FROM THE KENDAL AND SEDBERGH DISTRICTS. 169 
in Bannisdale Slates, is exposed in a railway-cutting, being about 
1 foot thick, and is only visible on the south side. The rock in con- 
tact is but little altered. The mica-crystals in the dyke and the 
principal joint-planes are parallel to the sides. Some 2 feet from 
this is another dyke, also about a foot wide, which does not reach 
the surface, and is doubtless an offshoot. 
(2) Dyke, Barley Bridge, Staveley. 
Characters.— Macroscopic. A rather compact, pale reddish-grey 
rock, of decomposed aspect, with numerous specks of pale celadon- 
green and very minute glimmering lines. 
Microscopic. The ground-mass is rather decomposed and of a light 
brick-red, from ferruginous staining ; but 1t was once probably either 
microcrystalline throughout, or exhibited a glassy base thickly 
crowded with acicular felspar-microliths, which still show traces of 
fluidal structure. There are many grains of iron peroxide (? hema- 
tite), and numerous grains or crystals of a mineral which is replaced 
partly by calcite and partly by a pellucid pale-green serpentinous 
mineral. One or two evidently have once included portions of the 
eround-mass. On the whole, it seems probable that this has 
been augite rather than hornblende. ‘There are also a fair number 
of scales of brown mica. 
The general character of this rock, and its comparative poverty in 
mica, make it better to remove it from the mica-traps, and name it 
a porphyrite. 
This dyke occurs exposed in the bed of the Kent, cutting the Ban- 
nisdale Slates at right angles to the bedding-planes, and hardly 
altering them. It is about 2 feet wide. 
(3) Dyke, Gill Bank, 14 mile N.N.E. of Staveley. 
Characters.— Macroscopic. Appears to be a finely crystalline mix- 
ture of a dull-red felspar and dark-green mineral resembling horn- 
blende, with a few small scales of black mica, having the general 
greet of a very fine-grained syenite. It weathers a rusty-brown 
colour. 
Microscopic. The rock has evidently been much altered subsequent 
to crystallization, but it appears to have been crystalline throughout. 
The felspar is much decomposed, stained reddish brown, being both 
frequently pierced with needles of zeolite and associated with secon- 
dary quartz. The common form of the crystals, and faint indication 
of twins, make it very probable that most of these are plagioclase. 
There are seyeral small scales of brown mica, some needles of apa- 
tite, numerous crystalline grains and belonites of iron peroxide, pro- 
bably hematite, and a considerable quantity of a rather fibrous dull 
green mineral, almost certainly decomposed hornblende, associated 
sometimes with a little calcite(?). Analysis :— 
