TRANSACTIONS OF THE SECTIONS. 87 
clay-slate. On the eastern flank of Black Comb I found the same beds of coarse 
greenstone slate wrapping round the clay-slate, and separated from the upper beds 
of finer roofing-slate by a line of fault running north and south, and nearly following 
a road running from Beck Bank on to Stoneside Fell. On the south-western border 
of Black Comb the new red sandstone comes up to the clay-slate. 
It appears then, if my observations are correct, that the Black Comb range on the 
east of Eskdale consists of an axis of elevation running north and south, and which 
has elevated both the clay-slate and the lower beds of the greenstone slate in con- 
formable position ; and that the latter have a north-westerly dip towards the granite 
in the lower part of the valley. As we have the same lower beds of the greenstone 
slate in the range of the Screes on the south-east of Wast Water dipping towards the 
south-east, there seems good evidence to conclude that Eskdale and Miterdale, taken 
together, may be considered as a broad synclinal valley subdivided by subordinate 
anticlinal ridges. We must then consider this as a great valley of denudation, 
exposing the granite in its lower parts, and Scaw Fell and the other lofty mountains 
at its head, consisting of the setting on of the higher beds of the great greenstone 
slate formation. 
It remains to be ascertained whether the granite is eruptive and intrusive, or meta- 
morphic, in the latter case consisting of the lower beds of the greenstone slate, which 
lying at the bottom of a trough, have been more exposed than the neighbouring 
strata to the central heat, and also have been more deeply covered up. 
I think all the direct evidence on the spot is strongly in favour of the latter sup- 
position. Sedgwick, who examined this district with great care many years ago, 
states that the granite is everywhere bordered by a belt of transition metamorphic 
rocks, by which it appears to graduate into the greenstone slate. 
These transition beds between the greenstone slate and granite may be well 
observed in the course of the stream running from Devock Water into the Esk, and 
also under the Screes at the foot of Wast Water. 
The unaltered rocks in the hills about Devock Water consist of a bluish grey 
felstone porphyry, with small crystals of quartz or hornblende. The first change 
on approaching the granite is that this rock loses its porphyritic character, and be- 
comes a very dark, almost black compact greenstone. The next change is to a soft 
crumbling rock, with an entire change of colour to various shades of red, yellow, or 
pinkish grey ; after this, finally, a transition through several varieties of quartzoze 
and crystalline rock to compact crystalline granite. In the Eskdale granite the mica 
is very commonly wanting or replaced by hornblende. 
The thickness of these transition beds is various. Under the Screes they did not 
seem to me to occupy more than 60 or 80 feet; but near Devock Water between 
200 and 300 feet. 
An important point to be observed here is, whether the upper limit of the granite 
is on the whole conformable to the dip of the greenstone strata above it. The whole 
of the Screes is so hardened by heat and so shattered, that it is difficult to ascertain 
the dip of small portions, though the whole mass evidently has an easterly dip. The 
line of soft metamorphic rocks marking the upper limit of the granite is seen near 
the foot of Wast Water, apparently running quite confermably under the beds of 
greenstone slate of Screes. The position of the granite near Burnmoor Tarn, at the 
foot of Scaw Fell, is also quite analogous to that at Devock Water. 
I think I may be justified in saying that the direct evidence to be obtained on the 
spot, in the case both of the Skiddaw and of the Eskdale granite, is in favour of their 
metamorphic character. It will make my argument more clear and intelligible, if I 
proceed to notice in the same manner the direct evidence to be obtained by observa- 
tion upon the spot, as it appeared to me at the time, in the case of the other igneous 
rocks of the district, the syenite of Ennerdale, and the granite of Shap Fells, before 
I inquire what objections may be raised to this hypothesis, and what may be alleged 
for or against the contrary hypothesis, that these igneous rocks are not metamorphic, 
but eruptive and intrusive. 
The syenite of Ennerdale occupies an intermediate position, as is seen upon the 
map, between the clay-slate and the greenstone slate. Is it an intrusive eruptive 
rock, or is it metamorphic, consisting of some of the upper beds of the clay-slate 
changed into syenite? 
