GEOLOGY 
The decomposition products of the lava have been reconstituted, and 
have given rise to Epidote (after Saponite), Garnets, Biotite, Hornblende, 
Felspar and other minerals ; while the limestones, where so acted upon, 
have passed into crystalline marbles, like those of the counties of Perth, 
Aberdeen and Inverness, and now yield Idocrase and other ordinary lime 
silicates which occur in impure limestones in general when these are 
affected by prolonged contact metamorphism. 
Another result of the same cause has been the welding of the cleav- 
age planes, which has taken place in zones of variable width around the 
intrusive masses, by which the slates have been recompacted. 
(4) Life of the Devonian Period.—In Cumberland not a single trace 
of organic remains of any kind occurs in connection with the rocks of 
this period, because they were mostly of desert origin, and barren of life. 
It may, however, be well to make reference to the fact that a great 
abundance and variety of animal life is known to have existed in the 
seas of the same period. The organic remains found elsewhere in the 
deposits formed in the old inland lakes of this time inform us of a great 
advance in the evolution of vertebrate life, for we find in these rocks a 
considerable variety of fishes whose zoological grades extend from some 
of the simplest to some as highly organized as any yet living in the 
waters of the present day. Furthermore, vegetation had advanced to an 
equal extent. 
(7) Continental conditions accompanied by an arid climate, with 
the land undergoing slow upheaval, continued for a very long time after 
the decline of the volcanic episode. We know by the important series of 
changes which elsewhere took place in both the organic and the inorganic 
world that this period must have been one of enormous length. In 
Cumberland there exist only very fragmentary records of these changes, 
because the period succeeding that which has just been noticed was one 
during which a vast thickness of the older strata, including almost every 
trace of the volcanic cones, was slowly and gradually swept away. There 
is some reason for believing that at the period next to be considered the 
area now occupied by Cumberland and Westmorland consisted of a low- 
land tract which lay at the foot of a great mountain region nearly co- 
incident with the area occupied at present by the southern uplands of 
Scotland and the Cheviots. From this area the torrents which were 
formed during the irregular periods when rain fell, by degrees transported 
vast quantities of shingle, gravel and sand from the mountain area lying 
to the north-west, and gradually spread these wasted fragments of the 
old northern land over a large part of the area under consideration. 
This fact is rendered quite evident by an examination of the materials 
of the conglomerates of the Upper Old Red Sandstone in Cumberland. 
At Melmerby these contain abundant fragments of the Cheviot andesites, 
together with some rocks from the southern uplands of Scotland ; while 
the same conglomerates at the foot of Ullswater, which form the 
rounded hills, Easter and Wester Mell Fells, yield abundant representa- 
tives of the Silurian and Ordovician greywackes of the south of Scot- 
2I 
