1870.] NICcHOLSON—LOWER GREEN SLATES AND PORPHYRIES. 603 
which forms the summit of Wallow Crag and Falcon Crag corre- 
sponds to that which succeeds the great slate-band of Honister, in 
Seatoller Fell. 4. The slates and breccias which occur in the lower 
part of the Watendlath valley, and again at Watendlath village, are 
undoubtedly the equivalents of the Borrowdale Slates. At Watend- 
lath village this band appears to be shifted considerably to the south, 
since it can be traced across the southern end of Brund Fell nearly 
as far as Rosthwaite, in Borrowdale; and the prolongation of this 
line of strike would carry it out to Seatoller, whereas the slates 
on the western side of Borrowdale do not extend further to the 
south than Castle Crag, about a mile to the north of Seatoller. 
Fig. 2.—Section from Keswick to Watendlath. Distance four miles. 
Castle- Great Wallow Falcon Thwaite 
Keswick. head. Wood. Crag. Crag. Lowdore. House. Watendlath. 
‘ t 1 1 1 
! 
' 
! 
1 
4 
1 
1 
H 
SSs 
a, Skiddaw Slates. 
b. Lowest trap of the Green-slate series. 
c. Ashes, breccias, and amygdaloids, with some trappean beds. 
d. Second trap of the Green-slate series. 
III. Lower portion of the Green-slate Series between Keswick and 
the Vale of St. John. 
Crossing the north and south ridge which divides the depression 
in which Derwentwater is situated from the parallel valley of 
Naddle Beck, the base of the Green-slate series is seen close to the 
farm of Rake Foot in the form of a greenish grey felspathic trap, 
which is continuous to the west with the trap of Castle Head, and 
is traceable eastwards into the valley of Naddle Beck. Here, close 
to a farm called Dale-bottom, it is seen resting upon the Skiddaw 
Slates in the course of a small stream which flows down from a hill 
known as the Pike. In both places this lowest trap is overlain by 
a series of red and green breccias, which, however, are of consider- 
ably less thickness than further to the west in Wallow Crag. Inter- 
calated in these breccias in the Pike is a large mass of felspathic 
trap, sometimes porphyritic ; and this is succeeded by an exceedingly 
fine amygdaloid, the cavities of which are sometimes of very large 
size, and are filled either with cale-spar or with agatescent quartz. 
The strata which form the Pike are, thus, essentially the same as 
those which occur in Wallow Crag; but the breccias have to a great 
extent thinned out in their passage eastwards. 
Southwards, the strata which form the Pike are succeeded by a 
great series of bedded traps with a few ashy beds, the former greatly 
