TATE: LAKE COUNTRY ROCKS. 249 
[22a] Quartz-Felsite (grey): THRELKELD Quarry. Porphyritic 
crystals of guartz and felspar in a microcrystalline intergrowth of 
the same minerals. The large quartz crystals have been fractured, 
and have had their edges fused, this zoning extinguishing uniformly 
with the body of the crystal. They contain enclosures in linear 
symmetry. Mica brown, strongly pleochroic: or in patches of 
chloritoid substance with feeble pleochroism. The felspathic com- 
ponents are kaolinised giving feeble aggregate polarisation. 
[224] Quartz-Felsite (red): Low Ricco, St. Joun’s VALE. 
A microcrystalline ground-mass, consisting of rectangular grains of 
clear guartz with felspars, mostly of prismatic habit, moulded thereon. 
The porphyritic elements in this slide are all felspars, being chiefly 
orthoclase with a few oligoclase crystals often zoned. Microperthite 
structure shown here: many are fractured, the fragments lying in 
juxtaposition indicating movement during recurrent phase prior to 
final consolidation. 
[20] Augite granophyre: Carrock Fett. A granophyric ground- 
mass moulded upon microporphyritic crystals of felspar mostly 
plagioclase in square sections. The orthoclase crystals extinguish 
simultaneously with the surrounding micropegmatite. Qwarfz in 
small allotriomorphic grains. Brown augife at one time figured as an 
important constituent ; it is now represented chiefly by iron-oxide 
blotches with here and there a patch or small crystal zoned by iron- 
oxide. Epidote in pale green patches feebly pleochroic, but double 
refraction stronger than the pyroxenes. Note the pseudospheerulitic 
Structure giving black cross when rotated between crossed Nicols. 
[8] Quartz Felsite: Armor Dyke. A granophyric structure— 
an intimate mixture of quartz and felspar—the ground-mass pseudo- 
spherulitic, giving a black cross between crossed Nicols. This 
encloses a few crystals of felspar and guarts. Mica in brown flakes 
and green (pleochroic) or colourless (bleached). Garnefs minute, 
bright with strong outlines (isotropic). The section is coated 
_ besprinkled with slender spindles of a pale green a 
substance which remains dark between pews Nicols. “Sihene : 
_ brown, feebly dichroic, enclosed i in the te fom — ce 
Cottipare with sli 
34: : Ae 
[34] Quartz Felsite : utvkicte Dice. Pornpiile, rystals of | 
quartz, reseed and etn ell in a microfelsitic matrix, here and there 
feebly pseu , clear; numerous minute cavities - 
with | crore arcs ‘also enol portions of ig matrix. — 
_ Felspars both orthoclase arid pi showing 
_ Microperthite structure. Biotite mostly green, x "tittle brown. 
pee 8 rey little, and a few minute — — 
Be a ae Oe oe 
