ORES OF GOLD 59

quartz-veins, The granite and schists are covered unconformably
 by the quartzites, slates, and conglomerates of the
Witwatersrand System. The thicker beds of conglomerate
are known as Reef; the thin beds which have undergone
Prolonged wave action are known as the “ Leaders "and are
the ore or * Banket.” That name has the same root as banquet,
 and was given to the rock either from its resemblance
te the sweetmeat, hardbake, or to the bread containing
raisins used by Boer farmers when travelling. The typical

Quartz Pebble

. Fie. 20.—SEcTION OF Main REEF LEADER.
Section of specimen of the Main Reef Leader of the Meyer and
Charlton Mine, Johannesburg, x 25 dia. Under the edge of the
Pebble which occupies the upper part are grains of quartz, and three
crystals of pyrite (marked by horizontal lines). In the cement are
humerous particles of gold—black lines and dots, The slide is cut
from a sample containing 1383 dwt. to the ton. The matrix is no
more altered than adiacent Banket containing 2 dwt. to the ton.

pebbles in the Banket are somewhat bun-shaped, as they
have been swept to and fro by the tide until the lower side
Was worn flat and the upper side smoothed by the wash of
sand over it. The pebbles may be 10 inches high where the
Leader is only 3 inches thick, so that they project above it.
In the upper part of the Rand System some conglomerates,
that rest unconformably on the gold-bearing reefs, contain
pebbles of gold-bearing Banket, which therefore received its
gold before the deposition of the overlying conglomerates.
Above the Witwatersrand Svstem, and separated from it