GEOLOGY OF THE SOUTH AFRICAN REPUBLIC 5. 
and 1893 called the attention of outside capital to the mines 
again. In 1894 the Transvaal furnished one-fifth of the total 
gold product of the world, and was only exceeded among indi- 
vidual nations by the United States and Australia. 
GEOLOGY. 
The geological formations of South Africa are grouped by 
most geologists under the following four heads given in descend- 
ing order: (1) recent deposits, (2) Karoo formation, (3) Cape 
formation, (4) Primary formation. 
Recent deposits —There is apparently no evidence of recent 
glacial action inSouth Africa. Dunn, in his early descriptions of 
the diamond deposits, attributed a glacial origin to certain 
bowlders observed near the Kimberley district, but afterwards 
withdrew this explanation of their origin as untenable. Furlonge 
says of the De Kaap region: ‘I have diligently searched for, but 
failed to find, evidences of glacial action, phenomena with which 
I happen to be very familiar from my residence in the Lake 
Superior district and the country north of it.” Other geologists. 
do not refer directly to the question, but all note the great 
extent of what they call laterite,t a formation which appears to 
result from the surface decomposition of rock-in-place, and to be 
similar to that found in the Appalachian region of the United 
States south of the limits of glaciation. This surface disintegra- 
tion is so deep and so widespread that outcrops are few and 
prospecting is thereby rendered difficult. While placer gravels. 
are infrequent and of limited extent, according to Schenck, gold 
is obtained by hydraulic washing of the laterite (or saprolite) 
of diabase beds and of surface flows covering the Cape forma- 
tion in the Lydenburg district, north of the Crocodile River. 
Furlonge, in his description of the De Kaap region, remarks on 
the large areas of decomposed granite in flat places and natural 
*G. F. Becker proposes the term saprolite (from campés = rotten) for decomposed 
rock in place, objecting to the use of /a/erite, because in its original sense it had a 
lithological signification, and applies in part to transported material. Gold-fields of 
the Appalachians, p. 43. Sixteenth Ann. Report Director U.S. Geol. Survey, Wash. , 
1895. 
