Page:Quarterly Journal of the Geological Society of London, vol. 25.djvu/439

1869.] of 20 feet, where it cuts into the western wall (fig. 3). It extends with a slight northerly dip to a depth of 120 feet, terminating there quite abruptly in the reef; whether it does so likewise in the

Fig. 1. — Plan, showing the general character of the Reef.

Fig. 2. — Cross Section, showing bend in the Reef.

Fig. 3. — Plan of Reef, showing first bar of Granite.

country, on both sides, has not been ascertained. It is about 7 feet thick, and consists at the surface of a fine-grained felspathic (euritic) granite; it becomes, however, more coarse-grained in depth. There is no displacement or change observable in the reef where this vein crosses it.

The second granite vein appears at the surface about 10 feet south of the engine-shaft, running right across the reef and dipping southward (irregularly steeper and flatter) at a mean angle of 50°. It is about 6 feet thick and solid where intersecting the reef, but divides on the eastern side into two, and on the western one into