NO. 2 BIBLIOGRAPHY OF TIN HESS 177 



TRANSVAAL AND RHODESIA (Continued) 



1179. DAVEY, T. G. Trans-Zambesian mining. 



Mg. Journ. Railw. Comm. Gaz., Vol. 73, 1903, London, p. 158. 



" In many instances the granite and porphyries, which I traversed, show promising 

 indications of the presence of tin." Whole reference. 



1180. GRIFFITH, H. D. Largest tin producing fields in the world. 



South African Mines, December 3, 1904, Johannesburg, 2000 words. 

 " Abstract of a report on the Bushveld tin properties; character of deposits, results 

 of development, and estimate of costs." 



1181. HALL, A. L. The geological survey of the northeastern portions of the 



Pretoria district, including the tin fields. 



Transvaal Mines Department, Report Geological Survey for 1904 (1905), Pretoria, pp. 

 37-44, pis. 15, 22, map 1. 



The larger part of the article is devoted to the general geology of the district. A 

 coarse red granite at Bushveld (Enkeldoorn), 42 miles northeast of Pretoria, ia 

 apparently the youngest of the rock's except diabase, and is intrusive in a felsite. 

 Finer grained portions, probably a later phase, carry the cassiterite in microscopic 

 grains. One lode is about 12 feet wid at the surface, and is said to carry 1.5 per cent 

 tin. The Vlaklaagte deposits are 12 miles further northeast. Here cassiterite is 

 rather evenly distributed through a gray granite cutting the coarse red granite. 

 Cassiterite crystals are % inch and less long. Topaz and mica also occur, and the 

 author supposes the deposit to be due to pneumatolytic action. 



1182. . Geological notes on the Bushveld tin fields and surrounding 



area. 



Trans. Geol. Soc. South Africa, Vol. 8, 1905, Johannesburg, pp. 47-55, pis. 9, 10, 

 [geol. map and section of vein]. 

 Practically the same article as No. 1181. 



1183. JOHNSON, J. B. The tin, molybdenum and lead occurrences near Pot- 



gietersrust. 



Trans. Geol. Soc. South Africa, Vol. 10, 1908, Johannesburg, pp. 115-119. 



The tin deposits occur between the Magalakwin and Sterk rivers. A quartz 

 vein carries coarsely crystalline cassiterite, which is sparsely distributed in fine 

 crystals through the granite for a width of 40 yards. Fluorite is an accompaniment in 

 both vein and granite. Peculiar round pipes in the granite also carry cassiterite. 

 Other minerals with the cassiterite are molybdenite, pyrite, chalcopyrite, arsenopyrite, 

 galena, copper, tourmaline and a greenish mica. Attributes tin, molybdenum and lead 

 deposits to pneumatolytic metasomatism. 



1183a. KYNASTON, H. Cassiterite deposits of the Waterberg. 



South African Mg. Journ., Nov. 21, Dec. 12, 1008, Johannesburg. See 1183b. 



11831). . Report on a preliminary examination of the cassiterite de- 

 posits of Zaaiplaats, and some of the neighboring farms of the Water- 

 berg district. 



Transvaal Mines Dep., Rep. Geol. Surv. for 1907 (1908), Pretoria, pp. 91-102, figs. 5-7. 



Reprint: South African Mg. Journ., Nov. 21, and Dec. 12, 1908, Johannesburg. 



Deposits at Zaaiplaats, Groenfontein and Roodepoort are described. 



The cassiterite occurs in the red (Bushveld) granite in pipes and chutes. The 

 former are cylindrical bodies of altered granite impregnated with ore and sometimes 

 surrounded with a selvage of tourmaline, fluorspar, copper and arsenic pyrites, 

 specular iron ore, blende, galena, stibnite, wolframite, and molybdenite. 



