701 15 0

48

0 0

30

12

0

118 10 0

293 17 12

The author's practical experience was largely gained as the manager of several mines on the Colonia property.

4. Jamestown Belt.-North of Junction there is a band, generally called the "North Kaap," which can be followed interruptedly towards the north (Plate II.).

This ranks lower in importance than the main belt. The reefs are sparsely distributed in the valley and in the small ranges on both sides of the North Kaap river, interbedded with the talcose schist and shale strata. On the west side there is granite, and on the east hornblende rock, while frequent granite veins occur in the belt, which are in connection with the main

mass. Even in the northern part the granite can be followed right through the belt. The reefs are so disturbed by diorite dykes as to render them expensive to mine, owing to the extensive fouling and frequent changes in the dip. It is only in a few places near the main belt that the disturbance is comparatively small.

The light blue or milky quartz which occurs as blocks in a pot-clay is traversed by many broken quartz veinlets, while the reef itself is shifted out of position (Fig. 44).

The reef contains much visible gold and occasional patches of auriferous pyrites.

It runs through talcose schists, sometimes has quartzite on the hanging-wall and similar chutes to those in the main belt. When prospecting in this belt care should be taken not to attach too much importance to the rich lodes or large bodies (pockets) found in it. The clay contains glassy quartz. As the gold is found in the loose material and not in the solid quartz, the inference is that the deposit is an alluvial one (Fig. 45).

The numerous gash veins characteristic of this belt cut through all the rocks, whether stratified or not, and consist of superficially decomposed hard blocks of slate, quartz, quartzite, and igneous rock, with the interstices filled up with clay and small pieces of quartz. It is considered to be an alluvial deposit (Fig. 46).

Fig. 46.-Reef in granite.-a, Weathered crust (the gold-bearing
part); b, blocks of rocks; c, granite.

Jamestown was formerly a camp, but all that is now left of it consists of the remains of old huts. The district abounds in alluvial deposits, and, as the North Kaap river traverses it, these can be easily and economically washed for gold.

As the gash veins are in many cases rich in ore, this belt should prove a splendid field for diggers with limited means.

5. The Jamestown Gold Output.-The following lists, extracted from the reports of the Chamber of Mines at Barberton, will give some idea of the amount of gold obtained from this district :