THE GEOLOGY OF SOUTH-EASTERN KINCARDINESHIRE. 945 
the rock might be mistaken for a voleanic conglomerate. The enclosed blocks are 
similar to the boulders in the underlying conglomerate. Probably the xenoliths were 
collected by the lava as it flowed over an unconsolidated gravel. 
At the base of the group everywhere along the southern limb of the syncline we find 
a very coarse “ Highland” conglomerate whose chief constituents are well-rounded 
quartzites. Locally it contains boulders of the underlying basalts. Comparing it with 
the “Highland” conglomerates of the Crawton group, we notice at once a marked 
decrease in the proportion of boulders derived from the Jasper and Green-rock series. 
This zone of coarse conglomerate is succeeded by a belt made up of finer conglomerates, 
associated with sandstones and flagey beds; sometimes the sandstones, sometimes the 
fine conglomerates predominate. This belt may be traced along the strike by a line of 
‘quarries mostly now disused. Three Wells quarry, near Bervie, is still worked, and 
there I was fortunate enough to find a good specimen of Cephalaspis Lyelli. As the 
base of the lavas is approached we begin to find, particularly in the north-eastern part 
of the area, intercalations of the voleanic conglomerates and tuffs which occupy almost 
the whole thickness of this group along the northern limb of the syncline. 
(b) The Volcanic Conglomerates and Tuffs.—The volcanic conglomerates and tuffs, 
which occur at intervals interbedded with the ordinary conglomerates and sandstones 
along the southern limb of the syncline, attain a considerable thickness in the vicinity 
of Law of Lumgair. It should be noted, however, that the width of the outcrop there 
is in great part accounted for by the low angle of dip. From Mid Fiddes westwards 
they form almost the whole thickness of the Arbuthnott group, taking the place which 
is occupied by the hypersthene andesites and basalts and the ordinary sediments in 
the south-eastern part of the area. Their base rests on the hornblende andesite of 
Harlingtongue, and their upper limit is found a short distance above the top of the 
Knock Hill lavas. Westwards from the Knock Hill the top of the series may be traced 
in an east-and-west direction as far as. Glensaugh, while the basal members swing 
round the Hlfhill anticline, and, as we have seen, along with the accompanying andesite 
cross the Bervie Water near the Horse Pot, Dillavaird. In the drift-covered country 
to the east of the Bervie the only satisfactory exposures of these beds are found ina 
stream section a short distance west of the Bridge of Bogincabers. Near the ford of 
Dillavaird the beds strike north and south and dip towards the west at an angle of 30°. 
In the neighbourhood of Drumtochty Castle the direction of strike is almost east and 
west, and, consequently, at Glensaugh the series is almost entirely cut out by the 
Highland fault. The direction of strike changes again to south-west and north-east, 
and a very fine section of the volcanic conglomerates and their associated tuffs is seen 
in the Ferdun burn at the Clattering Bridge. There, although the base of the series is 
not seen, it attains a thickness of about 2000 feet. From the Clattering Bridge west- 
wards these rocks may be hammered in almost every stream section, until, the direction 
of strike changing gradually to west-south-west and east-north-east, they are eventually 
lost against the Highland fault about half a mile from the river North Esk. 
