2r56 J. C. BEAXXER OUTLINES OF THE GEOLOGY OF BRAZIL 



just as they do in Bahia, and that they occur in the Permian where they 

 have been redeposited, and that outside of existing Carboniferous and 

 Permian areas they occur where the older beds have been removed during 

 long periods of denudation. 



The next higher beds are the Lower Permian sediments, whose contact 

 with the Archean enters the southern end of the State from Sao Paulo 

 just north of the city of Jacuhy, and runs northward and eastward past 

 Formiga, Pitangu}^, Santa Luzia, west of Diamantina, east of Montes 

 Claros, Monte Alto, in Bahia, and seems to end east of the Eio Sao Fran- 

 cisco at a point about thirty kilometers south of Bom Jesus da Lapa. 

 The Lower Permian has not hitherto been recognized as such in the State 

 of Minas Geraes, and the reference of certain beds to that horizon is 

 based partly on the character of the rocks and partly on their tying up 

 with the known Lower Permian of the State of Sao Paulo. The position 

 of the base of the series as shown on the map has been gathered from 

 miscellaneous notes on the geology of the region, and can not therefore 

 be accepted as anything more than an attempt to locate the margin of the 

 series believed to be Lower Permian. The question of the Permian as a 

 whole and the evidence bearing on it is discussed under the head of 

 "Permian," at page 38. 



The rocks of the series are shales, sandstones, limestones, and con- 

 glomerates that have been but little affected by folding or faulting. In 

 Minas these beds form extensive tablelands and are deeply trenched by 

 the streams. There seems to be strong presumptive evidence of glacial 

 deposits at the base of the series at several places, but it requires con- 

 firmation, so far as Minas is concerned. 



The large area of limestone in the valley of the Eio Sao Francisco in 

 the north end of the state and north of the confluence of the Sao Fran- 

 cisco and the Eio das Velhas has not been studied. It is assumed that 

 these limestones are of the same age as those east of the river, namely, 

 Permian. See discussion under Permian. 



There are a few small lake deposits in the state of Tertiary age. The 

 best known are those at Gandarella and at Fonseca, which have been de- 

 scribed by Gorceix.'^ 



The Gandarella basin is northwest of Ouro Preto, about half way be- 

 tween Conceicao and Santo Antonio. The rocks are clays, gravels, sands, 

 and lignites. One bed of lignite is a meter in thickness. 



The Fonseca basin is northeast of Ouro Preto, near the village of that 

 name and close to Eio Piracicaba, east of the town of Agua Quente. The 



■^3 H. Gorceix : Bacias terciarias d'agiia doce. Annaes da Escola de Minas no. 3, pp. 

 95-114. Rio, 1884. 



