ORES OF GOLD 59 
quartz-veins, The granite and schists are covered uncon- 
formably 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 ban- 
quet, 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