212 J. C. BRAXXER OUTLIXES OF THE GEOLOGY OF BRAZIL 



poststriaius, the last two from mountains on the Matto Grosso frontier,^^ 

 lead to the conclusion that the Permian probably underlies all of the 

 Parana Yallev west of Parana and Santa Catharina, and that some of 

 the limestones of southern Matto Grosso, called ^'Bodoquena'' by Dr. 

 Lisboa, may yet prove to be of Permian age. 



The rocks of the Permian in Brazil seem to be mostly sandstones and 

 shales slightly disturbed, but they include extensive beds of limestone — 

 all of them cut here and there by eruptive dikes. In" Sao Paulo, Parana, 

 and Santa Catharina the Lower Permian contains glacial till with 

 striated boulders. The glaciated Permian beds in the States of Sao 

 Paulo and Parana are described by Prof. J. B. Woodworth, to whose 

 paper the reader is referred.^^ The base of the Permian is fairly well 

 located across the State of Sao Paulo, but north of the Sao Paulo-Minas 

 frontier the eastern margin of the series has been tentatively located with 

 difficulty and with doubt. The evidence of the northward extension of 

 the beds recognized in Sao Paulo as Permian are here brought together. 

 It is assumed that the faceted boulders found by Dr. Lisboa in the region 

 between Eio Borrachudo and Eio Abaete may have come from Lower 

 Permian glacial beds, as he suspected ;^^ for Dr. Lisboa distinctly repu- 

 diated the idea of Pleistocene giaciation in connection with these boulders, 

 and that the region in which the faceted pebbles were found had been 

 glaciated in Permian times was definitely taken into consideration by 

 him. After mentioning the Permian deposits of southern Brazil, he 

 adds : 



"But in the central region in the great basin of the upper Sao Francisco 

 they (the Permian beds) have never been identified. So far as the geology of 

 the region is known, however, there is nothing positively against this hy- 

 pothesis (of Permian giaciation), and any undoubted observation that sup- 

 ports it will be of great geologic importance for this country." -" 



Thus Dr. Lisboa was the first geologist to suspect and to suggest the 

 full meaning of the Permian data in the State of Minas Geraes. 



Additional notes by Dr. Francisco de Paulo Oliveira on the geology of 

 the region between Pitanguy and the lead mines of Eibeirao do Chumbo, 

 an affluent of Rio Abaete, are of interest in this connection f^ at page 48 

 he savs : 



^" J. V. Siemiradski : Geologische Reisebeobachtungen in Siidbrasilien, p. 39. 



^^ J. B. Woodworth : Geological expedition to Brazil and Chile. Bui. Mus. Comp, Zool., 

 vol. Ivi, no. 1. Cambridge. Mass., 1912. 



1® M. A. R. Lisboa : The occurrence of faceted pebbles on the central plateau of Brazil. 

 Am. Jour. Sci., January, 1907. vol. xxiii, pp. 9-19. 



20 Miguel A. R. Lisboa : Occorrencia de seixos facetados no planalto central brasileiro. 

 Annaes da Escola de Minas de Ouro Preto. no. 8, pp. 25-39. Ouro Preto. 1906. 



21 Francisco de Paula Oliveira : Exploragao das minas de galena do Ribeirao do 

 Chumbo. Annaes da Escola de Minas de Ouro Preto. no. 1. Rio de Janeiro. 1881, pp. 

 35-94. 



