214 J. C. BEANNER OUTLINES OF THE GEOLOGY OF BRAZIL 



"Mr. Draper has been up about Areado, and, following down the Pindabybas, 

 he and Mr. Pontie found an exposure of conglomerate four or five meters thick 

 with big boulders of granite. Draper calls it the Dwyka. This is not far from 

 where I found a small exposure of the same nature south of Areado. I have 

 word of similar beds of conglomerate on the north side of the Caboclo above 

 the Fabrica de Oliveira." 



Mr. F. W. Bunyan, who visited both regions, tells me that the rocks 

 exposed at the junction of Rio das Yelhas and Eio Sao Francisco are 

 remarkably like the Permian till beds at Harare and Faixina, in sonthern 

 Sao Panlo.^° This observation was made without any suggestion or ques- 

 tion by me. Upon receiving this information in regard to a particular 

 locality, I looked up the notes of other observers made at that place with 

 the following results : 



Dr. Theodore Sampaio, who visited this place in 1879, says he found 

 on the sides of the Serra de Manga ^^um schisto avermelhado que aqui 

 parece constituir o embasamento do planalto e muito seixo rolado." ^^ 



At Jequitah}^, a village nine leagues east of the mouth of Rio das 

 Velhas, Derby found "a pudding-stone containing well worn boulders of 

 quartz, jasper, gneiss, quartzite, and amorphous limestone, some of them 

 of great size." ^^ 



At the mouth of Rio das Velhas, James W. Wells, an English engineer, 

 observed ''a sheet of unstratified clay, interspersed with pebbles and 

 boulders overlying the rock in places. . . . The boulders are usually 

 masses of a kind of greenstone . . . and they are entirely foreign to 

 the rocks they often rest upon.'^ ^^ 



The demarcation between the Lower and the Upper Permian seems to 

 be well defined in the State of Sao Paulo, but north of there, for lack of 

 fossils, no separation can be made save on the hypothesis that the same 

 division probably continues northward into Minas. A comparison of the 

 order of the beds as given for the rocks by Dr. Oliveira in the article 

 cited above^® shows the presence of a bituminous shale that brings to mind 

 the Iraty bituminous shale so characteristic of the base of the Upper 

 Permian in Sao Paulo and Parana. The order of the rocks as given by 

 him is : 



25 Letter of December 19, 1917. 



26 "O Rio de Sao Francisco e a Chapada Diamantina," p. 89. 



" O. A. Derby : Reconhecimento geologico de Valle do Sao Ffancisco, p. 5 do annexo 

 ao Relatorio de W. Milnor Roberts . . . sobre o exame do Rio Sao Francisco. Rio de 

 Janeiro, 1880. 



Also in the Archivos do Museu Nacional, vol. iv, p. 102. 



28 J. W. Wells: Three thousand miles through Brazil, vol. ii, p. 373. London, 1886. 



29 Annaes da Escola da Minas, no. 1, p. 53. 



