Page:Transactions of the Geological Society, 1st series, vol. 4.djvu/153



The intersection and heave of the east and west veins by the north and south veins in Huel Peever, form an interesting part in the detail of its history; although such occurrences are by no means rare, as they are found to exist in a greater or lesser degree in almost every mine traversed by north and south, or non-metalliferous veins. But some remarkable and almost peculiar circumstances belonging to the downward direction or underlie of the several veins in Huel Peever remained to be noticed: these are of so complex a nature, as to render a verbal description difficult; but they are of great interest in a geological point of view.

The channel of porphyry, and copper vein near it, being in no degree connected with the ensuing detail, are wholly omitted in the accompanying transverse section, which represents the underlie of the tin, copper and flucan veins on the west side of the cross vein y.



The underlie of the tin vein is towards the south, 2 feet in every fathom, that of the copper vein is towards the north, 4 feet in a fathom, so that the horizontal distance between them at the surface being 31 fathoms, they would have come in contact at the depth of about 31 fathoms, but for the intervention of the flucan vein on the south of the copper vein. The underlie of this flucan is towards the north, and much quicker than that of the copper vein, being about 14 feet in every fathom; and by the transverse section it will be seen that the flucan overtook the copper vein at A, and cut it short at the distance of about 22 fathoms, measured along its inclination, from the surface; whence pursuing its direction in a strait line about 14 fathoms, it met with, and in like manner, interrupted the course of the tin vein at B at about 26 fathoms measured along its underlie, or 24 fathoms perpendicular from the surface; after which the flucan or slide proceeded regularly.