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called sienite, forms the two inferior mountain ridges, called
Irton Fell and Muncaster Fell; it extends to some distance on
both sides of the river Esk, and may be seen shooting up in
places, almost as far as Bootle, and also at Wasdale Head. At
Nether-wasdale it becomes a finer grained sienite, in which form
it extends through the mountains quite across Ennerdale, as far
as Scale Force, and to the side of Buttermere Lake. It contains
veins of red hematite and micaceous iron ore. Another variety of
granite with reddish felspar in large crystals, is found on Shap
Fells, and may be observed in situ on the road side near
Wasdale Bridge, about four miles south of Shap.
Carrock Fell consists of a rock generally referred to the class
of sienite, varying its appearance in different parts of the
mountain. It contains (besides the usual ingredients of quartz
and felspar) hypersthene and magnetic or titaniferous iron ore in
various proportions. Near this a considerable quantity of lead
ore and some copper has been procured: the lead is smelted and
refined hard by, and yields a good portion of silver.
A reddish porphyritic rock occurs on both sides of St. John's
Vale, from two to three miles east of Keswick; and a vein or dyke
apparently related to the same, but far more beautiful, (being
composed of crystals of quartz and bright red felspar, imbedded
in a brownish red compact felspar,) is found on Armboth Fell, six
miles S.S.E. of Keswick.
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