270 J. C. BRAXNER OUTLINES OF THE GEOLOGY OF BRAZIL 



Eschwege, Ferrand, Graga, Gorceix, Harder, Leith, Lisboa, and Scott. 

 Derby points out, however, in his paper on "The iron ores of Brazil," 

 published in "The iron-ore resources of the world" (Stockholm, 1910, 

 page 817), that the work on the Minas iron ores reported in his paper 

 was done almost exclusively by Dr. Gonzaga de Campos. 



Many other minerals are known, but as yet they are not developed. 

 Among these the following appear to be the more important : 



Nickel has been found in the Archean area of southern Minas. The 

 deposits are described by H. E. Williams, of the Servigo Geologico do 

 Brasil, the title of whose paper is given below. 



Platinum has long been known to occur in connection with the aurif- 

 erous iron sands of the old Gongo Soco mines and in the alluvial diamond 

 deposits. 'No effort has been made to recover it. 



Marbles and limestones are found in great abundance, but, aside from 

 their local use for the manufacture of lime, they are undeveloped. The 

 marbles are mostly from the Archean regions. Especially attractive 

 varieties of marble are reported from Gandarella.'^^ Amorphous lime- 

 stones are abundant in the Permian regions, in the upper part of the 

 Valley of Eio das Yelhas, and in the northern part of the state, near the 

 Eio Sao Francisco. At Paineiras, near Uberaba, limestone is quarried 

 in what are supposed to be Cretaceous rocks. 



Asbestos is reported from the vicinity of Santa Luzia. 



Talc is abundant in the Brazilian complex associated with metamor- 

 phic rocks. 



Mica is known at Bicas, Fonseca, Manhuassii, Santa Luzia, and it is to 

 be looked for in pegmatite dikes anywhere within the Archean area of the 

 state. 



Niter deposits are found in the limestone caves of the state. 



Graphite is found in veins in the Archean rocks in the vicinity of 

 Minas Novas and at Sao Miguel. The deposits are described by Dr. J. C. 

 da Costa Sena."^^ 



Extensive deposits of bauxite have been found by Dr. George Chalmers 

 at Motiica on the property of the Saint John del Eey Mining Company 

 near Villa Nova de Lima.* 



Phenacites are found at Piracicaba. 



The mineral waters of Minas are among the important economic geo- 

 logic products of the state. The thermal waters of Poco de Caldas are 



76 p (3e Paula Oliveira : Revista Industrial de Minas, vol. iv, p. 275, 30 de Margo de 

 1897. 



'''^ Annaes da Escola de Minas, vol. ii, pp. 125-129. Rio de Janeiro, 1886. 



* Eightv-eightli Ann. Rept. of the directors of the Saint John del Rev Mining Company, 

 London, June, 1919, pp. 59-60. 



