CHAP. XXXIX 
THE PLATEAU OF SKYE 
251 
vegetation are plentiful among the stratified intercalations, even forming 
thin seams of lignite and coal, one of which was formerly worked. That 
volcanic eruptions, though possibly of a feebler kind, continued during the 
interval between the basalt-outflows at this locality, is shown by the thick 
accumulation of tuff and by the occurrence of abundant lapilli of fine basic 
pumice among the shales, even to a distance of several miles from the 
vent. 
Another conspicuous intercalation of sedimentary materials in the Skye 
plateau occurs on the Talisker cliffs at the mouth of Loch hracadale, where, 
on the face of the great precipice of Eudha nan Clach, some conspicuous 
bands of lilac and red are interspersed among the basalts. These bands 
were noticed by Macculloch, who described them as varieties of “ iron-clay.” 1 
Fio. 284. — “MacleocVs Maidens ” and part of Basalt Cliffs of Skye. 
I have not had an opportunity of examining them except from the sea at a 
little distance. But they suggest a similarity to some of the variegated 
clays between the upper and lower basalt series of Antrim. 
Though good coal is not well developed in the Tertiary volcanic 
plateaux of the British Isles, it has already been pointed out that coaly 
layers are abundant, and that as the vegetable matter may confidently be 
assumed always to indicate terrestrial vegetation, the presence of the car- 
bonaceous bands may be regarded as good evidence of some lapse of time 
between the eruption of the basalts which they separate. I have also called 
attention to the fact that the vegetable material is more especially observ- 
able in the highest parts of a group of intercalated sediments between two 
sheets of basalt. This relation, so strikingly exhibited in the isle of Oanna, 
as already observed, is also to be remarked in the Skye plateau. 1 may 
' here cite an interesting example which occurs at the base of the lofty sea- 
cliff of An Ceannaich, to the south of Dunvegan Head, on the west coast of 
Skye (Fig. 285). At the base of the precipice, ledges of a highly cellular 
basalt (a) show a singularly scoriaceous and amygdaloidal structure, with 
1 Western Islands, vol. i. p. 376. 
