assume a bleached aspect and become indurated. The material filling 
this vent is an agglomerate made up mainly of pieces of Torridon Sandstone 
and grit which, though generally small, occasionally measure a foot across, 
and in one case were found to reach a length of four feet. They are not 
as a rule markedly altered, but some of them have acquired a glazed or 
Fig. 309. — View of neck-like mass of breccia, Brocliel, Raasay. 
vitreous texture. Besides these fragments of the general rock of the dis- 
trict, there occur abundant lapilli of a basic volcanic rock, found by Mr. 
Teall to consist of porphyritic felspar, extremely minute acicular microlites 
of felspar, somewhat irregular transparent spaces now occupied by a 
yellowish-green substance, and interstitial matter. At the south end of 
the vent a small mass of decayed basalt appears to pierce the agglomerate. 
Though there is no indication of the age of these necks, they agree so 
closely in general character with known vents of the Tertiary volcanic 
plateaux that there cannot be much hesitation in regarding them as dating 
from the same great period of basalt-eruption. But no relic now exists 
anywhere around of lavas or tuffs ejected from them. They rise on the bare 
Applecross hills, 1000 feet above sea-level, two miles from the shore, and about 
ten miles from the nearest outlier of the basalt-plateau in the Dun Can of 
Raasay. If they once discharged streams of lava that united with the rest of 
the plateau, the total destruction- of this lava affords another impressive picture 
of the waste which the volcanic rocks of the Inner Hebrides have undergone. 
The large proportion of Torridon Sandstone blocks in these two Apple- 
cross necks suggests, however, that the orifices never became active volcanic 
1 Trans. Gcol. Soc. Edin. vii. (1894), p. 35. 
