82 J. C. BRANNER GEOLOGY OF NORTHEAST COAST OF BRAZIL 



Near Sao Caetano schists alternate with the granites, and the schists 

 appear to form a belt lying north of the granites of Caruarti but south 

 of those of the Serra Imburana. West and south of Sao Caetano the 

 rocks are more like gneisses, but they show the banded structure of 

 schists. West of Sao Caetano for 3 or 4 kilometers the dip of the rocks 

 is south and about 65 to 70 degrees ; farther west the dip is north and 

 about 80 degrees. 



There are limestones in the vicinity of Sao Caetano, but I was unable to 

 visit the quarries. Dombre saw these deposits and states that they form 

 a bed having an east-west strike at two outcrops, but he does not men- 

 tion the thickness of the rocks.* 



Through the courtesy of Dr Antonio Pai Pires Ferreira, the director 

 of the Estrada de Ferro Central, I received a specimen of the limestone 

 from the quarries south of Sao Caetano. It is a beautiful fine grained 

 marble, capable of a high polish. 



The following analysis by Professor L. R. Lennox shows it to be a re- 

 markably pure limestone : 



A nalysis of the Sao Caetano Marble 



Per cent. 



Silica (Si0 2 ) 14 



Oxide of iron and alumina (Fe 2 3 and A1 2 3 ) 14 



Lime (CaO) 55.19 



Magnesia (MgO) 40 



Carbonic acid (C0 2 ) 43.80 



Phosphoric acid not determined 



99.67 



Antonio Olyntho (kilometers 180), the last station on this line, is 

 likewise the highest, and has an elevation of 565 meters above sealevel. 

 Before the arrival of the railway this place was known as Curralinho. 

 The country around is a part of the elevated plateau extending west 

 from the Serra da Russa. The valley of the Ipojuca is here a rolling 

 flat valley, with mountains visible on the horizon to the north and to 

 the southeast. 



There are several good exposures of rocks at the station and north of 

 the Y, and also along the railway track east of the station. In the cut 

 north of the Y there are five or six faults from 2 to 4 meters apart and 

 striking approximately east-west. The rocks here dip north at a high 

 angle. The notes made at Antonio Olyntho station say that " the 

 schistose metamorphic rocks have shales interbedded with them." But 

 the metamorphic rocks appear to be tuffs, so that the series was probably 



* Viagens do Engenheh'O Dombre ao Interior da Provincia de Pernambuco em 1874 e 1875. 

 Recife, 1898, p. 14. 



