40 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 5S 



BOLIVIA (Continued) 

 155b. EVekding, — . Unterlagen zu einer bergmannischen Lagerstattenbegu- 

 tachtung in bolivianisclien Zinnerzbezirk. 



Gliick. Berg, liiitt. Zeit. Kicd. Westph., 45 Jahr., 1900, Essen, pp. 1325-1333. 



156. Fawns, Sydney. Tin deposits of tlie world. 



Mg'. Journ. Railw. Comm. Gaz., 1905, London. 



Deposits of Bolivia, pp. 112-124. Small outline map. 



No new material. Taken from Pasley'.s, Chas. S., " The tin mines of Bolivia." 



'Trans. Inst. Mg. Met.. Vol. 7, 189S-1899, London, pp. 70-90, 95; Roberts, Malcolm, 

 " Chorloque tin mines," op. cit.. Vol. 9, 1900-1901; and Min. Ind., New York and 

 London, 1903. 



157. Forbes, David. Researches on the mineralogy of South America. 



London, Edinburgh, Dublin, Philos. Mag. Journ. Sci., ser. 4, Vol. 29, 1865, pp. 

 133-136; Vol. 30, 1865, London, pp. 139-142. 



First article treats of the occurrence of tin ore in Bolivia; second article describes 

 the different kinds of tin ore of Bolivia. 



Frenzel, a. See No. 1611. 



Describes cylindrite from Bolivia. 



158. Frochot, Maurice. L'etain en Bolivie. 



Ann. Mines, ser. 9, Vol. 19, 1901, pp. 186-222. 



Extract: Bol. Min. Indust. Constr., Ano IS, Nos. 7, 8, 1902, Lima, Peril, pp. 

 51-53, 59-62. 



Digest: Trans. Inst. Mg. Eng., Vol. 23, 1901-1902, London and Newcastle-upon-Tyne, 

 pp. 715-716. 



Geol. Centr., Vol. 1, iOOl, Leipzig, p. 707. 



35 tin mines at work; cost of production very heavy; no such deposits known 

 in Peru or Chili; Oruro district largest producer; geological conditions extremely 

 varied; Huanuni' mine credited with two-thirds of output of State; situated in a 

 sort of stockwork in Mount Posconi, 10,500 feet high; in most cases SnOo gives 

 way to stanniferous pyrites at depth of 13O'-160', one vein is filled with pure 

 tinstone to a depth of 650' or more; 9 miles south are mines of Challa and 

 Apacheta where is a vein 25 to 30 feet thick which in parts can be dug with a 

 spade (where pyritiferous). Many " veneros " in this neighborhood not well worked. 

 Fifty miles north of Oruro is Colquiri, where the Spaniards used to work silver 

 ores but neglected tin, as usual. Tin veins close at hand are still untouched. In 

 the mountains of Tres Cruces, (20,000' alt.) the Sayaquiri vein is 25 feet thick. 

 Ore rather poor, associated with iron pyrites and wolframite, but some crj'stalline 

 ore runs 70 per cent tin. 



Avicaya mines are productive and rock is compact porphyry. In the department 

 of La Paz, the mines of Milluni, Huayna Potosi and Chocaltaya are all on one 

 ore belt 12 miles in length. Veins, appear to be of very recent origin, for they 

 occur near fossiliferous gypsum-bearing bods and red claj's which have been faulted 

 by disturbances that raised the neighboring Andes. Are in slates of Silurian or 

 pre-Silurian age. Many veins not worked. Bolivian tin ores are not connected 

 with plutonic granite, but appear to be connected genetically with thermal springs, 

 which hold metallic sulphides in solution and were the outcome of Cretaceous and 

 Tertiary volcanic eruptions. 



159. FucHS, B., et Launay, L. de. Traite des gites mineraux et metalliferes. 



Vol. 2, 1803, Paris, pp. 107-158. 



Brief note upon the occurrence of tin in Bolivia. 



160. Gautier, Ferdinand. Observation sur la formation des filons d'etain. 



Actes Soc. sci. Chili, Vol. 5, 1895, Santiago, pp. 82-84. 

 Theories on deposition of tin veins near Chorolque, Bolivia. 



