Page:Transactions of the Geological Society, 1st series, vol. 2.djvu/159

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149
Mr. William Phillips on the Veins of Cornwall.

Cross Course which traversed the Manor Old Load, and was first noticed at about 116 fathoms from the surface: the Cross Course was at that place about 21/2 feet wide, but was narrower above, and consisted of quartz accompanied by a continuous flucan, which also was found with the silver. For some fathoms in depth after the first discovery of the silver, the Cross Course consisted for about 8 or 9 feet, and in some places for 3 fathoms, north and south of its junction with the Manor Old Load, of silver mingled with sulphuret of lead, iron pyrites, bismuth, cobalt, wolfram, &c. and these substances continued to abound and to traverse the copper load so long as it was rich while in contact with the cross vein.

It was noticed in the paper of Mr. Hitchins above alluded to, that the Rusty Cross Course, next on the east to Convocation Cross Course, also produced some silver, although not in sufficient quantity to pay the expenses of procuring it. This cross course consisted of quartz accompanied by a vein of flucan, sometimes on one side of it and sometimes on the other, together with iron pyrites occasionally.

The extent north and south of the channel of porphyry, or, to use the miners term, of elvan, which forms so conspicuous a feature in the section of Pleasure, Fancy and North Herland veins, is not known. Its effect in compressing the east and west veins is worthy of attention, and is noted on the ground plan, which, together with the accompanying sections are given from original documents now in my possession.

Section of Pleasure, Fancy, and North Herland Copper Mines.

Transactions of the Geological Society, 1st series, vol. 2 figure page 0592 fig. 10.png

The mines united under the name of Herland and Drannack were formerly worked separately, but were united on account of