268 J. C. BRAXXER OUTLINES OF THE GEOLOGY OF BRAZIL 



ist, who spent forty-seven years (1833-1880) in his Brazilian explora- 

 tions. His materials were described by various specialists, notably by 

 Hansen, Liitken, Qnatrefages, Eeinhardt, Warming, and Winge. 



The hard cones of earth built over the surface of the ground by ter- 

 mites ("white ants") in many parts of the interior are impressive and 

 are probably of some geologic importance. The true ants also make 

 extensive underground galleries. 



Economic geology. — Minas Geraes is the chief mining State of Brazil.'^* 

 It has an unusually large number of minerals of economic importance, 

 though only gold, manganese, iron, and diamonds have ever been exten- 

 sively worked. It was in Minas that gold was first discovered in Brazil, 

 about 1693, and the earliest mining done in that country was for gold in 

 what is now that state. For some years Brazil was the leading gold- 

 producing country of the world. Though there have been and still are 

 a few notable rock mines in the old Paleozoic series where the gold origi- 

 nated, most of the gold of Brazil has come from placer deposits. Among 

 the many writers on the gold deposits of Minas whose papers are worthy 

 of especial attention are Claussen, Eschwege, Ferrand, and Ferraz. 



The discovery of diamonds in Minas became known about 1724,* and 

 from a few years after that until the discovery of the diamond mines of 

 South Africa, Minas was the leading diamond-^^roducing region of the 

 world. The diamonds have come chiefly from the placer deposits, though 

 many stones have been found in situ, especially about Grao Mogol. The 

 diamonds are not so widely distributed as gold. Something about the 

 theories of the origin and distribution of diamonds will be found under 

 the head of "diamonds," at page 234. The following authors have written 

 on the diamond deposits of Minas : Galogeras, Campos, Claussen, Derby, 

 Eschwege, Gorceix, Mawe, Hussak, Heusser and Claraz, and Oliveira. 



The manganese deposits of Minas first attracted attention in 1893, and 

 in 1894, 1,430 tons of the ore were exported,^" and since 1896 that state 

 has been one of the great manganese-producing regions of the world. 



■^^ For references to the mining laws of Brazil and of Minas Geraes, see "Mining laws," 

 at page 16 et seq. 



* Tlie discovery of diamonds was claimed to have been made in 1723 or 1724 hy Ber- 

 nardo da Fonseca Lobo, and his claim was i-ecognized hy the crown of Portugal February 

 26, 1734 (Revista do Archivo Publico Mineiro. Anno II. fasc. 2. pp. 271-273. Ouro 

 Preto, 1897). As a reward "The King, our Lord . . . sees fit to bestow upon him 

 the post of chief captain of the Villa do Principe [now called Serro] during his lifetime, 

 residence of the same every triennium. the office of notary of the Villa do Principe, and 

 one hundred milreis pension money for his two sisters. Maria Nunes Machado and Mar- 

 garida Nunes Machado. . . . from which each of them shall cede twelve milreis to 

 the persons they are to marry that they may receive the habits of the Order of Christ 

 which he will have bestowed upon them at Occidental Lisbon April 12. 1734." 



's Herbert K. Scott : The manganese ores of Brazil. Journal of the Iron and Steel 

 Institute, vol. Ivii. p. 189. London, 1900. 



