FROM THE KENDAL AND SEDBERGH DISTRICTS. VEG 
Waterit nace nahin 3°69 
COB Iie Bean aL 1371133 
SiO cine ahd nantes 32°31 
TO) ies ashes syarrahe easel: 12:15 
Bese bis ie isa atte 1:97 
HeO a triher tes iver tic 5:99 
NEOs Sauk Me a 0-13 
CaO: a Syh eoeraay lh 17°68 
MIS ORES nah sei ce 8:24. 
ARROW A: Sm btsale nS. 4:09 
INNO vince tosis 0:43 
99°81 
Its general appearance and the proportions of potash and soda seem 
to justify us in calling this rock a minette-felsite ; but the percentage 
of silica, even when allowance is made for the large percentage of 
calcic carbonate (probably in great pait due to infiltration), is low for 
an orthoclase rock. If all the CO, is in combination with the CaO, 
that would imply about 29°5 of CaCO, ; and removing this, the silica 
percentage would rise to about 46. 
These two dykes belong to a group of about four which are ex- 
posed in and near the little stream of Helm Gill, on the north side 
of the valley above Dent. They are generally from 2 to 3 feet thick, 
and similar in character, those from which specimens were taken 
being the most different. They weather a deep warm brown, with 
a roughish surface and slightly rounded outline. The rock is 
extremely tough. They are intrusive in the Coniston Limestone. 
The rock beneath the upper dyke is an impure limestone. It is 
much indurated, and contains specks of a bright green mineral 
resembling smaragdite. A more argillaceous rock lower down was 
only a little indurated and rather broken. 
(14) Cross Haw Beck. 
Characters.— Macroscopic. A rather pale violet-grey, dusty-looking 
rock, containing numerous small crystals of black mica, and occa- 
sional small scales of a pale-brown mica, with silvery lustre. A 
polished surface, however, shows it to be a crystalline mass of a dead- 
white felspathic mineral, a greenish-grey mineral, and black mica. 
Microscopic. The rock has probably been a crystalline mixture of 
felspar, biotite, iron peroxide, and augite, but it has undergone much 
alteration. The first suggests orthoclase, but is greatly altered, the 
second and third minerals only being at all well preserved ; the last 
is commonly replaced by calcite and various decomposition-products. 
In some cases the mineral still retains a cleavage resembling that of 
augite, but has lost its usual influence on polarized light—a thing 
which I have elsewhere noted in decomposed augitic rocks. There 
is also probably a little potash-mica. 
The rock, then, may be named minette. It forms a narrow dyke, 
imperfectly exposed, in the bed of a stream in the Coniston Flags, 
(15) First Tributary (on W.) to Backside Beck, Westerdale. 
Character.—Macroscopic. The rock is compact in texture, and dull 
Q.J.G.8. No. 137. N 
