:28o 



The Ohio Naturalist. 



[Vol. XI, No. 4, 



Sao Bento series. . . .Sandstones, shale and eruptives..900 m. 

 (Triassic) 



Rocinha limestone 3 m." 



Passa Dois series 

 (Permian) 



Santa 



Catharina - 

 System 



Tubarao series 

 (Permo-Carboniferous) 



Estrada Nova, gray and 

 variegated shales with 

 cherty concretions and 

 sandv beds loO m. (223 m. 



Iraty black shale (contains 

 Mesosaurns and Stereo- 

 sternum) 70 m. 



Palermo shales 90 m. 



Rio Bonito shales and 

 sandstones (Coal Meas- 

 ures and Glossopteris 

 flora) 1.58 m. 



180 m. 



Orleans conglomerate 5 m. 



— yellow sandstones 

 and shales to granite 

 floor 27 m. 



The lower member of the Carboniferous consists of sandstones 

 and shales resting on the granite. Overlying these is the Orleans 

 conglomerate which is made up of "botilders of granite, quartzite 

 and other hard rocks, some of which are 20 to 25 cm. in diameter" 

 imbedded in clay. This conglomeratic character is common 

 throughout southern Brazil. At "several localities near Rio 

 Negro, 10 kilometers from any outcrop of granite," it contains 

 "granite boulders in vast numbers up to 3 meters in diameter, all 

 imbedded in a fine and apparently unstratified gray muddy 

 sediment. "'■'' White thinks this deposit corresponds in age to the 

 Dwyka conglomerate (Peniiian) of South Africa, to which it 

 bears much resemblance, and that it is of glacial origin. 



The Rio Bonito beds (Coal Measures) consist of partly consoli- 

 dated yellowish and grayish white sandstones interbeddcd with 

 gray shales and several beds of coal. The coals of Brazil are all 

 poor. In the lower part of the Rio Bonito beds is the Bonito 

 coal, locally making up most of the formation. Its thickness 

 frequently runs as high as 2.5 and even 3.22 meters and is quite 

 persistent in the Minas region, but it contains much shale and 

 the coal is of poor quality. 



Above the Bonito coal bed is a horizon containing many plant 

 remains, among which the abundant fossils belong to the genera 

 Sigillaria and Glossopteris.^-'' The only other important coal bed 



32. White, I. C, loc. cit., p. 51. 



33. White, T. C, loc. cit., p. 79. 



