|
Page 150:-
Garnets are found imbedded in some of the rocks on Castlerigg
Fell and Great Gable. An amygdaloid rock, containing nodules of
calcareous spar, and sometimes of agate, opal, or calcedony, is
met with in several places - as near Honister Crag - between
Bowder Stone and Rosthwaite - on Castlerigg Fell, near Keswick -
and in Wolf Crag, on the road to Matterdale. A curious mixed
rock, of basaltic appearance, is found near Berrier; it skirts
the north side of Caldbeck Fells, forms the hill called Binsey,
and may be seen on the north side of the Derwent, near to
Cockermouth.
The fine green or pale-blue roofing slate occurs in beds (called
by the workmen, veins): the most natural position of the cleavage
or bate of the slate appears to be vertical; but it is to be
found in various degrees of inclination, both with respect to the
horizon, and the planes of stratification. The direction of the
slaty cleavage bears most commonly towards the north-east and
south-west; while the dip or inclination is more variable: the
former may be ascribed to some general operation of nature; the
latter being influenced by local circumstances - such as the
weight of a mountain pressing upon one side, while the other side
is wanting a support. The direction and inclination of the strata
are more distinguishable by stripes and alternations in the
colour and texture, than by any natural partings or strata seams;
and the slates are split of various thicknesses, according to
their fineness of grain, and the discretion and skill of the
workman, without any previous indication of the place where they
may be so divided. They do not naturally separate into thin
flakes, like those of the former division; but some of them, when
long used, are subject to a peculiar species of decay,
|