CHAP. XXXI 
THE VENTS OF EASTERN FIFE 
Si 
neck. The accompanying ground-plan (Fig. 217) represents this structure as 
seen in the neck which forms the headland at Elie harbour. Alternations of 
coarse and fine tuff with bands of coarse agglomerate, 
dipping at angles of 60° and upwards, may be traced 
round about half of the circle. The incomplete part 
may have been destroyed by the formation of another 
contiguous neck immediately to the east. To the 
west of Earlsferry another large, but also imperfect, 
circle may be traced in one of the shore necks. A 
quarter of a mile farther west rises the great cliff- 
line of Kincraig, where a large neck has been cut 
open into a range of precipices 200 feet high, as well 
as into a tide-washed platform more than half a mile 
long. The inward dip and high angles of the tuff 
are admirably laid bare along that portion of the 
coast-line. The section in which almost every bed 
can be seen, and where, therefore, there is no need 
for hypothetical restoration, is as shown in Fig. 218. 
I have already referred to the frequently abund- 
ant pieces of stratified tuft, found as ejected blocks 
in vents filled with tuff, and to the derivation of 
these blocks from tuff originally deposited within the 
crater. There can, I think, be little hesitation in 
regarding the stratification of these Fife vents as a 
record of successive deposits of volcanic detritus inside 
the vents. The general dip inwards from the outer 
rim of the vent strikingly recalls that of some modern 
volcanoes. By way of illustration, I give here a 
section of part of the outer rim of the crater of the 
Island of Volcano, sketched by myself in the year 
1870 while ascending the mountain from the north 
side (Fig. 220). The crater wall at this point con- 
sists of two distinct parts — an older tuff (a), which 
may have been in great measure cleared out of the 
crater before the ejection of the newer tuff (6). The 
latter lies on the outer slope of the cone at the usual 
angle of 30°. It folds over the crest of the rim, 
and dips down to the flat tuff- covered crater 
bottom, at an angle of 37°. These are its natural angles of lepose. 
Applying modern analogies of this kind, I have been led to conclude 
that the stratification so conspicuous in the tuff of the vents in the east ot 
Fife and in the Carboniferous series of the Lothians belongs to the interior 
of the crater and the upper part of the volcanic funnel. 1 These stratified 
i Further illustrations of this characteristic structure of some vents will be found in the account 
of the Tertiary vents of the Faroe Isles in Chapter xli. See also the remarks m the introductoi j 
chapters, vol. i. p. 63. 
VOL. II 
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