|
|
Page 159:-
stones found in the beds of the rivers Kent and Lune; thus
furnishing materials for paving the streets, and repairing the
roads in the vicinity.
A rock of fine-grained sienite is observed near the foot of
Coniston Lake; and one containing a large portion of mica appears
in Crosthwaite. The strata seams are more distinct this than in
the preceding division; but, like that, it is not marked by any
natural partings in the plane of cleavage. A quarry one mile from
Brathay on the road towards Hawkshead, yields excellent flags for
flooring; and they are manufactured into tombstones with good
effect, by Mr. Webster of Kendal, and by Mr. Bromley of Keswick.
This quarry affords a good example of the stratification (or, as
some will have it, the rhomboidal crystallization) of these
rocks. The cleavage is here nearly perpendicular; and the strata,
being from one foot to five in thickness, dip to the south-east
at an angle of about thirty degrees. In some districts the layers
are so much diminished in thickness, that slates and tables are
formed in the plane of the stratification, instead of that of the
cleavage; and this has probably given rise to the notion of two
distinct cleavages crossing each other under a certain angle.
Roofing slate (called black slate, to distinguish it from the
pale-blue of the second division) is manufactured in large
quantities in the district between Ulverston and Broughton; which
is well situated for shipping either by the river Duddon or by
canal from Ulverston.
|
