Deposition of Gold in Smith Africa. — (Jzyszkowski. 319 
Deposits of the u de Knap"" district. Structure of the ter~ 
rane enclosing these deposits. 
In the k 'de Kaap 1 ' district, according to a report by Mr. 
Van Gember, reviewed by Mr. F. Schiff in the "Genie civil" 
we find first granite, then the Swaziland formation of Mr. 
Schenk in steeply inclined strata, and the Cape formation 
generally but gently inclined. The general direction of the 
Swazi beds is east-west. All the formations are cut by erup- 
tives. Northeast dykes occur in the granite. Others with an 
east-west trend occur interbedded with the strata and associ- 
ated with metalliferous deposits, as in the Rio Tinto region of 
Spain. The granites are cut by auriferous quartz veins which 
are generally supposed to be too poor for exploitation. 
In the Swazi formation the gold-bearing deposits are between 
the strata, following the planes of stratification or at their 
contact with the dioryte. There are also veins which cut the 
strata. The former are the most productive, as in the Sheba 
for example. Mr. Van Gember rightly believes all these de- 
posits to be veins. The gold is found associated with the 
pyrite, and also free. The gold content of the pyrite is higher 
than in the Witwatersrand. 
In the Cape formation of the " de Kaap " region there are 
found beds of auriferous conglomerate which attain a thick- 
ness as great as 10 meters ; but their gold content is small and 
irregularly disseminated. The study of these auriferous 
horizons deserves more particular attention. 
District of Lydenburg. — Mashonaland. — Matabeleland. 
In the district of Lydenburg the gold deposits occur in the 
dolomyte which is but little inclined in the regions where it 
has been invaded by eruptive rocks. 
Two auriferous horizons are known and a great number of 
claims have been taken on them. Four mines are already de- 
veloped. The deposition of the auriferous quartz has occurred 
in different strata and small veins of great importance are 
also often found. The fact that we wish to emphasize here is 
that the beds are horizontal, and auriferous horizons (ni- 
veaux) have been formed. 
In Mashonaland and Matabeleland many explorations are 
actually in progress in the east-west strata supposed to be of 
the same nature as these of the '-de Kaap" district. 
